NETMOD L. Lhotka Internet-Draft CZ.NIC Intended status: Standards Track May 25, 2012 Expires: November 26, 2012 A YANG Data Model for Routing Configuration draft-ietf-netmod-routing-cfg-03 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 expected that this module 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, 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 November 26, 2012. 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 carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must Lhotka Expires November 26, 2012 [Page 1] Internet-Draft YANG Routing Configuration May 2012 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 4.1.1. Configuration of IPv6 Router Interfaces . . . . . . . 10 4.2. Route . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.3. Routing Tables . . . . . . . . . . . . . . . . . . . . . . 12 4.4. Routing Protocols . . . . . . . . . . . . . . . . . . . . 13 4.4.1. Routing Pseudo-Protocols . . . . . . . . . . . . . . . 14 4.4.2. Defining New Routing Protocols . . . . . . . . . . . . 14 4.5. Route Filters . . . . . . . . . . . . . . . . . . . . . . 17 4.6. RPC Operations . . . . . . . . . . . . . . . . . . . . . . 18 4.6.1. Operation "active-route" . . . . . . . . . . . . . . . 18 4.6.2. Operation "route-count" . . . . . . . . . . . . . . . 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 . . . . . . . . . . . . . . . 34 8. IPv6 Unicast Routing YANG Module . . . . . . . . . . . . . . . 38 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 47 10. Security Considerations . . . . . . . . . . . . . . . . . . . 49 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 50 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 51 12.1. Normative References . . . . . . . . . . . . . . . . . . . 51 12.2. Informative References . . . . . . . . . . . . . . . . . . 51 Appendix A. Example: Adding a New Routing Protocol . . . . . . . 52 Appendix B. Example: Reply to the NETCONF Message . . . . . 55 Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . 60 C.1. Changes Between Versions -02 and -03 . . . . . . . . . . . 60 C.2. Changes Between Versions -01 and -02 . . . . . . . . . . . 60 C.3. Changes Between Versions -00 and -01 . . . . . . . . . . . 61 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 62 Lhotka Expires November 26, 2012 [Page 2] Internet-Draft YANG Routing Configuration May 2012 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, advanced functions such as route filtering or policy routing etc. To this end, it is expected that the core routing data model will be augmented by numerous modules developed by other IETF working groups. Lhotka Expires November 26, 2012 [Page 3] Internet-Draft YANG Routing Configuration May 2012 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 o message 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 RPC operation 2.1. Glossary of New Terms Lhotka Expires November 26, 2012 [Page 4] Internet-Draft YANG Routing Configuration May 2012 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. direct route: a route to a directly connected network. 2.2. Prefixes in Data Node Names In this document, names of data nodes 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 | | | | | | 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] | +--------+---------------------------+--------------+ Table 1: Prefixes and corresponding YANG modules Lhotka Expires November 26, 2012 [Page 5] Internet-Draft YANG Routing Configuration May 2012 3. Objectives The initial design of the core routing data model was driven by the following objectives: o 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). o Simple routing setups, such as static routing, should be configurable in a simple way, ideally without any need to develop additional YANG modules. o On the other hand, the core routing framework must allow for complicated setups involving multiple routing tables and multiple routing protocols, as well as controlled redistributions of routing information. o Device vendors will want to map the data models built on this generic framework to their proprietary data models and configuration interfaces. Therefore, the framework should be flexible enough to facilitate such a mapping and accommodate data models with different logic. Lhotka Expires November 26, 2012 [Page 6] Internet-Draft YANG Routing Configuration May 2012 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 (":"). +--rw routing +--rw router [name] | +--rw name | +--rw router-id? | +--rw description? | +--rw enabled? | +--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? Lhotka Expires November 26, 2012 [Page 7] Internet-Draft YANG Routing Configuration May 2012 | | +--rw type | | +--rw connected-routing-tables | | | +--rw routing-table [name] | | | +--rw name | | | +--rw import-filter? | | | +--rw export-filter? | | +--rw static-routes | | +--rw v4ur:ipv4 | | | +--rw v4ur:route [seqno] | | | +--rw v4ur:seqno | | | +--rw v4ur:description? | | | +--rw v4ur:outgoing-interface? | | | +--rw v4ur:dest-prefix | | | +--rw v4ur:next-hop? | | +--rw v6ur:ipv6 | | +--rw v6ur:route [seqno] | | +--rw v6ur:seqno | | +--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 source-protocol | | +--ro age | | +--ro v4ur:outgoing-interface? | | +--ro v4ur:dest-prefix? | | +--ro v4ur:next-hop? | | +--ro v6ur:outgoing-interface? | | +--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. Lhotka Expires November 26, 2012 [Page 8] Internet-Draft YANG Routing Configuration May 2012 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. 