| RTGWG | Y. Qu |
| Internet-Draft | Huawei |
| Intended status: Informational | J. Tantsura |
| Expires: September 4, 2018 | Nuage Networks |
| A. Lindem | |
| Cisco | |
| X. Liu | |
| Jabil | |
| A. Shaikh | |
| March 3, 2018 |
A YANG Data Model for Routing Policy Management
draft-ietf-rtgwg-policy-model-02
This document defines a YANG data model for configuring and managing routing policies in a vendor-neutral way and based on actual operational practice. The model provides a generic policy framework which can be augmented with protocol-specific policy configuration.
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 September 4, 2018.
Copyright (c) 2018 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.
This document describes a YANG [RFC7950] data model for routing policy configuration based on operational usage and best practices in a variety of service provider networks. The model is intended to be vendor-neutral, in order to allow operators to manage policy configuration in a consistent, intuitive way in heterogeneous environments with routers supplied by multiple vendors.
The YANG modules in this document conform to the Network Management Datastore Architecture (NMDA)[I-D.ietf-netmod-revised-datastores].
This model does not aim to be feature complete -- it is a subset of the policy configuration parameters available in a variety of vendor implementations, but supports widely used constructs for managing how routes are imported, exported, and modified across different routing protocols. The model development approach has been to examine actual policy configurations in use across a number of operator networks. Hence the focus is on enabling policy configuration capabilities and structure that are in wide use.
Despite the differences in details of policy expressions and conventions in various vendor implementations, the model reflects the observation that a relatively simple condition-action approach can be readily mapped to several existing vendor implementations, and also gives operators an intuitive and straightforward way to express policy without sacrificing flexibility. A side affect of this design decision is that legacy methods for expressing policies are not considered. Such methods could be added as an augmentation to the model if needed.
Consistent with the goal to produce a data model that is vendor neutral, only policy expressions that are deemed to be widely available in existing major implementations are included in the model. Those configuration items that are only available from a single implementation are omitted from the model with the expectation they will be available in separate vendor-provided modules that augment the current model.
The routing policy module has three main parts:
The module makes use of the standard Internet types, such as IP addresses, autonomous system numbers, etc., defined in RFC 6991.
Policies are expressed as a sequence of top-level policy definitions each of which consists of a sequence of policy statements. Policy statements in turn consist of simple condition-action tuples. Conditions may include multiple match or comparison operations, and similarly, actions may effect multiple changes to route attributes, or indicate a final disposition of accepting or rejecting the route. This structure is shown below.
+--rw routing-policy
+--rw policy-definitions
+--rw policy-definition* [name]
+--rw name string
+--rw statements
+--rw statement* [name]
+--rw name string
+--rw conditions
| ...
+--rw actions
...
The models provides a set of generic sets that can be used for matching in policy conditions. These sets are applicable for route selection across multiple routing protocols. They may be further augmented by protocol-specific models which have their own defined sets. The supported defined sets include:
The model structure for defined sets is shown below.
+--rw routing-policy
+--rw defined-sets
| +--rw prefix-sets
| | +--rw prefix-set* [name]
| | +--rw name string
| | +--rw mode? enumeration
| | +--rw prefixes
| | +--rw prefix* [ip-prefix masklength-range]
| | +--rw ip-prefix inet:ip-prefix
| | +--rw masklength-range string
| +--rw neighbor-sets
| | +--rw neighbor-set* [name]
| | +--rw name string
| | +--rw address* inet:ip-address
| +--rw tag-sets
| +--rw tag-set* [name]
| +--rw name string
| +--rw tag-value* tag-type
Policy statements consist of a set of conditions and actions (either of which may be empty). Conditions are used to match route attributes against a defined set (e.g., a prefix set), or to compare attributes against a specific value.
Match conditions may be further modified using the match-set-options configuration which allows operators to change the behavior of a match. Three options are supported:
Not all options are appropriate for matching against all defined sets (e.g., match ALL in a prefix set does not make sense). In the model, a restricted set of match options is used where applicable.
