Request for Comments: 8022
Category: Standards Track
ISSN: 2070-1721
CZ.NIC
A. Lindem
Cisco Systems
November 2016
A YANG Data Model for Routing Management
Abstract
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This document contains a specification of three YANG modules and one submodule. Together they form the core routing data model that serves as a framework for configuring and managing a routing subsystem. It is expected that these modules will be augmented by additional YANG modules defining data models for control-plane protocols, route filters, and other functions. The core routing data model provides common building blocks for such extensions -- routes, Routing Information Bases (RIBs), and control-plane protocols.
Status of This Memo
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This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc8022.
Copyright Notice
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Copyright © 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.
Table of Contents
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1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology and Notation . . . . . . . . . . . . . . . . . . 3 2.1. Glossary of New Terms . . . . . . . . . . . . . . . . . . 4 2.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 5 2.3. Prefixes in Data Node Names . . . . . . . . . . . . . . . 5 3. Objectives . . . . . . . . . . . . . . . . . . . . . . . . . 6 4. The Design of the Core Routing Data Model . . . . . . . . . . 6 4.1. System-Controlled and User-Controlled List Entries . . . 8 5. Basic Building Blocks . . . . . . . . . . . . . . . . . . . . 9 5.1. Route . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5.2. Routing Information Base (RIB) . . . . . . . . . . . . . 9 5.3. Control-Plane Protocol . . . . . . . . . . . . . . . . . 10 5.3.1. Routing Pseudo-Protocols . . . . . . . . . . . . . . 10 5.3.2. Defining New Control-Plane Protocols . . . . . . . . 11 5.4. Parameters of IPv6 Router Advertisements . . . . . . . . 12 6. Interactions with Other YANG Modules . . . . . . . . . . . . 13 6.1. Module "ietf-interfaces" . . . . . . . . . . . . . . . . 13 6.2. Module "ietf-ip" . . . . . . . . . . . . . . . . . . . . 13 7. Routing Management YANG Module . . . . . . . . . . . . . . . 14 8. IPv4 Unicast Routing Management YANG Module . . . . . . . . . 26 9. IPv6 Unicast Routing Management YANG Module . . . . . . . . . 32 9.1. IPv6 Router Advertisements Submodule . . . . . . . . . . 37 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 47 11. Security Considerations . . . . . . . . . . . . . . . . . . . 48 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 49 12.1. Normative References . . . . . . . . . . . . . . . . . . 49 12.2. Informative References . . . . . . . . . . . . . . . . . 50 Appendix A. The Complete Data Trees . . . . . . . . . . . . . . 51 A.1. Configuration Data . . . . . . . . . . . . . . . . . . . 51 A.2. State Data . . . . . . . . . . . . . . . . . . . . . . . 52 Appendix B. Minimum Implementation . . . . . . . . . . . . . . . 53 Appendix C. Example: Adding a New Control-Plane Protocol . . . . 54 Appendix D. Data Tree Example . . . . . . . . . . . . . . . . . 56 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 64 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 64
1. Introduction
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This document contains a specification of the following YANG modules:
- The "ietf-routing" module provides generic components of a routing data model.
- The "ietf-ipv4-unicast-routing" module augments the "ietf-routing" module with additional data specific to IPv4 unicast.
- The "ietf-ipv6-unicast-routing" module augments the "ietf-routing" module with additional data specific to IPv6 unicast. Its submodule "ietf-ipv6-router-advertisements" also augments the "ietf-interfaces" [RFC7223] and "ietf-ip" [RFC7277] modules with IPv6 router configuration variables required by [RFC4861].
These modules together define the so-called core routing data model, which is intended as a basis for future data model development covering more-sophisticated routing systems. While these three modules can be directly used for simple IP devices with static routing (see Appendix B), their main purpose is to provide essential building blocks for more-complicated data models involving multiple control-plane protocols, multicast routing, additional address families, and advanced functions such as route filtering or policy routing. To this end, it is expected that the core routing data model will be augmented by numerous modules developed by various IETF working groups.
2. Terminology and Notation
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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].
The following terms are defined in [RFC6241]:
- client
- message
- protocol operation
- server
The following terms are defined in [RFC7950]:
- action
- augment
- configuration data
- container
- container with presence
- data model
- data node
- feature
- leaf
- list
- mandatory node
- module
- schema tree
- state data
- RPC (Remote Procedure Call) operation
2.1. Glossary of New Terms
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core routing data model: YANG data model comprising "ietf-routing", "ietf-ipv4-unicast-routing", and "ietf-ipv6-unicast-routing" modules. direct route: a route to a directly connected network. Routing Information Base (RIB): An object containing a list of routes together with other information. See Section 5.2 for details. system-controlled entry: An entry of a list in state data ("config false") that is created by the system independently of what has been explicitly configured. See Section 4.1 for details. user-controlled entry: An entry of a list in state data ("config false") that is created and deleted as a direct consequence of certain configuration changes. See Section 4.1 for details.
2.2. Tree Diagrams
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A simplified graphical representation of the complete data tree is presented in Appendix A, and similar diagrams of its various subtrees appear in the main text.
- Brackets "[" and "]" enclose list keys.
- Curly braces "{" and "}" contain names of optional features that make the corresponding node conditional.
- Abbreviations before data node names: "rw" means configuration (read-write), "ro" state data (read-only), "-x" RPC operations or actions, and "-n" notifications.
- Symbols after data node names: "?" means an optional node, "!" a container with presence, and "*" denotes a "list" or "leaf-list".
- Parentheses enclose choice and case nodes, and case nodes are also marked with a colon (":").
- Ellipsis ("...") stands for contents of subtrees that are not shown.
2.3. Prefixes in Data Node Names
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In this document, names of data nodes, actions, and other data model objects are often used without a prefix, as long as it is clear from the context in which YANG module each name is defined. Otherwise, names are prefixed using the standard prefix associated with the corresponding YANG module, as shown in Table 1.
+--------+---------------------------+-----------+ | Prefix | YANG module | Reference | +--------+---------------------------+-----------+ | if | ietf-interfaces | [RFC7223] | | ip | ietf-ip | [RFC7277] | | rt | ietf-routing | Section 7 | | v4ur | ietf-ipv4-unicast-routing | Section 8 | | v6ur | ietf-ipv6-unicast-routing | Section 9 | | yang | ietf-yang-types | [RFC6991] | | inet | ietf-inet-types | [RFC6991] | +--------+---------------------------+-----------+
Table 1: Prefixes and Corresponding YANG Modules
3. Objectives
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The initial design of the core routing data model was driven by the following objectives:
- The data model should be suitable for the common address families -- in particular, IPv4 and IPv6 -- and for unicast and multicast routing, as well as Multiprotocol Label Switching (MPLS).
- A simple IP routing system, such as one that uses only static routing, should be configurable in a simple way, ideally without any need to develop additional YANG modules.
- On the other hand, the core routing framework must allow for complicated implementations involving multiple Routing Information Bases (RIBs) and multiple control-plane protocols, as well as controlled redistributions of routing information.
- Because device vendors will want to map the data models built on this generic framework to their proprietary data models and configuration interfaces, the framework should be flexible enough to facilitate that and accommodate data models with different logic.
4. The Design of the Core Routing Data Model
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The core routing data model consists of three YANG modules and one submodule. The first module, "ietf-routing", defines the generic components of a routing system. The other two modules, "ietf-ipv4- unicast-routing" and "ietf-ipv6-unicast-routing", augment the "ietf- routing" module with additional data nodes that are needed for IPv4 and IPv6 unicast routing, respectively. The "ietf-ipv6-unicast- routing" module has a submodule, "ietf-ipv6-router-advertisements", that augments the "ietf-interfaces" [RFC7223] and "ietf-ip" [RFC7277] modules with configuration variables for IPv6 router advertisements as required by [RFC4861]. Figures 1 and 2 show abridged views of the configuration and state data hierarchies. See Appendix A for the complete data trees.
+--rw routing
+--rw router-id? +--rw control-plane-protocols | +--rw control-plane-protocol* [type name] | +--rw type | +--rw name | +--rw description? | +--rw static-routes | +--rw v6ur:ipv6 | | ... | +--rw v4ur:ipv4 | ... +--rw ribs +--rw rib* [name] +--rw name +--rw address-family? +--rw description?
