I2RS working group | S. Hares |
Internet-Draft | Huawei |
Intended status: Standards Track | R. White |
Expires: September 22, 2016 | |
March 21, 2016 |
Filter-Based RIB Data Model
draft-hares-rtgwg-fb-rib-00
This document defines a yang data model for a Filter-based Routing Information Base (RIB) Yang data model. A routing system uses the Filter-based RIB to program FIB entries that process incoming packets by matching on multiple fields (n-tuple) within the packet and then performing a specified action on it. The FB-RIB can also specify an action to forward the packet according to the FIB entries programmed using the RIBs of its routing instance.
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 http://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 September 22, 2016.
Copyright (c) 2016 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 (http://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.
This document provides a yang module for flow filter n-tuple policy that is locally configured. This flow filter policy has also been called Policy routing in some implementations.
This document defines a yang data model for a Filter-based Routing Information Base (RIB) Yang data model. A routing system uses the Filter-based RIB to program FIB entries that process incoming packets by matching on multiple fields within the packet and then performing a specified action on it. The FB-RIB can also specify an action to forward the packet according to the FIB entries programmed using the RIBs of its routing instance.
Filter-based routing is a technique used to make packet forwarding decisions based on a n-tuple filter that is matched to the incoming packets and the specified action. It should be noted that that this is distinct from the static routes in the following RIBS:
A Filter-Based RIB (Routing Information Base) is contained in a routing instance. It contains a list of filters (match-action conditions), a list of interface the filter-based forwarding operates on. Filter-based RIBs (FB-RIBs) operate only on the interface the FB-RIB are configured on.
A Filter Based RIB uses packet forwarding policy. If packet reception is considered an event, then the I2RS Filter-based RIB uses a minimalistic Event-Condition-Action policy. A Filter-based RIB entry specifies matche filters for the fields in a packet (which may include layer 1 to layer 3 header fields, transport or application fields) or size of the packet or interface received on. The matches are contained in an ordered list of filters which contain pairs of match condition-action (aka event-condition-action).
If all matches fail, the default action is to forward the packet using FIB entries that were programmed by the default Routing Informational Base (RIB) manager configured in the Filter-Based RIB (FB-RB)
Actions in the condition-action pair may impact forwarding or set something in the packet that will impact forwarding. Policy actions are typically applied before applying QoS constraints since policy actions may override QoS constraint.
The Filter-Based RIB resides in ephemeral state as does the I2RS RIB and I2RS topology models.
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]
In this document, these words will appear with that interpretation only when in ALL CAPS. Lower case uses of these words are not to be interpreted as carrying RFC-2119 significance.
The High-level Yang graphical representation uses the following symbols:
The Top-level Yang structure for a global FB-RIB types (similar to acl) is not defined. The Filter-Based RIB should be defined under this structure under a routing instance. The two things under this RIB would be: configured Filter-Based RIB (aka Policy routing), I2RS reboot Ephemeral Filter-Based RIB. ACLs [I-D.ietf-netmod-acl-model] have the potential to be augmented to be included, but this version of this document does address that issue.
The purpose of this section is illustrate why the flow specification policy installed in yang modules loaded into intended configuration needs to be able to be compared. After demonstrating why this is needed, this section suggests a structure for filter-based RIBS.
BGP's Flow Specification (BGP-FS) configures filter-based policy in the local BGP configuration, and passes this information in BGP packets (in NLRI and Extended Communities). The BGP-FS YANG model [I-D.wu-idr-flowspec-yang-cfg] specifies the locally configuration, and the derived state that includes the BGP Flow Specifications received. BGP-FS processing may install the locally configured BGP Flow specification in the local FB-RIB. If it does, this policy is like any other locally configured policy.
ietf-fb-rib module +--rw routing-instance +--rw ietf-fb-rib +--rw default-instance-name string +--rw default-router-id rt:router-id +--rw config-fb-rib // config state uses fb-ribs +--rw I2rs-fb-rib // ephemeral state uses fb-ribs +--rw BGP-FB-RIB // Install derived uses fb-ribs // BGP-FS policy state Figure 6: Global FB RIB Yang Structure
The BGP-FS may installed the flow policy received from a remote BGP peer and stored in derived state. This policy has a different characteristics as it will disappear if the peer connection between the two peers drops, or if the peer changes the BGP-FS policy. Due to the ephemeral nature of the BGP-FS, it should be installed unique. Otherwise, If the local configuration state changes, it cannot differentiate between the true configured state and the ephemeral states (I2RS ephemeral and BGP-session ephemeral). Both I2RS ephemeral and BGP-session ephemeral policy will disappear upon a reboot.
