--- 1/draft-ietf-netmod-routing-cfg-05.txt 2012-11-15 14:14:22.909425534 +0100 +++ 2/draft-ietf-netmod-routing-cfg-06.txt 2012-11-15 14:14:23.009426258 +0100 @@ -1,46 +1,46 @@ NETMOD L. Lhotka Internet-Draft CZ.NIC -Intended status: Standards Track October 4, 2012 -Expires: April 7, 2013 +Intended status: Standards Track November 15, 2012 +Expires: May 19, 2013 - A YANG Data Model for Routing Configuration - draft-ietf-netmod-routing-cfg-05 + A YANG Data Model for Routing Management + draft-ietf-netmod-routing-cfg-06 Abstract This document contains a specification of three YANG modules. Together they form the core routing data model which serves as a - framework for configuring a routing subsystem. It is therefore + 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 individual routing protocols and other related functions. The core routing data model provides common - building blocks for such configurations - router instances, routes, + building blocks for such extensions - router instances, routes, routing tables, routing protocols and route filters. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on April 7, 2013. + This Internet-Draft will expire on May 19, 2013. Copyright Notice Copyright (c) 2012 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 @@ -48,78 +48,81 @@ to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology and Notation . . . . . . . . . . . . . . . . . . . 4 2.1. Glossary of New Terms . . . . . . . . . . . . . . . . . . 4 - 2.2. Prefixes in Data Node Names . . . . . . . . . . . . . . . 5 - 3. Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 4. The Design of the Core Routing Data Model . . . . . . . . . . 7 - 4.1. Router . . . . . . . . . . . . . . . . . . . . . . . . . . 10 + 2.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 5 + 2.3. Prefixes in Data Node Names . . . . . . . . . . . . . . . 5 + 3. Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . 7 + 4. The Design of the Core Routing Data Model . . . . . . . . . . 8 + 4.1. Router . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.1.1. Configuration of IPv6 Router Interfaces . . . . . . . 11 - 4.2. Routes . . . . . . . . . . . . . . . . . . . . . . . . . . 12 - 4.3. Routing Tables . . . . . . . . . . . . . . . . . . . . . . 12 - 4.4. Routing Protocols . . . . . . . . . . . . . . . . . . . . 14 + 4.2. Routes . . . . . . . . . . . . . . . . . . . . . . . . . . 13 + 4.3. Routing Tables . . . . . . . . . . . . . . . . . . . . . . 13 + 4.4. Routing Protocols . . . . . . . . . . . . . . . . . . . . 15 4.4.1. Routing Pseudo-Protocols . . . . . . . . . . . . . . . 15 - 4.4.2. Defining New Routing Protocols . . . . . . . . . . . . 15 - 4.5. Route Filters . . . . . . . . . . . . . . . . . . . . . . 18 - 4.6. RPC Operations . . . . . . . . . . . . . . . . . . . . . . 19 - 5. Interactions with Other YANG Modules . . . . . . . . . . . . . 20 - 5.1. Module "ietf-interfaces" . . . . . . . . . . . . . . . . . 20 - 5.2. Module "ietf-ip" . . . . . . . . . . . . . . . . . . . . . 20 - 6. Routing YANG Module . . . . . . . . . . . . . . . . . . . . . 22 - 7. IPv4 Unicast Routing YANG Module . . . . . . . . . . . . . . . 36 - 8. IPv6 Unicast Routing YANG Module . . . . . . . . . . . . . . . 40 + 4.4.2. Defining New Routing Protocols . . . . . . . . . . . . 16 + 4.5. Route Filters . . . . . . . . . . . . . . . . . . . . . . 17 + 4.6. RPC Operations . . . . . . . . . . . . . . . . . . . . . . 18 + 5. Interactions with Other YANG Modules . . . . . . . . . . . . . 19 + 5.1. Module "ietf-interfaces" . . . . . . . . . . . . . . . . . 19 + 5.2. Module "ietf-ip" . . . . . . . . . . . . . . . . . . . . . 19 + 6. Routing YANG Module . . . . . . . . . . . . . . . . . . . . . 21 + 7. IPv4 Unicast Routing YANG Module . . . . . . . . . . . . . . . 35 + 8. IPv6 Unicast Routing YANG Module . . . . . . . . . . . . . . . 39 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 49 10. Security Considerations . . . . . . . . . . . . . . . . . . . 51 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 52 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 53 12.1. Normative References . . . . . . . . . . . . . . . . . . . 53 12.2. Informative References . . . . . . . . . . . . . . . . . . 53 - Appendix A. Example: Adding a New Routing Protocol . . . . . . . 54 - Appendix B. Example: NETCONF Reply . . . . . . . . . . . . 56 - Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . 61 - C.1. Changes Between Versions -04 and -05 . . . . . . . . . . . 61 - C.2. Changes Between Versions -03 and -04 . . . . . . . . . . . 61 - C.3. Changes Between Versions -02 and -03 . . . . . . . . . . . 62 - C.4. Changes Between Versions -01 and -02 . . . . . . . . . . . 62 - C.5. Changes Between Versions -00 and -01 . . . . . . . . . . . 63 - Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 64 + Appendix A. The Complete Data Tree . . . . . . . . . . . . . . . 54 + Appendix B. Example: Adding a New Routing Protocol . . . . . . . 56 + Appendix C. Example: NETCONF Reply . . . . . . . . . . . . 59 + Appendix D. Change Log . . . . . . . . . . . . . . . . . . . . . 64 + D.1. Changes Between Versions -05 and -06 . . . . . . . . . . . 64 + D.2. Changes Between Versions -04 and -05 . . . . . . . . . . . 64 + D.3. Changes Between Versions -03 and -04 . . . . . . . . . . . 65 + D.4. Changes Between Versions -02 and -03 . . . . . . . . . . . 65 + D.5. Changes Between Versions -01 and -02 . . . . . . . . . . . 66 + D.6. Changes Between Versions -00 and -01 . . . . . . . . . . . 66 + Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 68 1. Introduction This document contains a specification of the following YANG modules: o Module "ietf-routing" provides generic components of a routing data model. o Module "ietf-ipv4-unicast-routing" augments the "ietf-routing" module with additional data specific to IPv4 unicast. o Module "ietf-ipv6-unicast-routing" augments the "ietf-routing" module with additional data specific to IPv6 unicast, including the router configuration variables required by [RFC4861]. These modules together define the so-called core routing data model, which is proposed as a basis for the development of data models for - more sophisticated routing configurations. While these three modules - can be directly used for simple IP devices with static routing, their - main purpose is to provide essential building blocks for more - complicated setups involving multiple routing 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 other IETF working groups. + configuration and management of more sophisticated routing systems. + While these three modules can be directly used for simple IP devices + with static routing, their main purpose is to provide essential + building blocks for more complicated setups involving multiple + routing 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 other IETF working groups. 2. Terminology and Notation 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]: o client @@ -129,41 +132,34 @@ o protocol operation o server The following terms are defined in [RFC6020]: o augment o configuration data - o container - o data model o data node - o data type - - o identity - o mandatory node o module - o operational state data - - o prefix + o state data o RPC operation 2.1. Glossary of New Terms + active route: a route which is actually used for sending packets. If there are multiple candidate routes with a matching destination prefix, then it is up to the routing algorithm to select the active route (or several active routes in the case of multi-path routing). core routing data model: YANG data model resulting from the combination of "ietf-routing", "ietf-ipv4-unicast-routing" and "ietf-ipv6-unicast-routing" modules. @@ -162,38 +158,59 @@ prefix, then it is up to the routing algorithm to select the active route (or several active routes in the case of multi-path routing). core routing data model: YANG data model resulting from the combination of "ietf-routing", "ietf-ipv4-unicast-routing" and "ietf-ipv6-unicast-routing" modules. direct route: a route to a directly connected network. -2.2. Prefixes in Data Node Names +2.2. Tree Diagrams + + 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. The meaning of the symbols in these + diagrams is as follows: + + o Brackets "[" and "]" enclose list keys. + + o Abbreviations before data node names: "rw" means configuration + (read-write) and "ro" state data (read-only). + + o Symbols after data node names: "?" means an optional node and "*" + denotes a "leaf-list". + + o Parentheses enclose choice and case nodes, and case nodes are also + marked with a colon (":"). + + o Ellipsis ("...") stands for contents of subtrees that are not + shown. + +2.3. Prefixes in Data Node Names In this document, names of data nodes, RPC methods and other data model objects are used mostly 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 | +--------+---------------------------+--------------+ | ianaaf | iana-afn-safi | [IANA-IF-AF] | | | | | | if | ietf-interfaces | [YANG-IF] | | | | | | ip | ietf-ip | [YANG-IP] | | | | | - | rip | example-rip | Appendix A | + | rip | example-rip | Appendix B | | | | | | rt | ietf-routing | Section 6 | | | | | | v4ur | ietf-ipv4-unicast-routing | Section 7 | | | | | | v6ur | ietf-ipv6-unicast-routing | Section 8 | | | | | | yang | ietf-yang-types | [RFC6021] | | | | | | inet | ietf-inet-types | [RFC6021] | @@ -225,122 +242,75 @@ flexible enough to facilitate such a mapping and accommodate data models with different logic. 