Figure 1: Configuration Data Hierarchy
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+--ro routing-state +--ro router-id? +--ro interfaces | +--ro interface* +--ro control-plane-protocols | +--ro control-plane-protocol* [type name] | +--ro type | +--ro name +--ro ribs +--ro rib* [name] +--ro name +--ro address-family +--ro default-rib? +--ro routes | +--ro route* | ...
Figure 2: State Data Hierarchy
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As can be seen from Figures 1 and 2, the core routing data model introduces several generic components of a routing framework: routes, RIBs containing lists of routes, and control-plane protocols. Section 5 describes these components in more detail.
4.1. System-Controlled and User-Controlled List Entries
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The core routing data model defines several lists in the schema tree, such as "rib", that have to be populated with at least one entry in any properly functioning device, and additional entries may be configured by a client.
In such a list, the server creates the required item as a so-called system-controlled entry in state data, i.e., inside the "routing- state" container.
An example can be seen in Appendix D: the "/routing-state/ribs/rib" list has two system-controlled entries named "ipv4-master" and "ipv6-master".
Additional entries may be created in the configuration by a client, e.g., via the NETCONF protocol. These are so-called user-controlled entries. If the server accepts a configured user-controlled entry, then this entry also appears in the state data version of the list.
Corresponding entries in both versions of the list (in state data and configuration) have the same value of the list key.
A client may also provide supplemental configuration of system- controlled entries. To do so, the client creates a new entry in the configuration with the desired contents. In order to bind this entry to the corresponding entry in the state data list, the key of the configuration entry has to be set to the same value as the key of the state entry.
Deleting a user-controlled entry from the configuration list results in the removal of the corresponding entry in the state data list. In contrast, if a system-controlled entry is deleted from the configuration list, only the extra configuration specified in that entry is removed but the corresponding state data entry remains in the list.
5. Basic Building Blocks
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This section describes the essential components of the core routing data model.
5.1. Route
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Routes are basic elements of information in a routing system. The core routing data model defines only the following minimal set of route attributes:
- "destination-prefix": address prefix specifying the set of destination addresses for which the route may be used. This attribute is mandatory.
- "route-preference": an integer value (also known as administrative distance) that is used for selecting a preferred route among routes with the same destination prefix. A lower value means a more preferred route.
- "next-hop": determines the outgoing interface and/or next-hop address(es), or a special operation to be performed with a packet.
Routes are primarily state data that appear as entries of RIBs (Section 5.2) but they may also be found in configuration data, for example, as manually configured static routes. In the latter case, configurable route attributes are generally a subset of attributes defined for RIB routes.
5.2. Routing Information Base (RIB)
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Every implementation of the core routing data model manages one or more Routing Information Bases (RIBs). A RIB is a list of routes complemented with administrative data. Each RIB contains only routes of one address family. An address family is represented by an identity derived from the "rt:address-family" base identity.
In the core routing data model, RIBs are state data represented as entries of the list "/routing-state/ribs/rib". The contents of RIBs are controlled and manipulated by control-plane protocol operations that may result in route additions, removals, and modifications. This also includes manipulations via the "static" and/or "direct" pseudo-protocols; see Section 5.3.1.
For every supported address family, exactly one RIB MUST be marked as the so-called default RIB to which control-plane protocols place their routes by default.
Simple router implementations that do not advertise the feature "multiple-ribs" will typically create one system-controlled RIB per supported address family and mark it as the default RIB.
More-complex router implementations advertising the "multiple-ribs" feature support multiple RIBs per address family that can be used for policy routing and other purposes.
The following action (see Section 7.15 of [RFC7950]) is defined for the "rib" list:
- active-route -- return the active RIB route for the destination address that is specified as the action's input parameter.
5.3. Control-Plane Protocol
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The core routing data model provides an open-ended framework for defining multiple control-plane protocol instances, e.g., for Layer 3 routing protocols. Each control-plane protocol instance MUST be assigned a type, which is an identity derived from the "rt:control-plane-protocol" base identity. The core routing data model defines two identities for the direct and static pseudo- protocols (Section 5.3.1).
Multiple control-plane protocol instances of the same type MAY be configured.
5.3.1. Routing Pseudo-Protocols
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The core routing data model defines two special routing protocol types -- "direct" and "static". Both are in fact pseudo-protocols, which means that they are confined to the local device and do not exchange any routing information with adjacent routers.
Every implementation of the core routing data model MUST provide exactly one instance of the "direct" pseudo-protocol type. It is the source of direct routes for all configured address families. Direct routes are normally supplied by the operating system kernel, based on the configuration of network interface addresses; see Section 6.2.
A pseudo-protocol of the type "static" allows for specifying routes manually. It MAY be configured in zero or multiple instances, although a typical configuration will have exactly one instance.
5.3.2. Defining New Control-Plane Protocols
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It is expected that future YANG modules will create data models for additional control-plane protocol types. Such a new module has to define the protocol-specific configuration and state data, and it has to integrate it into the core routing framework in the following way:
- A new identity MUST be defined for the control-plane protocol, and its base identity MUST be set to "rt:control-plane-protocol" or to an identity derived from "rt:control-plane-protocol".
- Additional route attributes MAY be defined, preferably in one place by means of defining a YANG grouping. The new attributes have to be inserted by augmenting the definitions of the nodes
/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route and-
/rt:routing-state/rt:ribs/rt:rib/rt:output/rt:route,
and possibly other places in the configuration, state data, notifications, and input/output parameters of actions or RPC operations.
- Configuration parameters and/or state data for the new protocol can be defined by augmenting the "control-plane-protocol" data node under both "/routing" and "/routing-state".
By using a "when" statement, the augmented configuration parameters and state data specific to the new protocol SHOULD be made conditional and valid only if the value of "rt:type" or "rt:source-protocol" is equal to (or derived from) the new protocol's identity.
It is also RECOMMENDED that protocol-specific data nodes be encapsulated in an appropriately named container with presence. Such a container may contain mandatory data nodes that are otherwise forbidden at the top level of an augment.
The above steps are implemented by the example YANG module for the Routing Information Protocol (RIP) in Appendix C.
5.4. Parameters of IPv6 Router Advertisements
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YANG module "ietf-ipv6-router-advertisements" (Section 9.1), which is a submodule of the "ietf-ipv6-unicast-routing" module, augments the configuration and state data of IPv6 interfaces with definitions of the following variables as required by Section 6.2.1 of [RFC4861]:
- send-advertisements
- max-rtr-adv-interval
- min-rtr-adv-interval
- managed-flag
- other-config-flag
- link-mtu
- reachable-time
- retrans-timer
- cur-hop-limit
- default-lifetime
- prefix-list: a list of prefixes to be advertised.
-
The following parameters are associated with each prefix in the list:
- valid-lifetime
- on-link-flag
- preferred-lifetime
- autonomous-flag
NOTES:
1. The "IsRouter" flag, which is also required by [RFC4861], is implemented in the "ietf-ip" module [RFC7277] (leaf "ip:forwarding").
- The original specification [RFC4861] allows the implementations to decide whether the "valid-lifetime" and "preferred-lifetime" parameters remain the same in consecutive advertisements or decrement in real time. However, the latter behavior seems problematic because the values might be reset again to the (higher) configured values after a configuration is reloaded. Moreover, no implementation is known to use the decrementing behavior. The "ietf-ipv6-router-advertisements" submodule therefore stipulates the former behavior with constant values.
6. Interactions with Other YANG Modules
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The semantics of the core routing data model also depends on several configuration parameters that are defined in other YANG modules.
6.1. Module "ietf-interfaces"
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The following boolean switch is defined in the "ietf-interfaces" YANG module [RFC7223]:
/if:interfaces/if:interface/if:enabled
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If this switch is set to "false" for a network-layer interface, then all routing and forwarding functions MUST be disabled on this interface.
-
6.2. Module "ietf-ip"
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The following boolean switches are defined in the "ietf-ip" YANG module [RFC7277]:
/if:interfaces/if:interface/ip:ipv4/ip:enabled
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If this switch is set to "false" for a network-layer interface, then all IPv4 routing and forwarding functions MUST be disabled on this interface.
/if:interfaces/if:interface/ip:ipv4/ip:forwarding
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If this switch is set to "false" for a network-layer interface, then the forwarding of IPv4 datagrams through this interface MUST be disabled. However, the interface MAY participate in other IPv4 routing functions, such as routing protocols.
