Internet Engineering Task Force (IETF) L. Wang Request for Comments: 8431 Individual Category: Standards Track M. Chen ISSN: 2070-1721 Huawei A. Dass Ericsson H. Ananthakrishnan Netflix S. Kini Individual N. Bahadur Uber September 2018
A YANG Data Model for the Routing Information Base (RIB)
Abstract
This document defines a YANG data model for the Routing Information Base (RIB) that aligns with the Interface to the Routing System (I2RS) RIB information model.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8431.
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Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
The Interface to the Routing System (I2RS) [RFC7921] provides read and write access to the information and state within the routing process that exists inside the routing elements; this is achieved via protocol message exchange between I2RS clients and I2RS agents associated with the routing system. One of the functions of I2RS is to read and write data of the Routing Information Base (RIB). [I2RS-REQS] introduces a set of RIB use cases. The RIB information model is defined in [RFC8430].
This document defines a YANG data model [RFC7950] [RFC6991] for the RIB that satisfies the RIB use cases and aligns with the RIB information model.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
The following figure shows an overview of the structure tree of the ietf-i2rs-rib module. To give a whole view of the structure tree, some details of the tree are omitted. The relevant details are introduced in the subsequent subsections.
RIB capability negotiation is very important because not all of the hardware will be able to support all kinds of nexthops, and there might be a limitation on how many levels of lookup can be practically performed. Therefore, a RIB data model needs to specify a way for an external entity to learn about the functional capabilities of a network device.
At the same time, nexthop chains can be used to specify multiple headers over a packet before that particular packet is forwarded. Not every network device will be able to support all kinds of nexthop chains along with the arbitrary number of headers that are chained together. The RIB data model needs a way to expose the nexthop chaining capability supported by a given network device.
This module uses the feature and if-feature statements to achieve above capability advertisement.
A routing instance, in the context of the RIB information model, is a collection of RIBs, interfaces, and routing protocol parameters. A routing instance creates a logical slice of the router and can allow multiple different logical slices, across a set of routers, to communicate with each other. The routing protocol parameters control the information available in the RIBs. More details about a routing instance can be found in Section 2.2 of [RFC8430].
For a routing instance, there can be multiple RIBs. Therefore, this model uses "list" to express the RIBs. The structure tree is shown below:
+--rw routing-instance +--rw name string +--rw interface-list* [name] | +--rw name if:interface-ref +--rw router-id? yang:dotted-quad +--rw lookup-limit? uint8 +--rw rib-list* [name] +--rw name string +--rw address-family address-family-definition +--rw ip-rpf-check? boolean +--rw route-list* [route-index] ... // refer to Section 2.3
A route is essentially a match condition and an action following that match. The match condition specifies the kind of route (e.g., IPv4, MPLS, Media Access Control (MAC), Interface, etc.) and the set of fields to match on.
A route MUST contain the ROUTE_PREFERENCE attribute (see Section 2.3 of [RFC8430]).
In addition, a route MUST associate with the following status attributes in responses to a RIB writing/reading operation:
o Active: Indicates whether a route has at least one fully resolved nexthop and is therefore eligible for installation in the FIB.
o Installed: Indicates whether the route got installed in the FIB.
o Reason: Indicates the specific reason that caused the failure, e.g., "Not authorized".
In addition, a route can be associated with one or more optional route-attributes (e.g., route-vendor-attributes).
A RIB will have a number of routes, so the routes are expressed as a list under a specific RIB. Each RIB has its own route list.