I2RS architecture [I-D.ietf-i2rs-architecture] specifies that by default the Local configuration will win if the local configuration changes. In the NETCONF/NETMOD language, the "last write wins".
An example will help illustrate this:
The I2RS [I-D.ietf-i2rs-architecture] also allows that the preference between local-configuration and I2RS ephemeral state can be determined by operator-applied policy. However, illustrations of this are out of scope for this version of this document.
There are three levels in the Filter-Based RIBs (FB-RIB) structure:
All structures have two types: configuration/ephemeral state and operational state.
This yang model describes three types of FB-RIBS: configuration, I2RS, and BGP Flow Specification. The configuration FB-RIB yang module is config state ("config true" and "ephemeral false") and survives a reboot. The I2RS FB-RB yang model is reboot ephemeral ("config true" and "ephemeral true"). The BGP Flow Specification Filter-Based RIB stores policy which is received by the BGP peers, and can be considered policy configured as part of BGP infrastructure ("config true" and "peer-ephemeral true;")
Configuration RIBS bgp-fs-fb-rib - is the BGP processes installation of the BGP Flow Specification (BGP-FS) policy rules from remote peers. Locally configured BGP-FS rules are configured in the BGP peer structure. +-----------------------------------------+ | routing instance | +-------|-------------|----------------|--+ | | | | | | +---------|----+ +-----|-----+ +--------|-----+ |config-fb-rib | |i2rs-fb-rib| |bgp-fs-fb-rib | +------|-------+ +-----|------+ +------|------+ |............:....|...............| : (uses common structures : in separate lists of FB-RIBs) +--------|----+ |fb-ribs* | | | +--|----------+ | Figure 3: Routing instance with three types of Filter-FIB lists
The following section provides the high level yang structure diagrams for the following levels of structures for both config/ephemeral state and operationa.
These structures are contained within the yang section in this draft.
The packet-reception ECA policy yang module is contained in the draft [I-D.hares-i2rs-pkt-eca-data-model].
For those who desire more information regarding the logic behind the I2RS Filter-Based RIB, please see the Informational Model at: [I-D.kini-i2rs-fb-rib-info-model].
The Top-level Yang structure for a global FB-RIB types (similar to acl) is not defined for filter-based RIBS. The I2RS Filter-Based RIB should be defined under this structure under a routing instance. The three things under this RIB would be: configured Filter-Based RIB (aka Policy routing), I2RS reboot Ephemeral Filter-Based RIB, and BGP Flow Specification's Filter-Based RIB. All of these RIBs have similar actions.
There are two types top-level structures for ietf-fb-ribs: config and operational state.
Augments rt:logical-network-elements:\ :logical-network-element:network-instances: \ network-instance ietf-fb-rib module +--rw ietf-fb-rib +--rw default-instance-name string +--rw default-router-id rt:router-id +--rw config-fb-ribs if-feature "config-filter-based-RIB"; uses fb-ribs; +--rw i2rs-fb-ribs if-feature "I2RS-filter-based-RIB"; uses fb-rib-t:fb-ribs; +--rw bgp-fs-fb-ribs if-feature "BGP-FS-filter-based-RIB"; uses fb-rib-t:fb-ribs; Figure 5: configuration state
The Top-level Yang structure for a global configuration of Filter-Based RIBs are:
Augments rt:logical-network-elements:\ :logical-network-element:network-instances: \ network-instance ietf-fb-rib module +--rw ietf-fb-rib-opstate +--rw default-instance-name string +--rw default-router-id rt:router-id +--rw config-fb-rib-opstate if-feature "config-filter-based-RIB"; uses fb-rib-t:fb-ribs-oper-status; +--rw i2rs-fb-rib-opstate { if-feature "I2RS-filter-based-RIB"; uses fb-rib-t:fb-ribs-oper-status; +--rw bgp-fs-fb-rib-opstate if-feature "BGP-FS-filter-based-RIB"; uses fb-rib-t:fb-ribs-oper-status; Figure 5: operational state
The Top-level Yang structure for a global operational state of Filter-Based RIBs are:
The Top-level yang structures at the Filter-Based RIB level have two types: configuration and operational state.