4. The Design of the Core Routing Data Model The core routing data model consists of three YANG modules. 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 combined data hierarchy is shown in - Figure 1, where brackets enclose list keys, "rw" means configuration, - "ro" operational state data, and "?" means optional node. - Parentheses enclose choice and case nodes, and case nodes are also - marked with a colon (":"). + routing, respectively. An abridged view of the data hierarchy is + given in Figure 1. See Appendix A for the complete data tree. +--rw routing +--rw router [name] | +--rw name | +--rw type? | +--rw enabled? | +--rw router-id? | +--rw description? | +--rw main-routing-tables | | +--rw main-routing-table [address-family safi] | | +--rw address-family | | +--rw safi | | +--rw name? | +--rw interfaces | | +--rw interface [name] | | +--rw name | | +--rw v6ur:ipv6-router-advertisements - | | +--rw v6ur:send-advertisements? - | | +--rw v6ur:max-rtr-adv-interval? - | | +--rw v6ur:min-rtr-adv-interval? - | | +--rw v6ur:managed-flag? - | | +--rw v6ur:other-config-flag? - | | +--rw v6ur:link-mtu? - | | +--rw v6ur:reachable-time? - | | +--rw v6ur:retrans-timer? - | | +--rw v6ur:cur-hop-limit? - | | +--rw v6ur:default-lifetime? - | | +--rw v6ur:prefix-list - | | +--rw v6ur:prefix [prefix-spec] - | | +--rw v6ur:prefix-spec - | | +--rw (control-adv-prefixes)? - | | +--:(no-advertise) - | | | +--rw v6ur:no-advertise? - | | +--:(advertise) - | | +--rw v6ur:valid-lifetime? - | | +--rw v6ur:on-link-flag? - | | +--rw v6ur:preferred-lifetime? - | | +--rw v6ur:autonomous-flag? + | | ... | +--rw routing-protocols | +--rw routing-protocol [name] | +--rw name | +--rw description? | +--rw enabled? | +--rw type | +--rw connected-routing-tables - | | +--rw connected-routing-table [name] - | | +--rw name - | | +--rw import-filter? - | | +--rw export-filter? + | | ... | +--rw static-routes - | +--rw v4ur:ipv4 - | | +--rw v4ur:route [id] - | | +--rw v4ur:id - | | +--rw v4ur:description? - | | +--rw v4ur:outgoing-interface? - | | +--rw v4ur:dest-prefix - | | +--rw v4ur:next-hop? - | +--rw v6ur:ipv6 - | +--rw v6ur:route [id] - | +--rw v6ur:id - | +--rw v6ur:description? - | +--rw v6ur:outgoing-interface? - | +--rw v6ur:dest-prefix - | +--rw v6ur:next-hop? + | ... +--rw routing-tables | +--rw routing-table [name] | +--rw name | +--rw address-family | +--rw safi | +--rw description? | +--ro routes | | +--ro route - | | +--ro outgoing-interface? - | | +--ro source-protocol - | | +--ro last-updated? - | | +--ro v4ur:dest-prefix? - | | +--ro v4ur:next-hop? - | | +--ro v6ur:dest-prefix? - | | +--ro v6ur:next-hop? + | | ... | +--rw recipient-routing-tables | +--rw recipient-routing-table [name] - | +--rw name - | +--rw filter? - | - | + | ... +--rw route-filters +--rw route-filter [name] +--rw name +--rw description? +--rw type Figure 1: Data hierarchy of the core routing data model. As can be seen from Figure 1, the core routing data model introduces several generic components of a routing framework: routers, routing - tables containing routes, routing protocols and route filters. The - following subsections describe these components in more detail. + tables containing lists of routes, routing protocols and route + filters. The following subsections describe these components in more + detail. By combining the components in various ways, and possibly augmenting them with appropriate contents defined in other modules, various routing setups can be realized. +--------+ | direct | +---+ +--------------+ +---+ +--------------+ | routes |--->| F |--->| |<---| F |<---| | +--------+ +---+ | main | +---+ | additional | | routing | | routing | @@ -352,21 +322,21 @@ +---+ +---+ +---+ +---+ | F | | F | | F | | F | +---+ +---+ +---+ +---+ ^ | ^ | | v | v +----------+ +----------+ | routing | | routing | | protocol | | protocol | +----------+ +----------+ - Figure 2: Example setup of the routing subsystem + Figure 2: Example setup of a routing system The example in Figure 2 shows a typical (though certainly not the only possible) organization of a more complex routing subsystem for a single address family. Several of its features are worth mentioning: o Along with the main routing table, which must always be present, an additional routing table is configured. o Each routing protocol instance, including the "static" and "direct" pseudo-protocols, is connected to one routing table with @@ -382,42 +352,42 @@ 4.1. Router Each router instance in the core routing data model represents a logical router. The exact semantics of this term is left to implementations. For example, router instances may be completely isolated virtual routers or, alternatively, they may internally share certain information. An implementation MAY support multiple types of logical routers simultaneously. Instances of all router types are organized as - entries of the same flat "router" list. In order to distinguish - router instances belonging to the same type, the "type" leaf is + entries of the same flat "router" list. In order to discriminate + router instances belonging to different types, the "type" leaf is defined as a child of the "router" node. An implementation MAY pose restrictions on allowed router types and on the number of supported instances for each type. For example, a simple router implementation may support only one router instance of the default type "standard-router". Each network layer interface has to be assigned to one or more router instances in order to be able to participate in packet forwarding, routing protocols and other operations of those router instances. The assignment is accomplished by creating a corresponding entry in the list of router interfaces ("rt:interface"). The key of the list entry MUST be the name of a configured network layer interface, i.e., the value of a node /if:interfaces/if:interface/if:name defined in the "ietf-interfaces" module [YANG-IF]. In YANG terms, the list of router interfaces is modeled as the "list" node rather than "leaf-list" in order to allow for adding, via - augmentation, other configuration or operational state data related - to the corresponding router interface. + augmentation, other configuration or state data related to the + corresponding router interface. Implementations MAY specify additional rules for the assignment of interfaces to logical routers. For example, it may be required that the sets of interfaces assigned to different logical routers be disjoint. 4.1.1. Configuration of IPv6 Router Interfaces The module "ietf-ipv6-unicast-routing" augments the definition of the data node "rt:interface" with definitions of the following @@ -436,148 +405,140 @@ o link-mtu, o reachable-time, o retrans-timer, o cur-hop-limit, o default-lifetime, - o prefix-list: a list of prefixes to be advertised. The following - parameters are associated with each prefix in the list: + o 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. The definitions and descriptions of the above parameters can be found in the text of the module "ietf-ipv6-unicast-routing" (Section 8). NOTES: 1. The "IsRouter" flag, which is also required by [RFC4861], is - implemented in the "ietf-ip" module [YANG-IP] (leaf "ip:ip- + implemented in the "ietf-ip" module [YANG-IP] (leaf "ip: forwarding"). 2. 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-unicast-routing" module therefore assumes the former behavior with constant values. 4.2. Routes - Routes are basic units of information in a routing system. The core - routing data model defines only the following minimal set of route - attributes: + Routes are basic elements of information in a routing system. The + core routing data model defines only the following minimal set of + route attributes: o "destination-prefix": IP prefix specifying the set of destination addresses for which the route may be used. This attribute is mandatory. o "next-hop": IP address of an adjacent router or host to which packets with destination addresses belonging to "destination- prefix" should be sent. o "outgoing-interface": network interface that should be used for sending packets with destination addresses belonging to "destination-prefix". The above list of route attributes suffices for a simple static routing configuration. It is expected that future modules defining routing protocols will add other route attributes such as metrics or preferences. Routes and their attributes are used both in configuration data, for - example as manually configured static routes, and in operational - state data, for example as entries in routing tables. + example as manually configured static routes, and in state data, for + example as entries in routing tables. 