/if:interfaces/if:interface/ip:ipv6/ip:enabled
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If this switch is set to "false" for a network-layer interface, then all IPv6 routing and forwarding functions MUST be disabled on this interface.
/if:interfaces/if:interface/ip:ipv6/ip:forwarding
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If this switch is set to "false" for a network-layer interface, then the forwarding of IPv6 datagrams through this interface MUST be disabled. However, the interface MAY participate in other IPv6 routing functions, such as routing protocols.
In addition, the "ietf-ip" module allows for configuring IPv4 and IPv6 addresses and network prefixes or masks on network-layer interfaces. Configuration of these parameters on an enabled interface MUST result in an immediate creation of the corresponding direct route. The destination prefix of this route is set according to the configured IP address and network prefix/mask, and the interface is set as the outgoing interface for that route.
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7. Routing Management YANG Module
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<CODE BEGINS> file "ietf-routing@2016-11-04.yang"
module ietf-routing { yang-version "1.1"; namespace "urn:ietf:params:xml:ns:yang:ietf-routing"; prefix "rt"; import ietf-yang-types { prefix "yang"; } import ietf-interfaces { prefix "if"; }-
organization
"IETF NETMOD (NETCONF Data Modeling Language) Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
-
WG Chair:
-
-
-
Lou Berger
<mailto:lberger@labn.net>
-
-
WG Chair:
-
-
-
Kent Watsen
<mailto:kwatsen@juniper.net>
-
-
Editor: Ladislav Lhotka <mailto:lhotka@nic.cz> Editor: Acee Lindem <mailto:acee@cisco.com>";-
description
"This YANG module defines essential components for the management
of a routing subsystem.
Copyright © 2016 IETF Trust and the persons identified as authors of the code. 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).
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and 'OPTIONAL' in the module text are to be interpreted as described in RFC 2119.
This version of this YANG module is part of RFC 8022; see the RFC itself for full legal notices.";
revision 2016-11-04 { description "Initial revision."; reference "RFC 8022: A YANG Data Model for Routing Management"; } /* Features */-
feature multiple-ribs {
description
-
"This feature indicates that the server supports user-defined
RIBs.
Servers that do not advertise this feature SHOULD provide exactly one system-controlled RIB per supported address family and make it also the default RIB. This RIB then appears as an entry of the list /routing-state/ribs/rib."; }-
feature router-id {
description
-
"This feature indicates that the server supports configuration
of an explicit 32-bit router ID that is used by some routing protocols.
Servers that do not advertise this feature set a router ID algorithmically, usually to one of the configured IPv4 addresses. However, this algorithm is implementation specific."; } /* Identities */ identity address-family { description "Base identity from which identities describing address families are derived."; } identity ipv4 { base address-family; description "This identity represents IPv4 address family."; } identity ipv6 { base address-family; description "This identity represents IPv6 address family."; } identity control-plane-protocol { description "Base identity from which control-plane protocol identities are derived."; }-
identity routing-protocol {
base control-plane-protocol;
description-
"Identity from which Layer 3 routing protocol identities are
derived."; } identity direct { base routing-protocol; description "Routing pseudo-protocol that provides routes to directly connected networks."; } identity static { base routing-protocol; description "Static routing pseudo-protocol."; } /* Type Definitions */ typedef route-preference { type uint32; description "This type is used for route preferences."; } /* Groupings */ grouping address-family { description "This grouping provides a leaf identifying an address family."; leaf address-family { type identityref { base address-family; } mandatory "true"; description "Address family."; } }-
grouping router-id {
description "This grouping provides router ID."; leaf router-id { type yang:dotted-quad; description "A 32-bit number in the form of a dotted quad that is used by some routing protocols identifying a router."; reference "RFC 2328: OSPF Version 2."; } } grouping special-next-hop { description "This grouping provides a leaf with an enumeration of special next hops."; leaf special-next-hop { type enumeration { enum blackhole { description "Silently discard the packet."; } enum unreachable { description "Discard the packet and notify the sender with an error message indicating that the destination host is unreachable."; } enum prohibit { description "Discard the packet and notify the sender with an error message indicating that the communication is administratively prohibited."; } enum receive { description "The packet will be received by the local system."; } } description "Options for special next hops."; } }-
grouping next-hop-content {
description "Generic parameters of next hops in static routes."; choice next-hop-options { mandatory "true"; description "Options for next hops in static routes. It is expected that further cases will be added through augments from other modules."; case simple-next-hop {-
-
description
-
"This case represents a simple next hop consisting of the
-
-
next-hop address and/or outgoing interface.
-
Modules for address families MUST augment this case with a leaf containing a next-hop address of that address family."; leaf outgoing-interface { type if:interface-ref; description "Name of the outgoing interface."; } } case special-next-hop { uses special-next-hop; } case next-hop-list { container next-hop-list { description "Container for multiple next-hops."; list next-hop { key "index"; description "An entry of a next-hop list. Modules for address families MUST augment this list with a leaf containing a next-hop address of that address family."; leaf index { type string; description "A user-specified identifier utilized to uniquely reference the next-hop entry in the next-hop list. The value of this index has no semantic meaning other than for referencing the entry."; } leaf outgoing-interface { type if:interface-ref; description "Name of the outgoing interface."; } } } } } } grouping next-hop-state-content { description "Generic parameters of next hops in state data."; choice next-hop-options { mandatory "true"; description "Options for next hops in state data. It is expected that further cases will be added through augments from other modules, e.g., for recursive next hops."; case simple-next-hop { description "This case represents a simple next hop consisting of the next-hop address and/or outgoing interface. Modules for address families MUST augment this case with a leaf containing a next-hop address of that address family."; leaf outgoing-interface { type if:interface-state-ref; description "Name of the outgoing interface."; } } case special-next-hop { uses special-next-hop; } case next-hop-list { container next-hop-list { description "Container for multiple next hops."; list next-hop { description "An entry of a next-hop list. Modules for address families MUST augment this list with a leaf containing a next-hop address of that address family."; leaf outgoing-interface { type if:interface-state-ref; description "Name of the outgoing interface."; } } } } } } grouping route-metadata { description "Common route metadata."; leaf source-protocol { type identityref { base routing-protocol; } mandatory "true"; description "Type of the routing protocol from which the route originated."; } leaf active { type empty; description "Presence of this leaf indicates that the route is preferred among all routes in the same RIB that have the same destination prefix."; } leaf last-updated { type yang:date-and-time; description "Time stamp of the last modification of the route. If the route was never modified, it is the time when the route was inserted into the RIB."; } } /* State data */-
container routing-state {
config "false"; description "State data of the routing subsystem."; uses router-id { description "Global router ID. It may be either configured or assigned algorithmically by the implementation."; } container interfaces { description "Network-layer interfaces used for routing."; leaf-list interface { type if:interface-state-ref; description "Each entry is a reference to the name of a configured network-layer interface."; } } container control-plane-protocols { description "Container for the list of routing protocol instances."; list control-plane-protocol { key "type name"; description "State data of a control-plane protocol instance. An implementation MUST provide exactly one system-controlled instance of the 'direct' pseudo-protocol. Instances of other control-plane protocols MAY be created by configuration."; leaf type { type identityref { base control-plane-protocol; } description "Type of the control-plane protocol."; } leaf name { type string; description "The name of the control-plane protocol instance. For system-controlled instances this name is persistent, i.e., it SHOULD NOT change across reboots."; } } } container ribs { description "Container for RIBs."; list rib { key "name"; min-elements "1"; description "Each entry represents a RIB identified by the 'name' key. All routes in a RIB MUST belong to the same address family. An implementation SHOULD provide one system-controlled default RIB for each supported address family."; leaf name { type string; description "The name of the RIB."; } uses address-family; leaf default-rib { if-feature "multiple-ribs"; type boolean; default "true"; description "This flag has the value of 'true' if and only if the RIB is the default RIB for the given address family. By default, control-plane protocols place their routes in the default RIBs."; } container routes { description "Current content of the RIB."; list route { description "A RIB route entry. This data node MUST be augmented with information specific for routes of each address family."; leaf route-preference { type route-preference; description "This route attribute, also known as administrative distance, allows for selecting the preferred route among routes with the same destination prefix. A smaller value means a more preferred route."; } container next-hop { description "Route's next-hop attribute."; uses next-hop-state-content; } uses route-metadata; } } action active-route { description "Return the active RIB route that is used for the destination address. Address-family-specific modules MUST augment input parameters with a leaf named 'destination-address'."; output {-
-
-
container route {
-
description
"The active RIB route for the specified destination.