module: fb-rib-types: +--rw fb-ribs +--rw fb-rib* [rib-name] | +--rw rib-name string | | rw fb-type identityref / ephemeral or not | +--rw rib-afi rt:address-family | +--rw fb-rib-intf* [name] | | +--rw name string | | +--rw intf if:interface | +--rw default-rib | | +--rw rt-rib rt:routing:routing-instance:name | | +--rw config-rib string; // config rib name | | +--rw i2rs-rib:routing-instance:name | | +--rw i2rs-rib string; //ephemeral rib name | | +--rw bgp-instance-name string | | +--rw bgp-rib string //session ephemeral | +--rw fb-rib-refs | | +--rw fb-rib-update-ref uint32 /count of writes | +--rw instance-using* | | device:networking-instance:networking-instance-name | +--use pkt-eca:pkt-eca-policy-set Figure 6: FB RIB Type Structure
The Top-level Yang structure for the FB-RIB types is:
HIgh Level Yang +--rw fb-ribs-oper-status +--rw fb-rib-oper-status* [fb-rib-name] uses pkt-eca:pkt-eca-opstate
<CODE BEGINS> file "ietf-fb-rib-types@2016-01-26.yang" module ietf-fb-rib-types { yang-version "1"; // namespace namespace "urn:ietf:params:xml:ns:yang:ietf-fb-rib-types"; prefix "fb-rib-t"; import ietf-interfaces {prefix "if";} import ietf-access-control-list {prefix "acl";} import ietf-routing {prefix "rt";} import ietf-pkt-eca-policy {prefix "pkt-eca";} // meta organization "IETF"; contact "email: sriganesh.kini@ericsson.com email: cengiz@packetdesign.com email: anoop@ieee.duke.edu email: ivandean@gmal.org email: shares@ndzh.com; email: linda.dunbar@huawei.com; email: russ@riw.com; email: Jeff.Tantsura@ericsson.com; "; description "This module describes a YANG model for the I2RS Filter-based RIB Types. These types specify types for the Filter-Based RIB. Copyright (c) 2015 IETF Trust and the persons identified as the document authors. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info)."; revision "2016-01-26" { description "Filter-Based RIB protocol "; reference "draft-hares-i2rs-fb-rib-data-model-01"; } typedef fb-rib-policy-type-def { type identityref { base "fb-rib-policy-type"; } description "This type is used to refer to FB-RIB type"; } identity fb-rib-policy-type { description "Types of filter-based policies acl and eca"; } identity fb-rib-acl { base fb-rib-policy-type; description "filter based policy based on access-lists"; } identity fb-bnp-eca-rules { base fb-rib-policy-type; description "filter based policy based on qos forwarding rules"; } typedef fb-rules-status { type identityref { base "fb-rule-opstat"; } description "This type is used to refer to FB-RIB type"; } identity fb-rule-opstat { description "operational statues for filter rules inactive and active"; } identity fb-rule-inactive { base fb-rule-opstat; description "policy rule is inactive"; } identity fb-rule-active { base fb-rule-opstat; description "policy rule is active"; } grouping fb-rib-rule-order-status { leaf statement-order { type uint16; description "order identifier"; } leaf statement-oper_status { type fb-rules-status; description "status of rule"; } description "filter-rib policy rule order and status"; } grouping fb-rib-group-order-status { leaf group-order{ type uint16; description "group order"; } leaf group-refcnt { type uint16; description "refcnt for this group"; } leaf group-installed { type uint16; description "number of rules installed"; } description "fb-rib group list order and status info."; } grouping fb-rib-status-info { leaf fb-rib-update-ref { type uint64; description "number of updates to this FB RIB since last reboot"; } description "FB-RIB update info"; } grouping default-fb-rib { leaf default-rib { type string; description "default ribs for normal and ephemeral filter-based rib should use rt:routing:routing-instance:name"; } leaf i2rs-instance { type string; description "default I2RS RIB should use