A nexthop represents an object resulting from a route lookup. As illustrated in Figure 4 of [RFC8430], to support various use cases (e.g., load-balancing, protection, multicast, or a combination of them), the nexthop is modeled as a multilevel structure and supports recursion. The first level of the nexthop includes the following four types:
o Base: The "base" nexthop is the foundation of all other nexthop types. It includes the following basic nexthops:
* nexthop-id
* IPv4 address
* IPv6 address
* egress-interface
* egress-interface with IPv4 address
* egress-interface with IPv6 address
* egress-interface with MAC address
* logical-tunnel
* tunnel-encapsulation
* tunnel-decapsulation
* rib-name
o Chain: The "chain" nexthop provides a way to perform multiple operations on a packet by logically combining them.
o Load-Balance: The "load-balance" nexthop is designed for a load- balance case where it normally will have multiple weighted nexthops.
o Protection: The "protection" nexthop is designed for a protection scenario where it normally will have primary and standby nexthop.
o Replicate: The "replicate" nexthop is designed for multiple destinations forwarding.
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The structure tree of nexthop is shown in the following figures.
o rib-add: Add a RIB to a routing instance. The following are passed as the input parameters: the name of the RIB, the address family of the RIB, and (optionally) whether the RPF check is enabled. The output is the result of the add operation:
* true - success
* false - failed (when failed, the I2RS agent may return the specific reason that caused the failure)
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o rib-delete: Delete a RIB from a routing instance. When a RIB is deleted, all routes installed in the RIB will be deleted. A rib- name is passed as the input parameter. The output is the result of the delete operation:
* true - success
* false - failed (when failed, the I2RS agent may return the specific reason that caused the failure)
o route-add: Add a route or a set of routes to a RIB. The following are passed as the input parameters: the name of the RIB, the route prefix(es), the route-attributes, the route-vendor-attributes, the nexthop, and the "whether to return failure details" indication. Before calling the route-add rpc, it is required to call the nh- add rpc to create and/or return the nexthop identifier. However, in situations when the nexthop already exists and the nexthop-id is known, this action is not expected. The output is a combination of the route operation states while querying the appropriate node in the data tree, which includes:
* success-count: the number of routes that were successfully added;
* failed-count: the number of the routes that failed to be added; and,
* failure-detail: this shows the specific routes that failed to be added.
o route-delete: Delete a route or a set of routes from a RIB. The following are passed as the input parameters: the name of the RIB, the route prefix(es), and the "whether to return failure details" indication. The output is a combination of route operation states, which includes:
* success-count: the number of routes that were successfully deleted;
* failed-count: the number of the routes that failed to be deleted; and,
* failure-detail: this shows the specific routes that failed to be deleted.
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o route-update: Update a route or a set of routes. The following are passed as the input parameters: the name of the RIB, the route prefix(es), the route-attributes, the route-vendor-attributes, or the nexthop. The match conditions can be either route prefix(es), route-attributes, route-vendor-attributes, or nexthops. The update actions include the following: update the nexthops, update the route-attributes, and update the route-vendor-attributes. The output is a combination of the route operation states, which includes:
* success-count: the number of routes that were successfully updated;
* failed-count: the number of the routes that failed to be updated; and,
* failure-detail: this shows the specific routes that failed to be updated.
o nh-add: Add a nexthop to a RIB. The following are passed as the input parameters: the name of the RIB and the nexthop. The network node is required to allocate a nexthop identifier to the nexthop. The outputs include the result of the nexthop add operation.
* true - success (when success, a nexthop identifier will be returned to the I2RS client)
* false - failed (when failed, the I2RS agent may return the specific reason that caused the failure)
o nh-delete: Delete a nexthop from a RIB. The following are passed as the input parameters: the name of the RIB and a nexthop or nexthop identifier. The output is the result of the delete operation:
* true - success
* false - failed (when failed, the I2RS agent may return the specific reason that caused the failure)
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The structure tree of rpcs is shown in following figure.
Asynchronous notifications are sent by the RIB manager of a network device to an external entity when some event triggers on the network device. An implementation of this RIB data model MUST support sending two kinds of asynchronous notifications.
1. Route change notification:
o Installed (indicates whether the route got installed in the FIB)
o Active (indicates whether a route has at least one fully resolved nexthop and is therefore eligible for installation in the FIB)
o Reason (e.g., "Not authorized")
2. Nexthop resolution status notification
Nexthops can be fully resolved or unresolved.