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 | +--------+ +---+ | table | +---+ | table | | static |--->| F |--->| |--->| F |--->| | | routes | +---+ +--------------+ +---+ +--------------+ +--------+ ^ | ^ | | v | v +---+ +---+ +---+ +---+ | F | | F | | F | | F | +---+ +---+ +---+ +---+ ^ | ^ | | v | v +----------+ +----------+ | routing | | routing | | protocol | | protocol | +----------+ +----------+ Figure 2: Example setup of the routing subsystem 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 which it can exchange routes (in both directions, except for the "static" and "direct" pseudo-protocols). o Routing tables may also be connected to each other and exchange routes in either direction (or both). o Route exchanges along all connections may be controlled by means of route filters, denoted by "F" in Figure 2. Lhotka Expires November 26, 2012 [Page 9] Internet-Draft YANG Routing Configuration May 2012 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. Network layer interfaces must be assigned to a router instance in order to be able to participate in packet forwarding, routing protocols and other operations of that router instance. 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]. 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. Apart from the key, each entry of the "rt:interface" list MAY contain other configuration or operational state data related to the corresponding router interface. 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 configuration variables as required by [RFC4861], sec. 6.2.1: o send-advertisements, o max-rtr-adv-interval, o min-rtr-adv-interval, o managed-flag, o other-config-flag, o link-mtu, o reachable-time, o retrans-timer, Lhotka Expires November 26, 2012 [Page 10] Internet-Draft YANG Routing Configuration May 2012 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: * 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). NOTE: The "IsRouter" flag, which is also required by [RFC4861], is implemented by the "ietf-ip" module [YANG-IP] (leaf "ip:ip- forwarding"). 4.2. Route Routes are basic units 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 the 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 should suffice 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. Lhotka Expires November 26, 2012 [Page 11] Internet-Draft YANG Routing Configuration May 2012 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 "age": number of seconds since the route was created or last updated. Each routing table may only contain 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 translated into 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 routing table MUST be present for each router instance and each address family supported by that router instance. It is the so- called main routing table to which all routing protocol instances supporting the given address family SHOULD be connected by default. For the two address families that are part of the core routing data model, the names of the main routing tables SHOULD be as follows: o "main-ipv4-unicast" for IPv4 unicast, o "main-ipv6-unicast" for IPv6 unicast. Additional routing tables MAY 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 naming scheme for additional routing tables, as well as restrictions on the number and configurability of routing tables are implementation-specific. The way how the routing system uses information from routing tables is outside the scope of this document. Typically, implementations will either use a forwarding table, or perform a direct look-up in Lhotka Expires November 26, 2012 [Page 12] Internet-Draft YANG Routing Configuration May 2012 the main routing table in conjunction with a route cache. 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. In addition, a route filter may be configured for each recipient routing table, which selects and/or manipulates the routes that are passed on between the source and recipient routing table. 4.4. Routing Protocols The core routing data model provides an open-ended framework for defining multiple routing protocol instances. Each of them is identified by a name, which MUST be unique within a router instance. Each protocol MUST be assigned a type, which MUST be 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. Routes learned from the network by a routing protocol are passed to the connected routing table(s) and vice versa - routes appearing in a routing table are passed to all routing protocols connected to the table (except "direct" and "static" pseudo-protocols) and may be advertised by that protocol to the network. 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: o import filter controls which routes are passed from a routing protocol instance to the routing table, o export filter controls which routes the routing protocol instance may receive from the connected routing table. Note that, for historical reasons, the terms import and export are used from the viewpoint of a routing table. Lhotka Expires November 26, 2012 [Page 13] Internet-Draft YANG Routing Configuration May 2012 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 contain 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. Direct routes SHOULD by default appear in the main routing table for each configured address family. However, using the framework defined in this document, the target routing table for direct routes MAY be changed by connecting the "direct" protocol instance to a non-default routing table. Direct routes can also be filtered before they appear in the 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 implementation will have exactly one instance per logical router. 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 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 "rt:route" inside "rt:routing-table", and possibly to other places in the configuration, operational 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). Lhotka Expires November 26, 2012 [Page 14] Internet-Draft YANG Routing Configuration May 2012 o Other configuration parameters and operational state data can be defined by augmenting the "routing-protocol" data node. By using the "when" statement, this augment SHOULD be made conditional and valid only if the value of the "rt:type" child leaf equals to the new protocol's identity. It is RECOMMENDED that both per-interface and other configuration data specific to the new protocol be encapsulated in an appropriately named container. 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: Lhotka Expires November 26, 2012 [Page 15] Internet-Draft YANG Routing Configuration May 2012 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:router/rt:routing-tables/rt:routing-table/" + "rt:routes/rt:route" { when "../../../../rt:routing-protocols/" + "rt:routing-protocol[rt:name=current()/rt:source-protocol]/" + "rt:type='rip:rip'" { description "This augment is only valid if the source protocol from which the route originated is RIP."; } 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: Lhotka Expires November 26, 2012 [Page 16] Internet-Draft YANG Routing Configuration May 2012 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 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."; } } } 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. Route filters are global, which means that a configured route filter Lhotka Expires November 26, 2012 [Page 17] Internet-Draft YANG Routing Configuration May 2012 may be used by any or all router instances. By itself, the route filtering framework defined in this document allows for applying only the extreme routing policies which are represented by the following pre-defined route filter types: o "deny-all-route-filter": all routes are blocked, o "allow-all-route-filter": all routes are permitted. It is expected that real route filtering frameworks will be developed separately. Each route filter is identified by a name which MUST be unique within a router instance. Its type MUST be specified by the "type" identity reference - this opens the space for multiple route filtering framework implementations. The default value for the route filter type is the identity "deny-all-route-filter". 4.6. RPC Operations The "ietf-routing" module defines two RPC operations: o active-route, o route-count. Their parameters and semantics are described in the following subsections. 4.6.1. Operation "active-route" Description: Retrieve one or more active routes from the forwarding information base (FIB) of a router instance, i.e., the route(s) that are currently used by that router instance for sending datagrams to the destination whose address is provided as an input parameter. Parameters: router-name: Name of the router instance whose FIB is to be queried. destination-address: Network layer destination address for which the active routes are requested. Lhotka Expires November 26, 2012 [Page 18] Internet-Draft YANG Routing Configuration May 2012 Positive Response: One or more "route" elements containing the active route(s). Negative Response: If the logical router is not found, the server sends an "rpc- error" message with "error-tag" set to "missing-element", and "error-app-tag" set to "router-not-found". If no route exists for the given destination address, the server sends an "rpc-error" message with "error-tag" set to "data- missing" and "error-app-tag" set to "no-route". 4.6.2. Operation "route-count" Description: Retrieve the total number of routes in a routing table. Parameters: router-name: Name of the logical router containing the routing table. routing-table: Name of the routing table. Positive Response: Element "number-of-routes" containing the requested nonnegative number. Negative Response: If the logical router or the routing table is not found, the server sends an "rpc-error" message with "error-tag" set to "missing-element", and "error-app-tag" set to "router-not- found" or "routing-table-not-found", respectively. Lhotka Expires November 26, 2012 [Page 19] Internet-Draft YANG Routing Configuration May 2012 5. Interactions with Other YANG Modules The semantics of the core routing data model also depends on several configuration parameters that are defined in other YANG modules. The following subsections describe these interactions. 