i2rs-rib:routing-instance:name"; } leaf rib-name { type string; description "name of RIB"; } leaf fb-rib-update-ref { type uint64; description " number of updates to this FB RIB since last reboot"; } description "I2RS RIB which will be used even if none of the policy match"; } grouping fb-ribs { list fib-rib { key fb-rib-name; leaf fb-rib-name { type string; mandatory true; description "RIB name"; } uses rt:address-family; list fb-rib-intf { key "name"; leaf name { type if:interface-ref; description "A reference to the name of a configured network layer interface."; } description "This represents the list of interfaces associated with this routing instance. The interface list helps constrain the boundaries of packet forwarding. Packets coming on these interfaces are directly associated with the given routing instance. The interface list contains a list of identifiers, with each identifier uniquely identifying an interface."; } uses default-fb-rib; list instance-using { key instance-name; leaf instance-name { type string; description " name of instance using this fb-rib rt:routing-instance"; } description "instances using this fb-rib"; } list fb-rib-group { key group-name; leaf group-name { type string; description "policy-group name"; } leaf fb-group-policy-type { type fb-rib-policy-type-def; description "Policy type (acl/eca)"; } list acl-group { key name; leaf name { type string; description "name of access list group"; } list acls { key fb-acl-name; leaf fb-acl-name { type acl:access-control-list-ref; description "acl list name associated with FB-RIB list"; } leaf fb-acl-type { type acl:acl-type; description "acl type"; } description "list of acls"; } description "acl group entry"; } list pkt-eca-rules { key name; leaf eca-group-name { type pkt-eca:pkt-eca-rule-ref; description "ECA rule"; } description "list of eca groups"; } uses fb-rib-group-order-status; description "list of ordered policy groups "; } description "Configuration of an filter-based rib list"; } description "fb-rib group"; } } <CODE ENDS>
<CODE BEGINS> file "ietf-fb-rib@2016-02-09.yang" module ietf-fb-rib { yang-version "1"; // namespace namespace "urn:ietf:params:xml:ns:yang:ietf-fb-rib"; // replace with iana namespace when assigned prefix "fb-rib"; // import some basic inet types import ietf-yang-types {prefix "yang";} import ietf-fb-rib-types { prefix "fb-rib-t";} // meta organization "IETF"; contact "email: sriganesh.kini@ericsson.com email: cengiz@packetdesign.com email: anoop@ieee.duke.edu email: ivandean@gmail.org email: shares@ndzh.com; email: linda.dunbar@huawei.com; email: russ@riw.com; "; description "This Top level module describes a YANG model for the I2RS Filter-based RIB which is an global protocol independent FB RIB module."; revision "2016-02-09" { description "initial revision"; reference "draft-hares-i2rs-fb-rib-data-model-01"; } feature config-filter-based-RIB { description "This feature means that a node support config filter-based rib."; } feature I2RS-filter-based-RIB { description "This feature means that a node support I2RS filter-based rib."; } feature BGP-FS-filter-based-RIB { description "This feature means that a node support BGP FS filter-based rib."; } container ietf-fb-rib { presence "top-level structure for configuration"; leaf default-instance-name { type string; mandatory true; description "A routing instance is identified by its name, INSTANCE_name. This MUST be unique across all routing instances in a given network device."; } leaf default-router-id { type yang:dotted-quad; description "Default router id"; } container config-fb-rib { if-feature config-filter-based-RIB; uses fb-rib-t:fb-ribs; description "config filter-based RIB"; } container i2rs-fb-rib { if-feature I2RS-filter-based-RIB; uses fb-rib-t:fb-ribs; description "bgp-fs