A resolved nexthop has an adequate level of information to send the outgoing packet towards the destination by forwarding it on an interface to a directly connected neighbor.
An unresolved nexthop is something that requires the RIB manager to determine the final resolved nexthop. In one example, a nexthop could be an IP address. The RIB manager would resolve how to reach that IP address, e.g., by checking if that particular IP address is reachable by regular IP forwarding, by an MPLS tunnel, or by both. If the RIB manager cannot resolve the nexthop, then the nexthop remains in an unresolved state and is NOT a suitable candidate for installation in the FIB.
An implementation of this RIB data model MUST support sending route- change notifications whenever a route transitions between the following states:
o from the active state to the inactive state
o from the inactive state to the active state
o from the installed state to the uninstalled state
o from the uninstalled state to the installed state
A single notification MAY be used when a route transitions from inactive/uninstalled to active/installed or in the other direction.
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The structure tree of notifications is shown in the following figure.
description "This module defines a YANG data model for Routing Information Base (RIB) that aligns with the I2RS RIB information model.
Copyright (c) 2018 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 8341; see the RFC itself for full legal notices.";
feature nexthop-tunnel { description "This feature means that a node supports tunnel nexthop capability."; }
feature nexthop-chain { description "This feature means that a node supports chain nexthop capability."; }
feature nexthop-protection { description "This feature means that a node supports protection nexthop capability."; }
feature nexthop-replicate { description "This feature means that a node supports replicate nexthop capability.";
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}
feature nexthop-load-balance { description "This feature means that a node supports load-balance nexthop capability."; }
feature ipv4-tunnel { description "This feature means that a node supports IPv4 tunnel encapsulation capability."; }
feature ipv6-tunnel { description "This feature means that a node supports IPv6 tunnel encapsulation capability."; }
feature mpls-tunnel { description "This feature means that a node supports MPLS tunnel encapsulation capability."; }
feature vxlan-tunnel { description "This feature means that a node supports Virtual eXtensible Local Area Network (VXLAN) tunnel encapsulation capability."; reference "RFC 7348"; }
feature gre-tunnel { description "This feature means that a node supports GRE tunnel encapsulation capability."; reference "RFC 2784"; }
feature nvgre-tunnel { description "This feature means that a node supports Network Virtualization Using GRE (NVGRE) tunnel encapsulation capability."; reference "RFC 7637"; }
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feature route-vendor-attributes { description "This feature means that a node supports route vendor attributes."; }
//Identities and Type Definitions
identity mpls-label-action { description "Base identity from which all MPLS label operations are derived.
The MPLS label stack operations include: push - to add a new label to a label stack pop - to pop the top label from a label stack swap - to exchange the top label of a label stack with a new label"; }
"Base identity from which all tunnel decapsulation actions are derived. Tunnel decapsulation actions include ipv4-decapsulation (to decapsulate an IPv4 tunnel) ipv6-decapsulation (to decapsulate an IPv6 tunnel)"; }
identity ipv4-decapsulation { base tunnel-decapsulation-action; description "IPv4 tunnel decapsulation."; }
identity ipv6-decapsulation { base tunnel-decapsulation-action; description "IPv6 tunnel decapsulation."; }
typedef tunnel-decapsulation-action-definition { type identityref { base tunnel-decapsulation-action; } description "Tunnel decapsulation definition."; }
identity ttl-action { description "Base identity from which all TTL actions are derived."; }
identity no-action { base ttl-action; description "Do nothing regarding the TTL."; }
identity copy-to-inner { base ttl-action; description "Copy the TTL of the outer header to the inner header."; }
identity decrease-and-copy-to-inner { base ttl-action;
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description "Decrease TTL by one and copy the TTL to the inner header."; }
identity decrease-and-copy-to-next { base ttl-action; description "Decrease TTL by one and copy the TTL to the next header; for example, when MPLS label swapping, decrease the TTL of the in_label and copy it to the out_label."; }
typedef ttl-action-definition { type identityref { base ttl-action; } description "TTL action definition."; }
identity hop-limit-action { description "Base identity from which all hop limit actions are derived."; }
identity hop-limit-no-action { base hop-limit-action; description "Do nothing regarding the hop limit."; }
identity hop-limit-copy-to-inner { base hop-limit-action; description "Copy the hop limit of the outer header to the inner header."; }
typedef hop-limit-action-definition { type identityref { base hop-limit-action; } description "IPv6 hop limit action definition.";
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}
identity special-nexthop { description "Base identity from which all special nexthops are derived."; }
identity discard { base special-nexthop; description "This indicates that the network device should drop the packet and increment a drop counter."; }
identity discard-with-error { base special-nexthop; description "This indicates that the network device should drop the packet, increment a drop counter, and send back an appropriate error message (like ICMP error)."; }
identity receive { base special-nexthop; description "This indicates that the traffic is destined for the network device, e.g., protocol packets or Operations, Administration, and Maintenance (OAM) packets. All locally destined traffic SHOULD be throttled to avoid a denial-of-service attack on the router's control plane. An optional rate-limiter can be specified to indicate how to throttle traffic destined for the control plane."; }
identity cos-value { base special-nexthop; description "Cos-value special nexthop."; }
typedef special-nexthop-definition {
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type identityref { base special-nexthop; } description "Special nexthop definition."; }
identity ip-route-match-type { description "Base identity from which all route match types are derived. The route match type could be: match source, or match destination, or match source and destination."; }
identity match-ip-src { base ip-route-match-type; description "Source route match type."; }
identity match-ip-dest { base ip-route-match-type; description "Destination route match type"; }
identity match-ip-src-dest { base ip-route-match-type; description "Source and Destination route match type"; }
typedef ip-route-match-type-definition { type identityref { base ip-route-match-type; } description "IP route match type definition."; }
identity address-family { description "Base identity from which all RIB address families are derived."; }
typedef address-family-definition { type identityref { base address-family; } description "RIB address family definition."; }
identity route-type { description "Base identity from which all route types are derived."; }
identity ipv4-route { base route-type; description "IPv4 route type."; }
identity ipv6-route { base route-type; description "IPv6 route type.";
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}
identity mpls-route { base route-type; description "MPLS route type."; }
identity ieee-mac { base route-type; description "MAC route type."; }
identity interface { base route-type; description "Interface route type."; }
typedef route-type-definition { type identityref { base route-type; } description "Route type definition."; }
identity tunnel-type { description "Base identity from which all tunnel types are derived."; }
identity ipv4-tunnel { base tunnel-type; description "IPv4 tunnel type"; }
identity ipv6-tunnel { base tunnel-type; description "IPv6 tunnel type"; }
identity mpls-tunnel { base tunnel-type;
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description "MPLS tunnel type"; }
identity gre-tunnel { base tunnel-type; description "GRE tunnel type"; }
identity vxlan-tunnel { base tunnel-type; description "VXLAN tunnel type"; }
identity nvgre-tunnel { base tunnel-type; description "NVGRE tunnel type"; }
typedef tunnel-type-definition { type identityref { base tunnel-type; } description "Tunnel type definition."; }
identity route-state { description "Base identity from which all route states are derived."; }
identity active { base route-state; description "Active state."; }
identity inactive { base route-state; description "Inactive state."; }
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typedef route-state-definition { type identityref { base route-state; } description "Route state definition."; }
identity nexthop-state { description "Base identity from which all nexthop states are derived."; }
identity resolved { base nexthop-state; description "Resolved nexthop state."; }
identity unresolved { base nexthop-state; description "Unresolved nexthop state."; }
typedef nexthop-state-definition { type identityref { base nexthop-state; } description "Nexthop state definition."; }
identity route-installed-state { description "Base identity from which all route installed states are derived."; }
identity uninstalled { base route-installed-state; description "Uninstalled state."; }
identity installed { base route-installed-state;
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description "Installed state."; }
typedef route-installed-state-definition { type identityref { base route-installed-state; } description "Route installed state definition."; }
//Route Change Reason Identities
identity route-change-reason { description "Base identity from which all route change reasons are derived."; }
identity lower-route-preference { base route-change-reason; description "This route was installed in the FIB because it had a lower route preference value (and thus was more preferred) than the route it replaced."; }
identity higher-route-preference { base route-change-reason; description "This route was uninstalled from the FIB because it had a higher route preference value (and thus was less preferred) than the route that replaced it."; }
identity resolved-nexthop { base route-change-reason; description "This route was made active because at least one of its nexthops was resolved."; }
identity unresolved-nexthop { base route-change-reason; description "This route was made inactive because all of its nexthops are unresolved.";
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}
typedef route-change-reason-definition { type identityref { base route-change-reason; } description "Route change reason definition."; }
typedef nexthop-preference-definition { type uint8 { range "1..99"; } description "Nexthop-preference is used for protection schemes. It is an integer value between 1 and 99. Lower values are preferred. To download N nexthops to the FIB, the N nexthops with the lowest value are selected. If there are more than N nexthops that have the same preference, an implementation of the I2RS client should select N nexthops and download them. As for how to select the nexthops, this is left to the implementations."; }
typedef nexthop-lb-weight-definition { type uint8 { range "1..99"; } description "Nexthop-lb-weight is used for load-balancing. Each list member SHOULD be assigned a weight between 1 and 99. The weight determines the proportion of traffic to be sent over a nexthop used for forwarding as a ratio of the weight of this nexthop divided by the sum of the weights of all the nexthops of this route that are used for forwarding. To perform equal load-balancing, one MAY specify a weight of 0 for all the member nexthops. The value 0 is reserved for equal load-balancing and, if applied, MUST be applied to all member nexthops. Note that the weight of 0 is special because of historical reasons. It's typically used in hardware devices to signify ECMP."; }
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typedef nexthop-ref { type leafref { path "/iir:routing-instance" + "/iir:rib-list" + "/iir:route-list" + "/iir:nexthop" + "/iir:nexthop-id"; } description "A nexthop reference that provides an indirection reference to a nexthop."; }
//Groupings
grouping route-prefix { description "The common attributes used for all types of route prefixes."; leaf route-index { type uint64; mandatory true; description "Route index."; } container match { description "The match condition specifies the kind of route (IPv4, MPLS, etc.) and the set of fields to match on."; choice route-type { description "Route types: IPv4, IPv6, MPLS, MAC, etc."; case ipv4 { description "IPv4 route case."; container ipv4 { description "IPv4 route match."; choice ip-route-match-type { description "IP route match type options: match source, or match destination, or match source and destination."; case dest-ipv4-address { leaf dest-ipv4-prefix { type inet:ipv4-prefix; mandatory true;
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description "An IPv4 destination address as the match."; } } case src-ipv4-address { leaf src-ipv4-prefix { type inet:ipv4-prefix; mandatory true; description "An IPv4 source address as the match."; } } case dest-src-ipv4-address { container dest-src-ipv4-address { description "A combination of an IPv4 source and an IPv4 destination address as the match."; leaf dest-ipv4-prefix { type inet:ipv4-prefix; mandatory true; description "The IPv4 destination address of the match."; } leaf src-ipv4-prefix { type inet:ipv4-prefix; mandatory true; description "The IPv4 source address of the match."; } } } } } } case ipv6 { description "IPv6 route case."; container ipv6 { description "IPv6 route match."; choice ip-route-match-type { description "IP route match type options: match source, match destination, or match source and destination."; case dest-ipv6-address { leaf dest-ipv6-prefix {
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type inet:ipv6-prefix; mandatory true; description "An IPv6 destination address as the match."; } } case src-ipv6-address { leaf src-ipv6-prefix { type inet:ipv6-prefix; mandatory true; description "An IPv6 source address as the match."; } } case dest-src-ipv6-address { container dest-src-ipv6-address { description "A combination of an IPv6 source and an IPv6 destination address as the match."; leaf dest-ipv6-prefix { type inet:ipv6-prefix; mandatory true; description "The IPv6 destination address of the match."; } leaf src-ipv6-prefix { type inet:ipv6-prefix; mandatory true; description "The IPv6 source address of the match."; } } } } } } case mpls-route { description "MPLS route case."; leaf mpls-label { type uint32; mandatory true; description "The label used for matching."; } } case mac-route { description
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"MAC route case."; leaf mac-address { type yang:mac-address; mandatory true; description "The MAC address used for matching."; } } case interface-route { description "Interface route case."; leaf interface-identifier { type if:interface-ref; mandatory true; description "The interface used for matching."; } } } } }
grouping route { description "The common attributes used for all types of routes."; uses route-prefix; container nexthop { description "The nexthop of the route."; uses nexthop; } //In the information model, it is called route-statistic container route-status { description "The status information of the route."; leaf route-state { type route-state-definition; config false; description "Indicate a route's state: active or inactive."; } leaf route-installed-state { type route-installed-state-definition; config false; description "Indicate that a route's installed states: installed or uninstalled."; }
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leaf route-reason { type route-change-reason-definition; config false; description "Indicate the reason that caused the route change."; } } container route-attributes { description "Route attributes."; uses route-attributes; } container route-vendor-attributes { description "Route vendor attributes."; uses route-vendor-attributes; } }
grouping nexthop-list { description "A generic nexthop list."; list nexthop-list { key "nexthop-member-id"; description "A list of nexthops."; leaf nexthop-member-id { type uint32; mandatory true; description "A nexthop identifier that points to a nexthop list member. A nexthop list member is a nexthop."; } } }
grouping nexthop-list-p { description "A nexthop list with preference parameter."; list nexthop-list { key "nexthop-member-id"; description "A list of nexthop."; leaf nexthop-member-id { type uint32; mandatory true; description
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"A nexthop identifier that points to a nexthop list member. A nexthop list member is a nexthop."; } leaf nexthop-preference { type nexthop-preference-definition; mandatory true; description "Nexthop-preference is used for protection schemes. It is an integer value between 1 and 99. Lower values are more preferred. To download a primary/standby/tertiary group to the FIB, the nexthops that are resolved and are most preferred are selected."; } } }
grouping nexthop-list-w { description "A nexthop list with a weight parameter."; list nexthop-list { key "nexthop-member-id"; description "A list of nexthop."; leaf nexthop-member-id { type uint32; mandatory true; description "A nexthop identifier that points to a nexthop list member. A nexthop list member is a nexthop."; } leaf nexthop-lb-weight { type nexthop-lb-weight-definition; mandatory true; description "The weight of a nexthop of the load-balance nexthops."; } } }
grouping nexthop { description "The nexthop structure."; leaf nexthop-id { type uint32;
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description "An identifier that refers to a nexthop."; } leaf sharing-flag { type boolean; description "To indicate whether a nexthop is sharable or non-sharable: true - sharable (which means the nexthop can be shared with other routes) false - non-sharable (which means the nexthop can not be shared with other routes)"; } choice nexthop-type { description "Nexthop type options."; case nexthop-base { container nexthop-base { description "The base nexthop."; uses nexthop-base; } } case nexthop-chain { if-feature "nexthop-chain"; container nexthop-chain { description "A chain nexthop."; uses nexthop-list; } } case nexthop-replicate { if-feature "nexthop-replicate"; container nexthop-replicate { description "A replicate nexthop."; uses nexthop-list; } } case nexthop-protection { if-feature "nexthop-protection"; container nexthop-protection { description "A protection nexthop."; uses nexthop-list-p; } } case nexthop-load-balance {