Comparison conditions may similarly use options to change how route attributes should be tested, e.g., for equality or inequality, against a given value.
While most policy conditions will be added by individual routing protocol models via augmentation, this routing policy model includes several generic match conditions and also the ability to test which protocol or mechanism installed a route (e.g., BGP, IGP, static, etc.). The conditions included in the model are shown below.
+--rw routing-policy
+--rw policy-definitions
+--rw policy-definition* [name]
+--rw name string
+--rw statements
+--rw statement* [name]
+--rw conditions
| +--rw call-policy?
| +--rw install-protocol-eq?
| +--rw match-interface
| | +--rw interface?
| +--rw match-prefix-set
| | +--rw prefix-set?
| | +--rw match-set-options?
| +--rw match-neighbor-set
| | +--rw neighbor-set?
| | +--rw match-set-options?
| | match-set-options-restricted-type
| +--rw match-tag-set
| +--rw tag-set?
| +--rw match-set-options?
match-set-options-restricted-type
When policy conditions are satisfied, policy actions are used to set various attributes of the route being processed, or to indicate the final disposition of the route, i.e., accept or reject.
Similar to policy conditions, the routing policy model includes generic actions in addition to the basic route disposition actions. These are shown below.
+--rw routing-policy
+--rw policy-definitions
+--rw policy-definition* [name]
+--rw statements
+--rw statement* [name]
+--rw actions
+--rw policy-result? policy-result-type
Policy 'subroutines' (or nested policies) are supported by allowing policy statement conditions to reference other policy definitions using the call-policy configuration. Called policies apply their conditions and actions before returning to the calling policy statement and resuming evaluation. The outcome of the called policy affects the evaluation of the calling policy. If the called policy results in an accept-route (either explicit or by default), then the subroutine returns an effective boolean true value to the calling policy. For the calling policy, this is equivalent to a condition statement evaluating to a true value and evaluation of the policy continues (see Section 4). Note that the called policy may also modify attributes of the route in its action statements. Similarly, a reject-route action returns false and the calling policy evaluation will be affected accordingly. Consequently, a subroutine cannot explicitly accept or reject a route. Rather it merely provides an indication that 'call-policy' condition returns boolean true or false indicating whether or not the condition matches. Route acceptance or rejection is solely determined by the top-level policy.
Note that the called policy may itself call other policies (subject to implementation limitations). The model does not prescribe a nesting depth because this varies among implementations. For example, some major implementation may only support a single level of subroutine recursion. As with any routing policy construction, care must be taken with nested policies to ensure that the effective return value results in the intended behavior. Nested policies are a convenience in many routing policy constructions but creating policies nested beyond a small number of levels (e.g., 2-3) should be discouraged.
Evaluation of each policy definition proceeds by evaluating its corresponding individual policy statements in order. When a condition statement in a policy statement is satisfied, the corresponding action statement is executed. If the action statement has either accept-route or reject-route actions, evaluation of the current policy definition stops, and no further policy definitions in the chain are evaluated.
If the condition is not satisfied, then evaluation proceeds to the next policy statement. If none of the policy statement conditions are satisfied, then evaluation of the current policy definition stops, and the next policy definition in the chain is evaluated. When the end of the policy chain is reached, the default route disposition action is performed (i.e., reject-route unless an alternate default action is specified for the chain).
Routing policy is applied by defining and attaching policy chains in various routing contexts. Policy chains are sequences of policy definitions (described in Section 3) that have an associated direction (import or export) with respect to the routing context in which they are defined. The routing policy model defines an apply-policy grouping that can be imported and used by other models. As shown below, it allows definition of import and export policy chains, as well as specifying the default route disposition to be used when no policy definition in the chain results in a final decision.
+--rw apply-policy
| +--rw import-policy*
| +--rw default-import-policy? default-policy-type
| +--rw export-policy*
| +--rw default-export-policy? default-policy-type
The default policy defined by the model is to reject the route for both import and export policies.