4.3. Routing Tables Routing tables are lists of routes complemented with administrative data, namely: o "source-protocol": name of the routing protocol from which the route was originally obtained. o "last-updated": the date and time when the route was last updated, or inserted into the routing table. - Each routing table may contain only routes of the same address + Each routing table must contain only routes of the same address family. Address family information consists of two parameters - "address-family" and "safi" (Subsequent Address Family Identifier, SAFI). The permitted values for these two parameters are defined by IANA and represented using YANG enumeration types "ianaaf:address- family" and "ianaaf:subsequent-address-family" [IANA-IF-AF]. In the core routing data model, the "routing-table" node represents - configuration while the descendant list of routes is defined as - operational state data. The contents of route lists are controlled - and manipulated by routing protocol operations which may result in - route additions, removals and modifications. This also includes - manipulations via the "static" and/or "direct" pseudo-protocols, see - Section 4.4.1. - - One or more routing tables MUST be configured for each address family - supported by the server. Each router instance MUST designate, for - every address family that the router instance supports, exactly one - routing table as its main routing table. This is accomplished by - creating an entry in the "main-routing-table" list, which contains a - reference to the routing table that is selected as main. - - Main routing tables serve the following purposes: - - o The router instance always installs direct routes for an address - family to that address family's main routing table. + configuration while the descendant list of routes is defined as state + data. The contents of route lists are controlled and manipulated by + routing protocol operations which may result in route additions, + removals and modifications. This also includes manipulations via the + "static" and/or "direct" pseudo-protocols, see Section 4.4.1. - o By default, a routing protocol SHOULD be connected to the main - routing table of each address family supported by that routing - protocol. See Section 4.4 for further explanation. + In order to activate an address family for use within a router + instance, a client configures an entry of the list /routing/router/ + main-routing-tables/main-routing-table. This entry contains a + reference to a routing table which henceforth serves as the so-called + main routing table for the router instance and address family. + Section 4.4 explains the role of main routing tables. Routing tables are global, which means that a configured routing table may be used by any or all router instances. Server implementations MAY pose restrictions regarding the number of supported routing tables, and rules for configuration and use of routing tables. For example: o A server may support no more than one routing table per address family. o Router instances (of a certain type) may not be allowed to share routing tables, i.e., each routing table is used by no more than one router instance. For servers supporting multiple routing tables per address family, additional tables can be configured by creating new entries in the "routing-table" list, either as a part of factory-default configuration, or by a client's action. - The way how the routing system uses information from routing tables - for actual packet forwarding is outside the scope of this document. + The way how a routing system uses information from routing tables for + actual packet forwarding is outside the scope of this document. Every routing table can serve as a source of routes for other routing tables. To achieve this, one or more recipient routing tables may be specified in the configuration of the source routing table. Optionally, a route filter may be configured for any or all recipient routing tables. Such a route filter then selects and/or manipulates - the routes that are passed on between the source and recipient - routing table. + the routes that are passed between the source and recipient routing + table. A routing table MUST NOT appear among its own recipient routing tables. A recipient routing table also MUST be of the same address family as its source routing table.Consequently, configuration of recipient routing tables makes sense only for servers supporting multiple routing tables per address family. Servers supporting only one routing table per address family MAY therefore decide to remove the container "recipient-routing-tables", together with its contents, from the data model. @@ -585,183 +546,130 @@ The core routing data model provides an open-ended framework for defining multiple routing protocol instances within each router instance. Each routing protocol instance MUST be assigned a type, which is an identity derived from the "rt:routing-protocol" base identity. The core routing data model defines two identities for the direct and static pseudo-protocols (Section 4.4.1). Each routing protocol instance is connected to exactly one routing table for each address family that the routing protocol instance - supports. By default, every routing protocol instance SHOULD be - connected to the main routing table or tables. An implementation MAY - allow any or all routing protocol instances to be configured to use a - different routing table. + supports. Routes learned from the network by a routing protocol are + normally installed into the connected routing table(s) and, + conversely, routes from the connected routing table(s) are normally + injected into the routing protocol. However, routing protocol + implementations MAY specify rules that restrict this exchange of + routes in either direction (or both directions). - Routes learned from the network by a routing protocol are passed to - the connected routing table(s) and vice versa, subject to routing - protocol specific rules and restrictions. + A routing table is connected to a routing protocol instance by + creating a corresponding entry in the "connected-routing-table" list. + If such an entry is not configured for an address family, then the + main routing table MUST be used as the connected routing table for + this address family. In addition, two independent route filters (see Section 4.5) may be - defined for a routing protocol instance to control the exchange of - routes in both directions between the routing protocol instance and - the connected routing table: + configured for each connected routing table to apply client-defined + policies controlling the exchange of routes in both directions + between the routing protocol instance and the connected routing + table: - o import filter controls which routes are passed from a routing + o import filter controls which routes are passed from the routing protocol instance to the connected routing table, o export filter controls which routes the routing protocol instance - may receive from the connected routing table. + receives from the connected routing table. - Note that, for historical reasons, the terms import and export are - used from the viewpoint of a routing table. + Note that the terms import and export are used from the viewpoint of + a routing table. 4.4.1. Routing Pseudo-Protocols 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 neighboring routers. Routes from both "direct" and "static" protocol instances are passed to the connected routing table (subject to route filters, if any), but an exchange in the opposite direction is not allowed. Every router instance MUST implement exactly one instance of the "direct" pseudo-protocol type. The name of this instance MUST also be "direct". 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 5.2. The "direct" pseudoprotocol + interface addresses, see Section 5.2. The "direct" pseudo-protocol MUST always be connected to the main routing tables of all supported - address families. This means that direct routes are always installed - in the main routing tables. However, direct routes MAY be filtered - before they appear in the main routing table. + address families. Unlike other routing protocol types, this + connection cannot be changed in the configuration. Direct routes MAY + be filtered before they appear in the main routing table. 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 per logical router. + Static routes are configured within the "static-routes" container, + see Figure 3. + + +--rw static-routes + +--rw v4ur:ipv4 + | +--rw v4ur:route [id] + | +--rw v4ur:id + | +--rw v4ur:description? + | +--rw v4ur:outgoing-interface? + | +--rw v4ur:dest-prefix + | +--rw v4ur:next-hop? + +--rw v6ur:ipv6 + +--rw v6ur:route [id] + +--rw v6ur:id + +--rw v6ur:description? + +--rw v6ur:outgoing-interface? + +--rw v6ur:dest-prefix + +--rw v6ur:next-hop? + + Figure 3: Structure of "static-routes" subtree. + 4.4.2. Defining New Routing Protocols It is expected that future YANG modules will create data models for additional routing protocol types. Such a new module has to define - the protocol-specific configuration and operational state data, and - it has to fit it into the core routing framework in the following - way: + the protocol-specific configuration and state data, and it has to fit + it into the core routing framework in the following way: o A new identity MUST be defined for the routing protocol and its base identity MUST be set to "rt:routing-protocol", or to an identity derived from "rt:routing-protocol". o Additional route attributes MAY be defined, preferably in one place by means of defining a YANG grouping. The new attributes - have to be inserted as operational state data by augmenting the - definition of the node + have to be inserted as state data by augmenting the definition of + the node + /rt:routing-tables/rt:routing-table/rt:route, - and possibly to other places in the configuration, operational - state data and RPC input or output. + and possibly to other places in the configuration, state data and + RPC input or output. o Per-interface configuration parameters can be added by augmenting the data node "rt:interface" (the list of router interfaces). - o Other configuration parameters and operational state data can be - defined by augmenting the "routing-protocol" data node. + o Other configuration parameters and state data can be defined by + augmenting the "routing-protocol" data node. By using the "when" statement, the augmented per-interface and other configuration parameters specific to the new protocol SHOULD be made conditional and valid only if the value of "rt:type" is equal to the new protocol's identity. It is also RECOMMENDED that the protocol- specific data be encapsulated in appropriately named containers. The above steps are implemented by the example YANG module for the - RIP routing protocol in Appendix A. First, the module defines a new - identity for the RIP protocol: - - identity rip { - base rt:routing-protocol; - description "Identity for the RIP routing protocol."; - } - - New route attributes specific to the RIP protocol ("metric" and - "tag") are defined in a grouping and then added to the route - definitions appearing in "routing-table" and in the output part of - the "active-route" RPC method: - - grouping route-content { - description - "RIP-specific route content."; - leaf metric { - type rip-metric; - } - leaf tag { - type uint16; - default "0"; - description - "This leaf may be used to carry additional info, e.g. AS - number."; - } - } - - augment "/rt:routing/rt:routing-tables/rt:routing-table/" - + "rt:routes/rt:route" { - description - "RIP-specific route components."; - uses route-content; - } - - augment "/rt:active-route/rt:output/rt:route" { - description - "Add RIP-specific route content."; - uses route-content; - } - - Per-interface configuration data are defined by the following - "augment" statement: - - augment "/rt:routing/rt:router/rt:interfaces/rt:interface" { - when "../../rt:routing-protocols/rt:routing-protocol/rt:type = " - + "'rip:rip'"; - container rip { - description - "Per-interface RIP configuration."; - leaf enabled { - type boolean; - default "true"; - } - leaf metric { - type rip-metric; - default "1"; - } - } - } - Finally, global RIP configuration data are integrated into the "rt: - routing-protocol" node by using the following "augment" statement, - which is again valid only for routing protocol instances whose type - is "rip:rip": - - augment "/rt:routing/rt:router/rt:routing-protocols/" - + "rt:routing-protocol" { - when "rt:type = 'rip:rip'"; - container rip { - leaf update-interval { - type uint8 { - range "10..60"; - } - units "seconds"; - default "30"; - description - "Time interval between periodic updates."; - } - } - } + RIP routing protocol in Appendix B. 4.5. Route Filters The core routing data model provides a skeleton for defining route filters that can be used to restrict the set of routes being exchanged between a routing protocol instance and a connected routing table, or between a source and a recipient routing table. Route filters may also manipulate routes, i.e., add, delete, or modify their attributes. @@ -794,26 +701,21 @@ o active-route: query the routing system for the active route(s) that are currently used for sending datagrams to a destination host whose address is passed as an input parameter. o route-count: retrieve the total number of entries in a routing table. 5. Interactions with Other YANG Modules The semantics of the core routing data model also depend on several - configuration parameters that are defined in other YANG modules. The - following subsections describe these interactions. - - In all cases, the relevant parts of the core routing data model are - disabled but MUST NOT be deleted from the configuration by the - server. + configuration parameters that are defined in other YANG modules. 5.1. Module "ietf-interfaces" The following boolean switch is defined in the "ietf-interfaces" YANG module [YANG-IF]: /if:interfaces/if:interface/if:enabled If this switch is set to "false" for a given network layer interface, the device MUST behave exactly as if that interface was @@ -822,54 +724,54 @@ 5.2. Module "ietf-ip" The following boolean switches are defined in the "ietf-ip" YANG module [YANG-IP]: /if:interfaces/if:interface/ip:ipv4/ip:enabled If this switch is set to "false" for a given interface, then all IPv4 routing functions related to that interface MUST be disabled. - /if:interfaces/if:interface/ip:ipv4/ip:ip-forwarding + /if:interfaces/if:interface/ip:ipv4/ip:forwarding If this switch is set to "false" for a given interface, then the forwarding of IPv4 datagrams to and from this interface MUST be disabled. However, the interface may participate in other routing functions, such as routing protocols. /if:interfaces/if:interface/ip:ipv6/ip:enabled If this switch is set to "false" for a given interface, then all IPv6 routing functions related to that interface MUST be disabled. - /if:interfaces/if:interface/ip:ipv6/ip:ip-forwarding + /if:interfaces/if:interface/ip:ipv6/ip:forwarding If this switch is set to "false" for a given interface, then the forwarding of IPv6 datagrams to and from this interface MUST be disabled. However, the interface may participate in other routing functions, such as routing protocols. In addition, the "ietf-ip" module allows for configuring IPv4 and IPv6 addresses and subnet masks on network layer interfaces. Configuration of these parameters on an enabled interface MUST result - in an immediate creation of the corresponding direct route (usually - in the main routing table). Its destination prefix is set according - to the configured IP address and subnet mask, and the interface is - set as the outgoing interface for that route. + in an immediate creation of the corresponding direct route. The + destination prefix of this route is set according to the configured + IP address and subnet mask, and the interface is set as the outgoing + interface for that route. 6. Routing YANG Module RFC Ed.: In this section, replace all occurrences of 'XXXX' with the actual RFC number and all occurrences of the revision date below with the date of RFC publication (and remove this note). - file "ietf-routing@2012-10-04.yang" + file "ietf-routing@2012-11-15.yang" module ietf-routing { namespace "urn:ietf:params:xml:ns:yang:ietf-routing"; prefix "rt"; import ietf-yang-types { prefix "yang"; } @@ -914,25 +816,25 @@ 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). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices. "; - revision 2012-10-04 { + revision 2012-11-15 { description "Initial revision."; reference - "RFC XXXX: A YANG Data Model for Routing Configuration"; + "RFC XXXX: A YANG Data Model for Routing Management"; } /* Identities */ identity router-type { description "Base identity from which router type identities are derived. It is primarily intended for discriminating among different types of logical routers or router virtualization. @@ -971,50 +873,63 @@ identity deny-all-route-filter { base route-filter; description "Route filter that blocks all routes."; } identity allow-all-route-filter { base route-filter; description - "Route filter that permits all routes. - "; + "Route filter that permits all routes."; } /* Type Definitions */ typedef router-ref { type leafref { path "/rt:routing/rt:router/rt:name"; } description "This type is used for leafs that reference a router instance."; } + typedef routing-table-ref { + type leafref { + path "/rt:routing/rt:routing-tables/rt:routing-table/rt:name"; + } + description + "This type is used for leafs that reference a routing table."; + } + typedef route-filter-ref { + type leafref { + path "/rt:routing/rt:route-filters/rt:route-filter/rt:name"; + } + description + "This type is used for leafs that reference a route filter."; + } + /* Groupings */ grouping afn-safi { leaf address-family { type ianaaf:address-family; mandatory "true"; description - "Address family of routes in the routing table."; + "Address family."; } leaf safi { type ianaaf:subsequent-address-family; mandatory "true"; description - "Subsequent address family identifier of routes in the - routing table."; + "Subsequent address family."; } description "This grouping provides two parameters specifying address family and subsequent address family."; } grouping route-content { description "Generic parameters of routes."; leaf outgoing-interface { @@ -1027,83 +942,82 @@ /* RPC Methods */ rpc active-route { description "Return the active route (or multiple routes, in the case of multi-path routing) to a destination address. Parameters 1. 'router-name', - 2. 'destination-address'. If the router instance with 'router-name' doesn't exist, then - this operation shall fail with error-tag 'data-missing' and + this operation SHALL fail with error-tag 'data-missing' and error-app-tag 'router-not-found'. If no active route for 'destination-address' exists, no output - is returned - the server shall send an containing + is returned - the server SHALL send an containing a single element . "; input { leaf router-name { type router-ref; mandatory "true"; description "Name of the router instance whose forwarding information base is being queried."; } container destination-address { uses afn-safi; description "Network layer destination address. - Address family specific modules must augment this + Address family specific modules MUST augment this container with a leaf named 'address'. "; } } output { list route { uses afn-safi; uses route-content; description - "Route contents specific for each address family should be - defined through augmenting."; + "List of active routes. + + Route contents specific for each address family is + expected be defined through augmenting. + "; } } } rpc route-count { description "Return the current number of routes in a routing table. Parameters: 1. 'routing-table-name'. If the routing table with the name specified in - 'routing-table-name' doesn't exist, then this operation shall + 'routing-table-name' doesn't exist, then this operation SHALL fail with error-tag 'data-missing' and error-app-tag 'routing-table-not-found'. "; input { leaf routing-table { - type leafref { - path "/routing/routing-tables/routing-table/name"; - } + type routing-table-ref; mandatory "true"; description "Name of the routing table."; } - } output { leaf number-of-routes { type uint32; mandatory "true"; description "Number of routes in the routing table."; } } } @@ -1108,112 +1022,107 @@ } } /* Data Nodes */ container routing { description "Routing parameters."; list router { key "name"; - unique "router-id"; description - "Each list entry is a container for configuration and - operational state data of a single (logical) router. - - Network layer interfaces assigned to the router must have - their entries in the 'interfaces' list. + "Each list entry is a container for configuration and state + data of a single (logical) router instance. "; leaf name { type string; description "An arbitrary name of the router instance."; } leaf type { type identityref { base router-type; } default "rt:standard-router"; description "This leaf specifies the router type. It is primarily intended as a means for discriminating among different types of logical routers, route virtualization, master-slave arrangements etc., while keeping all such router instances in the same flat list. - - Standard router instances should use the default value. "; } leaf enabled { type boolean; default "true"; description "Enable/disable the router instance. If this parameter is false, the parent router instance is disabled, despite any other configuration that might be present. "; } leaf router-id { type inet:ipv4-address; description "Global router ID in the form of an IPv4 address. - An implementation may select a value if this parameter is + An implementation MAY select a value if this parameter is not configured. - Routing protocols may override this global parameter + Routing protocols MAY override this global parameter inside their configuration. "; } leaf description { type string; description "Textual description of the router."; } container main-routing-tables { description "Main routing tables used by the router instance."; list main-routing-table { - must "address-family=//routing/routing-tables/" + must "address-family=/routing/routing-tables/" + "routing-table[name=current()/name]/" - + "address-family and safi=//routing/routing-tables/" + + "address-family and safi=/routing/routing-tables/" + "routing-table[name=current()/name]/safi" { error-message "Address family mismatch."; description - "The entry's address family must match that of the + "The entry's address family MUST match that of the referenced routing table."; } key "address-family safi"; description "Each list entry specifies the main routing table for one address family. - The main routing table receives direct routes, and all - routing protocols should be connected to the main - routing table(s) by default. + The main routing table is operationally connected to all + routing protocols for which a connected routing table + has not been explicitly configured. + + The 'direct' pseudo-protocol is always connected to the + main routing table. Address families that don't have their entry in this - list must not be used in the rest of the router instance + list MUST NOT be used in the rest of the router instance configuration. "; uses afn-safi; leaf name { - type leafref { - path "/routing/routing-tables/routing-table/name"; - } + type routing-table-ref; description "Name of an existing routing table to be used as the - main routing table for the given router and address - family."; + main routing table for the given router instance and + address family."; } } } container interfaces { description "Router interface parameters."; list interface { key "name"; description "List of network layer interfaces assigned to the router @@ -1262,72 +1171,79 @@ } mandatory "true"; description "Type of the routing protocol - an identity derived from the 'routing-protocol' base identity."; } container connected-routing-tables { description "Container for connected routing tables."; list connected-routing-table { - must "not(//routing/routing-tables/" + must "not(/routing/routing-tables/" + "routing-table[name=current()/" + "preceding-sibling::connected-routing-table/" - + "name]/address-family=//routing/routing-tables/" + + "name]/address-family=/routing/routing-tables/" + "routing-table[name=current()/name]/" - + "address-family and //routing/routing-tables/" + + "address-family and /routing/routing-tables/" + "routing-table[name=current()/" + "preceding-sibling::connected-routing-table/" - + "name]/safi=//routing/routing-tables/" + + "name]/safi=/routing/routing-tables/" + "routing-table[name=current()/name]/safi)" { error-message "Duplicate address family for " - + "connected routing table."; + + "connected routing tables."; + description - "For each AFN/SAFI pair there may be at most one - connected routing table."; + "For each AFN/SAFI pair there MUST NOT be more than + one connected routing table."; } key "name"; description "List of routing tables to which the routing protocol - instance is connected. + instance is connected (at most one routing table per + address family). - If no connected routing table is defined for an - address family, the routing protocol should be - connected by default to the main routing table for - that address family. + If no connected routing table is configured for an + address family, the routing protocol MUST be + operationally connected to the main routing table + for that address family. "; leaf name { - type leafref { - path "/routing/routing-tables/routing-table/name"; + must "../../../type != 'rt:direct' or " + + "../../../../../main-routing-tables/ " + + "main-routing-table/name=." { + error-message "The 'direct' protocol can be " + + "connected only to a main routing " + + "table."; + description + "For the 'direct' pseudo-protocol, the connected + routing table must always be a main routing + table."; } + type routing-table-ref; description "Name of an existing routing table."; } leaf import-filter { - type leafref { - path "/routing/route-filters/route-filter/name"; - } + type route-filter-ref; description "Reference to a route filter that is used for filtering routes passed from this routing protocol instance to the routing table specified by the 'name' sibling node. If this leaf is not present, the behavior is protocol-specific, but typically it means that all routes are accepted. "; } leaf export-filter { - type leafref { - path "/routing/route-filters/route-filter/name"; - } + type route-filter-ref; description "Reference to a route filter that is used for filtering routes passed from the routing table specified by the 'name' sibling node to this routing protocol instance. If this leaf is not present, the behavior is protocol-specific - typically it means that all routes are accepted. @@ -1339,117 +1255,113 @@ } container static-routes { when "../type='rt:static'" { description "This container is only valid for the 'static' routing protocol."; } description "Configuration of 'static' pseudo-protocol. - Address family specific modules should augment this - node with lists of routes. + Address family specific modules augment this node with + their lists of routes. "; } } } } container routing-tables { description "Container for configured routing tables."; list routing-table { key "name"; description "Each entry represents a routing table identified by the - 'name' key. All routes in a routing table must have the - same AFN and SAFI."; + 'name' key. All routes in a routing table MUST belong to + the same address family."; leaf name { type string; description "An arbitrary name of the routing table."; } uses afn-safi; leaf description { type string; description "Textual description of the routing table."; } container routes { config "false"; description - "Current contents of the routing table (operational state - data)."; + "Current contents of the routing table (state data)."; list route { description - "A routing table entry. This data node must augmented - with information specific for routes of each address - family."; + "A routing table entry. This data node MUST be + augmented with information specific for routes of each + address family."; uses route-content; leaf source-protocol { - type leafref { - path "/routing/router/routing-protocols/" - + "routing-protocol/name"; - } + type string; mandatory "true"; description - "The name of an existing routing protocol instance - from which the route comes."; + 'Routing protocol instance from which the route + originated. + + It must be either "direct" or the name of a + configured routing protocol instance. + '; } 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 routing table."; } } } container recipient-routing-tables { description "Container for recipient routing tables."; list recipient-routing-table { must "name != ../../name" { error-message "Source and recipient routing tables " + "are identical."; description - "A routing table must not appear among its recipient + "A routing table MUST NOT appear among its recipient routing tables."; } - must "//routing/routing-tables/" + must "/routing/routing-tables/" + "routing-table[name=current()/name]/" - + "address-family=../../address-family and //routing/" + + "address-family=../../address-family and /routing/" + "routing-tables/routing-table[name=current()/name]/" + "safi=../../safi" { + error-message "Address family mismatch."; description - "Address family of the recipient routing table must + "Address family of the recipient routing table MUST match the source table."; } key "name"; description "List of routing tables that receive routes from this routing table."; leaf name { - type leafref { - path "/routing/routing-tables/routing-table/name"; - } + type routing-table-ref; description "The name of the recipient routing table."; - } leaf filter { - type leafref { - path "/routing/route-filters/route-filter/name"; - } + type route-filter-ref; description "A route filter which is applied to the routes passed - on to the recipient routing table."; + to the recipient routing table."; } } } } } container route-filters { description "Container for configured route filters."; list route-filter { key "name"; @@ -1488,21 +1399,21 @@ } 7. IPv4 Unicast Routing YANG Module RFC Ed.: In this section, replace all occurrences of 'XXXX' with the actual RFC number and all occurrences of the revision date below with the date of RFC publication (and remove this note). - file "ietf-ipv4-unicast-routing@2012-10-04.yang" + file "ietf-ipv4-unicast-routing@2012-11-15.yang" module ietf-ipv4-unicast-routing { namespace "urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing"; prefix "v4ur"; import ietf-routing { prefix "rt"; } @@ -1523,42 +1434,41 @@ WG Chair: Juergen Schoenwaelder Editor: Ladislav Lhotka "; description "This YANG module augments the 'ietf-routing' module with basic - configuration and operational state data for IPv4 unicast - routing. + configuration and state data for IPv4 unicast routing. Copyright (c) 2012 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). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices. "; - revision 2012-10-04 { + revision 2012-11-15 { description "Initial revision."; reference - "RFC XXXX: A YANG Data Model for Routing Configuration"; + "RFC XXXX: A YANG Data Model for Routing Management"; } /* Groupings */ grouping route-content { description "Parameters of IPv4 unicast routes."; leaf dest-prefix { type inet:ipv4-prefix; description @@ -1628,48 +1538,49 @@ } leaf description { type string; description "Textual description of the route."; } uses rt:route-content; uses route-content { refine "dest-prefix" { mandatory "true"; + } } } } } augment "/rt:routing/rt:routing-tables/rt:routing-table/rt:routes/" + "rt:route" { - when "../../rt:address-family='ipv4' and " - + "../../rt:safi='nlri-unicast'" { + when "../../rt:address-family = 'ipv4' and ../../rt:safi = " + + "'nlri-unicast'" { description "This augment is valid only for IPv4 unicast."; } description "This augment defines the content of IPv4 unicast routes."; uses route-content; } } 8. IPv6 Unicast Routing YANG Module RFC Ed.: In this section, replace all occurrences of 'XXXX' with the actual RFC number and all occurrences of the revision date below with the date of RFC publication (and remove this note). - file "ietf-ipv6-unicast-routing@2012-10-04.yang" + file "ietf-ipv6-unicast-routing@2012-11-15.yang" module ietf-ipv6-unicast-routing { namespace "urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing"; prefix "v6ur"; import ietf-routing { prefix "rt"; } @@ -1698,42 +1609,41 @@ WG Chair: Juergen Schoenwaelder Editor: Ladislav Lhotka "; description "This YANG module augments the 'ietf-routing' module with basic - configuration and operational state data for IPv6 unicast - routing. + configuration and state data for IPv6 unicast routing. Copyright (c) 2012 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). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices. "; - revision 2012-10-04 { + revision 2012-11-15 { description "Initial revision."; reference - "RFC XXXX: A YANG Data Model for Routing Configuration"; + "RFC XXXX: A YANG Data Model for Routing Management"; } /* Groupings */ grouping route-content { description "Specific parameters of IPv6 unicast routes."; leaf dest-prefix { type inet:ipv6-prefix; description @@ -1781,231 +1690,276 @@ + "ip:enabled='true'" { description "This augment is only valid for router interfaces with enabled IPv6."; } description "IPv6-specific parameters of router interfaces."; container ipv6-router-advertisements { description "Parameters of IPv6 Router Advertisements."; - reference - "RFC 4861: Neighbor Discovery for IP version 6 (IPv6)."; 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"; } must ". <= 0.75 * ../max-rtr-adv-interval" { description - "The value must be no greater than - 3/4*max-rtr-adv-interval."; + "The value MUST NOT be greater than 75 % of + 'max-rtr-adv-interval'."; } units "seconds"; description "The minimum time allowed between sending unsolicited multicast Router Advertisements from the interface. - Must be no greater than 0.75 * max-rtr-adv-interval. - - Its default value is dynamic: + 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 boolean 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 boolean 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. The value 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. The value zero means unspecified (by this router)."; + reference + "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - + AdvRetransTimer."; } leaf cur-hop-limit { type uint8; default "64"; description "The default value to be placed in the Cur Hop Limit field in the Router Advertisement messages sent by the router. The value should be set to the current diameter of the Internet. The value zero means unspecified (by this router). - The default should be set to the value specified in IANA + The default SHOULD be set to the value specified in IANA Assigned Numbers that was in effect at the time of implementation. "; reference - "IANA: IP Parameters, - http://www.iana.org/assignments/ip-parameters"; + "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. 