filter-based RIB"; } container bgp-fs-fb-rib { if-feature BGP-FS-filter-based-RIB; uses fb-rib-t:fb-ribs; description "bgp fs filter-based RIB of filter-based routes recieved from peers."; } description "fb-rib augments routing instance"; } container ietf-fb-rib-opstate { presence "top-level structure for op-state"; config "false"; leaf default-instance-name { type string; mandatory true; description "A routing instance is identified by its name, INSTANCE_name. This MUST be unique across all routing instances in a given network device."; } leaf default-router-id { type yang:dotted-quad; description "Default router id"; } container config-fb-rib-opstate { if-feature config-filter-based-RIB; uses fb-rib-t:fb-ribs-oper-status; description "config filter-based RIB"; } container i2rs-fb-rib-opstate { if-feature I2RS-filter-based-RIB; uses fb-rib-t:fb-ribs-oper-status; description "i2rs filter-based RIB"; } container bgp-fs-fb-rib-opstate { if-feature BGP-FS-filter-based-RIB; uses fb-rib-t:fb-ribs-oper-status; description "bgp fs filter-based RIB"; } description "fb-rib augments routing instance"; } } <CODE ENDS>
TBD
A I2RS RIB is ephemeral data store that will dyanamically change traffic paths set by the routing configuration. An I2RS FB-RIB provides dynamic Event-Condition-Action policy that will further change the operation of forwarding by allow dyanmic policy and ephemeral RIBs to alter the traffic paths set by routing configuration. Care must be taken in deployments to use the appropriate security and operational control to make use of the tools the I2RS RIB and I2RS FB-RIB provide.
[I-D.acee-rtgwg-yang-rib-extend] | Lindem, A. and Y. Qu, "RIB YANG Data Model", Internet-Draft draft-acee-rtgwg-yang-rib-extend-01, March 2016. |
[I-D.hares-i2rs-fb-rib-data-model] | Hares, S., Kini, S., Dunbar, L., Krishnan, R., Bogdanovic, D. and R. White, "Filter-Based RIB Data Model", Internet-Draft draft-hares-i2rs-fb-rib-data-model-02, February 2016. |
[I-D.hares-i2rs-pkt-eca-data-model] | Hares, S., Wu, Q. and R. White, "Filter-Based Packet Forwarding ECA Policy", Internet-Draft draft-hares-i2rs-pkt-eca-data-model-02, February 2016. |
[I-D.ietf-i2rs-rib-data-model] | Wang, L., Ananthakrishnan, H., Chen, M., amit.dass@ericsson.com, a., Kini, S. and N. Bahadur, "A YANG Data Model for Routing Information Base (RIB)", Internet-Draft draft-ietf-i2rs-rib-data-model-04, November 2015. |
[I-D.ietf-netmod-routing-cfg] | Lhotka, L. and A. Lindem, "A YANG Data Model for Routing Management", Internet-Draft draft-ietf-netmod-routing-cfg-21, March 2016. |
[I-D.wu-idr-flowspec-yang-cfg] | Wu, N., Zhuang, S. and A. Choudhary, "A YANG Data Model for Flow Specification", Internet-Draft draft-wu-idr-flowspec-yang-cfg-02, October 2015. |
[I-D.ietf-i2rs-architecture] | Atlas, A., Halpern, J., Hares, S., Ward, D. and T. Nadeau, "An Architecture for the Interface to the Routing System", Internet-Draft draft-ietf-i2rs-architecture-13, February 2016. |
[I-D.ietf-i2rs-rib-info-model] | Bahadur, N., Kini, S. and J. Medved, "Routing Information Base Info Model", Internet-Draft draft-ietf-i2rs-rib-info-model-08, October 2015. |
[I-D.ietf-i2rs-usecase-reqs-summary] | Hares, S. and M. Chen, "Summary of I2RS Use Case Requirements", Internet-Draft draft-ietf-i2rs-usecase-reqs-summary-01, May 2015. |
[I-D.ietf-netmod-acl-model] | Bogdanovic, D., Koushik, K., Huang, L. and D. Blair, "Network Access Control List (ACL) YANG Data Model", Internet-Draft draft-ietf-netmod-acl-model-07, March 2016. |
[I-D.kini-i2rs-fb-rib-info-model] | Kini, S., Hares, S., Dunbar, L., Ghanwani, A., Krishnan, R., Bogdanovic, D. and R. White, "Filter-Based RIB Information Model", Internet-Draft draft-kini-i2rs-fb-rib-info-model-03, February 2016. |
[RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |