YANG Data Model for DHCPv6 Configuration
draft-ietf-dhc-dhcpv6-yang-04

Abstract

This document describes a YANG data model [RFC6020] for the configuration and management of DHCPv6 servers, relays, and clients.

Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on May 1, 2018.

Copyright Notice

Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.

Table of Contents

• 1. Introduction
• 1.1. Terminology
• 2. DHCPv6 Tree Diagram
• 2.1. DHCPv6 Server Tree Diagrams
• 2.2. DHCPv6 Relay Tree Diagrams
• 2.3. DHCPv6 Client Tree Diagrams
• 2.4. Notifications Mechanism for DHCPv6
• 3. DHCPv6 YANG Model
• 4. Security Considerations (TBD)
• 5. IANA Considerations (TBD)
• 6. Acknowledgements
• 7. References
• 7.1. Normative References
• 7.2. Informative References
• Authors' Addresses

1. Introduction

DHCPv6 [RFC3315] is widely used for supplying configuration and other relevant parameters to clients in IPv6 networks. This document defines a DHCPv6 YANG data model, containing sub-modules for the configuration and management of DHCPv6 servers, relays and clients. A single YANG model covering all of these elements provides an operator with a common interface for the management of the entire DHCPv6 deployment in their network.

Since the publication of the original DHCPv6 specification, there have been a large number of addional documents that update the protocol's operation, add new functions and define new options. The YANG model described in this document incorporates all relevent changes. A full list of the documents which have been considedered in the development of this model is included in Appendix A.

IF - Commment - Does anyone have this list?

It is worth noting that as DHCPv6 is itself a device configuration protocol, it is not the intention of this document to replace the configuration of DHCPv6 options and parameters using the DHCPv6 protocol with the configuration of DHCPv6 options using NETCONF/YANG. The DHCPv6 client model is intended for the configuration of the DHCPv6 client function and also for obtaining read-only state data from the client which has been learnt via the normal DHCPv6 message flow. This gives an operator a better method for managing DHCPv6 clients and simplifies troubleshooting.

1.1. Terminology

The reader should be familiar with the terms defined in DHCPv6 [RFC3315] and other relevant documents.

The DHCPv6 tree diagrams provide a concise representation of a YANG module to help the reader understand the module structure.

A simplified graphical representation of the data model is provided in this d cument. For a description of the symbols in these diagrams, please refer to [I-D.ietf-netmod-yang-tree-diagrams].

2. DHCPv6 Tree Diagram

2.1. DHCPv6 Server Tree Diagrams

module: ietf-dhcpv6
    +--rw server!
       +--rw serv-attributes
       |  +--rw name?                string
       |  +--rw duid
       |  |  +--rw (duid-type)?
       |  |     +--:(duid-llt)
       |  |     |  +--rw duid-llt-hardware-type?      uint16
       |  |     |  +--rw duid-llt-time?               yang:timeticks
       |  |     |  +--rw duid-llt-link-layer-addr?    yang:mac-address
       |  |     +--:(duid-en)
       |  |     |  +--rw duid-en-enterprise-number?   uint32
       |  |     |  +--rw duid-en-identifier?          string
       |  |     +--:(duid-ll)
       |  |        +--rw duid-ll-hardware-type?       uint16
       |  |        +--rw duid-ll-time?                yang:timeticks
       |  +--rw ipv6-address*        inet:ipv6-address
       |  +--rw description?         string
       |  +--rw pd-function          boolean
       |  +--rw stateless-service    boolean
       |  +--rw rapid-commit         boolean
       |  +--rw interfaces-config*   string
       |  +--rw vendor-info
       |     +--rw ent-num    uint32
       |     +--rw data*      string
       +--rw option-sets
       |  +--rw option-set* [option-set-id]
       |     +--rw option-set-id                   uint8
       |     +--rw new-or-standard-option* [option-code]
       |     |  +--rw option-code           uint16
       |     |  +--rw option-name           string
       |     |  +--rw option-description    string
       |     |  +--rw option-reference?     string
       |     |  +--rw option-value          string
       |     +--rw user-class-value?               string
       |     +--rw enterprise-number?              uint32
       |     +--rw store-client-link-layer?        boolean
       |     +--rw preference-option
       |     |  +--rw enable              boolean
       |     |  +--rw preference-value    uint8
       |     +--rw sip-server-option
       |     |  +--rw enable        boolean
       |     |  +--rw sip-server* [sip-serv-id]
       |     |     +--rw sip-serv-id             uint8
       |     |     +--rw sip-serv-domain-name    string
       |     |     +--rw sip-serv-addr           inet:ipv6-address
       |     +--rw dns-config-option
       |     |  +--rw enable        boolean
       |     |  +--rw dns-server* [dns-serv-id]
       |     |     +--rw dns-serv-id      uint8
       |     |     +--rw dns-serv-addr    inet:ipv6-address
       |     +--rw domain-searchlist-option
       |     |  +--rw enable               boolean
       |     |  +--rw domain-searchlist* [domain-searchlist-id]
       |     |     +--rw domain-searchlist-id        uint8
       |     |     +--rw domain-search-list-entry    string
       |     +--rw nis-config-option
       |     |  +--rw enable        boolean
       |     |  +--rw nis-server* [nis-serv-id]
       |     |     +--rw nis-serv-id      uint8
       |     |     +--rw nis-serv-addr    inet:ipv6-address
       |     +--rw nis-plus-config-option
       |     |  +--rw enable             boolean
       |     |  +--rw nis-plus-server* [nis-plus-serv-id]
       |     |     +--rw nis-plus-serv-id      uint8
       |     |     +--rw nis-plus-serv-addr    inet:ipv6-address
       |     +--rw sntp-server-option
       |     |  +--rw enable         boolean
       |     |  +--rw sntp-server* [sntp-serv-id]
       |     |     +--rw sntp-serv-id      uint8
       |     |     +--rw sntp-serv-addr    inet:ipv6-address
       |     +--rw info-refresh-time-option
       |     |  +--rw enable               boolean
       |     |  +--rw info-refresh-time    yang:timeticks
       |     +--rw cli-fqdn-option
       |     |  +--rw enable                    boolean
       |     |  +--rw server-initiate-update    boolean
       |     |  +--rw client-initiate-update    boolean
       |     |  +--rw modify-name-from-cli      boolean
       |     +--rw posix-timezone-option
       |     |  +--rw enable      boolean
       |     |  +--rw tz-posix    string
       |     +--rw posix-timezone-db-option
       |     |  +--rw enable         boolean
       |     |  +--rw tz-database    string
       |     +--rw ntp-server-option
       |     |  +--rw enable        boolean
       |     |  +--rw ntp-server* [ntp-serv-id]
       |     |     +--rw ntp-serv-id                    uint8
       |     |     +--rw ntp-serv-addr-suboption        inet:ipv6-address
       |     |     +--rw ntp-serv-mul-addr-suboption    inet:ipv6-address
       |     |     +--rw ntp-serv-fqdn-suboption        string
       |     +--rw network-boot-option
       |     |  +--rw enable       boolean
       |     |  +--rw boot-file* [boot-file-id]
       |     |     +--rw boot-file-id          uint8
       |     |     +--rw suitable-arch-type*   uint16
       |     |     +--rw suitable-net-if*      uint32
       |     |     +--rw boot-file-url         string
       |     |     +--rw boot-file-paras* [para-id]
       |     |        +--rw para-id      uint8
       |     |        +--rw parameter    string
       |     +--rw aftr-name-option
       |     |  +--rw enable                  boolean
       |     |  +--rw tunnel-endpoint-name    string
       |     +--rw kerberos-option
       |     |  +--rw enable                boolean
       |     |  +--rw default-realm-name    string
       |     |  +--rw kdc-info* [kdc-id]
       |     |     +--rw kdc-id            uint8
       |     |     +--rw priority          uint16
       |     |     +--rw weight            uint16
       |     |     +--rw transport-type    uint8
       |     |     +--rw port-number       uint16
       |     |     +--rw kdc-ipv6-addr     inet:ipv6-address
       |     |     +--rw realm-name        string
       |     +--rw addr-selection-option
       |     |  +--rw enable          boolean
       |     |  +--rw a-bit-set       boolean
       |     |  +--rw p-bit-set       boolean
       |     |  +--rw policy-table* [policy-id]
       |     |     +--rw policy-id     uint8
       |     |     +--rw label         uint8
       |     |     +--rw precedence    uint8
       |     |     +--rw prefix-len    uint8
       |     |     +--rw prefix        inet:ipv6-prefix
       |     +--rw sol-max-rt-option
       |     |  +--rw enable              boolean
       |     |  +--rw sol-max-rt-value    yang:timeticks
       |     +--rw inf-max-rt-option
       |     |  +--rw enable              boolean
       |     |  +--rw inf-max-rt-value    yang:timeticks
       |     +--rw pcp-server-option
       |     |  +--rw enable        boolean
       |     |  +--rw pcp-server* [pcp-serv-id]
       |     |     +--rw pcp-serv-id      uint8
       |     |     +--rw pcp-serv-addr    inet:ipv6-address
       |     +--rw s46-rule-option
       |     |  +--rw enable      boolean
       |     |  +--rw s46-rule* [rule-id]
       |     |     +--rw rule-id           uint8
       |     |     +--rw rule-type         enumeration
       |     |     +--rw prefix4-len       uint8
       |     |     +--rw ipv4-prefix       inet:ipv4-prefix
       |     |     +--rw prefix6-len       uint8
       |     |     +--rw ipv6-prefix       inet:ipv6-prefix
       |     |     +--rw port-parameter
       |     |        +--rw offset      uint8
       |     |        +--rw psid-len    uint8
       |     |        +--rw psid        uint16
       |     +--rw s46-br-option
       |     |  +--rw enable    boolean
       |     |  +--rw br* [br-id]
       |     |     +--rw br-id           uint8
       |     |     +--rw br-ipv6-addr    inet:ipv6-address
       |     +--rw operator-option-ipv6-address
       |     |  +--rw enable                boolean
       |     |  +--rw operator-ipv6-addr* [operator-ipv6-addr-id]
       |     |     +--rw operator-ipv6-addr-id    uint8
       |     |     +--rw operator-ipv6-addr       inet:ipv6-address
       |     +--rw operator-option-single-flag
       |     |  +--rw enable    boolean
       |     |  +--rw flag* [flag-id]
       |     |     +--rw flag-id       uint8
       |     |     +--rw flag-value    boolean
       |     +--rw operator-option-ipv6-prefix
       |     |  +--rw enable                  boolean
       |     |  +--rw operator-ipv6-prefix* [operator-ipv6-prefix-id]
       |     |     +--rw operator-ipv6-prefix-id      uint8
       |     |     +--rw operator-ipv6-prefix6-len    uint8
       |     |     +--rw operator-ipv6-prefix         inet:ipv6-prefix
       |     +--rw operator-option-int32
       |     |  +--rw enable      boolean
       |     |  +--rw int32val* [int32val-id]
       |     |     +--rw int32val-id    uint8
       |     |     +--rw int32val       uint32
       |     +--rw operator-option-int16
       |     |  +--rw enable      boolean
       |     |  +--rw int16val* [int16val-id]
       |     |     +--rw int16val-id    uint8
       |     |     +--rw int16val       uint16
       |     +--rw operator-option-int8
       |     |  +--rw enable     boolean
       |     |  +--rw int8val* [int8val-id]
       |     |     +--rw int8val-id    uint8
       |     |     +--rw int8val       uint8
       |     +--rw operator-option-uri
       |     |  +--rw enable    boolean
       |     |  +--rw uri* [uri-id]
       |     |     +--rw uri-id    uint8
       |     |     +--rw uri       string
       |     +--rw operator-option-textstring
       |     |  +--rw enable        boolean
       |     |  +--rw textstring* [textstring-id]
       |     |     +--rw textstring-id    uint8
       |     |     +--rw textstring       string
       |     +--rw operator-option-var-data
       |     |  +--rw enable      boolean
       |     |  +--rw int32val* [var-data-id]
       |     |     +--rw var-data-id    uint8
       |     |     +--rw var-data       binary
       |     +--rw operator-option-dns-wire
       |     |  +--rw enable                      boolean
       |     |  +--rw operator-option-dns-wire*
       |     |          [operator-option-dns-wire-id]
       |     |     +--rw operator-option-dns-wire-id    uint8
       |     |     +--rw operator-option-dns-wire       binary
       |     +--rw s46-dmr-option
       |     |  +--rw enable    boolean
       |     |  +--rw dmr* [dmr-id]
       |     |     +--rw dmr-id             uint8
       |     |     +--rw dmr-prefix-len     uint8
       |     |     +--rw dmr-ipv6-prefix    inet:ipv6-prefix
       |     +--rw s46-v4-v6-binding-option
       |        +--rw enable    boolean
       |        +--rw ce* [ce-id]
       |           +--rw ce-id               uint8
       |           +--rw ipv4-addr           inet:ipv4-address
       |           +--rw bind-prefix6-len    uint8
       |           +--rw bind-ipv6-prefix    inet:ipv6-prefix
       |           +--rw port-parameter
       |              +--rw offset      uint8
       |              +--rw psid-len    uint8
       |              +--rw psid        uint16
       +--rw network-ranges
       |  +--rw option-set-id?   uint8
       |  +--rw network-range* [network-range-id]
       |     +--rw network-range-id       uint8
       |     +--rw network-description    string
       |     +--rw network-prefix         inet:ipv6-prefix
       |     +--rw inherit-option-set     boolean
       |     +--rw option-set-id          uint8
       |     +--rw reserved-addresses
       |     |  +--rw static-binding* [cli-id]
       |     |  |  +--rw cli-id         uint32
       |     |  |  +--rw duid
       |     |  |  |  +--rw (duid-type)?
       |     |  |  |     +--:(duid-llt)
       |     |  |  |     |  +--rw duid-llt-hardware-type?      uint16
       |     |  |  |     |  +--rw duid-llt-time?
       |     |  |  |     |  |       yang:timeticks
       |     |  |  |     |  +--rw duid-llt-link-layer-addr?
       |     |  |  |     |          yang:mac-address
       |     |  |  |     +--:(duid-en)
       |     |  |  |     |  +--rw duid-en-enterprise-number?   uint32
       |     |  |  |     |  +--rw duid-en-identifier?          string
       |     |  |  |     +--:(duid-ll)
       |     |  |  |        +--rw duid-ll-hardware-type?       uint16
       |     |  |  |        +--rw duid-ll-time?
       |     |  |  |                yang:timeticks
       |     |  |  +--rw reserv-addr*   inet:ipv6-address
       |     |  +--rw other-reserv-addr*   inet:ipv6-address
       |     +--rw reserved-prefixes
       |     |  +--rw static-binding* [cli-id]
       |     |  |  +--rw cli-id               uint32
       |     |  |  +--rw duid
       |     |  |  |  +--rw (duid-type)?
       |     |  |  |     +--:(duid-llt)
       |     |  |  |     |  +--rw duid-llt-hardware-type?      uint16
       |     |  |  |     |  +--rw duid-llt-time?
       |     |  |  |     |  |       yang:timeticks
       |     |  |  |     |  +--rw duid-llt-link-layer-addr?
       |     |  |  |     |          yang:mac-address
       |     |  |  |     +--:(duid-en)
       |     |  |  |     |  +--rw duid-en-enterprise-number?   uint32
       |     |  |  |     |  +--rw duid-en-identifier?          string
       |     |  |  |     +--:(duid-ll)
       |     |  |  |        +--rw duid-ll-hardware-type?       uint16
       |     |  |  |        +--rw duid-ll-time?
       |     |  |  |                yang:timeticks
       |     |  |  +--rw reserv-prefix-len    uint8
       |     |  |  +--rw reserv-prefix        inet:ipv6-prefix
       |     |  +--rw exclude-prefix-len     uint8
       |     |  +--rw exclude-prefix         inet:ipv6-prefix
       |     |  +--rw other-reserv-prefix* [reserv-id]
       |     |     +--rw reserv-id     uint8
       |     |     +--rw prefix-len    uint8
       |     |     +--rw prefix        inet:ipv6-prefix
       |     +--rw address-pools
       |     |  +--rw address-pool* [pool-id]
       |     |  |  +--rw pool-id               uint8
       |     |  |  +--rw pool-prefix           inet:ipv6-prefix
       |     |  |  +--rw start-address         inet:ipv6-address-no-zone
       |     |  |  +--rw end-address           inet:ipv6-address-no-zone
       |     |  |  +--rw renew-time            yang:timeticks
       |     |  |  +--rw rebind-time           yang:timeticks
       |     |  |  +--rw preferred-lifetime    yang:timeticks
       |     |  |  +--rw valid-lifetime        yang:timeticks
       |     |  |  +--ro total-ipv6-count      uint64
       |     |  |  +--ro used-ipv6-count       uint64
       |     |  |  +--rw utilization-ratio     threshold
       |     |  |  +--rw inherit-option-set    boolean
       |     |  |  +--rw option-set-id         uint8
       |     |  +--ro binding-info* [cli-id]
       |     |     +--ro cli-id    uint32
       |     |     +--ro duid
       |     |     |  +--ro (duid-type)?
       |     |     |     +--:(duid-llt)
       |     |     |     |  +--ro duid-llt-hardware-type?      uint16
       |     |     |     |  +--ro duid-llt-time?
       |     |     |     |  |       yang:timeticks
       |     |     |     |  +--ro duid-llt-link-layer-addr?
       |     |     |     |          yang:mac-address
       |     |     |     +--:(duid-en)
       |     |     |     |  +--ro duid-en-enterprise-number?   uint32
       |     |     |     |  +--ro duid-en-identifier?          string
       |     |     |     +--:(duid-ll)
       |     |     |        +--ro duid-ll-hardware-type?       uint16
       |     |     |        +--ro duid-ll-time?
       |     |     |                yang:timeticks
       |     |     +--ro cli-ia* [iaid]
       |     |        +--ro ia-type     string
       |     |        +--ro iaid        uint32
       |     |        +--ro cli-addr*   inet:ipv6-address
       |     |        +--ro pool-id     uint8
       |     +--rw prefix-pools
       |     |  +--rw prefix-pool* [pool-id]
       |     |  |  +--rw pool-id               uint8
       |     |  |  +--rw prefix                inet:ipv6-prefix
       |     |  |  +--rw prefix-length         uint8
       |     |  |  +--rw renew-time            yang:timeticks
       |     |  |  +--rw rebind-time           yang:timeticks
       |     |  |  +--rw preferred-lifetime    yang:timeticks
       |     |  |  +--rw valid-lifetime        yang:timeticks
       |     |  |  +--rw utilization-ratio     threshold
       |     |  |  +--rw inherit-option-set    boolean
       |     |  |  +--rw option-set-id         uint8
       |     |  +--ro binding-info* [cli-id]
       |     |     +--ro cli-id      uint32
       |     |     +--ro duid
       |     |     |  +--ro (duid-type)?
       |     |     |     +--:(duid-llt)
       |     |     |     |  +--ro duid-llt-hardware-type?      uint16
       |     |     |     |  +--ro duid-llt-time?
       |     |     |     |  |       yang:timeticks
       |     |     |     |  +--ro duid-llt-link-layer-addr?
       |     |     |     |          yang:mac-address
       |     |     |     +--:(duid-en)
       |     |     |     |  +--ro duid-en-enterprise-number?   uint32
       |     |     |     |  +--ro duid-en-identifier?          string
       |     |     |     +--:(duid-ll)
       |     |     |        +--ro duid-ll-hardware-type?       uint16
       |     |     |        +--ro duid-ll-time?
       |     |     |                yang:timeticks
       |     |     +--ro cli-iapd* [iaid]
       |     |        +--ro iaid              uint32
       |     |        +--ro cli-prefix*       inet:ipv6-prefix
       |     |        +--ro cli-prefix-len*   uint8
       |     |        +--ro pool-id           uint8
       |     +--rw hosts
       |        +--rw host* [cli-id]
       |           +--rw cli-id                  uint32
       |           +--rw duid
       |           |  +--rw (duid-type)?
       |           |     +--:(duid-llt)
       |           |     |  +--rw duid-llt-hardware-type?      uint16
       |           |     |  +--rw duid-llt-time?
       |           |     |  |       yang:timeticks
       |           |     |  +--rw duid-llt-link-layer-addr?
       |           |     |          yang:mac-address
       |           |     +--:(duid-en)
       |           |     |  +--rw duid-en-enterprise-number?   uint32
       |           |     |  +--rw duid-en-identifier?          string
       |           |     +--:(duid-ll)
       |           |        +--rw duid-ll-hardware-type?       uint16
       |           |        +--rw duid-ll-time?
       |           |                yang:timeticks
       |           +--rw inherit-option-set      boolean
       |           +--rw option-set-id           uint8
       |           +--rw nis-domain-name?        string
       |           +--rw nis-plus-domain-name?   string
       +--rw relay-opaque-paras
       |  +--rw relays* [relay-name]
       |     +--rw relay-name        string
       |     +--rw interface-info* [if-name]
       |     |  +--rw if-name         string
       |     |  +--rw interface-id    string
       |     +--rw subscribers* [subscriber]
       |     |  +--rw subscriber       uint8
       |     |  +--rw subscriber-id    string
       |     +--rw remote-host* [ent-num]
       |        +--rw ent-num      uint32
       |        +--rw remote-id    string
       +--rw rsoo-enabled-options
       |  +--rw rsoo-enabled-option* [option-code]
       |     +--rw option-code    uint16
       |     +--rw description    string
       +--ro packet-stats
          +--ro solicit-count          uint32
          +--ro request-count          uint32
          +--ro renew-count            uint32
          +--ro rebind-count           uint32
          +--ro decline-count          uint32
          +--ro release-count          uint32
          +--ro info-req-count         uint32
          +--ro advertise-count        uint32
          +--ro confirm-count          uint32
          +--ro reply-count            uint32
          +--ro reconfigure-count      uint32
          +--ro relay-forward-count    uint32
          +--ro relay-reply-count      uint32
          

Figure 1: DHCPv6 Data Model Structure

Introduction of important nodes:

• serv-attributes: This container contains basic attributes of a DHCPv6 server such as DUID, server name and so on. Some optional functions that can be provided by the server is also included.
• duid: Each server and client has only one DUID (DHCP Unique Identifier). The DUID here identifies a unique DHCPv6 server for clients. DUID consists of a two-octet type field and an arbitrary length (no more than 128 bytes) content field.
• pd-function: Whether the server can act as a delegating router to perform prefix delegation [RFC3633].
• operator-option-ipv6-address, operator-option-single-flag, operator-option-ipv6-prefix, operator-option-int32, operator-option-int16, operator-option-int8, operator-option-uri, operator-option-textstring, operator-option-var-data, operator-option-dns-wire: are generic option formats described in [RFC7227].
• stateless-service: A boolean value specifies whether the server support client-server exchanges involving two messages defined in [RFC3315].
• rapid-commit: Setting the value to '1' represents the server support the Solicit-Reply message exchange. '0' means the server will simply ignore the Rapid Commit option in Solicit message.
• interfaces-config: A leaf list to denote which one or more interfaces the server should listen on. The default value is to listen on all the interfaces. This node is also used to set a unicast address for the server to listen with a specific interface. For example, if the server is being configured to listen on a unicast address assigned to a specific interface, the format "eth1/2001:db8::1" can be used.
• option-sets: DHCPv6 employs various options to carry additional information and parameters in DHCP messages. This container defines all the possible options that need to be configured at the server side. The relevant RFCs that define those options include: [RFC3315], [RFC3319], [RFC3646], [RFC3898], [RFC4242], [RFC4704], [RFC4833], [RFC5908], [RFC5970], [RFC4075], [RFC6334], [RFC6784], [RFC7078], [RFC7083], [RFC7291], [RFC7598].
• option-set: A server may allow different option sets to be configured for different conditions (i.e. different networks, clients and etc). This "option-set" list enables various sets of options being defined and configured in a single server. Different sets are distinguished by the key called "option-set-id". All the possible options discussed above are defined in the list and each option is corresponding to a container. Since all the options in the list are optional, each container in this list has a boolean parameter called "enable" to indicate whether this option (container) will be included in the current option set or not. With the "new-or-standard-option" list, it is easy to extend the model when new options are defined. We could also use the "new-or-standard-option" list to define an IETF standard option.
• network-ranges: This model supports a hierarchy to achieve dynamic configuration. That is to say we could configure the server at different levels through this model. The top level is a global level which is defined as the container "network-ranges". The following levels are defined as sub-containers under it. The "network-ranges" contains the parameters (e.g. option-sets) that would be allocated to all the clients served by this server
• network-range: Under the "network-ranges" container, a "network-range" list is defined to configure the server at a network level which is also considered as the second level. Different network are identified by the key "network-range-id". This is because a server may have different configuration parameters (e.g. option sets) for different networks.
• address-pools: Under the "network-range" list, a container describes the DHCPv6 server's address pools for a specific network is defined. This container supports the server to be configured at a pool level.
• address-pool: A DHCPv6 server can be configured with several address pools for a specific network. This list defines such address pools which are distinguish by the key called "pool-id".
• binding-info: A list records a binding information for each DHCPv6 client that has already been allocated IPv6 addresses.
• prefix-pools: If a server supports prefix delegation function, this container under the "network-range" list will be valid to define the delegating router's prefix pools for a specific network. This container also supports the server to be configured at a pool level.
• prefix-pool: Similar to server's address pools, a delegating router can also be configured with multiple prefix pools specified by a list called "prefix-pool".
• binding-info: A list records a binding information for each DHCPv6 requesting router that has already been configured IPv6 prefixes.
• hosts: A server may also desire to be configured at a host level under some circumstances. This container include a list called "host" to allow the server carrying different parameters (e.g. option sets) for different hosts.
• relay-opaque-paras: This container contains some opaque values in Relay Agent options that need to be configured on the server side only for value match. Such Relay Agent options include Interface-Id option, Remote-Id option and Subscriber-Id option.
• rsoo-enabled-options: [RFC6422] requires that the server SHOULD have an administrator-configurable list of RSOO-enabled options. This container include a list called "rsoo-enabled-option" to allow new RSOO-enabled options to be defined at the server side.
• packet-stats: A container presents the packet statistics related to the DHCPv6 server.

2.2. DHCPv6 Relay Tree Diagrams

module: ietf-dhcpv6
    +--rw relay!
       +--rw relay-attributes
       |  +--rw name?          string
       |  +--rw description?   string
       |  +--rw dest-addrs*    inet:ipv6-address
       |  +--rw subscribers* [subscriber]
       |  |  +--rw subscriber       uint8
       |  |  +--rw subscriber-id    string
       |  +--rw remote-host* [ent-num]
       |  |  +--rw ent-num      uint32
       |  |  +--rw remote-id    string
       |  +--rw vendor-info
       |     +--rw ent-num    uint32
       |     +--rw data*      string
       +--rw relay-supplied-options-option
       |  +--rw rsoo-set* [rsoo-set-id]
       |     +--rw rsoo-set-id                     uint8
       |     +--rw erp-local-domain-name-option
       |        +--rw enable            boolean
       |        +--rw erp-for-client* [cli-id]
       |           +--rw cli-id      uint32
       |           +--rw duid
       |           |  +--rw (duid-type)?
       |           |     +--:(duid-llt)
       |           |     |  +--rw duid-llt-hardware-type?      uint16
       |           |     |  +--rw duid-llt-time?
       |           |     |  |       yang:timeticks
       |           |     |  +--rw duid-llt-link-layer-addr?
       |           |     |          yang:mac-address
       |           |     +--:(duid-en)
       |           |     |  +--rw duid-en-enterprise-number?   uint32
       |           |     |  +--rw duid-en-identifier?          string
       |           |     +--:(duid-ll)
       |           |        +--rw duid-ll-hardware-type?       uint16
       |           |        +--rw duid-ll-time?
       |           |                yang:timeticks
       |           +--rw erp-name    string
       +--rw relay-if* [if-name]
       |  +--rw if-name         string
       |  +--rw enable          boolean
       |  +--rw ipv6-address?   inet:ipv6-address
       |  +--rw interface-id?   string
       |  +--rw rsoo-set*       uint8
       |  +--rw pd-route* [pd-route-id]
       |  |  +--rw pd-route-id             uint8
       |  |  +--rw requesting-router-id    uint32
       |  |  +--rw delegating-router-id    uint32
       |  |  +--rw next-router             inet:ipv6-address
       |  |  +--rw last-router             inet:ipv6-address
       |  +--rw next-entity* [dest-addr]
       |     +--rw dest-addr       inet:ipv6-address
       |     +--rw available       boolean
       |     +--rw multicast       boolean
       |     +--rw server          boolean
       |     +--ro packet-stats
       |        +--ro cli-packet-rvd-count    uint32
       |        +--ro solicit-rvd-count       uint32
       |        +--ro request-rvd-count       uint32
       |        +--ro renew-rvd-count         uint32
       |        +--ro rebind-rvd-count        uint32
       |        +--ro decline-rvd-count       uint32
       |        +--ro release-rvd-count       uint32
       |        +--ro info-req-rvd-count      uint32
       |        +--ro relay-for-rvd-count     uint32
       |        +--ro relay-rep-rvd-count     uint32
       |        +--ro packet-to-cli-count     uint32
       |        +--ro adver-sent-count        uint32
       |        +--ro confirm-sent-count      uint32
       |        +--ro reply-sent-count        uint32
       |        +--ro reconfig-sent-count     uint32
       |        +--ro relay-for-sent-count    uint32
       |        +--ro relay-rep-sent-count    uint32
       +--ro relay-stats
          +--ro cli-packet-rvd-count      uint32
          +--ro relay-for-rvd-count       uint32
          +--ro relay-rep-rvd-count       uint32
          +--ro packet-to-cli-count       uint32
          +--ro relay-for-sent-count      uint32
          +--ro relay-rep-sent-count      uint32
          +--ro discarded-packet-count    uint32
          

Introduction of important nodes:

• relay-attributes: A container describes some basic attributes of the relay agent including some relay agent specific options data that need to be configured previously. Such options include Remote-Id option and Subscriber-Id option.
• dest-addrs: Each DHCPv6 relay agent may be configured with a list of destination addresses. This node defines such a list of IPv6 addresses that may include unicast addresses, multicast addresses or other addresses.
• relay-supplied-options-option: DHCPv6 relay agent could provide some information that would be useful to DHCPv6 client. Since relay agent cannot provide options directly to the client, [RFC6422] defines RSOO-enabled options to propose options for the server to send to the client. This container models such RSOO-enabled options.
• rsoo-set: This list under the "relay-supplied-options-option" container is similar to the "option-set" defined in server feature. It allows the relay to implement several sets of RSOO-enabled options for different interfaces. The list only include the EAP Re-authentication Protocol (ERP) Local Domain Name DHCPv6 Option defined in [RFC6440], since it is the only one RSOO-enabled options accepted by IANA so far.
• relay-if: A relay agent may have several interfaces, we should provide a way to configure and manage parameters on the interface-level. A list that describes specific interfaces and their corresponding parameters is employed to fulfil the configfuration. Here we use a string called "if-name" as the key of list.
• pd-route: A sub-container of "relay-if" which describes the route for delegated prefixes into the provider edge router.
• next-entity: This node defines a list that is used to describe the next hop entity of this relay agent. Different entities are distinguished by their addresses.
• packet-stats: A container shows packet state information of a specific data communication.
• relay-stats: The "relay-stats" container records and presents the overall packet statistics of the relay agent.

2.3. DHCPv6 Client Tree Diagrams

module: ietf-dhcpv6
    +--rw client!
       +--rw duid
       |  +--rw (duid-type)?
       |     +--:(duid-llt)
       |     |  +--rw duid-llt-hardware-type?      uint16
       |     |  +--rw duid-llt-time?               yang:timeticks
       |     |  +--rw duid-llt-link-layer-addr?    yang:mac-address
       |     +--:(duid-en)
       |     |  +--rw duid-en-enterprise-number?   uint32
       |     |  +--rw duid-en-identifier?          string
       |     +--:(duid-ll)
       |        +--rw duid-ll-hardware-type?       uint16
       |        +--rw duid-ll-time?                yang:timeticks
       +--rw client-if* [if-name]
          +--rw if-name                      string
          +--rw cli-id                       uint32
          +--rw description?                 string
          +--rw pd-function                  boolean
          +--rw rapid-commit                 boolean
          +--rw mo-tab
          |  +--rw m-tab    boolean
          |  +--rw o-tab    boolean
          +--rw oro-options
          |  +--rw oro-option* [option-code]
          |     +--rw option-code    uint16
          |     +--rw description    string
          +--rw client-configured-options
          |  +--rw new-or-standard-cli-option* [option-code]
          |  |  +--rw option-code           uint16
          |  |  +--rw option-name           string
          |  |  +--rw option-description    string
          |  |  +--rw option-reference?     string
          |  |  +--rw option-value          string
          |  +--rw user-class-option
          |  |  +--rw enable        boolean
          |  |  +--rw user-class* [user-class-id]
          |  |     +--rw user-class-id      uint8
          |  |     +--rw user-class-info    string
          |  +--rw vendor-class-option
          |  |  +--rw enable     boolean
          |  |  +--rw ent-num    uint32
          |  |  +--rw data*      string
          |  +--rw client-fqdn-option
          |  |  +--rw enable                    boolean
          |  |  +--rw fqdn                      string
          |  |  +--rw server-initiate-update    boolean
          |  |  +--rw client-initiate-update    boolean
          |  +--rw client-architecture-type-option
          |  |  +--rw enable                boolean
          |  |  +--rw architecture-types* [type-id]
          |  |     +--rw type-id           uint16
          |  |     +--rw most-preferred    boolean
          |  +--rw client-network-interface-option
          |  |  +--rw enable    boolean
          |  |  +--rw type      uint8
          |  |  +--rw major     uint8
          |  |  +--rw minor     uint8
          |  +--rw kerberos-principal-name-option
          |  |  +--rw enable            boolean
          |  |  +--rw principal-name    string
          |  +--rw client-link-layer-addr-option
          |     +--rw enable             boolean
          |     +--rw link-layer-type    uint16
          |     +--rw link-layer-addr    string
          +--ro identity-associations
          |  +--ro identity-association* [iaid]
          |     +--ro iaid                  uint32
          |     +--ro ia-type               string
          |     +--ro ipv6-addr*            inet:ipv6-address
          |     +--ro ipv6-prefix*          inet:ipv6-prefix
          |     +--ro prefix-length*        uint8
          |     +--ro t1-time               yang:timeticks
          |     +--ro t2-time               yang:timeticks
          |     +--ro preferred-lifetime    yang:timeticks
          |     +--ro valid-lifetime        yang:timeticks
          +--ro if-other-paras
          |  +--ro uni-dhcpv6-serv-addr*      inet:ipv6-address
          |  +--ro dns-paras
          |  |  +--ro domain-search-list    string
          |  |  +--ro dns-servers* [dns-serv-id]
          |  |     +--ro dns-serv-id      uint8
          |  |     +--ro dns-serv-addr    inet:ipv6-address
          |  +--ro sip-paras
          |  |  +--ro sip-servers* [sip-serv-id]
          |  |     +--ro sip-serv-id             uint8
          |  |     +--ro sip-serv-addr           inet:ipv6-address
          |  |     +--ro sip-serv-domain-name    string
          |  +--ro nis-paras
          |  |  +--ro nis-domain-name    string
          |  |  +--ro nis-server* [nis-serv-id]
          |  |     +--ro nis-serv-id      uint8
          |  |     +--ro nis-serv-addr    inet:ipv6-address
          |  +--ro nis-plus-paras
          |  |  +--ro nis-plus-domain-name    string
          |  |  +--ro nis-plus-server* [nis-plus-serv-id]
          |  |     +--ro nis-plus-serv-id      uint8
          |  |     +--ro nis-plus-serv-addr    inet:ipv6-address
          |  +--ro info-refresh-time?         yang:timeticks
          |  +--ro time-zone-paras
          |  |  +--ro tz-posix       string
          |  |  +--ro tz-database    string
          |  +--ro cli-fqdn?                  string
          |  +--ro ntp-paras
          |  |  +--ro ntp-server* [ntp-serv-id]
          |  |     +--ro ntp-serv-id          uint8
          |  |     +--ro ntp-serv-addr        inet:ipv6-address
          |  |     +--ro ntp-serv-mul-addr    inet:ipv6-address
          |  |     +--ro ntp-serv-fqdn        string
          |  +--ro sntp-paras
          |  |  +--ro sntp-server* [sntp-serv-id]
          |  |     +--ro sntp-serv-id      uint8
          |  |     +--ro sntp-serv-addr    inet:ipv6-address
          |  +--ro network-boot-paras
          |  |  +--ro boot-file* [boot-file-id]
          |  |     +--ro boot-file-id          uint8
          |  |     +--ro suitable-arch-type*   uint16
          |  |     +--ro suitable-net-if*      uint32
          |  |     +--ro boot-file-url         string
          |  |     +--ro boot-file-paras* [para-id]
          |  |        +--ro para-id      uint8
          |  |        +--ro parameter    string
          |  +--ro kerberos-paras
          |  |  +--ro default-realm-name    string
          |  |  +--ro kdc-info* [kdc-id]
          |  |     +--ro kdc-id            uint8
          |  |     +--ro priority          uint16
          |  |     +--ro weight            uint16
          |  |     +--ro transport-type    uint8
          |  |     +--ro port-number       uint16
          |  |     +--ro kdc-ipv6-addr     inet:ipv6-address
          |  |     +--ro realm-name        string
          |  +--ro addr-selection-paras
          |  |  +--ro automatic-row-add        boolean
          |  |  +--ro prefer-temporary-addr    boolean
          |  |  +--ro policy-table* [policy-id]
          |  |     +--ro policy-id     uint8
          |  |     +--ro label         uint8
          |  |     +--ro precedence    uint8
          |  |     +--ro prefix-len    uint8
          |  |     +--ro prefix        inet:ipv6-prefix
          |  +--ro sol-max-rt                 yang:timeticks
          |  +--ro inf-max-rt                 yang:timeticks
          |  +--ro pcp-server-paras
          |  |  +--ro pcp-server* [pcp-serv-id]
          |  |     +--ro pcp-serv-id      uint8
          |  |     +--ro pcp-serv-addr    inet:ipv6-address
          |  +--ro s46-rule-paras
          |  |  +--ro s46-rule* [rule-id]
          |  |     +--ro rule-id           uint8
          |  |     +--ro rule-type         enumeration
          |  |     +--ro ea-len            uint8
          |  |     +--ro prefix4-len       uint8
          |  |     +--ro ipv4-prefix       inet:ipv4-prefix
          |  |     +--ro prefix6-len       uint8
          |  |     +--ro ipv6-prefix       inet:ipv6-prefix
          |  |     +--ro port-parameter
          |  |        +--ro offset      uint8
          |  |        +--ro psid-len    uint8
          |  |        +--ro psid        uint16
          |  +--ro s46-br-paras
          |  |  +--ro br* [br-id]
          |  |     +--ro br-id           uint8
          |  |     +--ro br-ipv6-addr    inet:ipv6-address
          |  +--ro s46-dmr-paras
          |  |  +--ro dmr* [dmr-id]
          |  |     +--ro dmr-id             uint8
          |  |     +--ro dmr-prefix-len     uint8
          |  |     +--ro dmr-ipv6-prefix    inet:ipv6-prefix
          |  +--ro s46-v4-v6-binding-paras
          |  |  +--ro ipv4-addr                inet:ipv4-address
          |  |  +--ro bind-prefix6-len         uint8
          |  |  +--ro port-parameter
          |  |  |  +--ro offset      uint8
          |  |  |  +--ro psid-len    uint8
          |  |  |  +--ro psid        uint16
          |  |  +--ro erp-local-domain-name    string
          |  +--ro supported-options
          |     +--ro supported-option* [option-code]
          |        +--ro option-code    uint16
          |        +--ro description    string
          +--ro packet-stats
             +--ro solicit-count        uint32
             +--ro request-count        uint32
             +--ro renew-count          uint32
             +--ro rebind-count         uint32
             +--ro decline-count        uint32
             +--ro release-count        uint32
             +--ro info-req-count       uint32
             +--ro advertise-count      uint32
             +--ro confirm-count        uint32
             +--ro reply-count          uint32
             +--ro reconfigure-count    uint32
          

Introduction of important nodes:

• client-if: A client may have several interfaces, it is more reasonable to configure and manage parameters on the interface-level. The list defines a specific client interface and its data. Different interfaces are distinguished by the "ifName" key which is a configurable string value.
• duid: Each server and client has only one DUID (DHCP Unique Identifier). The DUID here will be carried in the Client ID option to identify a specific DHCPv6 client. This leaf are same as the "duid" leaf in "dhcpv6-server" feature.
• pd-function: Whether the client can act as a requesting router to request prefixes using prefix delegation ([RFC3633]).
• rapid-commit: '1' indicates a client can initiate a Solicit-Reply message exchange by adding a Rapid Commit option in Solicit message. '0' means the client is not allowed to add a Rapid Commit option to request addresses in a two-message exchange pattern.
• mo-tab: The management tab label indicates the operation mode of the DHCPv6 client. 'm'=1 and 'o'=1 indicate the client will use DHCPv6 to obtain all the configuration data. 'm'=1 and 'o'=0 are a meaningless combination. 'm'=0 and 'o'=1 indicate the client will use stateless DHCPv6 to obtain configuration data apart from addresses/prefixes data. 'm'=0 and 'o'=0 represent the client will not use DHCPv6 but use SLAAC to achieve configuration.
• oro-options: This container provide a way to configure the list of options that the client will request in its ORO option.
• client-configured-options: Similar to the server, the client also need to configure some options to fulfil some desired functions. This container include all the potential options that need to be configured at the client side. The relevant RFCs that define those options include: [RFC3315], [RFC4704], [RFC5970], [RFC6784], [RFC6939].
• identity-association: IA is a construct through which a server and a client can identify, group, and manage a set of related IPv6 addresses. The key of the "identity-association" list is a 4-byte number IAID defined in [RFC3315].
• if-other-paras: A client can obtain extra configuration data other than address and prefix information through DHCPv6 options. This container describes such data the client was configured through DHCPv6. The potential configuration data may include DNS server parameters, SIP server parameters and etc.
• supported-options: This state data container defines a list of options supported by the client for administrator to interrogate a client's capabilities.
• packet-stats: A container records all the packet status information of a specific interface.

2.4. Notifications Mechanism for DHCPv6

+--rw dhcpv6
   +-- ...
   |
   +--n notifications
      +--n dhcpv6-server-event
      |  +--n pool-running-out
      |  |  +--ro utilization-ratio            uint16
      |  |  +--ro duid                         duidtype
      |  |  +--ro serv-name?                   string
      |  |  +--ro pool-name                    string
      |  +--n invalid-client-detected
      |     +--ro duid                         duidtype
      |     +--ro description?                 string
      +--n dhcpv6-relay-event
      |  +--n topo-changed
      |     +--ro relay-if-name                string
      |     +--ro first-hop                    boolean
      |     +--ro last-entity-addr             inet:ipv6-address
      +--n dhcpv6-client-event
         +--n ia-lease-event
         |  +--ro event-type                   enumeration
         |  +--ro duid                         duidtype
         |  +--ro iaid                         uint32
         |  +--ro serv-name?                   string
         |  +--ro description?                 string
         +--n invalid-ia-detected
         |  +--ro duid                         duidtype
         |  +--ro iaid                         uint32
         |  +--ro serv-name?                   string
         |  +--ro description?                 string
         +--n retransmission-failed
         |  +--ro duid                         duidtype
         |  +--ro description                  enumeration
         +--n failed-status-turn-up
            +--ro duid                         duidtype
            +--ro status-code                  enumeration
          

Information about notifications:

• pool-running-out: raised when the address/prefix pool is going to run out. A threshold for utilization ratio of the pool has been defined in the server feature so that it will notify the administrator when the utilization ratio reaches the threshold, and such threshold is a settable parameter.
• invalid-client-detected: raised when the server has found a client which can be regarded as a potential attacker. Some description could also be included.
• topo-changed: raised when the topology of the relay agent is changed.
• ia-lease-event: raised when the client was allocated a new IA from the server or it renew/rebind/release its current IA.
• invalid-ia-detected: raised when the identity association of the client can be proved to be invalid. Possible condition includes duplicated address, illegal address, etc.
• retransmission-failed: raised when the retransmission mechanism defined in [RFC3315] is failed.
• failed-status-turn-up: raised when the client receives a message includes an unsuccessful Status Code option.

3. DHCPv6 YANG Model

This module imports typedefs from [RFC6991].

<CODE BEGINS> file "ietf-dhcpv6@2017-10-26.yang"
  module ietf-dhcpv6 {
    namespace "urn:ietf:params:xml:ns:yang:ietf-dhcpv6";
    prefix "dhcpv6";

    import ietf-inet-types {
      prefix inet;
      revision-date "2013-07-15";
    }
    import ietf-yang-types {
      prefix yang;
      revision-date "2013-07-15";
    }

    organization "dhc wg";
    contact "yong@csnet1.cs.tsinghua.edu.cn
      wangh13@mails.tsinghua.edu.cn
      lh.sunlinh@gmail.com
      Ted.Lemon@nominum.com
      ian.farrer@telekom.de
      sladjana.zechlin@telekom.de";

    description "This model defines a YANG data model that can be
      used to configure and manage DHCPv6 server, DHCPv6 relay and
      DHCPv6 client.";

    revision 2017-10-26 {
      description "version09: resolve feedbacks from IETF96";

      reference "I-D: draft-ietf-dhc-dhcpv6-yang-04";
    }

    revision 2016-06-18 {
      description "version08: resolve yang compiling error:
        top-level node must not be mandatory, wait for YANG
        doctor's review";

      reference "I-D: draft-ietf-dhc-dhcpv6-yang-03";
    }
    revision 2016-06-15 {
      description "version07: resolve yang compiling errors, wait
        for YANG doctor's review";

      reference "I-D: draft-ietf-dhc-dhcpv6-yang-02";
    }
    revision 2016-03-21 {
      description "version06: resolve feedbacks from IETF94";

      reference "I-D: draft-ietf-dhc-dhcpv6-yang-01";
    }
    revision 2015-10-16 {
      description "version05: Omit the feature statement. Modify
        model according to comments from Huawei. Also correct some
        grammar errors.";

      reference "I-D: draft-ietf-dhc-dhcpv6-yang-00";
    }
    revision 2015-09-25 {
      description "version04: Correct duid and grammar errors.";

      reference "I-D: draft-cui-dhc-dhcpv6-yang-04";
    }
    revision 2015-07-01 {
      description "version03: Correct grammar errors.";

      reference "I-D: draft-cui-dhc-dhcpv6-yang-03";
    }
    revision 2015-04-13 {
      description "version02: Correct grammar errors.";

      reference "I-D: draft-cui-dhc-dhcpv6-yang-02";
    }
    revision 2015-04-02 {
      description "version01: Correct grammar errors, Reuse
        groupings, Update 'dhcpv6-relay' feature, Add
        notifications.";

      reference "I-D: draft-cui-dhc-dhcpv6-yang-01";
    }
    revision 2015-03-04 {
      description "version00: Initial revision.";

      reference "I-D: draft-cui-dhc-dhcpv6-yang-00";
    }

    /*
     * Typedef
     */

    typedef threshold {
      type union {
        type uint16 {
          range 0..100;
        }
        type enumeration {
          enum "disabled" {
            description "No threshold";
          }
        }
      }
      description "Threshold value in percent";
    }

    /*
     * Grouping
     */

    grouping vendor-infor {
      description "Vendor information.";
      container vendor-info {
        description "";
        leaf ent-num {
          type uint32;
          mandatory true;
          description "enterprise number";
        }
        leaf-list data {
          type string;
          description "specific vendor info";
        }
      }
    }

    grouping duid {
      description "DHCP Unique Identifier";
      reference "RFC3315: Section 9";
      choice duid-type {
        description "Selects the format for the DUID.";
        case duid-llt {
          description "DUID Based on Link-layer Address Plus Time";
          reference "RFC3315 Section 9.2";
          leaf duid-llt-hardware-type {
            type uint16;
            description "Hardware type as assigned by IANA (RFC826).";
          }
          leaf duid-llt-time {
            type yang:timeticks;
            description "The time value is the time that the DUID is generated
              represented in seconds since midnight (UTC), January 1, 2000,
                          modulo 2^32.";
          }
          leaf duid-llt-link-layer-addr {
            type yang:mac-address;
            description "Link-layer address as described in RFC2464";
          }
        }
        case duid-en {
          description "DUID Assigned by Vendor Based on Enterprise Number";
          reference "RFC3315 Section 9.3";
          leaf duid-en-enterprise-number {
            type uint32;
            description "Vendor's registered Private Enterprise Number as
              maintained by IANA";
          }
          leaf duid-en-identifier {
            type string;
            description "Indentifier, unique to the device that is using it";
          }
        }
        case duid-ll {
          description "DUID Based on Link-layer Address";
          reference "RFC3315 Section 9.4";
          leaf duid-ll-hardware-type {
            type uint16;
            description "Hardware type as assigned by IANA (RFC826).";
          }
          leaf duid-ll-time {
            type yang:timeticks;
            description "The time value is the time that the DUID is generated
              represented in seconds since midnight (UTC), January 1, 2000,
                          modulo 2^32.";
          }
        }
      }
    }

    grouping portset-para {
      description "portset parameters";
      container port-parameter {
        description "port parameter";
        leaf offset {
          type uint8;
          mandatory true;
          description "offset in a port set";
        }
        leaf psid-len {
          type uint8;
          mandatory true;
          description "length of a psid";
        }
        leaf psid {
          type uint16;
          mandatory true;
          description "psid value";
        }
      }
    }

    /*
     * Data Nodes
     */

    container server {
      presence "Enables server";
      description "dhcpv6 server portion";
      container serv-attributes {
        description "This container contains basic attributes
          of a DHCPv6 server such as DUID, server name and so
          on. Some optional functions that can be provided by
          the server is also included.";
        leaf name {
          type string;
          description "server's name";
        }
        container duid {
          description "Sets the DUID";
          uses duid;
        }
        leaf-list ipv6-address {
          type inet:ipv6-address;
          description "Server's IPv6 address.";
        }
        leaf description {
          type string;
          description "Description of the server.";
        }
        leaf pd-function {
          type boolean;
          mandatory true;
          description "Whether the server can act as a
            delegating router to perform prefix delegation
            ([RFC3633]).";
        }
        leaf stateless-service {
          type boolean;
          mandatory true;
          description "A boolean value specifies whether
            the server support client-server exchanges
            involving two messages defined in ([RFC3315]).";
        }
        leaf rapid-commit {
          type boolean;
          mandatory true;
          description "A boolean value specifies whether
            the server support client-server exchanges
            involving two messages defined in ([RFC3315]).";
        }
        leaf-list interfaces-config {
          type string;
          description "A leaf list to denote which one or
            more interfaces the server should listen on. The
            default value is to listen on all the interfaces.
            This node is also used to set a unicast address
            for the server to listen with a specific interface.
              For example, if people want the server to listen
                on a unicast address with a specific interface, he
                can use the format like 'eth1/2001:db8::1'.";
        }
        uses vendor-infor;
      }
      container option-sets {
        description "DHCPv6 employs various options to carry
          additional information and parameters in DHCP messages.
          This container defines all the possible options that
          need to be configured at the server side.";
        list option-set {
          key option-set-id;
          description "A server may allow different option
            sets to be configured for different conditions
            (i.e. different networks, clients and etc). This
            'option-set' list enables various sets of options
            being defined and configured in a single server.
            Different sets are distinguished by the key called
            'option-set-id'. All the possible options discussed
            above are defined in the list and each option is
            corresponding to a container.";
          leaf option-set-id {
            type uint8;
            mandatory true;
            description "the option-set-id key";
          }
          list new-or-standard-option {
            key option-code;
            description "new or standard option";
            leaf option-code {
              type uint16;
              mandatory true;
              description "the option code key";
            }
            leaf option-name {
              type string;
              mandatory true;
              description "the new option's name";
            }
            leaf option-description {
              type string;
              mandatory true;
              description "description of new option";
            }
            leaf option-reference {
              type string;
              description "reference to the
                specification";
            }
            leaf option-value {
              type string;
              mandatory true;
              description "the new option's value";
            }
          }
          leaf user-class-value {
            type string;
            description "use class option's value";
          }
          leaf enterprise-number {
            type uint32;
            description "enterprise number";
          }
          leaf store-client-link-layer {
            type boolean;
            description "whether to store client's
              link layer address";
          }
          container preference-option {
            description "preference option";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this option will be included in the
                option set";
            }
            leaf preference-value {
              type uint8;
              mandatory true;
              description "the value for this option";
            }
          }
          container sip-server-option {
            description "sip server option";
            //Note - this container is currently modelling two options (21 & 22). It would allow the
            //config of a mixed list of domain names and addresses in a way that doesn't follow the
            //RFC. Needs to be broken into SIP Domain list and SIP Address list containers
            reference "RFC3319: Dynamic Host Configuration Protocol
              (DHCPv6) Options for Session Initiation Protocol (SIP)
              Servers";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list sip-server {
              key sip-serv-id;
              description "sip server info";
              leaf sip-serv-id {
                type uint8;
                mandatory true;
                description "sip server id";
              }
              leaf sip-serv-domain-name {
                type string;
                mandatory true;
                description "sip server domain
                  name";
              }
              leaf sip-serv-addr {
                type inet:ipv6-address;
                mandatory true;
                description "sip server addr";
              }
            }
          }
          container dns-config-option {
            description "OPTION_DNS_SERVERS (23) DNS recursive Name
              Server option";
            reference "RFC3646: DNS Configuration options for Dynamic
              Host Configuration Protocol for IPv6 (DHCPv6)";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list dns-server {
              key dns-serv-id;
              description "dns server info";
              leaf dns-serv-id {
                type uint8;
                mandatory true;
                description "DNS server list entry ID.";
              }
              leaf dns-serv-addr {
                type inet:ipv6-address;
                mandatory true;
                description "DNS server address.";
              }
            }
          }
          container domain-searchlist-option {
            description "OPTION_DOMAIN_LIST (24) Domain Search List Option";
            reference "RFC3646: DNS Configuration options for Dynamic
              Host Configuration Protocol for IPv6 (DHCPv6)";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list domain-searchlist {
              key domain-searchlist-id;
              description "dns server info";
              leaf domain-searchlist-id {
                type uint8;
                mandatory true;
                description "Domain seachlist entry ID.";
              }
              leaf domain-search-list-entry {
                type string;
                mandatory true;
                description "Domain search list entry.";
              }
            }
          }
          container nis-config-option {
            description "OPTION_NIS_SERVERS (27) Network Information Service (NIS)
              Servers Option.";
            reference "RFC3989: Network Information Service (NIS) Configuration
              Options for Dynamic Host Configuration Protocol for IPv6 (DHCPv6)";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list nis-server {
              key nis-serv-id;
              description "nis server info";
              leaf nis-serv-id {
                type uint8;
                mandatory true;
                description "nis server id";
              }
              leaf nis-serv-addr {
                type inet:ipv6-address;
                mandatory true;
                description "nis server addr";
              }
            }
          }
          container nis-plus-config-option {
            description "OPTION_NISP_SERVERS (28): Network Information Service V2
              (NIS+) Servers Option.";
            reference "RFC3989: Network Information Service (NIS) Configuration
              Options for Dynamic Host Configuration Protocol for IPv6 (DHCPv6)";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list nis-plus-server {
              key nis-plus-serv-id;
              description "NIS+ server information.";
              leaf nis-plus-serv-id {
                type uint8;
                mandatory true;
                description "nisp server id";
              }
              leaf nis-plus-serv-addr {
                type inet:ipv6-address;
                mandatory true;
                description "nisp server addr";
              }
            }
          }
          container sntp-server-option {
            description "OPTION_SNTP_SERVERS (31) Simple Network Time Protocol
              (SNTP) Servers Option";
            reference "RFC4075: Simple Network Time Protocol (SNTP) Configuration
              Option for DHCPv6";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list sntp-server {
              key sntp-serv-id;
              description "sntp server info";
              leaf sntp-serv-id {
                type uint8;
                mandatory true;
                description "sntp server id";
              }
              leaf sntp-serv-addr {
                type inet:ipv6-address;
                mandatory true;
                description "sntp server addr";
              }
            }
          }
          container info-refresh-time-option {
            description "OPTION_INFORMATION_REFRESH_TIME (32) Information Refresh
              Time option.";
            reference "RFC4242: Information Refresh Time Option for Dynamic Host
              Configuration Protocol for IPv6 (DHCPv6";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
               option will be included in the
               option set";
            }
            leaf info-refresh-time {
              type yang:timeticks;
              mandatory true;
              description "The refresh time.";
            }
          }
          container cli-fqdn-option {
            description "OPTION_CLIENT_FQDN (39) DHCPv6 Client FQDN Option";
            reference "RFC4704: The Dynamic Host Configuration Protocol for IPv6
              (DHCPv6) Client Fully Qualified Domain Name (FQDN) Option";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this option will be included in the
                option set";
            }
            leaf server-initiate-update {
              type boolean;
              mandatory true;
              description "server initiate";
            }
            leaf client-initiate-update {
              type boolean;
              mandatory true;
              description "client initiate";
            }
            leaf modify-name-from-cli {
              type boolean;
              mandatory true;
              description "modify by client";
            }
          }
          container posix-timezone-option {
            description "OPTION_NEW_POSIX_TIMEZONE (41) Posix Timezone option";
            reference "RFC4822: Timezone Options for DHCP";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this option will be included in the
                        option set";
            }
            leaf tz-posix {
              type string;
              mandatory true;
              description "TZ Posix IEEE 1003.1 String";
            }
          }
          container posix-timezone-db-option {
            description "OPTION_NEW_TZDB_TIMEZONE (42) Timezone Database option";
            reference "RFC4822: Timezone Options for DHCP";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this option will be included in the
                        option set";
            }
            leaf tz-database {
              type string;
              mandatory true;
              description "Reference to the TZ Database";
            }
          }
          container ntp-server-option {
            //This option looks like it needs work to correctly model the
            //option as defined in the RFC.
            description "OPTION_NTP_SERVER (56) NTP Server Option for DHCPv6";
            reference "RFC5908: Network Time Protocol (NTP) Server Option for
            DHCPv6";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this option will be included in the
                        option set";
            }
            list ntp-server {
              key ntp-serv-id;
              description "ntp server info";
              leaf ntp-serv-id {
                type uint8;
                mandatory true;
                description "ntp server id";
              }
              leaf ntp-serv-addr-suboption {
                type inet:ipv6-address;
                mandatory true;
                description "ntp server addr";
              }
              leaf ntp-serv-mul-addr-suboption {
                type inet:ipv6-address;
                mandatory true;
                description "ntp server multicast addr";
              }
              leaf ntp-serv-fqdn-suboption {
                type string;
                mandatory true;
                description "ntp server fqdn";
              }
            }
          }
          container network-boot-option {
            description "network boot option";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list boot-file {
              key boot-file-id;
              description "boot file info";
              leaf boot-file-id {
                type uint8;
                mandatory true;
                description "boot file id";
              }
              leaf-list suitable-arch-type {
                type uint16;
                description "architecture type";
              }
              leaf-list suitable-net-if {
                type uint32;
                description "network interface";
              }
              leaf boot-file-url {
                type string;
                mandatory true;
                description "url for boot file";
              }
              list boot-file-paras {
                key para-id;
                description "boot file parameters";
                leaf para-id {
                  type uint8;
                  mandatory true;
                  description "parameter id";
                }
                leaf parameter {
                  type string;
                  mandatory true;
                  description "parameter
                    value";
                }
              }
            }
          }
          container aftr-name-option {
            description "OPTION_AFTR_NAME (64) AFTR-Name DHCPv6 Option";
            reference "RFC6334: Dynamic Host Configuration Protocol for IPv6
            (DHCPv6) Option for Dual-Stack Lite";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this option will be included in the
              option set";
            }
            leaf tunnel-endpoint-name {
              type string;
              mandatory true;
              description "aftr name";
            }
          }
          container kerberos-option {
            //This needs re-working and possibly splitting into several option
            //containers to follow the RFC.
            description "kerberos option";
            reference "RFC6784: Kerberos Options for DHCPv6";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            leaf default-realm-name {
              type string;
              mandatory true;
              description "default realm name";
            }
            list kdc-info {
              key kdc-id;
              description "kdc info";
              leaf kdc-id {
                type uint8;
                mandatory true;
                description "kdc id";
              }
              leaf priority {
                type uint16;
                mandatory true;
                description "priority";
              }
              leaf weight {
                type uint16;
                mandatory true;
                description "weight";
              }
              leaf transport-type {
                type uint8;
                mandatory true;
                description "transport type";
              }
              leaf port-number {
                type uint16;
                mandatory true;
                description "port number";
              }
              leaf kdc-ipv6-addr {
                type inet:ipv6-address;
                mandatory true;
                description "kdc ipv6 addr";
              }
              leaf realm-name {
                type string;
                mandatory true;
                description "realm name";
              }
            }
          }
          container addr-selection-option {
            description "address selection option";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this option will be included in the
                        option set";
             }
                    leaf a-bit-set {
                      type boolean;
                      mandatory true;
                      description "a bit";
                    }
                    leaf p-bit-set {
                      type boolean;
                      mandatory true;
                      description "p bit";
                    }
                    list policy-table {
                      key policy-id;
                      description "policy table";
                      leaf policy-id {
                        type uint8;
                        mandatory true;
                        description "policy id";
                      }
                      leaf label {
                        type uint8;
                        mandatory true;
                        description "label";
                      }
                      leaf precedence {
                        type uint8;
                        mandatory true;
                        description "precedence";
                      }
                      leaf prefix-len {
                        type uint8;
                        mandatory true;
                        description "prefix length";
                      }
                      leaf prefix {
                        type inet:ipv6-prefix;
                        mandatory true;
                        description "prefix";
                      }
                    }
                  }
           container sol-max-rt-option {
                    description "OPTION_SOL_MAX_RT (82) sol max rt option";
                    reference "RFC7083: Modification to Default Values of
                      SOL_MAX_RT and INF_MAX_RT";
                    leaf enable {
                      type boolean;
                      mandatory true;
                      description "indicate whether this
                        option will be included in the
                        option set";
                    }
                    leaf sol-max-rt-value {
                      type yang:timeticks;
                      mandatory true;
                      description "sol max rt value";
                    }
                  }
           container inf-max-rt-option {
                    description "OPTION_INF_MAX_RT (83) inf max rt option";
                    reference "RFC7083: Modification to Default Values of
                      SOL_MAX_RT and INF_MAX_RT";
                    leaf enable {
                      type boolean;
                      mandatory true;
                      description "indicate whether this
                        option will be included in the
                        option set";
                    }
                    leaf inf-max-rt-value {
                      type yang:timeticks;
                      mandatory true;
                      description "inf max rt value";
                    }
                  }
           container pcp-server-option {
                    description "OPTION_V6_PCP_SERVER (86)
                      pcp server option";
                    reference "RFC7291: DHCP Options for the Port Control
                      Protocol (PCP)";
                    leaf enable {
                      type boolean;
                      mandatory true;
                      description "indicate whether this
                        option will be included in the
                        option set";
                    }
                    list pcp-server {
                      key pcp-serv-id;
                      description "pcp server info";
                      leaf pcp-serv-id {
                        type uint8;
                        mandatory true;
                        description "pcp server id";
                      }
                      leaf pcp-serv-addr {
                        type inet:ipv6-address;
                        mandatory true;
                        description "pcp server addr";
                      }
                    }
                  }
           container s46-rule-option {
                    description "s46 rule option";
                    reference "RFC7598: DHCPv6 Options for Configuration of
                      Softwire Address and Port-Mapped Clients";
                    leaf enable {
                      type boolean;
                      mandatory true;
                      description "indicate whether this
                        option will be included in the
                        option set";
                    }
                    list s46-rule {
                      key rule-id;
                      description "s46 rule";
                      leaf rule-id {
                        type uint8;
                        mandatory true;
                        description "rule id";
                      }
                      leaf rule-type {
                        type enumeration {
                          enum "BMR" {
                            description "BMR";
                          }
                          enum "FMR" {
                            description "FMR";
                          }
                        }
                        mandatory true;
                        description "rule type";
                      }
                      leaf prefix4-len {
                        type uint8;
                        mandatory true;
                        description "ipv4 prefix length";
                      }
                      leaf ipv4-prefix {
                        type inet:ipv4-prefix;
                        mandatory true;
                        description "ipv4 prefix";
                      }
                      leaf prefix6-len {
                        type uint8;
                        mandatory true;
                        description "ipv6 prefix length";
                      }
                      leaf ipv6-prefix {
                        type inet:ipv6-prefix;
                        mandatory true;
                        description "ipv6 prefix";
                      }
                      uses portset-para;
                    }
                  }
           container s46-br-option {
                    description "s46 br option";
                    reference "RFC7598: DHCPv6 Options for Configuration of
                      Softwire Address and Port-Mapped Clients";
                    leaf enable {
                      type boolean;
                      mandatory true;
                      description "indicate whether this
                        option will be included in the
                        option set";
                    }
                    list br {
                      key br-id;
                      description "br info";
                      leaf br-id {
                        type uint8;
                        mandatory true;
                        description "br id";
                      }
                      leaf br-ipv6-addr {
                        type inet:ipv6-address;
                        mandatory true;
                        description "br ipv6 addr";
                      }
                    }
                  }
          container operator-option-ipv6-address {
            description "operator ipv6 address option";
            reference "RFC7227: Guidelines for Creating New DHCPv6 Options";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list operator-ipv6-addr {
              key operator-ipv6-addr-id;
              description "operator ipv6 address info";
              leaf operator-ipv6-addr-id {
                type uint8;
                mandatory true;
                description "operator ipv6 address id";
              }
              leaf operator-ipv6-addr {
                type inet:ipv6-address;
                mandatory true;
                description "operator ipv6 address id";
              }
            }
          }
          container operator-option-single-flag {
            description "operator single flag";
            reference "RFC7227: Guidelines for Creating New DHCPv6
              Options";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list flag {
              key flag-id;
              description "operator single flag info";
              leaf flag-id {
                type uint8;
                mandatory true;
                description "operator single flag id";
              }
              leaf flag-value{
                type boolean;
                mandatory true;
                description "operator single flag value";
              }
            }
          }
          container operator-option-ipv6-prefix {
            description "operator ipv6 prefix option";
            reference "RFC7227: Guidelines for Creating New DHCPv6
              Options";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list operator-ipv6-prefix{
              key operator-ipv6-prefix-id;
              description "operator ipv6 prefix info";
              leaf operator-ipv6-prefix-id {
                type uint8;
                mandatory true;
                description "operator ipv6 prefix id";
              }
              leaf operator-ipv6-prefix6-len{
                type uint8;
                mandatory true;
                description "operator ipv6 prefix length";
              }
              leaf operator-ipv6-prefix {
                type inet:ipv6-prefix;
                mandatory true;
                description "operator ipv6 prefix";
              }
            }
          }
          container operator-option-int32 {
            description "operator integer 32 option";
            reference "RFC7227: Guidelines for Creating New DHCPv6
              Options";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list int32val{
              key int32val-id;
              description "operator integer 32 info";
              leaf int32val-id {
                type uint8;
                mandatory true;
                description "operator integer 32 id";
              }
              leaf int32val{
                type uint32;
                mandatory true;
                description "operator integer 32 value";
              }
            }
          }
          container operator-option-int16 {
            description "operator integer 16 option";
            reference "RFC7227: Guidelines for Creating New DHCPv6
              Options";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list int16val{
              key int16val-id;
              description "operator integer 16 info";
              leaf int16val-id {
                type uint8;
                mandatory true;
                description "operator integer 16 id";
              }
              leaf int16val{
                type uint16;
                mandatory true;
                description "operator integer 16 value";
              }
            }
          }
          container operator-option-int8 {
            description "operator integer 8 option";
            reference "RFC7227: Guidelines for Creating New DHCPv6
              Options";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list int8val{
              key int8val-id;
              description "operator integer 8 info";
              leaf int8val-id {
                type uint8;
                mandatory true;
                description "operator integer 8 id";
              }
              leaf int8val{
                type uint8;
                mandatory true;
                description "operator integer 8 value";
              }
            }
          }
          container operator-option-uri {
            description "operator uri option";
            reference "RFC7227: Guidelines for Creating New DHCPv6
              Options";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list uri{
              key uri-id;
              description "operator uri info";
              leaf uri-id {
                type uint8;
                mandatory true;
                description "operator uri id";
              }
              leaf uri{
                type string;
                mandatory true;
                description "operator uri value";
              }
            }
          }
          container operator-option-textstring {
            description "operator itext string option";
            reference "RFC7227: Guidelines for Creating New DHCPv6 Options";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list textstring{
              key textstring-id;
              description "operator text string info";
              leaf textstring-id {
                type uint8;
                mandatory true;
                description "operator text string id";
              }
              leaf textstring{
                type string;
                mandatory true;
                description "operator text string value";
              }
            }
          }
          container operator-option-var-data {
            description "operator variable length data option";
            reference "RFC7227: Guidelines for Creating New DHCPv6 Options";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list int32val{
              key var-data-id;
              description "operator ivariable length data info";
              leaf var-data-id {
                type uint8;
                mandatory true;
                description "operator variable length id";
              }
              leaf var-data{
                type binary;
                mandatory true;
                description "operator variable length value";
              }
            }
          }
          container operator-option-dns-wire {
            description "operator dns wire format domain name list option";
            reference "RFC7227: Guidelines for Creating New DHCPv6
              Options";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list operator-option-dns-wire{
              key operator-option-dns-wire-id;
              description "operator dns wire format info";
              leaf operator-option-dns-wire-id {
                type uint8;
                mandatory true;
                description "operator dns wire format id";
              }
              leaf operator-option-dns-wire{
                type binary;
                mandatory true;
                description "operator dns wire format value";
              }
            }
          }
          container s46-dmr-option {
            description "s46 dmr option";
            reference "RFC7598: DHCPv6 Options for Configuration of
              Softwire Address and Port-Mapped Clients";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list dmr {
              key dmr-id;
              description "dmr info";
              leaf dmr-id {
                type uint8;
                mandatory true;
                description "dmr id";
              }
              leaf dmr-prefix-len {
                type uint8;
                mandatory true;
                description "dmr prefix length";
              }
              leaf dmr-ipv6-prefix {
                type inet:ipv6-prefix;
                mandatory true;
                description "dmr ipv6 prefix";
              }
            }
          }
          container s46-v4-v6-binding-option {
            description "s46 binding option";
            reference "RFC7598: DHCPv6 Options for Configuration of
              Softwire Address and Port-Mapped Clients";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be included in the
                option set";
            }
            list ce {
              key ce-id;
              description "ce info";
              leaf ce-id {
                type uint8;
                mandatory true;
                description "ce id";
              }
              leaf ipv4-addr {
                type inet:ipv4-address;
                mandatory true;
                description "ce ipv4 addr";
              }
              leaf bind-prefix6-len {
                type uint8;
                mandatory true;
                description "bind ipv6 prefix
                  length";
              }
              leaf bind-ipv6-prefix {
                type inet:ipv6-prefix;
                mandatory true;
                description "bind ipv6 prefix";
              }
              uses portset-para;
            }
          }
        }
        //NB - The list of options needs to be updated with newer options.
      }
      container network-ranges {
        description "This model supports a hierarchy
          to achieve dynamic configuration. That is to
          say we could configure the server at different
          levels through this model. The top level is a
          global level which is defined as the container
          'network-ranges'. The following levels are
          defined as sub-containers under it. The
          'network-ranges' contains the parameters
          (e.g. option-sets) that would be allocated to
          all the clients served by this server.";
        leaf option-set-id {
          type uint8;
          description "a specific option set";
        }
        list network-range {
          key network-range-id;
          description "Under the 'network-ranges'
            container, a 'network-range' list is
            defined to configure the server at a
            network level which is also considered
            as the second level. Different network
            are identified by the key 'network-range-id'.
            This is because a server may have different
            configuration parameters (e.g. option sets)
            for different networks.";
          leaf network-range-id {
            type uint8;
            mandatory true;
            description "equivalent to subnet id";
          }
          leaf network-description {
            type string;
            mandatory true;
            description "description of the subnet";
          }
          leaf network-prefix {
            type inet:ipv6-prefix;
            mandatory true;
            description "subnet prefix";
          }
          leaf inherit-option-set {
            type boolean;
            mandatory true;
            description "indicate whether to inherit
              the configuration from higher level";
          }
          leaf option-set-id {
            type uint8;
            mandatory true;
            description "the selected option-set";
          }
          container reserved-addresses {
            description "reserved addresses";
            list static-binding {
              key cli-id;
              description "static binding of
                reserved addresses";
              leaf cli-id {
                type uint32;
                mandatory true;
                description "client id";
              }
              container duid {
                description "Sets the DUID";
                uses duid;
              }
              leaf-list reserv-addr {
                type inet:ipv6-address;
                description "reserved addr";
              }
            }
            leaf-list other-reserv-addr {
              type inet:ipv6-address;
              description "other reserved
                addr";
            }
          }
          container reserved-prefixes {
            description "reserved prefixes";
            list static-binding {
              key cli-id;
              description "static binding";
              leaf cli-id {
                type uint32;
                mandatory true;
                description "client id";
              }
              container duid {
                description "Sets the DUID";
                uses duid;
              }
              leaf reserv-prefix-len {
                type uint8;
                mandatory true;
                description "reserved
                  prefix length";
              }
              leaf reserv-prefix {
                type inet:ipv6-prefix;
                mandatory true;
                description
                  "reserved prefix";
              }
            }
            leaf exclude-prefix-len {
              type uint8;
              mandatory true;
              description "exclude prefix
                length";
            }
            leaf exclude-prefix {
              type inet:ipv6-prefix;
              mandatory true;
              description "exclude prefix";
            }
            list other-reserv-prefix {
              key reserv-id;
              description
                "other reserved prefix";
              leaf reserv-id {
                type uint8;
                mandatory true;
                description
                  "reserved prefix id";
              }
              leaf prefix-len {
                type uint8;
                mandatory true;
                description "prefix length";
              }
              leaf prefix {
                type inet:ipv6-prefix;
                mandatory true;
                description
                  "reserved prefix";
              }
            }
          }
          container address-pools {
            description "A container describes
              the DHCPv6 server's address pools.";
            list address-pool {
              key pool-id;
              description "A DHCPv6 server can
                be configured with several address
                pools. This list defines such
                address pools which are distinguish
                by the key called 'pool-name'.";
              leaf pool-id {
                type uint8;
                mandatory true;
                description "pool id";
              }
              leaf pool-prefix {
                type inet:ipv6-prefix;
                mandatory true;
                description "pool prefix";
              }
              leaf start-address {
                type inet:ipv6-address-no-zone;
                mandatory true;
                description "start address";
              }
              leaf end-address {
                type inet:ipv6-address-no-zone;
                mandatory true;
                description "end address";
              }
              leaf renew-time {
                type yang:timeticks;
                mandatory true;
                description "renew time";
              }
              leaf rebind-time {
                type yang:timeticks;
                mandatory true;
                description "rebind time";
              }
              leaf preferred-lifetime {
                type yang:timeticks;
                mandatory true;
                description "preferred lifetime
                  for IA";
              }
              leaf valid-lifetime {
                type yang:timeticks;
                mandatory true;
                description "valid liftime for IA";
              }
              leaf total-ipv6-count {
                type uint64;
                config "false";
                mandatory true;
                description "how many ipv6
                  addressses are in the pool";
              }
              leaf used-ipv6-count {
                type uint64;
                config "false";
                mandatory true;
                description "how many are
                  allocated";
              }
              leaf utilization-ratio {
                type threshold;
                mandatory true;
                description "the utilization ratio";
              }
              leaf inherit-option-set {
                type boolean;
                mandatory true;
                description "indicate whether to
                  inherit the configuration from
                  higher level";
              }
              leaf option-set-id {
                type uint8;
                mandatory true;
                description "the selected option-set";
              }
            }
            list binding-info {
              key cli-id;
              config "false";
              description "A list records a binding
                information for each DHCPv6 client
                that has already been allocated IPv6
                addresses.";
              leaf cli-id {
                type uint32;
                mandatory true;
                description "client id";
              }
              container duid {
                description "Sets the DUID";
                uses duid;
              }
              list cli-ia {
                key iaid;
                description "client IA";
                leaf ia-type {
                  type string;
                  mandatory true;
                  description "IA type";
                }
                leaf iaid {
                  type uint32;
                  mandatory true;
                  description "IAID";
                }
                leaf-list cli-addr {
                  type inet:ipv6-address;
                  description "client addr";
                }
                leaf pool-id {
                  type uint8;
                  mandatory true;
                  description "pool id";
                }
              }
            }
          }
          container prefix-pools {
            description "If a server supports prefix
              delegation function, this container will
              be used to define the delegating router's
              refix pools.";
            list prefix-pool {
              key pool-id;
              description "Similar to server's
                address pools, a delegating router
                can also be configured with multiple
                prefix pools specified by a list
                called 'prefix-pool'.";
              leaf pool-id {
                type uint8;
                mandatory true;
                description "pool id";
              }
              leaf prefix {
                type inet:ipv6-prefix;
                mandatory true;
                description "ipv6 prefix";
              }
              leaf prefix-length {
                type uint8;
                mandatory true;
                description "prefix length";
              }
              leaf renew-time {
                type yang:timeticks;
                mandatory true;
                description "renew time";
              }
              leaf rebind-time {
                type yang:timeticks;
                mandatory true;
                description "rebind time";
              }
              leaf preferred-lifetime {
                type yang:timeticks;
                mandatory true;
                description "preferred lifetime for
                  IA";
              }
              leaf valid-lifetime {
                type yang:timeticks;
                mandatory true;
                description "valid lifetime for IA";
              }
              leaf utilization-ratio {
                type threshold;
                mandatory true;
                description "utilization ratio";
              }
              leaf inherit-option-set {
                type boolean;
                mandatory true;
                description "whether to inherit
                  configuration from higher level";
              }
              leaf option-set-id {
                type uint8;
                mandatory true;
                description "the selected option-set";
              }
            }
            list binding-info {
              key cli-id;
              config "false";
              description "A list records a
                binding information for each
                DHCPv6 client that has already
                been allocated IPv6 addresses.";
              leaf cli-id {
                type uint32;
                mandatory true;
                description "client id";
              }
              container duid {
                description "Sets the DUID";
                uses duid;
              }
              list cli-iapd {
                key iaid;
                description "client IAPD";
                leaf iaid {
                  type uint32;
                  mandatory true;
                  description "IAID";
                }
                leaf-list cli-prefix {
                  type inet:ipv6-prefix;
                  description
                    "client ipv6 prefix";
                }
                leaf-list cli-prefix-len {
                  type uint8;
                  description
                    "client prefix length";
                }
                leaf pool-id {
                  type uint8;
                  mandatory true;
                  description "pool id";
                }
              }
            }
          }
          container hosts {
            description "hosts level";
            list host {
              key cli-id;
              description "specific host";
              leaf cli-id {
                type uint32;
                mandatory true;
                description "client id";
              }
              container duid {
                description "Sets the DUID";
                uses duid;
              }
              leaf inherit-option-set {
                type boolean;
                mandatory true;
                description "whether to inherit
                  configuration
                  from higher level";
              }
              leaf option-set-id {
                type uint8;
                mandatory true;
                description "the selected option-set";
              }
              leaf nis-domain-name {
                type string;
                description "nis domain name";
              }
              leaf nis-plus-domain-name {
                type string;
                description "nisp domain name";
              }
            }
          }
        }
      }
      container relay-opaque-paras {
        description "This container contains some
          opaque values in Relay Agent options that
          need to be configured on the server side
          only for value match. Such Relay Agent
          options include Interface-Id option,
                  Remote-Id option and Subscriber-Id option.";
        list relays {
          key relay-name;
          description "relay agents";
          leaf relay-name {
            type string;
            mandatory true;
            description "relay agent name";
          }
          list interface-info {
            key if-name;
            description "interface info";
            leaf if-name {
              type string;
              mandatory true;
              description "interface name";
            }
            leaf interface-id {
              type string;
              mandatory true;
              description "interface id";
            }
          }
          list subscribers {
            key subscriber;
            description "subscribers";
            leaf subscriber {
              type uint8;
              mandatory true;
              description "subscriber";
            }
            leaf subscriber-id {
              type string;
              mandatory true;
              description "subscriber id";
            }
          }
          list remote-host {
            key ent-num;
            description "remote host";
            leaf ent-num {
              type uint32;
              mandatory true;
              description "enterprise number";
            }
            leaf remote-id {
              type string;
              mandatory true;
              description "remote id";
            }
          }
        }
      }
      container rsoo-enabled-options {
        description "rsoo enabled options";
        list rsoo-enabled-option{
          key option-code;
          description "rsoo enabled option";
          leaf option-code {
            type uint16;
            mandatory true;
            description "option code";
          }
          leaf description {
            type string;
            mandatory true;
            description "description of the option";
          }
        }
      }
      container packet-stats {
        config "false";
        description "A container presents
          the packet statistics related to
          the DHCPv6 server.";
        leaf solicit-count {
          type uint32;
          mandatory true;
          description "solicit counter";
        }
        leaf request-count {
          type uint32;
          mandatory true;
          description "request counter";
        }
        leaf renew-count {
          type uint32;
          mandatory true;
          description "renew counter";
        }
        leaf rebind-count {
          type uint32;
          mandatory true;
          description "rebind counter";
        }
        leaf decline-count {
          type uint32;
          mandatory true;
          description "decline count";
        }
        leaf release-count {
          type uint32;
          mandatory true;
          description "release counter";
        }
        leaf info-req-count {
          type uint32;
          mandatory true;
          description "information request
            counter";
        }
        leaf advertise-count {
          type uint32;
          mandatory true;
          description "advertise counter";
        }
        leaf confirm-count {
          type uint32;
          mandatory true;
          description "confirm counter";
        }
        leaf reply-count {
          type uint32;
          mandatory true;
          description "reply counter";
        }
        leaf reconfigure-count {
          type uint32;
          mandatory true;
          description "reconfigure counter";
        }
        leaf relay-forward-count {
          type uint32;
          mandatory true;
          description "relay forward counter";
        }
        leaf relay-reply-count {
          type uint32;
          mandatory true;
          description "relay reply counter";
        }
      }
    }

    container relay {
      presence "Enables relay";
      description "dhcpv6 relay portion";
      container relay-attributes {
        description "A container describes
          some basic attributes of the relay
          agent including some relay agent
          specific options data that need to
          be configured previously. Such options
          include Remote-Id option and
          Subscriber-Id option.";
        leaf name {
          type string;
          description "relay agent name";
        }
        leaf description {
          type string;
          description "description of the relay agent";
        }
        leaf-list dest-addrs {
          type inet:ipv6-address;
          description "Each DHCPv6 relay agent may
            be configured with a list of destination
            addresses. This node defines such a list
            of IPv6 addresses that may include
            unicast addresses, multicast addresses
            or other addresses.";
        }
        list subscribers {
          key subscriber;
          description "subscribers";
          leaf subscriber {
            type uint8;
            mandatory true;
            description "subscriber";
          }
          leaf subscriber-id {
            type string;
            mandatory true;
            description "subscriber id";
          }
        }
        list remote-host {
          key ent-num;
          description "remote host";
          leaf ent-num {
            type uint32;
            mandatory true;
            description "enterprise number";
          }
          leaf remote-id {
            type string;
            mandatory true;
            description "remote id";
          }
        }
        uses vendor-infor;
      }
      container relay-supplied-options-option {
        description "relay supplied options option";
        list rsoo-set {
          key rsoo-set-id;
          description "rsoo set";
          leaf rsoo-set-id {
            type uint8;
            mandatory true;
            description "rsoo set id";
          }
          container erp-local-domain-name-option {
            description "erp local domain name option";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether
                this option is included in the
                rsoo set";
            }
            list erp-for-client {
              key cli-id;
              description "erp for client";
              leaf cli-id {
                type uint32;
                mandatory true;
                description "client id";
              }
              container duid {
                description "Sets the DUID";
                uses duid;
              }
              leaf erp-name {
                type string;
                mandatory true;
                description "erp name";
              }
            }
          }
        }
      }
      list relay-if {
        key if-name;
        description "A relay agent may have several
          interfaces, we should provide a way to configure
          and manage parameters on the interface-level. A
          list that describes specific interfaces and
          their corresponding parameters is employed to
          fulfil the configfuration. Here we use a string
          called 'if-name; as the key of list.";
        leaf if-name {
          type string;
          mandatory true;
          description "interface name";
        }
        leaf enable {
          type boolean;
          mandatory true;
          description
            "whether this interface is enabled";
        }
        leaf ipv6-address {
          type inet:ipv6-address;
          description
            "ipv6 address for this interface";
        }
        leaf interface-id {
          type string;
          description "interface id";
        }
        leaf-list rsoo-set {
          type uint8;
          description "configured rsoo set";
        }
        list pd-route {
          key pd-route-id;
          description "pd route";
          leaf pd-route-id {
            type uint8;
            mandatory true;
            description "pd route id";
          }
          leaf requesting-router-id {
            type uint32;
            mandatory true;
            description "requesting router id";
          }
          leaf delegating-router-id {
            type uint32;
            mandatory true;
            description "delegating router id";
          }
          leaf next-router {
            type inet:ipv6-address;
            mandatory true;
            description "next router";
          }
          leaf last-router {
            type inet:ipv6-address;
            mandatory true;
            description "previous router";
          }
        }
        list next-entity {
          key dest-addr;
          description "This node defines
            a list that is used to describe
            the next hop entity of this
            relay distinguished by their
            addresses.";
          leaf dest-addr {
            type inet:ipv6-address;
            mandatory true;
            description "destination addr";
          }
          leaf available {
            type boolean;
            mandatory true;
            description "whether the next entity
              is available or not";
          }
          leaf multicast {
            type boolean;
            mandatory true;
            description "whether the address is
              multicast or not";
          }
          leaf server {
            type boolean;
            mandatory true;
            description "whether the next entity
              is a server";
          }
          container packet-stats {
            config "false";
            description "packet statistics";
            leaf cli-packet-rvd-count {
              type uint32;
              mandatory true;
              description "client received packet
                counter";
            }
            leaf solicit-rvd-count {
              type uint32;
              mandatory true;
              description
                "solicit received counter";
            }
            leaf request-rvd-count {
              type uint32;
              mandatory true;
              description
                "request received counter";
            }
            leaf renew-rvd-count {
              type uint32;
              mandatory true;
              description
                "renew received counter";
            }
            leaf rebind-rvd-count {
              type uint32;
              mandatory true;
              description
                "rebind recevied counter";
            }
            leaf decline-rvd-count {
              type uint32;
              mandatory true;
              description
                "decline received counter";
            }
            leaf release-rvd-count {
              type uint32;
              mandatory true;
              description
                "release received counter";
            }
            leaf info-req-rvd-count {
              type uint32;
              mandatory true;
              description
                "information request counter";
            }
            leaf relay-for-rvd-count {
              type uint32;
              mandatory true;
              description
                "relay forward received counter";
            }
            leaf relay-rep-rvd-count {
              type uint32;
              mandatory true;
              description
                "relay reply received counter";
            }
            leaf packet-to-cli-count {
              type uint32;
              mandatory true;
              description
                "packet to client counter";
            }
            leaf adver-sent-count {
              type uint32;
              mandatory true;
              description
                "advertisement sent counter";
            }
            leaf confirm-sent-count {
              type uint32;
              mandatory true;
              description
                "confirm sent counter";
            }
            leaf reply-sent-count {
              type uint32;
              mandatory true;
              description
                "reply sent counter";
            }
            leaf reconfig-sent-count {
              type uint32;
              mandatory true;
              description
                "reconfigure sent counter";
            }
            leaf relay-for-sent-count {
              type uint32;
              mandatory true;
              description
                "relay forward sent counter";
            }
            leaf relay-rep-sent-count {
              type uint32;
              mandatory true;
              description
                "relay reply sent counter";
            }
          }
        }
      }
      container relay-stats {
        config "false";
        description "relay statistics";
        leaf cli-packet-rvd-count {
          type uint32;
          mandatory true;
          description "client packet received counter";
        }
        leaf relay-for-rvd-count {
          type uint32;
          mandatory true;
          description "relay forward received counter";
        }
        leaf relay-rep-rvd-count {
          type uint32;
          mandatory true;
          description "relay reply recevied counter";
        }
        leaf packet-to-cli-count {
          type uint32;
          mandatory true;
          description "packet to client counter";
        }
        leaf relay-for-sent-count {
          type uint32;
          mandatory true;
          description "relay forward sent counter";
        }
        leaf relay-rep-sent-count {
          type uint32;
          mandatory true;
          description "relay reply sent counter";
        }
        leaf discarded-packet-count {
          type uint32;
          mandatory true;
          description "discarded packet counter";
        }
      }
    }
    container client {
      presence "Enables client";
      description "dhcpv6 client portion";
      container duid {
        description "Sets the DUID";
        uses duid;
      }
      list client-if {
        key if-name;
        description "A client may have several
          interfaces, it is more reasonable to
          configure and manage parameters on
          the interface-level. The list defines
          specific client interfaces and their
          data. Different interfaces are distinguished
          by the key which is a configurable string
          value.";
        leaf if-name {
          type string;
          mandatory true;
          description "interface name";
        }
        leaf cli-id {
          type uint32;
          mandatory true;
          description "client id";
        }
        leaf description {
          type string;
          description
            "description of the client interface";
        }
        leaf pd-function {
          type boolean;
          mandatory true;
          description "Whether the client
            can act as a requesting router
            to request prefixes using prefix
            delegation ([RFC3633]).";
        }
        leaf rapid-commit {
          type boolean;
          mandatory true;
          description "'1' indicates a client can
            initiate a Solicit-Reply message exchange
            by adding a Rapid Commit option in Solicit
            message. '0' means the client is not allowed
            to add a Rapid Commit option to request
            addresses in a two-message exchange
            pattern.";
        }
        container mo-tab {
          description "The management tab
            label indicates the operation
            mode of the DHCPv6 client. 'm'=1
            and 'o'=1 indicate the client
            will use DHCPv6 to obtain all
            the configuration data. 'm'=1
            and 'o'=0 are a meaningless
            combination. 'm'=0 and 'o'=1
            indicate the client will use
            stateless DHCPv6 to obtain
            configuration data apart from
            addresses/prefixes data.
            'm'=0 and 'o'=0 represent the
            client will not use DHCPv6
            but use SLAAC to achieve
            configuration.";
          leaf m-tab {
            type boolean;
            mandatory true;
            description "m tab";
          }
          leaf o-tab {
            type boolean;
            mandatory true;
            description "o tab";
          }
        }
        container oro-options {
          description "oro options";
          list oro-option {
            key option-code;
            description "oro option";
            leaf option-code {
              type uint16;
              mandatory true;
              description "option code";
            }
            leaf description {
              type string;
              mandatory true;
              description "description of oro
                options";
            }
          }
        }
        container client-configured-options {
          description "client configured options";
          list new-or-standard-cli-option {
            key option-code;
            description "new or standard client option";
            leaf option-code {
              type uint16;
              mandatory true;
              description "option code";
            }
            leaf option-name {
              type string;
              mandatory true;
              description "option name";
            }
            leaf option-description {
              type string;
              mandatory true;
              description "description of client
                option";
            }
            leaf option-reference {
              type string;
              description "the reference of option";
            }
            leaf option-value {
              type string;
              mandatory true;
              description "the option value";
            }
          }
          container user-class-option {
            description "user class option";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be configured at the
                client";
            }
            list user-class {
              key user-class-id;
              description "user class";
              leaf user-class-id {
                type uint8;
                mandatory true;
                description "user class id";
              }
              leaf user-class-info {
                type string;
                mandatory true;
                description "user class info";
              }
            }
          }
          container vendor-class-option {
            description "vendor class option";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be configured at the
                client";
            }
            leaf ent-num {
              type uint32;
              mandatory true;
              description "enterprise number";
            }
            leaf-list data {
              type string;
              description "option data";
            }
          }
          container client-fqdn-option {
            description "client fqdn option";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be configured at the
                client";
            }
            leaf fqdn {
              type string;
              mandatory true;
              description "fqdn";
            }
            leaf server-initiate-update {
              type boolean;
              mandatory true;
              description "whether server initiate";
            }
            leaf client-initiate-update {
              type boolean;
              mandatory true;
              description "whether client initiate";
            }
          }
          container client-architecture-type-option {
            description
              "client architecture type option";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be configured at the
                client";
            }
            list architecture-types {
              key type-id;
              description "architecture types";
              leaf type-id {
                type uint16;
                mandatory true;
                description "type id";
              }
              leaf most-preferred {
                type boolean;
                mandatory true;
                description "most preferred flag";
              }
            }
          }
          container client-network-interface-option {
            description
              "client network interface option";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be configured at the
                client";
            }
            leaf type {
              type uint8;
              mandatory true;
              description "type";
            }
            leaf major {
              type uint8;
              mandatory true;
              description "major";
            }
            leaf minor {
              type uint8;
              mandatory true;
              description "minor";
            }
          }
          container kerberos-principal-name-option {
            description
              "kerberos principal name option";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be configured at the
                client";
            }
            leaf principal-name {
              type string;
              mandatory true;
              description "principal name";
            }
          }
          container client-link-layer-addr-option {
            description
              "client link layer address option";
            leaf enable {
              type boolean;
              mandatory true;
              description "indicate whether this
                option will be configured at the
                client";
            }
            leaf link-layer-type {
              type uint16;
              mandatory true;
              description "link layer type";
            }
            leaf link-layer-addr {
              type string;
              mandatory true;
              description "link layer address";
            }
          }
        }
        container identity-associations {
          config "false";
          description "IA is a construct through
            which a server and a client can identify,
                  group, and manage a set of related IPv6
                    addresses. The key of the list is a
                    4-byte number IAID defined in [RFC3315].";
          list identity-association {
            key iaid;
            description "IA";
            leaf iaid {
              type uint32;
              mandatory true;
              description "IAID";
            }
            leaf ia-type {
              type string;
              mandatory true;
              description "IA type";
            }
            leaf-list ipv6-addr {
              type inet:ipv6-address;
              description "ipv6 address";
            }
            leaf-list ipv6-prefix {
              type inet:ipv6-prefix;
              description "ipv6 prefix";
            }
            leaf-list prefix-length {
              type uint8;
              description "ipv6 prefix length";
            }
            leaf t1-time {
              type yang:timeticks;
              mandatory true;
              description "t1 time";
            }
            leaf t2-time {
              type yang:timeticks;
              mandatory true;
              description "t2 time";
            }
            leaf preferred-lifetime {
              type yang:timeticks;
              mandatory true;
              description "preferred lifetime";
            }
            leaf valid-lifetime {
              type yang:timeticks;
              mandatory true;
              description "valid lifetime";
            }
          }
        }
        container if-other-paras {
          config "false";
          description "A client can obtain
            extra configuration data other than
            address and prefix information through
            DHCPv6. This container describes such
            data the client was configured. The
            potential configuration data may
            include DNS server addresses, SIP
            server domain names, etc.";
          leaf-list uni-dhcpv6-serv-addr {
            type inet:ipv6-address;
            description "unicast server address";
          }
          container dns-paras {
            description "dns parameters";
            leaf domain-search-list {
              type string;
              mandatory true;
              description "domain search list";
            }
            list dns-servers {
              key dns-serv-id;
              description "dns servers";
              leaf dns-serv-id {
                type uint8;
                mandatory true;
                description "dns server id";
              }
              leaf dns-serv-addr {
                type inet:ipv6-address;
                mandatory true;
                description "dns server address";
              }
            }
          }
          container sip-paras {
            description "sip parameters";
            list sip-servers {
              key sip-serv-id;
              description "sip server info";
              leaf sip-serv-id {
                type uint8;
                mandatory true;
                description "sip server id";
              }
              leaf sip-serv-addr {
                type inet:ipv6-address;
                mandatory true;
                description "sip server address";
              }
              leaf sip-serv-domain-name {
                type string;
                mandatory true;
                description
                  "sip server domain name";
              }
            }
          }
          container nis-paras {
            description "nis parameters";
            leaf nis-domain-name {
              type string;
              mandatory true;
              description "nis domain name";
            }
            list nis-server {
              key nis-serv-id;
              description "nis server";
              leaf nis-serv-id {
                type uint8;
                mandatory true;
                description "nis server id";
              }
              leaf nis-serv-addr {
                type inet:ipv6-address;
                mandatory true;
                description "nis server address";
              }
            }
          }
          container nis-plus-paras {
            description "nisp parameters";
            leaf nis-plus-domain-name {
              type string;
              mandatory true;
              description "nisp domian name";
            }
            list nis-plus-server {
              key nis-plus-serv-id;
              description "nisp server";
              leaf nis-plus-serv-id {
                type uint8;
                mandatory true;
                description "nisp server id";
              }
              leaf nis-plus-serv-addr {
                type inet:ipv6-address;
                mandatory true;
                description "nisp server address";
              }
            }
          }
          leaf info-refresh-time {
            type yang:timeticks;
            description "info refresh time";
          }
          container time-zone-paras {
            description "time zone parameters";
            leaf tz-posix {
              type string;
              mandatory true;
              description "tz posix";
            }
            leaf tz-database {
              type string;
              mandatory true;
              description "tz database";
            }
          }
          leaf cli-fqdn {
            type string;
            description "client fqdn";
          }
          container ntp-paras {
            description "ntp parameters";
            list ntp-server {
              key ntp-serv-id;
              description "ntp server";
              leaf ntp-serv-id {
                type uint8;
                mandatory true;
                description "ntp server id";
              }
              leaf ntp-serv-addr {
                type inet:ipv6-address;
                mandatory true;
                description "ntp server address";
              }
              leaf ntp-serv-mul-addr {
                type inet:ipv6-address;
                mandatory true;
                description "ntp server multicast
                  address";
              }
              leaf ntp-serv-fqdn {
                type string;
                mandatory true;
                description "ntp server fqdn";
              }
            }
          }
          container sntp-paras {
            description "sntp parameters";
            list sntp-server {
              key sntp-serv-id;
              description "sntp server";
              leaf sntp-serv-id {
                type uint8;
                mandatory true;
                description "sntp server id";
              }
              leaf sntp-serv-addr {
                type inet:ipv6-address;
                mandatory true;
                description "sntp server address";
              }
            }
          }
          container network-boot-paras {
            description "network boot parameters";
            list boot-file {
              key boot-file-id;
              description "boot file";
              leaf boot-file-id {
                type uint8;
                mandatory true;
                description "boot file id";
              }
              leaf-list suitable-arch-type {
                type uint16;
                description "architecture type";
              }
              leaf-list suitable-net-if {
                type uint32;
                description "network interface";
              }
              leaf boot-file-url {
                type string;
                mandatory true;
                description "boot file url";
              }
              list boot-file-paras {
                key para-id;
                description "boot file parameters";
                leaf para-id {
                  type uint8;
                  mandatory true;
                  description "parameter id";
                }
                leaf parameter {
                  type string;
                  mandatory true;
                  description "parameter value";
                }
              }
            }
          }
          container kerberos-paras {
            description "kerberos parameters";
            leaf default-realm-name {
              type string;
              mandatory true;
              description "default realm name";
            }
            list kdc-info {
              key kdc-id;
              description "kdc info";
              leaf kdc-id {
                type uint8;
                mandatory true;
                description "kdc id";
              }
              leaf priority {
                type uint16;
                mandatory true;
                description "priority";
              }
              leaf weight {
                type uint16;
                mandatory true;
                description "weight";
              }
              leaf transport-type {
                type uint8;
                mandatory true;
                description "transport type";
              }
              leaf port-number {
                type uint16;
                mandatory true;
                description "port number";
              }
              leaf kdc-ipv6-addr {
                type inet:ipv6-address;
                mandatory true;
                description "kdc ipv6 address";
              }
              leaf realm-name {
                type string;
                mandatory true;
                description "realm name";
              }
            }
          }
          container addr-selection-paras {
            description "address selection parameters";
            leaf automatic-row-add {
              type boolean;
              mandatory true;
              description "row add";
            }
            leaf prefer-temporary-addr {
              type boolean;
              mandatory true;
              description "prefer temporary";
            }
            list policy-table {
              key policy-id;
              description "policy table";
              leaf policy-id {
                type uint8;
                mandatory true;
                description "policy id ";
              }
              leaf label {
                type uint8;
                mandatory true;
                description "label";
              }
              leaf precedence {
                type uint8;
                mandatory true;
                description "precedence";
              }
              leaf prefix-len {
                type uint8;
                mandatory true;
                description "prefix length";
              }
              leaf prefix {
                type inet:ipv6-prefix;
                mandatory true;
                description "prefix";
              }
            }
          }
          leaf sol-max-rt {
            type yang:timeticks;
            mandatory true;
            description "sol max rt";
          }
          leaf inf-max-rt {
            type yang:timeticks;
            mandatory true;
            description "inf max rt";
          }
          container pcp-server-paras {
            description "pcp server parameters";
            list pcp-server {
              key pcp-serv-id;
              description "pcp server";
              leaf pcp-serv-id {
                type uint8;
                mandatory true;
                description "pcp server id";
              }
              leaf pcp-serv-addr {
                type inet:ipv6-address;
                mandatory true;
                description "pcp server address";
              }
            }
          }
          container s46-rule-paras {
            description "s46 rule parameters";
            list s46-rule {
              key rule-id;
              description "s46 rule";
              leaf rule-id {
                type uint8;
                mandatory true;
                description "rule id";
              }
              leaf rule-type {
                type enumeration {
                  enum "BMR"{
                    description "BMR";
                }
                enum "FMR"{
                  description "FMR";
                }
                }
                mandatory true;
                description "rule type";
              }
              leaf ea-len {
                type uint8;
                mandatory true;
                description "EA bits length";
              }
              leaf prefix4-len {
                type uint8;
                mandatory true;
                description "ipv4 prefix length";
              }
              leaf ipv4-prefix {
                type inet:ipv4-prefix;
                mandatory true;
                description "ipv4 prefix";
              }
              leaf prefix6-len {
                type uint8;
                mandatory true;
                description "ipv6 prefix length";
              }
              leaf ipv6-prefix {
                type inet:ipv6-prefix;
                mandatory true;
                description "ipv6 prefix";
              }
              uses portset-para;
            }
          }
          container s46-br-paras {
            description "s46 br parameters";
            list br {
              key br-id;
              description "br";
              leaf br-id {
                type uint8;
                mandatory true;
                description "br id";
              }
              leaf br-ipv6-addr {
                type inet:ipv6-address;
                mandatory true;
                description "br ipv6 address";
              }
            }
          }
          container s46-dmr-paras {
            description "s46 dmr parameters";
            list dmr {
              key dmr-id;
              description "dmr";
              leaf dmr-id {
                type uint8;
                mandatory true;
                description "dmr id";
              }
              leaf dmr-prefix-len {
                type uint8;
                mandatory true;
                description "dmr prefix length";
              }
              leaf dmr-ipv6-prefix {
                type inet:ipv6-prefix;
                mandatory true;
                description "dmr prefix";
              }
            }
          }
          container s46-v4-v6-binding-paras {
            description "s46 v4 v6 binding parameters";
            leaf ipv4-addr {
              type inet:ipv4-address;
              mandatory true;
              description "ipv4 address";
            }
            leaf bind-prefix6-len {
              type uint8;
              mandatory true;
              description "bind ipv6 prefix";
            }
            uses portset-para;
            leaf erp-local-domain-name {
              type string;
              mandatory true;
              description "erp local domain name";
            }
          }
          container supported-options {
            description "supported options";
            list supported-option {
              key option-code;
              description "supported option";
              leaf option-code {
                type uint16;
                mandatory true;
                description "option code";
              }
              leaf description {
                type string;
                mandatory true;
                description
                  "description of supported
                  option";
              }
            }
          }
        }
        container packet-stats {
          config "false";
          description "A container records
            all the packet status information
            of a specific interface.";
          leaf solicit-count {
            type uint32;
            mandatory true;
            description "solicit counter";
          }
          leaf request-count {
            type uint32;
            mandatory true;
            description "request counter";
          }
          leaf renew-count {
            type uint32;
            mandatory true;
            description "renew counter";
          }
          leaf rebind-count {
            type uint32;
            mandatory true;
            description "rebind counter";
          }
          leaf decline-count {
            type uint32;
            mandatory true;
            description "decline counter";
          }
          leaf release-count {
            type uint32;
            mandatory true;
            description "release counter";
          }
          leaf info-req-count {
            type uint32;
            mandatory true;
            description "information request counter";
          }
          leaf advertise-count {
            type uint32;
            mandatory true;
            description "advertise counter";
          }
          leaf confirm-count {
            type uint32;
            mandatory true;
            description "confirm counter";
          }
          leaf reply-count {
            type uint32;
            mandatory true;
            description "reply counter";
          }
          leaf reconfigure-count {
            type uint32;
            mandatory true;
            description "recofigure counter";
          }
        }
      }
    }

    /*
     * Notifications
     */

    notification notifications {
      description "dhcpv6 notification module";
      container dhcpv6-server-event {
        description "dhcpv6 server event";
        container pool-running-out {
          description "raised when the
            address/prefix pool is going to
            run out.  A threshold for utilization
            ratio of the pool has been defined in
            the server feature so that it will
            notify the administrator when the
            utilization ratio reaches the threshold,
                        and such threshold is a settable
                          parameter";
          leaf utilization-ratio {
            type uint16;
            mandatory true;
            description "utilization ratio";
          }
          container duid {
            description "Sets the DUID";
            uses duid;
          }
          leaf serv-name {
            type string;
            description "server name";
          }
          leaf pool-name {
            type string;
            mandatory true;
            description "pool name";
          }
        }
        container invalid-client-detected {
          description "raised when the server
            has found a client which can be
            regarded as a potential attacker. Some
            description could also be included.";
          container duid {
            description "Sets the DUID";
            uses duid;
          }
          leaf description {
            type string;
            description "description of the event";
          }
        }
      }
      container dhcpv6-relay-event {
        description "dhcpv6 relay event";
        container topo-changed {
          description "raised when the topology
            of the relay agent is changed.";
          leaf relay-if-name {
            type string;
            mandatory true;
            description "relay interface name";
          }
          leaf first-hop {
            type boolean;
            mandatory true;
            description "first hop";
          }
          leaf last-entity-addr {
            type inet:ipv6-address;
            mandatory true;
            description "last entity address";
          }
        }
      }
      container dhcpv6-client-event {
        description "dhcpv6 client event";
        container ia-lease-event {
          description "raised when the
            client was allocated a new IA from
            the server or it renew/rebind/release
            its current IA";
          leaf event-type {
            type enumeration{
              enum "allocation" {
                description "allocate";
              }
              enum "rebind" {
                description "rebind";
              }
              enum "renew" {
                description "renew";
              }
              enum "release" {
                description "release";
              }
            }
            mandatory true;
            description "event type";
          }
          container duid {
            description "Sets the DUID";
            uses duid;
          }
          leaf iaid {
            type uint32;
            mandatory true;
            description "IAID";
          }
          leaf serv-name {
            type string;
            description "server name";
          }
          leaf description {
            type string;
            description "description of event";
          }
        }
        container invalid-ia-detected {
          description "raised when the identity
            association of the client can be proved
            to be invalid.  Possible condition includes
            duplicated address, illegal address, etc.";
          container duid {
            description "Sets the DUID";
            uses duid;
          }
          leaf cli-duid {
            type uint32;
            mandatory true;
            description "duid of client";
          }
          leaf iaid {
            type uint32;
            mandatory true;
            description "IAID";
          }
          leaf serv-name {
            type string;
            description "server name";
          }
          leaf description {
            type string;
            description "description of the event";
          }
        }
        container retransmission-failed {
          description "raised when the retransmission
            mechanism defined in [RFC3315] is failed.";
          container duid {
            description "Sets the DUID";
            uses duid;
          }
          leaf description {
            type enumeration {
              enum "MRC failed" {
                description "MRC failed";
              }
              enum "MRD failed" {
                description "MRD failed";
              }
            }
            mandatory true;
            description "description of failure";
          }
        }
        container failed-status-turn-up {
          description "raised when the client receives
            a message includes an unsuccessful Status Code
            option.";
          container duid {
            description "Sets the DUID";
            uses duid;
          }
          leaf status-code {
            type enumeration {
              enum "1" {
                description "UnspecFail";
              }
              enum "2" {
                description "NoAddrAvail";
              }
              enum "3" {
                description "NoBinding";
              }
              enum "4" {
                description "NotOnLink";
              }
              enum "5" {
                description "UseMulticast";
              }
            }
            mandatory true;
            description "employed status code";
          }
        }
      }
    }
  }
<CODE ENDS>
        

4. Security Considerations (TBD)

TBD

5. IANA Considerations (TBD)

This document registers the following YANG modules in the "YANG Module Names" registry [RFC6020].

name:

ietf-dhcpv6

namespace:

urn:ietf:params:xml:ns:yang:ietf-dhcpv6

prefix:

dhcpv6

reference:

TBD

6. Acknowledgements

The authors would like to thank Qi Sun, Lishan Li, Sladjana Zoric, Tomek Mrugalski, Marcin Siodelski, Bernie Volz and Bing Liu for their valuable comments and contributions to this work.

7. References

7.1. Normative References

7.2. Informative References

Authors' Addresses