grouping nexthop-base { description "The base nexthop."; choice nexthop-base-type { description "Nexthop base type options."; case special-nexthop { leaf special { type special-nexthop-definition; description "A special nexthop."; } } case egress-interface-nexthop { leaf outgoing-interface { type if:interface-ref; mandatory true; description "The nexthop is an outgoing interface."; } } case ipv4-address-nexthop { leaf ipv4-address { type inet:ipv4-address; mandatory true; description "The nexthop is an IPv4 address."; } } case ipv6-address-nexthop { leaf ipv6-address { type inet:ipv6-address; mandatory true; description "The nexthop is an IPv6 address."; } } case egress-interface-ipv4-nexthop {
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container egress-interface-ipv4-address { leaf outgoing-interface { type if:interface-ref; mandatory true; description "Name of the outgoing interface."; } leaf ipv4-address { type inet:ipv4-address; mandatory true; description "The nexthop points to an interface with an IPv4 address."; } description "The nexthop is an egress-interface and an IP address. This can be used in cases where, e.g., the IP address is a link-local address."; } } case egress-interface-ipv6-nexthop { container egress-interface-ipv6-address { leaf outgoing-interface { type if:interface-ref; mandatory true; description "Name of the outgoing interface."; } leaf ipv6-address { type inet:ipv6-address; mandatory true; description "The nexthop points to an interface with an IPv6 address."; } description "The nexthop is an egress-interface and an IP address. This can be used in cases where, e.g., the IP address is a link-local address."; } } case egress-interface-mac-nexthop { container egress-interface-mac-address { leaf outgoing-interface { type if:interface-ref; mandatory true; description "Name of the outgoing interface.";
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} leaf ieee-mac-address { type yang:mac-address; mandatory true; description "The nexthop points to an interface with a specific MAC address."; } description "The egress-interface must be an Ethernet interface. Address resolution is not required for this nexthop."; } } case tunnel-encapsulation-nexthop { if-feature "nexthop-tunnel"; container tunnel-encapsulation { uses tunnel-encapsulation; description "This can be an encapsulation representing an IP tunnel, MPLS tunnel, or others as defined in the info model. An optional egress-interface can be chained to the tunnel encapsulation to indicate which interface to send the packet out on. The egress-interface is useful when the network device contains Ethernet interfaces and one needs to perform address resolution for the IP packet."; } } case tunnel-decapsulation-nexthop { if-feature "nexthop-tunnel"; container tunnel-decapsulation { uses tunnel-decapsulation; description "This is to specify the decapsulation of a tunnel header."; } } case logical-tunnel-nexthop { if-feature "nexthop-tunnel"; container logical-tunnel { uses logical-tunnel; description "This can be an MPLS Label Switched Path (LSP) or a GRE tunnel (or others as defined in this document) that is represented by a unique identifier (e.g., name)."; }
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} case rib-name-nexthop { leaf rib-name { type string; description "A nexthop pointing to a RIB indicates that the route lookup needs to continue in the specified RIB. This is a way to perform chained lookups."; } } case nexthop-identifier { leaf nexthop-ref { type nexthop-ref; mandatory true; description "A nexthop reference that points to a nexthop."; } } } }
grouping logical-tunnel { description "A logical tunnel that is identified by a type and a tunnel name."; leaf tunnel-type { type tunnel-type-definition; mandatory true; description "A tunnel type."; } leaf tunnel-name { type string; mandatory true; description "A tunnel name that points to a logical tunnel."; } }
type inet:ipv4-address; mandatory true; description "The source IP address of the header."; } leaf dest-ipv4-address { type inet:ipv4-address; mandatory true; description "The destination IP address of the header."; } leaf protocol { type uint8; mandatory true; description "The protocol id of the header."; } leaf ttl { type uint8; description "The TTL of the header."; } leaf dscp { type uint8; description "The Differentiated Services Code Point (DSCP) field of the header."; } }