If no route exists in the RIB for the destination address, no output is returned.
-
-
Address-family-specific modules MUST augment this container with appropriate route contents."; container next-hop { description "Route's next-hop attribute."; uses next-hop-state-content; } uses route-metadata; } } } } } } /* Configuration Data */-
container routing {
description "Configuration parameters for the routing subsystem."; uses router-id { if-feature "router-id"; description "Configuration of the global router ID. Routing protocols that use router ID can use this parameter or override it with another value."; } container control-plane-protocols { description "Configuration of control-plane protocol instances."; list control-plane-protocol { key "type name"; description "Each entry contains configuration of a control-plane protocol instance."; leaf type { type identityref { base control-plane-protocol; } description "Type of the control-plane protocol - an identity derived from the 'control-plane-protocol' base identity."; } leaf name { type string; description "An arbitrary name of the control-plane protocol instance."; } leaf description { type string; description "Textual description of the control-plane protocol instance."; } container static-routes { when "derived-from-or-self(../type, 'rt:static')" { description "This container is only valid for the 'static' routing protocol."; } description "Configuration of the 'static' pseudo-protocol. Address-family-specific modules augment this node with their lists of routes."; } } } container ribs { description "Configuration of RIBs."; list rib { key "name"; description "Each entry contains configuration for a RIB identified by the 'name' key. Entries having the same key as a system-controlled entry of the list /routing-state/ribs/rib are used for configuring parameters of that entry. Other entries define additional user-controlled RIBs."; leaf name { type string; description "The name of the RIB.-
-
-
For system-controlled entries, the value of this leaf must be the same as the name of the corresponding entry in state data.
-
-
For user-controlled entries, an arbitrary name can be used."; } uses address-family { description "Address family of the RIB. It is mandatory for user-controlled RIBs. For system-controlled RIBs it can be omitted; otherwise, it must match the address family of the corresponding state entry."; refine "address-family" { mandatory "false"; } } leaf description { type string; description "Textual description of the RIB."; } } } } } <CODE ENDS> -
8. IPv4 Unicast Routing Management YANG Module
-
<CODE BEGINS> file "ietf-ipv4-unicast-routing@2016-11-04.yang"
module ietf-ipv4-unicast-routing { yang-version "1.1"; namespace "urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing"; prefix "v4ur"; import ietf-routing { prefix "rt"; } import ietf-inet-types { prefix "inet"; }-
organization
"IETF NETMOD (NETCONF Data Modeling Language) Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
-
WG Chair:
-
-
-
Lou Berger
<mailto:lberger@labn.net>
-
-
WG Chair:
-
-
-
Kent Watsen
<mailto:kwatsen@juniper.net>
-
-
Editor: Ladislav Lhotka <mailto:lhotka@nic.cz> Editor: Acee Lindem <mailto:acee@cisco.com>";-
description
"This YANG module augments the 'ietf-routing' module with basic
-
configuration and state data for IPv4 unicast routing.
-
-
Copyright © 2016 IETF Trust and the persons identified as authors of the code. 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).
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and 'OPTIONAL' in the module text are to be interpreted as described in RFC 2119.
This version of this YANG module is part of RFC 8022; see the RFC itself for full legal notices.";
revision 2016-11-04 { description "Initial revision."; reference "RFC 8022: A YANG Data Model for Routing Management"; } /* Identities */ identity ipv4-unicast { base rt:ipv4; description "This identity represents the IPv4 unicast address family."; } /* State data */ augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route" { when "derived-from-or-self(../../rt:address-family, " + "'v4ur:ipv4-unicast')" { description "This augment is valid only for IPv4 unicast."; } description "This leaf augments an IPv4 unicast route."; leaf destination-prefix { type inet:ipv4-prefix; description "IPv4 destination prefix."; } } augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route/" + "rt:next-hop/rt:next-hop-options/rt:simple-next-hop" { when "derived-from-or-self(../../../rt:address-family, " + "'v4ur:ipv4-unicast')" { description "This augment is valid only for IPv4 unicast."; } description "Augment 'simple-next-hop' case in IPv4 unicast routes."; leaf next-hop-address { type inet:ipv4-address; description "IPv4 address of the next hop."; } }-
augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route/"
+ "rt:next-hop/rt:next-hop-options/rt:next-hop-list/" + "rt:next-hop-list/rt:next-hop" { when "derived-from-or-self(../../../../../rt:address-family, " + "'v4ur:ipv4-unicast')" { description "This augment is valid only for IPv4 unicast."; } description "This leaf augments the 'next-hop-list' case of IPv4 unicast routes."; leaf address { type inet:ipv4-address; description "IPv4 address of the next-hop."; } } augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/rt:input" { when "derived-from-or-self(../rt:address-family, " + "'v4ur:ipv4-unicast')" { description "This augment is valid only for IPv4 unicast RIBs."; } description "This augment adds the input parameter of the 'active-route' action."; leaf destination-address { type inet:ipv4-address; description "IPv4 destination address."; } } augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/" + "rt:output/rt:route" { when "derived-from-or-self(../../rt:address-family, " + "'v4ur:ipv4-unicast')" { description "This augment is valid only for IPv4 unicast."; } description "This augment adds the destination prefix to the reply of the 'active-route' action."; leaf destination-prefix { type inet:ipv4-prefix; description "IPv4 destination prefix."; } }-
augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/"
+ "rt:output/rt:route/rt:next-hop/rt:next-hop-options/" + "rt:simple-next-hop" { when "derived-from-or-self(../../../rt:address-family, " + "'v4ur:ipv4-unicast')" { description "This augment is valid only for IPv4 unicast."; } description "Augment 'simple-next-hop' case in the reply to the 'active-route' action."; leaf next-hop-address { type inet:ipv4-address; description "IPv4 address of the next hop."; } } augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/" + "rt:output/rt:route/rt:next-hop/rt:next-hop-options/" + "rt:next-hop-list/rt:next-hop-list/rt:next-hop" { when "derived-from-or-self(../../../../../rt:address-family, " + "'v4ur:ipv4-unicast')" { description "This augment is valid only for IPv4 unicast."; } description "Augment 'next-hop-list' case in the reply to the 'active-route' action."; leaf next-hop-address { type inet:ipv4-address; description "IPv4 address of the next hop."; } } /* Configuration data */-
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:static-routes" { description "This augment defines the configuration of the 'static' pseudo-protocol with data specific to IPv4 unicast."; container ipv4 { description "Configuration of a 'static' pseudo-protocol instance consists of a list of routes."; list route { key "destination-prefix"; description "A list of static routes."; leaf destination-prefix { type inet:ipv4-prefix; mandatory "true"; description "IPv4 destination prefix."; } leaf description { type string; description "Textual description of the route."; } container next-hop { description "Configuration of next-hop."; uses rt:next-hop-content { augment "next-hop-options/simple-next-hop" { description "Augment 'simple-next-hop' case in IPv4 static routes."; leaf next-hop-address { type inet:ipv4-address; description "IPv4 address of the next hop."; } } augment "next-hop-options/next-hop-list/next-hop-list/" + "next-hop" { description "Augment 'next-hop-list' case in IPv4 static routes."; leaf next-hop-address { type inet:ipv4-address; description "IPv4 address of the next hop."; } } } } } } } } <CODE ENDS> -
9. IPv6 Unicast Routing Management YANG Module
-
<CODE BEGINS> file "ietf-ipv6-unicast-routing@2016-11-04.yang"
module ietf-ipv6-unicast-routing { yang-version "1.1"; namespace "urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing"; prefix "v6ur"; import ietf-routing { prefix "rt"; } import ietf-inet-types { prefix "inet"; } include ietf-ipv6-router-advertisements { revision-date 2016-11-04; }-
organization
"IETF NETMOD (NETCONF Data Modeling Language) Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
-
WG Chair:
-
-
-
Lou Berger
<mailto:lberger@labn.net>
-
-
WG Chair:
-
-
-
Kent Watsen
<mailto:kwatsen@juniper.net>
-
-
Editor: Ladislav Lhotka <mailto:lhotka@nic.cz> Editor: Acee Lindem <mailto:acee@cisco.com>";-
description
"This YANG module augments the 'ietf-routing' module with basic
-
configuration and state data for IPv6 unicast routing.