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 not assigned to any logical router at all. 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 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 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. Configuration of these parameters Lhotka Expires November 26, 2012 [Page 20] Internet-Draft YANG Routing Configuration May 2012 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. Lhotka Expires November 26, 2012 [Page 21] Internet-Draft YANG Routing Configuration May 2012 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@2012-05-24.yang" module ietf-routing { namespace "urn:ietf:params:xml:ns:yang:ietf-routing"; prefix "rt"; import ietf-inet-types { prefix "inet"; } import ietf-interfaces { prefix "if"; } import iana-afn-safi { prefix "ianaaf"; } organization "IETF NETMOD (NETCONF Data Modeling Language) Working Group"; contact "WG Web: WG List: WG Chair: David Kessens WG Chair: Juergen Schoenwaelder Editor: Ladislav Lhotka "; description "This YANG module defines essential components that may be used for configuring a routing subsystem. Copyright (c) 2012 IETF Trust and the persons identified as Lhotka Expires November 26, 2012 [Page 22] Internet-Draft YANG Routing Configuration May 2012 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 2012-05-24 { description "Initial revision."; reference "RFC XXXX: A YANG Data Model for Routing Configuration"; } /* Identities */ identity routing-protocol { description "Base identity from which routing protocol identities are derived."; } identity direct { base routing-protocol; description "Routing pseudo-protocol which provides routes to directly connected networks."; } identity static { base routing-protocol; description "Static routing pseudo-protocol."; } identity route-filter { description "Base identity from which all route filters are derived."; } identity deny-all-route-filter { base route-filter; Lhotka Expires November 26, 2012 [Page 23] Internet-Draft YANG Routing Configuration May 2012 description "Route filter that blocks all routes."; } identity allow-all-route-filter { base route-filter; description "Route filter that permits all routes. Note that use of this filter is equivalent to no filter at all. "; } /* 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."; } /* Groupings */ grouping afn-safi { leaf address-family { type ianaaf:address-family; default "ipv4"; description "Address family of routes in the routing table."; } leaf safi { type ianaaf:subsequent-address-family; default "nlri-unicast"; description "Subsequent address family identifier of routes in the routing table."; } description "This grouping provides two parameters specifying address family and subsequent address family."; } grouping route-content { description Lhotka Expires November 26, 2012 [Page 24] Internet-Draft YANG Routing Configuration May 2012 "Generic parameters of routes. A module for an address family should define a specific version of this grouping containing 'uses rt:route-content'. "; leaf outgoing-interface { type if:interface-ref; description "Outgoing interface."; } } /* 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 logical router with 'router-name' doesn't exist, then this operation will fail with error-tag 'missing-element' and error-app-tag 'router-not-found'. If there is no active route for 'destination-address', then this operation will fail with error-tag 'data-missing' and error-app-tag 'no-route'. "; 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. AFN/SAFI-specific modules must augment this container with a leaf named 'address'. Lhotka Expires November 26, 2012 [Page 25] Internet-Draft YANG Routing Configuration May 2012 "; } } output { list route { min-elements "1"; uses afn-safi; uses route-content; description "Route contents specific for each address family should be defined through augmenting."; } } } rpc route-count { description "Return the current number of routes in a routing table. Parameters: 1. 'router-name', 2. 'routing-table-name'. If the logical router with 'router-name' doesn't exist, then this operation will fail with error-tag 'missing-element' and error-app-tag 'router-not-found'. If the routing table with 'routing-table-name' doesn't exist, then this operation will fail with error-tag 'missing-element' and error-app-tag 'routing-table-not-found'. "; input { leaf router-name { type router-ref; mandatory "true"; description "Name of the router instance containing the routing table."; } leaf routing-table { type leafref { path "/routing/router/routing-tables/routing-table/name"; } mandatory "true"; description "Name of the routing table."; Lhotka Expires November 26, 2012 [Page 26] Internet-Draft YANG Routing Configuration May 2012 } } output { leaf number-of-routes { type uint32; mandatory "true"; description "Number of routes in the routing table."; } } } /* 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. '; leaf name { type string; description "The unique router name."; } 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 not configured. Routing protocols may override this global parameter inside their configuration. "; } leaf description { type string; description "Textual description of the router."; Lhotka Expires November 26, 2012 [Page 27] Internet-Draft YANG Routing Configuration May 2012 } leaf enabled { type boolean; default "true"; description "Enable the router. The default value is 'true'. If this parameter is false, the parent router instance is disabled, despite any other configuration that might be present. "; } container interfaces { description "Router interface parameters."; list interface { key "name"; description "List of network layer interfaces assigned to the router instance."; leaf name { type if:interface-ref; description "A reference to the name of a configured network layer interface."; } } } container routing-protocols { description "Container for the list of configured routing protocol instances."; list routing-protocol { key "name"; description "An instance of a routing protocol."; leaf name { type string; description "The name of the routing protocol instance."; } leaf description { type string; description "Textual description of the routing protocol instance."; } leaf type { Lhotka Expires November 26, 2012 [Page 28] Internet-Draft YANG Routing Configuration May 2012 type identityref { base routing-protocol; } 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 routing-table { must "not(../../../../routing-tables/" + "routing-table[rt:name=current()/" + "preceding-sibling::routing-table/name]/" + "address-family=../../../../routing-tables/" + "routing-table[rt:name=current()/name]/" + "address-family and ../../../../routing-tables/" + "routing-table[rt:name=current()/" + "preceding-sibling::routing-table/name]/safi=../" + "../../../routing-tables/" + "routing-table[rt:name=current()/name]/safi)" { error-message "Each routing protocol may have no " + "more than one connected routing " + "table for each AFN and SAFI."; description "For each AFN/SAFI pair there may be at most one connected routing table."; } key "name"; description "List of routing tables to which the routing protocol instance is connected. 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. "; leaf name { type leafref { path "../../../../../routing-tables/routing-table/" + "name"; } description "Reference to an existing routing table."; } leaf import-filter { Lhotka Expires November 26, 2012 [Page 29] Internet-Draft YANG Routing Configuration May 2012 type leafref { path "/routing/route-filters/route-filter/name"; } 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"; } 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, except for the 'direct' and 'static' pseudo-protocols which accept no routes from any routing table."; } } } container static-routes { must "../type='rt:static'" { error-message "Static routes may be configured only " + "for 'static' routing protocol."; description "This container is only valid for the 'static' routing protocol."; } description "Configuration of 'static' pseudo-protocol."; } } } container routing-tables { description "Container for configured routing tables."; list routing-table { key "name"; description "Each entry represents a routing table identified by the Lhotka Expires November 26, 2012 [Page 30] Internet-Draft YANG Routing Configuration May 2012 'name' key. All routes in a routing table must have the same AFN and SAFI."; leaf name { type string; description "The 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)."; list route { description "A routing table entry. This data node must 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"; } mandatory "true"; description "The name of the routing protocol instance from which the route comes. This routing protocol must be configured (automatically or manually) in the device."; } leaf age { type uint32; units "seconds"; mandatory "true"; description "The number of seconds since the parent route was created or last updated."; } } } container recipient-routing-tables { description Lhotka Expires November 26, 2012 [Page 31] Internet-Draft YANG Routing Configuration May 2012 "Container for recipient routing tables."; list recipient-routing-table { key "name"; description "A list of routing tables that receive routes from this routing table."; leaf name { type leafref { path "/routing/router/routing-tables/" + "routing-table/name"; } description "The name of the recipient routing table."; } leaf filter { type leafref { path "/routing/route-filters/route-filter/name"; } description "A route filter which is applied to the routes passed on to the recipient routing table."; } } } } } } container route-filters { description "Container for configured route filters."; list route-filter { key "name"; description "Route filters are used for filtering and/or manipulating routes that are passed between a routing protocol and a routing table or vice versa, or between two routing