Routing models that require the ability to apply routing policy may augment the routing policy model with protocol or other specific policy configuration. The routing policy model assumes that additional defined sets, conditions, and actions may all be added by other models.
An example of this is shown below, in which the BGP configuration model in [I-D.ietf-idr-bgp-model] adds new defined sets to match on community values or AS paths. The model similarly augments BGP-specific conditions and actions in the corresponding sections of the routing policy model.
+--rw routing-policy
+--rw defined-sets
+--rw prefix-sets
| +--rw prefix-set* [prefix-set-name]
| +--rw prefix-set-name
| +--rw prefix* [ip-prefix masklength-range]
| +--rw ip-prefix
| +--rw masklength-range
+--rw neighbor-sets
| +--rw neighbor-set* [neighbor-set-name]
| +--rw neighbor-set-name
| +--rw neighbor* [address]
| +--rw address
+--rw tag-sets
| +--rw tag-set* [tag-set-name]
| +--rw tag-set-name
| +--rw tag* [value]
| +--rw value
+--rw bgp-pol:bgp-defined-sets
+--rw bgp-pol:community-sets
| +--rw bgp-pol:community-set* [community-set-name]
| +--rw bgp-pol:community-set-name
| +--rw bgp-pol:community-member*
+--rw bgp-pol:ext-community-sets
| +--rw bgp-pol:ext-community-set*
| [ext-community-set-name]
| +--rw bgp-pol:ext-community-set-name
| +--rw bgp-pol:ext-community-member*
+--rw bgp-pol:as-path-sets
+--rw bgp-pol:as-path-set* [as-path-set-name]
+--rw bgp-pol:as-path-set-name
+--rw bgp-pol:as-path-set-member*
Routing policy configuration has a significant impact on network operations, and, as such, any related model carries potential security risks.
YANG data models are generally designed to be used with the NETCONF protocol over an SSH transport. This provides an authenticated and secure channel over which to transfer configuration and operational data. Note that use of alternate transport or data encoding (e.g., JSON over HTTPS) would require similar mechanisms for authenticating and securing access to configuration data.
Most of the data elements in the policy model could be considered sensitive from a security standpoint. Unauthorized access or invalid data could cause major disruption.
This YANG data model and the component modules currently use a temporary ad-hoc namespace. If and when it is placed on redirected for the standards track, an appropriate namespace URI will be registered in the IETF XML Registry". The routing policy YANG modules will be registered in the "YANG Module Names" registry [RFC6020].
The routing policy model is described by the YANG modules in the sections below.
<CODE BEGINS> file "ietf-routing-policy@2018-02-26.yang"
module ietf-routing-policy {
yang-version "1.1";
namespace "urn:ietf:params:xml:ns:yang:ietf-routing-policy";
prefix rt-pol;
import ietf-inet-types {
prefix "inet";
}
import ietf-yang-types {
prefix "yang";
}
import ietf-interfaces {
prefix "if";
}
import ietf-routing {
prefix "rt";
}
import ietf-interfaces-common {
prefix if-cmn;
}
import ietf-if-l3-vlan {
prefix "if-l3-vlan";
}
organization
"IETF RTGWG - Routing Area Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/rtgwg/>
WG List: <mailto:rtgwg@ietf.org>
Editor: Yingzhen Qu
<mailto:yingzhen.qu@huawei.com>
Jeff Tantsura
<mailto:jefftant.ietf@gmail.com>
Acee Lindem
<mailto:acee@cisco.com>
Xufeng Liu
<mailto:xufeng_liu@jabil.com>
Anees Shaikh
<mailto:aashaikh@google.com>";
description
"This module describes a YANG model for routing policy
configuration. It is a limited subset of all of the policy
configuration parameters available in the variety of vendor
implementations, but supports widely used constructs for
managing how routes are imported, exported, and modified across
different routing protocols. This module is intended to be used
in conjunction with routing protocol configuration modules
(e.g., BGP) defined in other models.
Route policy expression:
Policies are expressed as a set of top-level policy definitions,
each of which consists of a sequence of policy statements.
Policy statements consist of simple condition-action tuples.
Conditions may include mutiple match or comparison operations,
and similarly actions may be multitude of changes to route
attributes or a final disposition of accepting or rejecting the
route.
Route policy evaluation:
Policy definitions are referenced in routing protocol
configurations using import and export configuration statements.
The arguments are members of an ordered list of named policy
definitions which comprise a policy chain, and optionally, an
explicit default policy action (i.e., reject or accept).
Evaluation of each policy definition proceeds by evaluating its
corresponding individual policy statements in order. When a
condition statement in a policy statement is satisfied, the
corresponding action statement is executed. If the action
statement has either accept-route or reject-route actions,
policy evaluation of the current policy definition stops, and
no further policy definitions in the chain are evaluated.
If the condition is not satisfied, then evaluation proceeds to
the next policy statement. If none of the policy statement
conditions are satisfied, then evaluation of the current policy
definition stops, and the next policy definition in the chain is
evaluated. When the end of the policy chain is reached, the
default route disposition action is performed (i.e.,
reject-route unless an alternate default action is specified
for the chain).
Policy 'subroutines' (or nested policies) are supported by
allowing policy statement conditions to reference another policy
definition which applies conditions and actions from the
referenced policy before returning to the calling policy
statement and resuming evaluation. If the called policy
results in an accept-route (either explicit or by default), then
the subroutine returns an effective true value to the calling
policy. Similarly, a reject-route action returns false. If the
subroutine returns true, the calling policy continues to
evaluate the remaining conditions (using a modified route if the
subroutine performed any changes to the route).";
revision "2018-02-26" {
description
"Initial revision.";
reference
"RFC XXXX: Routing Policy Configuration Model for Service
Provider Networks";
}
// typedef statements
typedef default-policy-type {
// this typedef retained for name compatibiity with default
// import and export policy
type enumeration {
enum accept-route {
description
"Default policy to accept the route";
}
enum reject-route {
description
"Default policy to reject the route";
}
}
description
"Type used to specify route disposition in
a policy chain";
}
typedef policy-result-type {
type enumeration {
enum accept-route {
description "Policy accepts the route";
}
enum reject-route {
description "Policy rejects the route";
}
}
description
"Type used to specify route disposition in
a policy chain";
}
typedef tag-type {
type union {
type uint32;
type yang:hex-string;
}
description "Type for expressing route tags on a local system,
including IS-IS and OSPF; may be expressed as either decimal
or hexadecimal integer";
reference
"RFC 2178 - OSPF Version 2
RFC 5130 - A Policy Control Mechanism in IS-IS Using
Administrative Tags";
}
typedef match-set-options-type {
type enumeration {
enum any {
description "Match is true if given value matches any member
of the defined set";
}
enum all {
description "Match is true if given value matches all
members of the defined set";
}
enum invert {
description "Match is true if given value does not match any
member of the defined set";
}
}
default any;
description
"Options that govern the behavior of a match statement. The
default behavior is any, i.e., the given value matches any
of the members of the defined set";
}
// grouping statements
grouping prefix-set {
description
"Configuration data for prefix sets used in policy
definitions.";
leaf name {
type string;
description
"Name of the prefix set -- this is used as a label to
reference the set in match conditions";
}
leaf mode {
type enumeration {
enum ipv4 {
description
"Prefix set contains IPv4 prefixes only";
}
enum ipv6 {
description
"Prefix set contains IPv6 prefixes only";
}
enum mixed {
description
"Prefix set contains mixed IPv4 and IPv6 prefixes";
}
}
description
"Indicates the mode of the prefix set, in terms of which
address families (IPv4, IPv6, or both) are present. The
mode provides a hint, but the device must validate that all
prefixes are of the indicated type, and is expected to
reject the configuration if there is a discrepancy. The
MIXED mode may not be supported on devices that require
prefix sets to be of only one address family.";
}
}
grouping prefix-set-top {
description
"Top-level data definitions for a list of IPv4 or IPv6
prefixes which are matched as part of a policy";
container prefix-sets {
description
"Enclosing container ";
list prefix-set {
key "name";
description
"List of the defined prefix sets";
uses prefix-set;
uses prefix-top;
}
}
}
grouping prefix {
description
"Configuration data for a prefix definition";
leaf ip-prefix {
type inet:ip-prefix;
mandatory true;
description
"The prefix member in CIDR notation -- while the
prefix may be either IPv4 or IPv6, most
implementations require all members of the prefix set
to be the same address family. Mixing address types in
the same prefix set is likely to cause an error.";
}
leaf masklength-range {
type string {
pattern '([0-9]{2}\.\.[0-9]{2})|([0-9]{2})';
}
description
"Defines a range for the masklength, or 'exact' if
the prefix has an exact length.
Example: 10.3.192.0/21 through 10.3.192.0/24 would be
expressed as prefix: 10.3.192.0/21,
masklength-range: 21..24.
Example: 10.3.192.0/21 would be expressed as
prefix: 10.3.192.0/21,
masklength-range: exact";
}
}
grouping prefix-top {
description
"Top-level grouping for prefixes in a prefix list";
container prefixes {
description
"Enclosing container for the list of prefixes in a policy
prefix list";
list prefix-list {
key "ip-prefix masklength-range";
description
"List of prefixes in the prefix set";
uses prefix;
}
}
}
grouping neighbor-set {
description
"This grouping provides neighbor set definitions";
leaf name {
type string;
description
"Name of the neighbor set -- this is used as a label
to reference the set in match conditions";
}
leaf-list address {
type inet:ip-address;
description
"List of IP addresses in the neighbor set";
}
}
grouping neighbor-set-top {
description
"Top-level data definition for a list of IPv4 or IPv6
neighbors which can be matched in a routing policy";
container neighbor-sets {
description
"Enclosing container for the list of neighbor set
definitions";
list neighbor-set {
key "name";
description
"List of defined neighbor sets for use in policies.";
uses neighbor-set;
}
}
}
grouping tag-set {
description
"This grouping provides tag set definitions.";
leaf name {
type string;
description
"Name of the tag set -- this is used as a label to reference
the set in match conditions";
}
leaf-list tag-value {
type tag-type;
description
"Value of the tag set member";
}
}
grouping tag-set-top {
description
"Top-level data definitions for a list of tags which can
be matched in policies";
container tag-sets {
description
"Enclosing container for the list of tag sets.";
list tag-set {
key "name";
description
"List of tag set definitions.";
uses tag-set;
}
}
}
grouping match-set-options-group {
description
"Grouping containing options relating to how a particular set
should be matched";
leaf match-set-options {
type match-set-options-type;
description
"Optional parameter that governs the behavior of the
match operation";
}
}
grouping match-set-options-restricted-group {
description
"Grouping for a restricted set of match operation modifiers";
leaf match-set-options {
type match-set-options-type {
enum any {
description "Match is true if given value matches any
member of the defined set";
}
enum invert {
description "Match is true if given value does not match
any member of the defined set";
}
}
description
"Optional parameter that governs the behavior of the
match operation. This leaf only supports matching on ANY
member of the set or inverting the match. Matching on ALL
is not supported";
}
}
grouping match-interface-condition {
description
"This grouping provides interface match condition";
container match-interface {
leaf interface {
type leafref {
path "/if:interfaces/if:interface/if:name";
}
description
"Reference to a base interface. If a reference to a
subinterface is required, this leaf must be specified
to indicate the base interface.";
}
leaf subinterface {
type leafref {
path "/if:interfaces/if:interface/if-cmn:encapsulation"
+ "/if-l3-vlan:dot1q-vlan"
+ "/if-l3-vlan:outer-tag/if-l3-vlan:vlan-id";
}
description
"Reference to a subinterface -- this requires the base
interface to be specified using the interface leaf in
this container. If only a reference to a base interface
is requuired, this leaf should not be set.";
}
description
"Container for interface match conditions";
}
}
grouping prefix-set-condition {
description
"This grouping provides prefix-set conditions";
container match-prefix-set {
leaf prefix-set {
type leafref {
path "../../../../../../../defined-sets/" +
"prefix-sets/prefix-set/name";
}
description "References a defined prefix set";
}
uses match-set-options-restricted-group;
description
"Match a referenced prefix-set according to the logic
defined in the match-set-options leaf";
}
}
grouping neighbor-set-condition {
description
"This grouping provides neighbor-set conditions";
container match-neighbor-set {
leaf neighbor-set {
type leafref {
path "../../../../../../../defined-sets/neighbor-sets/" +
"neighbor-set/name";
require-instance true;
}
description "References a defined neighbor set";
}
description
"Match a referenced neighbor set according to the logic
defined in the match-set-options-leaf";
}
}
grouping tag-set-condition {
description
"This grouping provides tag-set conditions";
container match-tag-set {
leaf tag-set {
type leafref {
path "../../../../../../../defined-sets/tag-sets/tag-set" +
"/name";
require-instance true;
}
description "References a defined tag set";
}
uses match-set-options-restricted-group;
description
"Match a referenced tag set according to the logic defined
in the match-options-set leaf";
}
}
grouping generic-conditions {
description "Condition statement definitions for checking
membership in a generic defined set";
uses match-interface-condition;
uses prefix-set-condition;
uses neighbor-set-condition;
uses tag-set-condition;
}
grouping generic-actions {
description
"Definitions for common set of policy action statements that
manage the disposition or control flow of the policy";
leaf policy-result {
type policy-result-type;
description
"Select the final disposition for the route, either
accept or reject.";
}
}
grouping policy-conditions {
description
"Data for general policy conditions, i.e., those
not related to match-sets";
leaf call-policy {
type leafref {
path "../../../../../../" +
"rt-pol:policy-definitions/" +
"rt-pol:policy-definition/rt-pol:name";
require-instance true;
}
description
"Applies the statements from the specified policy
definition and then returns control the current
policy statement. Note that the called policy may
itself call other policies (subject to
implementation limitations). This is intended to
provide a policy 'subroutine' capability. The
called policy should contain an explicit or a
default route disposition that returns an
effective true (accept-route) or false
(reject-route), otherwise the behavior may be
ambiguous and implementation dependent";
}
leaf install-protocol-eq {
type identityref {
base rt:control-plane-protocol;
}
description
"Condition to check the protocol / method used to install
the route into the local routing table";
}
}
grouping policy-conditions-top {
description
"Top-level grouping for policy conditions";
container conditions {
description
"Condition statements for the current policy statement";
uses policy-conditions;
uses generic-conditions;
}
}
grouping policy-statements {
description
"Data for policy statements";
leaf name {
type string;
description
"Name of the policy statement";
}
}
grouping policy-actions {
description
"Grouping for policy actions";
uses generic-actions;
}
grouping policy-actions-top {
description
"Top-level grouping for policy actions";
container actions {
description
"Top-level container for policy action statements";
uses policy-actions;
}
}
grouping policy-statements-top {
description
"Top-level grouping for the policy statements list";
container statements {
description
"Enclosing container for policy statements";
list statement {
key "name";
ordered-by user;
description
"Policy statements group conditions and actions
within a policy definition. They are evaluated in
the order specified (see the description of policy
evaluation at the top of this module.";
uses policy-statements;
uses policy-conditions-top;
uses policy-actions-top;
}
}
}
grouping policy-definitions {
description
"This grouping provides policy definitions";
leaf name {
type string;
description
"Name of the top-level policy definition -- this name
is used in references to the current policy";
}
}
grouping apply-policy-import {
description
"Grouping for applying import policies";
leaf-list import-policy {
type leafref {
path "/rt-pol:routing-policy/rt-pol:policy-definitions/" +
"rt-pol:policy-definition/rt-pol:name";
require-instance true;
}
ordered-by user;
description
"List of policy names in sequence to be applied on
receiving a routing update in the current context, e.g.,
for the current peer group, neighbor, address family,
etc.";
}
leaf default-import-policy {
type default-policy-type;
default reject-route;
description
"Explicitly set a default policy if no policy definition
in the import policy chain is satisfied.";
}
}
grouping apply-policy-export {
description
"Grouping for applying export policies";
leaf-list export-policy {
type leafref {
path "/rt-pol:routing-policy/rt-pol:policy-definitions/" +
"rt-pol:policy-definition/rt-pol:name";
require-instance true;
}
ordered-by user;
description
"List of policy names in sequence to be applied on
sending a routing update in the current context, e.g.,
for the current peer group, neighbor, address family,
etc.";
}
leaf default-export-policy {
type default-policy-type;
default reject-route;
description
"Explicitly set a default policy if no policy definition
in the export policy chain is satisfied.";
}
}
grouping apply-policy {
description
"Configuration data for routing policies";
uses apply-policy-import;
uses apply-policy-export;
container apply-policy-state {
description
"Operational state associated with routing policy";
//TODO: identify additional state data beyond the intended
//policy configuration.
}
}
grouping apply-policy-group {
description
"Top level container for routing policy applications. This
grouping is intended to be used in routing models where
needed.";
container apply-policy {
description
"Anchor point for routing policies in the model.
Import and export policies are with respect to the local
routing table, i.e., export (send) and import (receive),
depending on the context.";
uses apply-policy;
}
}
container routing-policy {
description
"Top-level container for all routing policy";
container defined-sets {
description
"Predefined sets of attributes used in policy match
statements";
uses prefix-set-top;
uses neighbor-set-top;
uses tag-set-top;
}
container policy-definitions {
description
"Enclosing container for the list of top-level policy
definitions";
list policy-definition {
key "name";
description
"List of top-level policy definitions, keyed by unique
name. These policy definitions are expected to be
referenced (by name) in policy chains specified in import
or export configuration statements.";
uses policy-definitions;
uses policy-statements-top;
}
}
}
}
<CODE ENDS>
Below we show an example of XML-encoded configuration data using the routing policy and BGP models to illustrate both how policies are defined, and also how they can be applied. Note that the XML has been simplified for readability.
<?yfile include="file:///tmp/routing-policy-example-draft.xml"?>
| [I-D.ietf-netmod-revised-datastores] | Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K. and R. Wilton, "Network Management Datastore Architecture", Internet-Draft draft-ietf-netmod-revised-datastores-10, January 2018. |
| [RFC3688] | Mealling, M., "The IETF XML Registry", RFC 3688, January 2004. |
| [RFC4271] | Rekhter, Y., Li, T. and S. Hares, "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, January 2006. |
| [RFC6020] | Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, October 2014. |
| [RFC6991] | Schoenwaelder, J., "Common YANG Data Types", RFC 6991, July 2013. |
| [RFC7950] | Bjorklund, M., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016. |
| [I-D.ietf-idr-bgp-model] | Shaikh, A., Shakir, R., Patel, K., Hares, S., D'Souza, K., Bansal, D., Clemm, A., Zhdankin, A., Jethanandani, M. and X. Liu, "BGP Model for Service Provider Networks", Internet-Draft draft-ietf-idr-bgp-model-02, July 2016. |
The routing policy module defined in this draft is based on the OpenConfig route policy model. The authors would like to thank to OpenConfig for their contributions, especially Rob Shakir, Kevin D'Souza, and Chris Chase.
The authors are grateful for valuable contributions to this document and the associated models from: Ebben Aires, Luyuan Fang, Josh George, Acee Lindem, Stephane Litkowski, Ina Minei, Carl Moberg, Eric Osborne, Steve Padgett, Juergen Schoenwaelder, Jim Uttaro, and Russ White.
Updated the model to use IETF modules and be NMDA compliant.
Updated policy model with additional condition for matching interfaces.
This revision updates the draft name to reflect adoption as a working document in the RTGWG. Minor changes include updates to references and updated author contact information.