-
-
Copyright © 2016 IETF Trust and the persons identified as authors of the code. 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).
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and 'OPTIONAL' in the module text are to be interpreted as described in RFC 2119.
This version of this YANG module is part of RFC 8022; see the RFC itself for full legal notices.";
revision 2016-11-04 { description "Initial revision."; reference "RFC 8022: A YANG Data Model for Routing Management"; } /* Identities */ identity ipv6-unicast { base rt:ipv6; description "This identity represents the IPv6 unicast address family."; } /* State data */-
augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route" {
when "derived-from-or-self(../../rt:address-family, " + "'v6ur:ipv6-unicast')" { description "This augment is valid only for IPv6 unicast."; } description "This leaf augments an IPv6 unicast route."; leaf destination-prefix { type inet:ipv6-prefix; description "IPv6 destination prefix."; } } augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route/" + "rt:next-hop/rt:next-hop-options/rt:simple-next-hop" { when "derived-from-or-self(../../../rt:address-family, " + "'v6ur:ipv6-unicast')" { description "This augment is valid only for IPv6 unicast."; } description "Augment 'simple-next-hop' case in IPv6 unicast routes."; leaf next-hop-address { type inet:ipv6-address; description "IPv6 address of the next hop."; } } augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route/" + "rt:next-hop/rt:next-hop-options/rt:next-hop-list/" + "rt:next-hop-list/rt:next-hop" { when "derived-from-or-self(../../../../../rt:address-family, " + "'v6ur:ipv6-unicast')" { description "This augment is valid only for IPv6 unicast."; } description "This leaf augments the 'next-hop-list' case of IPv6 unicast routes."; leaf address { type inet:ipv6-address; description "IPv6 address of the next hop."; } }-
augment
"/rt:routing-state/rt:ribs/rt:rib/rt:active-route/rt:input" { when "derived-from-or-self(../rt:address-family, " + "'v6ur:ipv6-unicast')" { description "This augment is valid only for IPv6 unicast RIBs."; } description "This augment adds the input parameter of the 'active-route' action."; leaf destination-address { type inet:ipv6-address; description "IPv6 destination address."; } } augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/" + "rt:output/rt:route" { when "derived-from-or-self(../../rt:address-family, " + "'v6ur:ipv6-unicast')" { description "This augment is valid only for IPv6 unicast."; } description "This augment adds the destination prefix to the reply of the 'active-route' action."; leaf destination-prefix { type inet:ipv6-prefix; description "IPv6 destination prefix."; } } augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/" + "rt:output/rt:route/rt:next-hop/rt:next-hop-options/" + "rt:simple-next-hop" { when "derived-from-or-self(../../../rt:address-family, " + "'v6ur:ipv6-unicast')" { description "This augment is valid only for IPv6 unicast."; } description "Augment 'simple-next-hop' case in the reply to the 'active-route' action."; leaf next-hop-address { type inet:ipv6-address; description "IPv6 address of the next hop."; } }-
augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/"
+ "rt:output/rt:route/rt:next-hop/rt:next-hop-options/" + "rt:next-hop-list/rt:next-hop-list/rt:next-hop" { when "derived-from-or-self(../../../../../rt:address-family, " + "'v6ur:ipv6-unicast')" { description "This augment is valid only for IPv6 unicast."; } description "Augment 'next-hop-list' case in the reply to the 'active-route' action."; leaf next-hop-address { type inet:ipv6-address; description "IPv6 address of the next hop."; } } /* Configuration data */-
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/rt:static-routes" { description "This augment defines the configuration of the 'static' pseudo-protocol with data specific to IPv6 unicast."; container ipv6 { description "Configuration of a 'static' pseudo-protocol instance consists of a list of routes."; list route { key "destination-prefix"; description "A list of static routes."; leaf destination-prefix { type inet:ipv6-prefix; mandatory "true"; description "IPv6 destination prefix."; } leaf description { type string; description "Textual description of the route."; } container next-hop { description "Configuration of next-hop."; uses rt:next-hop-content { augment "next-hop-options/simple-next-hop" { description "Augment 'simple-next-hop' case in IPv6 static routes."; leaf next-hop-address { type inet:ipv6-address; description "IPv6 address of the next hop."; } } augment "next-hop-options/next-hop-list/next-hop-list/" + "next-hop" { description "Augment 'next-hop-list' case in IPv6 static routes."; leaf next-hop-address { type inet:ipv6-address; description "IPv6 address of the next hop."; } } } } } } } } <CODE ENDS> -
9.1. IPv6 Router Advertisements Submodule
-
<CODE BEGINS> file "ietf-ipv6-router-advertisements@2016-11-04.yang"
submodule ietf-ipv6-router-advertisements { yang-version "1.1"; belongs-to ietf-ipv6-unicast-routing { prefix "v6ur"; } import ietf-inet-types { prefix "inet"; } import ietf-interfaces { prefix "if"; } import ietf-ip { prefix "ip"; }-
organization
"IETF NETMOD (NETCONF Data Modeling Language) Working Group";
contact
"WG Web: <https://datatracker.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
-
WG Chair:
-
-
-
Lou Berger
<mailto:lberger@labn.net>
-
-
WG Chair:
-
-
-
Kent Watsen
<mailto:kwatsen@juniper.net>
-
-
Editor: Ladislav Lhotka <mailto:lhotka@nic.cz> Editor: Acee Lindem <mailto:acee@cisco.com>";-
description
"This YANG module augments the 'ietf-ip' module with
-
configuration and state data of IPv6 router advertisements.
-
-
Copyright © 2016 IETF Trust and the persons identified as authors of the code. 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).
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and 'OPTIONAL' in the module text are to be interpreted as described in RFC 2119.
This version of this YANG module is part of RFC 8022; see the RFC itself for full legal notices.";
reference
"RFC 4861: Neighbor Discovery for IP version 6 (IPv6).";
revision 2016-11-04 { description "Initial revision."; reference "RFC 8022: A YANG Data Model for Routing Management"; } /* State data */-
augment "/if:interfaces-state/if:interface/ip:ipv6" {
description "Augment interface state data with parameters of IPv6 router advertisements."; container ipv6-router-advertisements { description "Parameters of IPv6 Router Advertisements."; leaf send-advertisements { type boolean; description "A flag indicating whether or not the router sends periodic Router Advertisements and responds to Router Solicitations."; } leaf max-rtr-adv-interval { type uint16 { range "4..1800"; } units "seconds"; description "The maximum time allowed between sending unsolicited multicast Router Advertisements from the interface."; } leaf min-rtr-adv-interval { type uint16 { range "3..1350"; } units "seconds"; description "The minimum time allowed between sending unsolicited multicast Router Advertisements from the interface."; } leaf managed-flag { type boolean; description "The value that is placed in the 'Managed address configuration' flag field in the Router Advertisement."; } leaf other-config-flag { type boolean; description "The value that is placed in the 'Other configuration' flag field in the Router Advertisement."; } leaf link-mtu { type uint32; description "The value that is placed in MTU options sent by the router. A value of zero indicates that no MTU options are sent."; } leaf reachable-time { type uint32 { range "0..3600000"; } units "milliseconds"; description "The value that is placed in the Reachable Time field in the Router Advertisement messages sent by the router. A value of zero means unspecified (by this router)."; } leaf retrans-timer { type uint32; units "milliseconds"; description "The value that is placed in the Retrans Timer field in the Router Advertisement messages sent by the router. A value of zero means unspecified (by this router)."; } leaf cur-hop-limit { type uint8; description "The value that is placed in the Cur Hop Limit field in the Router Advertisement messages sent by the router. A value of zero means unspecified (by this router)."; } leaf default-lifetime { type uint16 { range "0..9000"; } units "seconds"; description "The value that is placed in the Router Lifetime field of Router Advertisements sent from the interface, in seconds. A value of zero indicates that the router is not to be used as a default router."; } container prefix-list { description "A list of prefixes that are placed in Prefix Information options in Router Advertisement messages sent from the interface. By default, these are all prefixes that the router advertises via routing protocols as being on-link for the interface from which the advertisement is sent."; list prefix { key "prefix-spec"; description "Advertised prefix entry and its parameters."; leaf prefix-spec { type inet:ipv6-prefix; description "IPv6 address prefix."; } leaf valid-lifetime { type uint32; units "seconds"; description "The value that is placed in the Valid Lifetime in the Prefix Information option. The designated value of all 1's (0xffffffff) represents infinity. An implementation SHOULD keep this value constant in consecutive advertisements except when it is explicitly changed in configuration."; } leaf on-link-flag { type boolean; description "The value that is placed in the on-link flag ('L-bit') field in the Prefix Information option."; } leaf preferred-lifetime { type uint32; units "seconds"; description "The value that is placed in the Preferred Lifetime in the Prefix Information option, in seconds. The designated value of all 1's (0xffffffff) represents infinity. An implementation SHOULD keep this value constant in consecutive advertisements except when it is explicitly changed in configuration."; } leaf autonomous-flag { type boolean; description "The value that is placed in the Autonomous Flag field in the Prefix Information option."; } } } } } /* Configuration data */-
augment "/if:interfaces/if:interface/ip:ipv6" {
description "Augment interface configuration with parameters of IPv6 router advertisements."; container ipv6-router-advertisements { description "Configuration of IPv6 Router Advertisements."; leaf send-advertisements { type boolean; default "false"; description "A flag indicating whether or not the router sends periodic Router Advertisements and responds to Router Solicitations."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvSendAdvertisements."; } leaf max-rtr-adv-interval { type uint16 { range "4..1800"; } units "seconds"; default "600"; description "The maximum time allowed between sending unsolicited multicast Router Advertisements from the interface."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - MaxRtrAdvInterval."; } leaf min-rtr-adv-interval { type uint16 { range "3..1350"; } units "seconds"; must ". <= 0.75 * ../max-rtr-adv-interval" { description "The value MUST NOT be greater than 75% of 'max-rtr-adv-interval'.";-
-
}
description-
"The minimum time allowed between sending unsolicited
multicast Router Advertisements from the interface.