tables. It is expected that other modules augment this list with contents specific for a particular route filter type."; leaf name { type string; description "The name of the route filter."; } leaf description { type string; description "Textual description of the route filter."; Lhotka Expires November 26, 2012 [Page 32] Internet-Draft YANG Routing Configuration May 2012 } leaf type { type identityref { base route-filter; } default "rt:deny-all-route-filter"; description "Type of the route-filter - an identity derived from the 'route-filter' base identity. The default value represents an all-blocking filter."; } } } } } Lhotka Expires November 26, 2012 [Page 33] Internet-Draft YANG Routing Configuration May 2012 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@2012-05-25.yang" module ietf-ipv4-unicast-routing { 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: WG List: WG Chair: David Kessens 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. Every implementation must preconfigure a routing table with the name 'main-ipv4-unicast', which is the main routing table for IPv4 unicast. Lhotka Expires November 26, 2012 [Page 34] Internet-Draft YANG Routing Configuration May 2012 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 2012-05-24 { description "Initial revision."; reference "RFC XXXX: A YANG Data Model for Routing Configuration"; } /* Groupings */ grouping route-content { description "Parameters of IPv4 unicast routes."; leaf dest-prefix { type inet:ipv4-prefix; description "IPv4 destination prefix."; } leaf next-hop { type inet:ipv4-address; description "IPv4 address of the next hop."; } } /* RPC Methods */ augment "/rt:active-route/rt:input/rt:destination-address" { when "address-family='ipv4' and safi='nlri-unicast'" { description "This augment is valid only for IPv4 unicast."; } description "The 'address' leaf augments the 'rt:destination-address' parameter of the 'rt:active-route' operation."; Lhotka Expires November 26, 2012 [Page 35] Internet-Draft YANG Routing Configuration May 2012 leaf address { type inet:ipv4-address; description "IPv4 destination address."; } } augment "/rt:active-route/rt:output/rt:route" { when "address-family='ipv4' and safi='nlri-unicast'" { description "This augment is valid only for IPv4 unicast."; } description "Contents of the reply to 'rt:active-route' operation."; uses route-content; } /* Data nodes */ 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 IPv4 unicast."; container ipv4 { description "Configuration of a 'static' pseudo-protocol instance consists of a list of routes."; list route { key "seqno"; ordered-by "user"; description "A user-ordered list of static routes."; leaf seqno { type uint32 { range "1..max"; } description "Sequential number of the route."; } leaf description { type string; description "Textual description of the route."; } uses rt:route-content; uses route-content { refine "dest-prefix" { Lhotka Expires November 26, 2012 [Page 36] Internet-Draft YANG Routing Configuration May 2012 mandatory "true"; } } } } } augment "/rt:routing/rt:router/rt:routing-tables/rt:routing-table/" + "rt:routes/rt:route" { 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; } } Lhotka Expires November 26, 2012 [Page 37] Internet-Draft YANG Routing Configuration May 2012 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@2012-05-24.yang" module ietf-ipv6-unicast-routing { namespace "urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing"; prefix "v6ur"; import ietf-routing { prefix "rt"; } 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: WG List: WG Chair: David Kessens WG Chair: Juergen Schoenwaelder Editor: Ladislav Lhotka "; description Lhotka Expires November 26, 2012 [Page 38] Internet-Draft YANG Routing Configuration May 2012 "This YANG module augments the 'ietf-routing' module with basic configuration and operational state data for IPv6 unicast routing. Every implementation must preconfigure a routing table with the name 'main-ipv6-unicast', which is the main routing table for IPv6 unicast. 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 2012-05-24 { description "Initial revision."; reference "RFC XXXX: A YANG Data Model for Routing Configuration"; } /* Groupings */ grouping route-content { description "Specific parameters of IPv6 unicast routes."; leaf dest-prefix { type inet:ipv6-prefix; description "IPv6 destination prefix."; } leaf next-hop { type inet:ipv6-address; description "IPv6 address of the next hop."; } } /* RPC Methods */ Lhotka Expires November 26, 2012 [Page 39] Internet-Draft YANG Routing Configuration May 2012 augment "/rt:active-route/rt:input/rt:destination-address" { when "address-family='ipv6' and safi='nlri-unicast'" { description "This augment is valid only for IPv6 unicast."; } description "The 'address' leaf augments the 'rt:destination-address' parameter of the 'rt:active-route' operation."; leaf address { type inet:ipv6-address; description "IPv6 destination address."; } } augment "/rt:active-route/rt:output/rt:route" { when "address-family='ipv6' and safi='nlri-unicast'" { description "This augment is valid only for IPv6 unicast."; } description "Contents of the reply to 'rt:active-route' operation."; uses route-content; } /* Data nodes */ augment "/rt:routing/rt:router/rt:interfaces/rt:interface" { when "/if:interfaces/if:interface[name=current()/name] " + "/ip:ipv6/ip:enabled='true'" { description "This augment is only valid for router interfaces with enabled IPv6. NOTE: Parameter 'is-router' is not included, it is expected that it will be implemented by the 'ietf-ip' module. "; } 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). RFC 4862: IPv6 Stateless Address Autoconfiguration. "; Lhotka Expires November 26, 2012 [Page 40] Internet-Draft YANG Routing Configuration May 2012 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."; } 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."; } 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. Must be no greater than 0.75 * max-rtr-adv-interval. Its default value is dynamic: - 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. "; } 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."; } leaf other-config-flag { type boolean; default "false"; description Lhotka Expires November 26, 2012 [Page 41] Internet-Draft YANG Routing Configuration May 2012 "The boolean value to be placed in the 'Other configuration' flag field in the Router Advertisement."; } 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."; } 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)."; } 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)."; } 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 Assigned Numbers that was in effect at the time of implementation. "; reference "IANA: IP Parameters, http://www.iana.org/assignments/ip-parameters"; } Lhotka Expires November 26, 2012 [Page 42] Internet-Draft YANG Routing Configuration May 2012 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 * max-rtr-adv-interval. "; } 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. "; 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. Lhotka Expires November 26, 2012 [Page 43] Internet-Draft YANG Routing Configuration May 2012 This may 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. Implementations may allow valid-lifetime to be specified in two ways: 1. a time that decrements in real time, that is, one that will result in a lifetime of zero at the specified time in the future, 2. a fixed time that stays the same in consecutive advertisements. "; } 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."; } leaf preferred-lifetime { type uint32; units "seconds"; 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. Implementations MAY allow preferred-lifetime to be specified in two ways: 1. a time that decrements in real time, that is, Lhotka Expires November 26, 2012 [Page 44] Internet-Draft YANG Routing Configuration May 2012 one that will result in a lifetime of zero at a specified time in the future, 2. a fixed time that stays the same in consecutive advertisements. "; } leaf autonomous-flag { type boolean; default "true"; description "The value to be placed in the Autonomous Flag field in the Prefix Information option."; } } } } } } } 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 "seqno"; ordered-by "user"; description "A user-ordered list of static routes."; leaf seqno { type uint32 { range "1..max"; } description "Sequential number of the route."; } leaf description { type string; description "Textual description of the route."; } uses rt:route-content; Lhotka Expires November 26, 2012 [Page 45] Internet-Draft YANG Routing Configuration May 2012 uses route-content { refine "dest-prefix" { mandatory "true"; } } } } } augment "/rt:routing/rt:router/rt:routing-tables/rt:routing-table/" + "rt:routes/rt:route" { 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; } } Lhotka Expires November 26, 2012 [Page 46] Internet-Draft YANG Routing Configuration May 2012 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]: ---------------------------------------------------------- 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]: Lhotka Expires November 26, 2012 [Page 47] Internet-Draft YANG Routing Configuration May 2012 ------------------------------------------------------------------- name: ietf-routing namespace: urn:ietf:params:xml:ns:yang:ietf-routing prefix: rt reference: RFC XXXX ------------------------------------------------------------------- ------------------------------------------------------------------- name: ietf-ipv4-unicast-routing namespace: urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing prefix: v4ur reference: RFC XXXX ------------------------------------------------------------------- ------------------------------------------------------------------- name: ietf-ipv6-unicast-routing namespace: urn:ietf:params:xml:ns:yang:ietf-ipv6-unicast-routing prefix: v6ur reference: RFC XXXX ------------------------------------------------------------------- Lhotka Expires November 26, 2012 [Page 48] Internet-Draft YANG Routing Configuration May 2012 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]. 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. 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 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. /rt:routing/rt:router/rt:route-filters/rt:route-filter This list specifies the configured route filters which represent the administrative policies for redistributing and modifying routing information. 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. Lhotka Expires November 26, 2012 [Page 49] Internet-Draft YANG Routing Configuration May 2012 11. Acknowledgments The author wishes to thank Martin Bjorklund, Joel Halpern, Thomas Morin, Tom Petch, Juergen Schoenwaelder, Dave Thaler and Yi Yang for their helpful comments and suggestions. Lhotka Expires November 26, 2012 [Page 50] Internet-Draft YANG Routing Configuration May 2012 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-02 (work in progress), April 2012. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, January 2004. [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, September 2007. [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for Network Configuration Protocol (NETCONF)", RFC 6020, 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-04 (work in progress), April 2012. [YANG-IP] Bjorklund, M., "A YANG Data Model for IP Configuration", draft-ietf-netmod-ip-cfg-03 (work in progress), April 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. Lhotka Expires November 26, 2012 [Page 51] Internet-Draft YANG Routing Configuration May 2012 Appendix A. 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@2012-05-24.yang" module example-rip { namespace "http://example.com/rip"; prefix "rip"; import ietf-routing { prefix "rt"; } identity rip { base rt:routing-protocol; description "Identity for the RIP routing protocol."; } typedef rip-metric { type uint8 { range "0..16"; } } 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."; } } Lhotka Expires November 26, 2012 [Page 52] Internet-Draft YANG Routing Configuration May 2012 augment "/rt:routing/rt:router/rt:routing-tables/rt:routing-table/" + "rt:routes/rt:route" { when "../../../../rt:routing-protocols/" + "rt:routing-protocol[rt:name=current()/rt:source-protocol]/" + "rt:type='rip:rip'" { description "This augment is only valid if the source protocol from which the route originated is RIP."; } 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; } 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"; } } } 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 Lhotka Expires November 26, 2012 [Page 53] Internet-Draft YANG Routing Configuration May 2012 "Time interval between periodic updates."; } } } } Lhotka Expires November 26, 2012 [Page 54] Internet-Draft YANG Routing Configuration May 2012 Appendix B. Example: Reply to the NETCONF Message 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" 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 network configuration Router "A" then could send the following XML document as its reply to the NETCONF message: eth0 ethernetCsmacd 05:00.0 192.0.2.1 24 2001:0db8:0:1::1 64 false eth1 ethernetCsmacd 05:00.1 198.51.100.1 24 2001:0db8:0:2::1 64 false Lhotka Expires November 26, 2012 [Page 56] Internet-Draft YANG Routing Configuration May 2012 rtr0 eth0 eth1 true 2001:db8:0:2::/64 direct rt:direct st0 Static routing is used for the internal network. rt:static 1 0.0.0.0/0 192.0.2.2 1 ::/0 2001:db8:0:1::2 Lhotka Expires November 26, 2012 [Page 57] Internet-Draft YANG Routing Configuration May 2012 main-ipv4-unicast main-ipv6-unicast main-ipv4-unicast 192.0.2.1/24 eth0 direct 3512 198.51.100.0/24 eth1 direct 3512 0.0.0.0/0 st0 192.0.2.2 2551 main-ipv6-unicast ipv6 nlri-unicast 2001:db8:0:1::/64 eth0 direct 3513 2001:db8:0:2::/64 eth1 Lhotka Expires November 26, 2012 [Page 58] Internet-Draft YANG Routing Configuration May 2012 direct 3513 ::/0 2001:db8:0:1::2 st0 2550 Lhotka Expires November 26, 2012 [Page 59] Internet-Draft YANG Routing Configuration May 2012 Appendix C. Change Log RFC Editor: remove this section upon publication as an RFC. C.1. 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". o For both RPCs, specification of negative responses was added. o Relaxed separation of router instances. o Assignment of interfaces to router instances needn't be disjoint. o Route filters are now global. o Added "allow-all-route-filter" for symmetry. o Added Section 5 about interactions with "ietf-interfaces" and "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.2. 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 reserved for documentation. o Direct routes appear by default in the FIB table. o Network layer interfaces must be assigned to a router instance. Additional interface configuration may be present. Lhotka Expires November 26, 2012 [Page 60] Internet-Draft YANG Routing Configuration May 2012 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.3. 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. o RPC operation "delete-route" was removed. o Illegal XPath references from "get-route" to the datastore were fixed. o Section "Security Considerations" was written. Lhotka Expires November 26, 2012 [Page 61] Internet-Draft YANG Routing Configuration May 2012 Author's Address Ladislav Lhotka CZ.NIC Email: lhotka@nic.cz Lhotka Expires November 26, 2012 [Page 62]