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. - The default value is dynamic and should be set to 3 * + The default value is dynamic and SHOULD be set to 3 * max-rtr-adv-interval. "; + reference + "RFC 4861: Neighbor Discovery for IP version 6 (IPv6) - + AdvDefaultLifeTime."; } container prefix-list { description "A list of prefixes to be placed in Prefix Information options in Router Advertisement messages sent from the interface. By default, all prefixes that the router advertises via routing protocols as being on-link for the interface from which the advertisement is sent. The link-local prefix - should not be included in the list of advertised prefixes. + 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 "Advertised prefix entry."; leaf prefix-spec { type inet:ipv6-prefix; description "IPv6 address prefix."; } choice control-adv-prefixes { default "advertise"; description "The prefix either may be explicitly removed from the set of advertised prefixes, or parameters with which it is advertised may be specified (default case)."; leaf no-advertise { type empty; description "The prefix will not be advertised. - This may be used for removing the prefix from the + 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, in seconds. 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 larger than + "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, in seconds. 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."; } } } } } } } + augment "/rt:routing/rt:router/rt:routing-protocols/" + "rt:routing-protocol/rt:static-routes" { description "This augment defines the configuration of the 'static' pseudo-protocol with data specific for IPv6 unicast."; + container ipv6 { description "Configuration of a 'static' pseudo-protocol instance consists of a list of routes."; list route { key "id"; ordered-by "user"; description "A user-ordered list of static routes."; leaf id { @@ -2029,31 +1983,30 @@ refine "dest-prefix" { mandatory "true"; } } } } } augment "/rt:routing/rt:routing-tables/rt:routing-table/rt:routes/" + "rt:route" { - when "../../rt:address-family='ipv6' and " - + "../../rt:safi='nlri-unicast'" { + when "../../rt:address-family = 'ipv6' and ../../rt:safi = " + + "'nlri-unicast'" { description "This augment is valid only for IPv6 unicast."; } description "This augment defines the content of IPv6 unicast routes."; uses route-content; } } - 9. IANA Considerations RFC Ed.: In this section, replace all occurrences of 'XXXX' with the actual RFC number (and remove this note). This document registers the following namespace URIs in the IETF XML registry [RFC3688]: @@ -2100,57 +2053,62 @@ ------------------------------------------------------------------- name: ietf-ipv6-unicast-routing namespace: urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing prefix: v6ur reference: RFC XXXX ------------------------------------------------------------------- 10. Security Considerations - The YANG modules defined in this document are designed to be accessed - via the NETCONF protocol [RFC6241]. The lowest NETCONF layer is the - secure transport layer and the mandatory-to-implement secure - transport is SSH [RFC6242]. + Configuration and state data conforming to the core routing data + model (defined in this document) are designed to be accessed via the + NETCONF protocol [RFC6241]. The lowest NETCONF layer is the secure + transport layer and the mandatory-to-implement secure transport is + SSH [RFC6242]. - A number of data nodes defined in the YANG modules 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", can have negative effects on the network if - the protocol operations are not properly protected. + A number of 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", can have negative effects on the network if the protocol + operations are not properly protected. The vulnerable "config true" subtrees and data nodes are the following: - /rt:routing/rt:router/rt:interfaces/rt:interface This list assigns a - network layer interface to a router instance and may also specify + /routing/router/interfaces/interface This list assigns a network + layer interface to a router instance and may also specify interface parameters related to routing. - /rt:routing/rt:router/rt:routing-protocols/rt:routing-protocol This - list specifies the routing protocols configured on a device. + /routing/router/routing-protocols/routing-protocol This list + specifies the routing protocols configured on a device. - /rt:routing/rt:route-filters/rt:route-filter This list specifies the + /routing/route-filters/route-filter This list specifies the configured route filters which represent administrative policies for redistributing and modifying routing information. + /routing/routing-tables/routing-table This list specifies the + configured routing tables used by 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. 11. Acknowledgments The author wishes to thank Martin Bjorklund, Joel Halpern, Wes Hardaker, Andrew McGregor, Thomas Morin, Tom Petch, - Juergen Schoenwaelder, Phil Shafer, Dave Thaler and Yi Yang for their - helpful comments and suggestions. + Bruno Rijsman, Juergen Schoenwaelder, Phil Shafer, Dave Thaler and + Yi Yang for their helpful comments and suggestions. 12. References 12.1. Normative References [IANA-IF-AF] Bjorklund, M., "IANA Interface Type and Address Family YANG Modules", draft-ietf-netmod-iana-if-type-04 (work in progress), June 2012. @@ -2169,46 +2127,139 @@ September 2010. [RFC6021] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6021, September 2010. [RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J., and A. Bierman, "NETCONF Configuration Protocol", RFC 6241, June 2011. [YANG-IF] Bjorklund, M., "A YANG Data Model for Interface - Configuration", draft-ietf-netmod-interfaces-cfg-06 (work - in progress), September 2012. + Configuration", draft-ietf-netmod-interfaces-cfg-08 (work + in progress), November 2012. [YANG-IP] Bjorklund, M., "A YANG Data Model for IP Configuration", - draft-ietf-netmod-ip-cfg-06 (work in progress), - September 2012. + draft-ietf-netmod-ip-cfg-07 (work in progress), + November 2012. 12.2. Informative References [RFC6087] Bierman, A., "Guidelines for Authors and Reviewers of YANG Data Model Documents", RFC 6087, January 2011. [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, June 2011. -Appendix A. Example: Adding a New Routing Protocol +Appendix A. The Complete Data Tree + + This appendix presents the complete data tree of the core routing + data model. See Section 2.2 for an explanation of symbols. Data + type of every leaf node is shown near the right end of the + corresponding line. + + +--rw routing + +--rw router [name] + | +--rw name string + | +--rw type? identityref + | +--rw enabled? boolean + | +--rw router-id? inet:ipv4-address + | +--rw description? string + | +--rw main-routing-tables + | | +--rw main-routing-table [address-family safi] + | | +--rw address-family ianaaf:address-family + | | +--rw safi ianaaf:subsequent-address-family + | | +--rw name? routing-table-ref + | +--rw interfaces + | | +--rw interface [name] + | | +--rw name if:interface-ref + | | +--rw v6ur:ipv6-router-advertisements + | | +--rw v6ur:send-advertisements? boolean + | | +--rw v6ur:max-rtr-adv-interval? uint16 + | | +--rw v6ur:min-rtr-adv-interval? uint16 + | | +--rw v6ur:managed-flag? boolean + | | +--rw v6ur:other-config-flag? boolean + | | +--rw v6ur:link-mtu? uint32 + | | +--rw v6ur:reachable-time? uint32 + | | +--rw v6ur:retrans-timer? uint32 + | | +--rw v6ur:cur-hop-limit? uint8 + | | +--rw v6ur:default-lifetime? uint16 + | | +--rw v6ur:prefix-list + | | +--rw v6ur:prefix [prefix-spec] + | | +--rw v6ur:prefix-spec inet:ipv6-prefix + | | +--rw (control-adv-prefixes)? + | | +--:(no-advertise) + | | | +--rw v6ur:no-advertise? empty + | | +--:(advertise) + | | +--rw v6ur:valid-lifetime? uint32 + | | +--rw v6ur:on-link-flag? boolean + | | +--rw v6ur:preferred-lifetime? uint32 + | | +--rw v6ur:autonomous-flag? boolean + | +--rw routing-protocols + | +--rw routing-protocol [name] + | +--rw name string + | +--rw description? string + | +--rw enabled? boolean + | +--rw type identityref + | +--rw connected-routing-tables + | | +--rw connected-routing-table [name] + | | +--rw name routing-table-ref + | | +--rw import-filter? route-filter-ref + | | +--rw export-filter? route-filter-ref + | +--rw static-routes + | +--rw v4ur:ipv4 + | | +--rw v4ur:route [id] + | | +--rw v4ur:id uint32 + | | +--rw v4ur:description? string + | | +--rw v4ur:outgoing-interface? if:interface-ref + | | +--rw v4ur:dest-prefix inet:ipv4-prefix + | | +--rw v4ur:next-hop? inet:ipv4-address + | +--rw v6ur:ipv6 + | +--rw v6ur:route [id] + | +--rw v6ur:id uint32 + | +--rw v6ur:description? string + | +--rw v6ur:outgoing-interface? if:interface-ref + | +--rw v6ur:dest-prefix inet:ipv6-prefix + | +--rw v6ur:next-hop? inet:ipv6-address + +--rw routing-tables + | +--rw routing-table [name] + | +--rw name string + | +--rw address-family ianaaf:address-family + | +--rw safi ianaaf:subsequent-address-family + | +--rw description? string + | +--ro routes + | | +--ro route + | | +--ro outgoing-interface? if:interface-ref + | | +--ro source-protocol string + | | +--ro last-updated? yang:date-and-time + | | +--ro v4ur:dest-prefix? inet:ipv4-prefix + | | +--ro v4ur:next-hop? inet:ipv4-address + | | +--ro v6ur:dest-prefix? inet:ipv6-prefix + | | +--ro v6ur:next-hop? inet:ipv6-address + | +--rw recipient-routing-tables + | +--rw recipient-routing-table [name] + | +--rw name routing-table-ref + | +--rw filter? route-filter-ref + +--rw route-filters + +--rw route-filter [name] + +--rw name string + +--rw description? string + +--rw type identityref + +Appendix B. Example: Adding a New Routing Protocol This appendix demonstrates how the core routing data model can be extended to support a new routing protocol. The YANG module "example-rip" shown below is intended only as an illustration rather than a real definition of a data model for the RIP routing protocol. For the sake of brevity, we do not follow all the guidelines specified in [RFC6087]. See also Section 4.4.2. - file "example-rip@2012-10-04.yang" - module example-rip { namespace "http://example.com/rip"; prefix "rip"; import ietf-routing { prefix "rt"; } @@ -2219,21 +2270,21 @@ } typedef rip-metric { type uint8 { range "0..16"; } } grouping route-content { description - "RIP-specific route content."; + "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. AS number."; } @@ -2231,86 +2282,96 @@ type rip-metric; } leaf tag { type uint16; default "0"; description "This leaf may be used to carry additional info, e.g. AS number."; } } + augment "/rt:routing/rt:routing-tables/rt:routing-table/rt:routes/" + "rt:route" { + description - "RIP-specific route components."; + "RIP-specific route attributes."; uses route-content; } augment "/rt:active-route/rt:output/rt:route" { description - "Add RIP-specific route content."; + "RIP-specific route attributes."; uses route-content; } augment "/rt:routing/rt:router/rt:interfaces/rt:interface" { when "../../rt:routing-protocols/rt:routing-protocol/rt:type = " - + "'rip:rip'"; + + "'rip:rip'" { + description + 'This augment is only valid for a routing protocol instance + of type "rip".'; + } container rip { description "Per-interface RIP configuration."; leaf enabled { type boolean; default "true"; } leaf metric { type rip-metric; default "1"; } } } augment "/rt:routing/rt:router/rt:routing-protocols/" + "rt:routing-protocol" { - when "rt:type = 'rip:rip'"; + when "rt:type = 'rip:rip'" { + description + 'This augment is only valid for a routing protocol instance + of type "rip".'; + } container rip { + description + "Global RIP configuration."; leaf update-interval { type uint8 { range "10..60"; } units "seconds"; default "30"; description "Time interval between periodic updates."; } } } } - - -Appendix B. Example: NETCONF Reply +Appendix C. Example: NETCONF Reply This section contains a sample reply to the NETCONF message, which could be sent by a server supporting (i.e., advertising them in the NETCONF message) the following YANG modules: o ietf-interfaces [YANG-IF], o ietf-ip [YANG-IP], o ietf-routing (Section 6), o ietf-ipv4-unicast-routing (Section 7), o ietf-ipv6-unicast-routing (Section 8). - We assume a simple network setup as shown in Figure 3: router "A" + We assume a simple network setup as shown in Figure 4: 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 @@ -2321,21 +2382,21 @@ eth0|192.0.2.1 +--------+--------+ | | | Router A | | | +--------+--------+ eth1|198.51.100.1 |2001:db8:0:2::1 | - Figure 3: Example network configuration + Figure 4: Example network configuration A reply to the NETCONF message sent by router "A" would then be as follows: 2001:db8:0:2::/64 - direct - rt:direct - - st0 Static routing is used for the internal network. rt:static 1 0.0.0.0/0 @@ -2439,28 +2497,20 @@ 1 ::/0 2001:db8:0:1::2 - - - ipv4-unicast - - - ipv6-unicast - - ipv4-unicast ipv4 nlri-unicast @@ -2507,25 +2556,47 @@ st0 2012-10-02T18:02:45+01:00 -Appendix C. Change Log +Appendix D. Change Log RFC Editor: remove this section upon publication as an RFC. -C.1. Changes Between Versions -04 and -05 +D.1. Changes Between Versions -05 and -06 + + o Document title changed: "Configuration" was replaced by + "Management". + + o New typedefs "routing-table-ref" and "route-filter-ref". + + o Double slashes "//" were removed from XPath expressions and + replaced with the single "/". + + o Removed uniqueness requirement for "router-id". + + o Complete data tree is now in Appendix A. + + o Changed type of "source-protocol" from "leafref" to "string". + + o Clarified the relationship between routing protocol instances and + connected routing tables. + + o Added a must constraint saying that a routing table connected to + the direct pseudo-protocol must not be a main routing table. + +D.2. Changes Between Versions -04 and -05 o Routing tables are now global, i.e., "routing-tables" is a child of "routing" rather than "router". o "must" statement for "static-routes" changed to "when". o Added "main-routing-tables" containing references to main routing tables for each address family. o Removed the defaults for "address-family" and "safi" and made them @@ -2546,35 +2617,35 @@ o The "direct" pseudo-protocol is always connected to main routing tables. o Entries in the list of connected routing tables renamed from "routing-table" to "connected-routing-table". o Added "must" constraint saying that a routing table must not be its own recipient. -C.2. Changes Between Versions -03 and -04 +D.3. Changes Between Versions -03 and -04 o Changed "error-tag" for both RPC methods from "missing element" to "data-missing". o Removed the decrementing behavior for advertised IPv6 prefix parameters "valid-lifetime" and "preferred-lifetime". o Changed the key of the static route lists from "seqno" to "id" because the routes needn't be sorted. o Added 'must' constraint saying that "preferred-lifetime" must not be greater than "valid-lifetime". -C.3. Changes Between Versions -02 and -03 +D.4. Changes Between Versions -02 and -03 o Module "iana-afn-safi" moved to I-D "iana-if-type". o Removed forwarding table. o RPC "get-route" changed to "active-route". Its output is a list of routes (for multi-path routing). o New RPC "route-count". @@ -2592,45 +2663,45 @@ "ietf-ip". o Added "router-id" leaf. o Specified the names for IPv4/IPv6 unicast main routing tables. o Route parameter "last-modified" changed to "age". o Added container "recipient-routing-tables". -C.4. Changes Between Versions -01 and -02 +D.5. Changes Between Versions -01 and -02 o Added module "ietf-ipv6-unicast-routing". - o The example in Appendix B now uses IP addresses from blocks + o The example in Appendix C now uses IP addresses from blocks reserved for documentation. o Direct routes appear by default in the forwarding table. o Network layer interfaces must be assigned to a router instance. Additional interface configuration may be present. o The "when" statement is only used with "augment", "must" is used elsewhere. o Additional "must" statements were added. o The "route-content" grouping for IPv4 and IPv6 unicast now includes the material from the "ietf-routing" version via "uses rt:route-content". o Explanation of symbols in the tree representation of data model hierarchy. -C.5. Changes Between Versions -00 and -01 +D.6. Changes Between Versions -00 and -01 o AFN/SAFI-independent stuff was moved to the "ietf-routing" module. o Typedefs for AFN and SAFI were placed in a separate "iana-afn- safi" module. o Names of some data nodes were changed, in particular "routing- process" is now "router". o The restriction of a single AFN/SAFI per router was lifted.