The default value to be used operationally if this leaf is not configured is determined as follows:
-
-
- if max-rtr-adv-interval >= 9 seconds, the default value is 0.33 * max-rtr-adv-interval; - otherwise, it is 0.75 * max-rtr-adv-interval."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - MinRtrAdvInterval."; } leaf managed-flag { type boolean; default "false"; description "The value to be placed in the 'Managed address configuration' flag field in the Router Advertisement."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvManagedFlag."; } leaf other-config-flag { type boolean; default "false"; description "The value to be placed in the 'Other configuration' flag field in the Router Advertisement."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvOtherConfigFlag."; } leaf link-mtu { type uint32; default "0"; description "The value to be placed in MTU options sent by the router. A value of zero indicates that no MTU options are sent."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvLinkMTU."; } leaf reachable-time { type uint32 { range "0..3600000"; } units "milliseconds"; default "0"; description "The value to be placed in the Reachable Time field in the Router Advertisement messages sent by the router. A value of zero means unspecified (by this router)."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvReachableTime."; } leaf retrans-timer { type uint32; units "milliseconds"; default "0"; description "The value to be placed in the Retrans Timer field in the Router Advertisement messages sent by the router. A value of zero means unspecified (by this router)."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvRetransTimer."; } leaf cur-hop-limit { type uint8; description "The value to be placed in the Cur Hop Limit field in the Router Advertisement messages sent by the router. A value of zero means unspecified (by this router). If this parameter is not configured, the device SHOULD use the value specified in IANA Assigned Numbers that was in effect at the time of implementation."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvCurHopLimit. IANA: IP Parameters, http://www.iana.org/assignments/ip-parameters"; } leaf default-lifetime { type uint16 { range "0..9000"; } units "seconds"; description "The value to be placed in the Router Lifetime field of-
-
-
Router Advertisements sent from the interface, in seconds. It MUST be either zero or between max-rtr-adv-interval and 9000 seconds. A value of zero indicates that the router is not to be used as a default router. These limits may be overridden by specific documents that describe how IPv6 operates over different link layers.
-
-
If this parameter is not configured, the device SHOULD use a value of 3 * max-rtr-adv-interval."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvDefaultLifeTime."; } container prefix-list { description "Configuration of prefixes to be placed in Prefix Information options in Router Advertisement messages sent from the interface.-
-
-
Prefixes that are advertised by default but do not have their entries in the child 'prefix' list are advertised with the default values of all parameters.
-
-
The link-local prefix SHOULD NOT be included in the list of advertised prefixes."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvPrefixList."; list prefix { key "prefix-spec"; description "Configuration of an advertised prefix entry."; leaf prefix-spec { type inet:ipv6-prefix; description "IPv6 address prefix."; } choice control-adv-prefixes { default "advertise"; description "Either the prefix is explicitly removed from the set of advertised prefixes, or the parameters with which it is advertised are specified (default case)."; leaf no-advertise { type empty; description "The prefix will not be advertised. This can be used for removing the prefix from the default set of advertised prefixes."; } case advertise { leaf valid-lifetime { type uint32; units "seconds"; default "2592000"; description "The value to be placed in the Valid Lifetime in the Prefix Information option. The designated value of all 1's (0xffffffff) represents infinity."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvValidLifetime."; } leaf on-link-flag { type boolean; default "true"; description "The value to be placed in the on-link flag ('L-bit') field in the Prefix Information option."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvOnLinkFlag."; } leaf preferred-lifetime { type uint32; units "seconds"; must ". <= ../valid-lifetime" { description "This value MUST NOT be greater than valid-lifetime."; } default "604800"; description "The value to be placed in the Preferred Lifetime in the Prefix Information option. The designated value of all 1's (0xffffffff) represents infinity."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvPreferredLifetime."; } leaf autonomous-flag { type boolean; default "true"; description "The value to be placed in the Autonomous Flag field in the Prefix Information option."; reference "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - AdvAutonomousFlag."; } } } } } } } } <CODE ENDS> -
10. IANA Considerations
-
This document registers the following namespace URIs in the "IETF XML Registry" [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:ietf-routing Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace.
This document registers the following YANG modules in the "YANG Module Names" registry [RFC6020]:
Name: ietf-routing Namespace: urn:ietf:params:xml:ns:yang:ietf-routing Prefix: rt Reference: RFC 8022 Name: ietf-ipv4-unicast-routing Namespace: urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing Prefix: v4ur Reference: RFC 8022 Name: ietf-ipv6-unicast-routing Namespace: urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing Prefix: v6ur Reference: RFC 8022
This document registers the following YANG submodule in the "YANG Module Names" registry [RFC6020]:
Name: ietf-ipv6-router-advertisements Module: ietf-ipv6-unicast-routing Reference: RFC 8022
11. Security Considerations
-
Configuration and state data conforming to the core routing data model (defined in this document) are designed to be accessed via a management protocol with a secure transport layer, such as NETCONF [RFC6241]. The NETCONF access control model [RFC6536] provides the means to restrict access for particular NETCONF users to a preconfigured subset of all available NETCONF protocol operations and content.
A number of configuration data nodes defined in the YANG modules belonging to the core routing data model are writable/creatable/ deletable (i.e., "config true" in YANG terms, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations to these data nodes, such as "edit-config" in NETCONF, can have negative effects on the network if the protocol operations are not properly protected.
The vulnerable "config true" parameters and subtrees are the following:
/routing/control-plane-protocols/control-plane-protocol: This list specifies the control-plane protocols configured on a device. /routing/ribs/rib: This list specifies the RIBs configured for the device.Unauthorized access to any of these lists can adversely affect the routing subsystem of both the local device and the network. This may lead to network malfunctions, delivery of packets to inappropriate destinations, and other problems.
12. References
12.1. Normative References
-
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <http://www.rfc-editor.org/info/rfc2119>. [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, <http://www.rfc-editor.org/info/rfc3688>. [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, DOI 10.17487/RFC4861, September 2007, <http://www.rfc-editor.org/info/rfc4861>. [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, <http://www.rfc-editor.org/info/rfc6020>. [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, <http://www.rfc-editor.org/info/rfc6241>. [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, <http://www.rfc-editor.org/info/rfc6991>. [RFC7223] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 7223, DOI 10.17487/RFC7223, May 2014, <http://www.rfc-editor.org/info/rfc7223>. [RFC7277] Bjorklund, M., "A YANG Data Model for IP Management", RFC 7277, DOI 10.17487/RFC7277, June 2014, <http://www.rfc-editor.org/info/rfc7277>. [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, <http://www.rfc-editor.org/info/rfc7950>.
12.2. Informative References
-
[RFC6087] Bierman, A., "Guidelines for Authors and Reviewers of YANG Data Model Documents", RFC 6087, DOI 10.17487/RFC6087, January 2011, <http://www.rfc-editor.org/info/rfc6087>. [RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, DOI 10.17487/RFC6536, March 2012, <http://www.rfc-editor.org/info/rfc6536>. [RFC7895] Bierman, A., Bjorklund, M., and K. Watsen, "YANG Module Library", RFC 7895, DOI 10.17487/RFC7895, June 2016, <http://www.rfc-editor.org/info/rfc7895>. [RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG", RFC 7951, DOI 10.17487/RFC7951, August 2016, <http://www.rfc-editor.org/info/rfc7951>.
Appendix A. The Complete Data Trees
-
This appendix presents the complete configuration and state data trees of the core routing data model. See Section 2.2 for an explanation of the symbols used. The data type of every leaf node is shown near the right end of the corresponding line.
A.1. Configuration Data
-
+--rw routing
+--rw router-id? yang:dotted-quad +--rw control-plane-protocols | +--rw control-plane-protocol* [type name] | +--rw type identityref | +--rw name string | +--rw description? string | +--rw static-routes | +--rw v6ur:ipv6 | | +--rw v6ur:route* [destination-prefix] | | +--rw v6ur:destination-prefix inet:ipv6-prefix | | +--rw v6ur:description? string | | +--rw v6ur:next-hop | | +--rw (v6ur:next-hop-options) | | +--:(v6ur:simple-next-hop) | | | +--rw v6ur:outgoing-interface? | | | +--rw v6ur:next-hop-address? | | +--:(v6ur:special-next-hop) | | | +--rw v6ur:special-next-hop? enumeration | | +--:(v6ur:next-hop-list) | | +--rw v6ur:next-hop-list | | +--rw v6ur:next-hop* [index] | | +--rw v6ur:index string | | +--rw v6ur:outgoing-interface? | | +--rw v6ur:next-hop-address? | +--rw v4ur:ipv4 | +--rw v4ur:route* [destination-prefix] | +--rw v4ur:destination-prefix inet:ipv4-prefix | +--rw v4ur:description? string | +--rw v4ur:next-hop | +--rw (v4ur:next-hop-options) | +--:(v4ur:simple-next-hop) | | +--rw v4ur:outgoing-interface? | | +--rw v4ur:next-hop-address? | +--:(v4ur:special-next-hop) | | +--rw v4ur:special-next-hop? enumeration | +--:(v4ur:next-hop-list) | +--rw v4ur:next-hop-list | +--rw v4ur:next-hop* [index] | +--rw v4ur:index string | +--rw v4ur:outgoing-interface? | +--rw v4ur:next-hop-address? +--rw ribs +--rw rib* [name] +--rw name string +--rw address-family? identityref +--rw description? string
A.2. State Data
-
+--ro routing-state | +--ro router-id? yang:dotted-quad | +--ro interfaces | | +--ro interface* if:interface-state-ref | +--ro control-plane-protocols | | +--ro control-plane-protocol* [type name] | | +--ro type identityref | | +--ro name string | +--ro ribs | +--ro rib* [name] | +--ro name string | +--ro address-family identityref | +--ro default-rib? boolean {multiple-ribs}? | +--ro routes | | +--ro route* | | +--ro route-preference? route-preference | | +--ro next-hop | | | +--ro (next-hop-options) | | | +--:(simple-next-hop) | | | | +--ro outgoing-interface? | | | | +--ro v6ur:next-hop-address? | | | | +--ro v4ur:next-hop-address? | | | +--:(special-next-hop) | | | | +--ro special-next-hop? enumeration | | | +--:(next-hop-list) | | | +--ro next-hop-list | | | +--ro next-hop* | | | +--ro outgoing-interface? | | | +--ro v6ur:address? | | | +--ro v4ur:address? | | +--ro source-protocol identityref | | +--ro active? empty | | +--ro last-updated? yang:date-and-time | | +--ro v6ur:destination-prefix? inet:ipv6-prefix | | +--ro v4ur:destination-prefix? inet:ipv4-prefix | +---x active-route | +---w input | | +---w v6ur:destination-address? inet:ipv6-address | | +---w v4ur:destination-address? inet:ipv4-address | +--ro output | +--ro route | +--ro next-hop | | +--ro (next-hop-options) | | +--:(simple-next-hop) | | | +--ro outgoing-interface? | | | +--ro v6ur:next-hop-address? | | | +--ro v4ur:next-hop-address? | | +--:(special-next-hop) | | | +--ro special-next-hop? enumeration | | +--:(next-hop-list) | | +--ro next-hop-list | | +--ro next-hop* | | +--ro outgoing-interface? | | +--ro v6ur:next-hop-address? | | +--ro v4ur:next-hop-address? | +--ro source-protocol identityref | +--ro active? empty | +--ro last-updated? yang:date-and-time | +--ro v6ur:destination-prefix? inet:ipv6-prefix | +--ro v4ur:destination-prefix? inet:ipv4-prefix
Appendix B. Minimum Implementation
-
Some parts and options of the core routing model, such as user- defined RIBs, are intended only for advanced routers. This appendix gives basic non-normative guidelines for implementing a bare minimum of available functions. Such an implementation may be used for hosts or very simple routers.
A minimum implementation does not support the feature "multiple-ribs". This means that a single system-controlled RIB is available for each supported address family -- IPv4, IPv6, or both. These RIBs are also the default RIBs. No user-controlled RIBs are allowed.
In addition to the mandatory instance of the "direct" pseudo- protocol, a minimum implementation should support configuring instance(s) of the "static" pseudo-protocol.
For hosts that are never intended to act as routers, the ability to turn on sending IPv6 router advertisements (Section 5.4) should be removed.
Platforms with severely constrained resources may use deviations for restricting the data model, e.g., limiting the number of "static" control-plane protocol instances.
Appendix C. Example: Adding a New Control-Plane Protocol
-
This appendix demonstrates how the core routing data model can be extended to support a new control-plane protocol. The YANG module "example-rip" shown below is intended as an illustration rather than a real definition of a data model for the Routing Information Protocol (RIP). For the sake of brevity, this module does not obey all the guidelines specified in [RFC6087]. See also Section 5.3.2.
module example-rip { yang-version "1.1"; namespace "http://example.com/rip"; prefix "rip"; import ietf-interfaces { prefix "if"; } import ietf-routing { prefix "rt"; } identity rip { base rt:routing-protocol; description "Identity for the Routing Information Protocol (RIP)."; } typedef rip-metric { type uint8 { range "0..16"; } }-
grouping route-content {
description "This grouping defines RIP-specific route attributes."; leaf metric { type rip-metric; } leaf tag { type uint16; default "0"; description "This leaf may be used to carry additional info, e.g., autonomous system (AS) number."; } } augment "/rt:routing-state/rt:ribs/rt:rib/rt:routes/rt:route" { when "derived-from-or-self(rt:source-protocol, 'rip:rip')" { description "This augment is only valid for a route whose source protocol is RIP."; } description "RIP-specific route attributes."; uses route-content; } augment "/rt:routing-state/rt:ribs/rt:rib/rt:active-route/" + "rt:output/rt:route" { description "RIP-specific route attributes in the output of 'active-route' RPC."; uses route-content; }-
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol" { when "derived-from-or-self(rt:type,'rip:rip')" { description "This augment is only valid for a routing protocol instance of type 'rip'."; } container rip { presence "RIP configuration"; description "RIP instance configuration."; container interfaces { description "Per-interface RIP configuration."; list interface { key "name"; description "RIP is enabled on interfaces that have an entry in this list, unless 'enabled' is set to 'false' for that entry."; leaf name { type if:interface-ref; } leaf enabled { type boolean; default "true"; } leaf metric { type rip-metric; default "1"; } } } leaf update-interval { type uint8 { range "10..60"; } units "seconds"; default "30"; description "Time interval between periodic updates."; } } } } -
Appendix D. Data Tree Example
-
This section contains an example of an instance data tree in the JSON encoding [RFC7951], containing both configuration and state data. The data conforms to a data model that is defined by the following YANG library specification [RFC7895]:
{
-
"ietf-yang-library:modules-state": {
"module-set-id": "c2e1f54169aa7f36e1a6e8d0865d441d3600f9c4", "module": [ { "name": "ietf-routing", "revision": "2016-11-04", "feature": [ "multiple-ribs", "router-id" ], "namespace": "urn:ietf:params:xml:ns:yang:ietf-routing", "conformance-type": "implement" }, { "name": "ietf-ipv4-unicast-routing", "revision": "2016-11-04", "namespace": "urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing", "conformance-type": "implement" }, { "name": "ietf-ipv6-unicast-routing", "revision": "2016-11-04", "namespace": "urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing", "conformance-type": "implement" }, { "name": "ietf-interfaces", "revision": "2014-05-08", "namespace": "urn:ietf:params:xml:ns:yang:ietf-interfaces", "conformance-type": "implement" }, { "name": "ietf-inet-types", "namespace": "urn:ietf:params:xml:ns:yang:ietf-inet-types", "revision": "2013-07-15", "conformance-type": "import" }, { "name": "ietf-yang-types", "namespace": "urn:ietf:params:xml:ns:yang:ietf-yang-types", "revision": "2013-07-15", "conformance-type": "import" }, { "name": "iana-if-type", "namespace": "urn:ietf:params:xml:ns:yang:iana-if-type", "revision": "", "conformance-type": "implement" }, { "name": "ietf-ip", "revision": "2014-06-16", "namespace": "urn:ietf:params:xml:ns:yang:ietf-ip", "conformance-type": "implement" } ] } }A simple network setup as shown in Figure 3 is assumed: router "A" uses static default routes with the "ISP" router as the next hop. IPv6 router advertisements are configured only on the "eth1" interface and disabled on the upstream "eth0" interface.
+-----------------+ | | | Router ISP | | | +--------+--------+ |2001:db8:0:1::2 |192.0.2.2 | | |2001:db8:0:1::1 eth0|192.0.2.1 +--------+--------+ | | | Router A | | | +--------+--------+ eth1|198.51.100.1 |2001:db8:0:2::1 |
Figure 3: Example of Network Configuration
-
The instance data tree could then be as follows:
{
-
"ietf-interfaces:interfaces": {
"interface": [
-
{
"name": "eth0", "type": "iana-if-type:ethernetCsmacd", "description": "Uplink to ISP.", "ietf-ip:ipv4": { "address": [ { "ip": "192.0.2.1", "prefix-length": 24 } ], "forwarding": true }, "ietf-ip:ipv6": { "address": [ { "ip": "2001:0db8:0:1::1", "prefix-length": 64 } ], "forwarding": true, "autoconf": { "create-global-addresses": false } } }, { "name": "eth1", "type": "iana-if-type:ethernetCsmacd", "description": "Interface to the internal network.", "ietf-ip:ipv4": { "address": [ { "ip": "198.51.100.1", "prefix-length": 24 } ], "forwarding": true }, "ietf-ip:ipv6": { "address": [ { "ip": "2001:0db8:0:2::1", "prefix-length": 64 } ], "forwarding": true, "autoconf": { "create-global-addresses": false }, "ietf-ipv6-unicast-routing:ipv6-router-advertisements": { "send-advertisements": true } } } ] }, "ietf-interfaces:interfaces-state": { "interface": [ { "name": "eth0", "type": "iana-if-type:ethernetCsmacd", "phys-address": "00:0C:42:E5:B1:E9", "oper-status": "up", "statistics": { "discontinuity-time": "2015-10-24T17:11:27+02:00" }, "ietf-ip:ipv4": { "forwarding": true, "mtu": 1500, "address": [ { "ip": "192.0.2.1", "prefix-length": 24 } ] }, "ietf-ip:ipv6": { "forwarding": true, "mtu": 1500, "address": [ { "ip": "2001:0db8:0:1::1", "prefix-length": 64 } ], "ietf-ipv6-unicast-routing:ipv6-router-advertisements": { "send-advertisements": false } } }, { "name": "eth1", "type": "iana-if-type:ethernetCsmacd", "phys-address": "00:0C:42:E5:B1:EA", "oper-status": "up", "statistics": { "discontinuity-time": "2015-10-24T17:11:29+02:00" }, "ietf-ip:ipv4": { "forwarding": true, "mtu": 1500, "address": [ { "ip": "198.51.100.1", "prefix-length": 24 } ] }, "ietf-ip:ipv6": { "forwarding": true, "mtu": 1500, "address": [ { "ip": "2001:0db8:0:2::1", "prefix-length": 64 } ], "ietf-ipv6-unicast-routing:ipv6-router-advertisements": { "send-advertisements": true, "prefix-list": { "prefix": [ { "prefix-spec": "2001:db8:0:2::/64" } ] } } } } ] }, "ietf-routing:routing": { "router-id": "192.0.2.1", "control-plane-protocols": { "control-plane-protocol": [ { "type": "ietf-routing:static", "name": "st0", "description": "Static routing is used for the internal network.", "static-routes": { "ietf-ipv4-unicast-routing:ipv4": { "route": [ { "destination-prefix": "0.0.0.0/0", "next-hop": { "next-hop-address": "192.0.2.2" } } ] }, "ietf-ipv6-unicast-routing:ipv6": { "route": [ { "destination-prefix": "::/0", "next-hop": { "next-hop-address": "2001:db8:0:1::2" } } ] } } } ] } }, "ietf-routing:routing-state": { "interfaces": { "interface": [ "eth0", "eth1" ] }, "control-plane-protocols": { "control-plane-protocol": [ { "type": "ietf-routing:static", "name": "st0" } ] }, "ribs": { "rib": [ { "name": "ipv4-master", "address-family": "ietf-ipv4-unicast-routing:ipv4-unicast", "default-rib": true, "routes": { "route": [ { "ietf-ipv4-unicast-routing:destination-prefix": "192.0.2.1/24", "next-hop": { "outgoing-interface": "eth0" }, "route-preference": 0, "source-protocol": "ietf-routing:direct", "last-updated": "2015-10-24T17:11:27+02:00" }, { "ietf-ipv4-unicast-routing:destination-prefix": "198.51.100.0/24", "next-hop": { "outgoing-interface": "eth1" }, "source-protocol": "ietf-routing:direct", "route-preference": 0, "last-updated": "2015-10-24T17:11:27+02:00" }, { "ietf-ipv4-unicast-routing:destination-prefix": "0.0.0.0/0", "source-protocol": "ietf-routing:static", "route-preference": 5, "next-hop": { "ietf-ipv4-unicast-routing:next-hop-address": "192.0.2.2" }, "last-updated": "2015-10-24T18:02:45+02:00" } ] } }, { "name": "ipv6-master", "address-family": "ietf-ipv6-unicast-routing:ipv6-unicast", "default-rib": true, "routes": { "route": [ { "ietf-ipv6-unicast-routing:destination-prefix": "2001:db8:0:1::/64", "next-hop": { "outgoing-interface": "eth0" }, "source-protocol": "ietf-routing:direct", "route-preference": 0, "last-updated": "2015-10-24T17:11:27+02:00" }, { "ietf-ipv6-unicast-routing:destination-prefix": "2001:db8:0:2::/64", "next-hop": { "outgoing-interface": "eth1" }, "source-protocol": "ietf-routing:direct", "route-preference": 0, "last-updated": "2015-10-24T17:11:27+02:00" }, { "ietf-ipv6-unicast-routing:destination-prefix": "::/0", "next-hop": { "ietf-ipv6-unicast-routing:next-hop-address": "2001:db8:0:1::2" }, "source-protocol": "ietf-routing:static", "route-preference": 5, "last-updated": "2015-10-24T18:02:45+02:00" } ] } } ] } } }
Acknowledgments
-
The authors wish to thank Nitin Bahadur, Martin Bjorklund, Dean Bogdanovic, Jeff Haas, Joel Halpern, Wes Hardaker, Sriganesh Kini, David Lamparter, Andrew McGregor, Jan Medved, Xiang Li, Stephane Litkowski, Thomas Morin, Tom Petch, Yingzhen Qu, Bruno Rijsman, Juergen Schoenwaelder, Phil Shafer, Dave Thaler, Yi Yang, Derek Man-Kit Yeung, and Jeffrey Zhang for their helpful comments and suggestions.
Authors' Addresses
-
Ladislav Lhotka
CZ.NICEmail:
lhotka@nic.cz
Acee Lindem
Cisco SystemsEmail:
acee@cisco.com