grouping ipv6-header { description "The IPv6 header encapsulation information."; leaf src-ipv6-address { type inet:ipv6-address; mandatory true; description "The source IP address of the header."; } leaf dest-ipv6-address { type inet:ipv6-address; mandatory true; description "The destination IP address of the header."; } leaf next-header { type uint8; mandatory true;
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description "The next header of the IPv6 header."; } leaf traffic-class { type uint8; description "The traffic class value of the header."; } leaf flow-label { type inet:ipv6-flow-label; description "The flow label of the header."; } leaf hop-limit { type uint8 { range "1..255"; } description "The hop limit of the header."; } }
grouping nvgre-header { description "The NVGRE header encapsulation information."; choice nvgre-type { description "NVGRE can use either an IPv4 or an IPv6 header for encapsulation."; case ipv4 { uses ipv4-header; } case ipv6 { uses ipv6-header; } } leaf virtual-subnet-id { type uint32; mandatory true; description "The subnet identifier of the NVGRE header."; } leaf flow-id { type uint8; description "The flow identifier of the NVGRE header."; } }
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grouping vxlan-header { description "The VXLAN encapsulation header information."; choice vxlan-type { description "NVGRE can use either an IPv4 or an IPv6 header for encapsulation."; case ipv4 { uses ipv4-header; } case ipv6 { uses ipv6-header; } } leaf vxlan-identifier { type uint32; mandatory true; description "The VXLAN identifier of the VXLAN header."; } }
grouping gre-header { description "The GRE encapsulation header information."; choice dest-address-type { description "GRE options: IPv4 and IPv6"; case ipv4 { leaf ipv4-dest { type inet:ipv4-address; mandatory true; description "The destination IP address of the GRE header."; } } case ipv6 { leaf ipv6-dest { type inet:ipv6-address; mandatory true; description "The destination IP address of the GRE header."; } } } leaf protocol-type { type uint16; mandatory true;
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description "The protocol type of the GRE header."; } leaf key { type uint64; description "The GRE key of the GRE header."; } }
grouping mpls-header { description "The MPLS encapsulation header information."; list label-operations { key "label-oper-id"; description "Label operations."; leaf label-oper-id { type uint32; description "An optional identifier that points to a label operation."; } choice label-actions { description "Label action options."; case label-push { container label-push { description "Label push operation."; leaf label { type uint32; mandatory true; description "The label to be pushed."; } leaf s-bit { type boolean; description "The s-bit ('Bottom of Stack' bit) of the label to be pushed."; } leaf tc-value { type uint8; description "The traffic class value of the label to be pushed."; } leaf ttl-value {
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type uint8; description "The TTL value of the label to be pushed."; } } } case label-swap { container label-swap { description "Label swap operation."; leaf in-label { type uint32; mandatory true; description "The label to be swapped."; } leaf out-label { type uint32; mandatory true; description "The out MPLS label."; } leaf ttl-action { type ttl-action-definition; description "The label TTL actions: - No-action - Copy to inner label - Decrease (the in-label) by 1 and copy to the out-label"; } } } } } }
"Tunnel decapsulation information."; choice tunnel-type { description "Nexthop tunnel type options."; case ipv4 { if-feature "ipv4-tunnel"; container ipv4-decapsulation { description "IPv4 decapsulation."; leaf ipv4-decapsulation { type tunnel-decapsulation-action-definition; mandatory true; description "IPv4 decapsulation operations."; } leaf ttl-action { type ttl-action-definition; description "The TTL actions: no-action or copy to inner header."; } } } case ipv6 { if-feature "ipv6-tunnel"; container ipv6-decapsulation { description "IPv6 decapsulation."; leaf ipv6-decapsulation { type tunnel-decapsulation-action-definition; mandatory true; description "IPv6 decapsulation operations."; } leaf hop-limit-action { type hop-limit-action-definition; description "The hop limit actions: no-action or copy to inner header."; } } } case mpls { if-feature "mpls-tunnel"; container label-pop { description "MPLS decapsulation."; leaf label-pop {
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type mpls-label-action-definition; mandatory true; description "Pop a label from the label stack."; } leaf ttl-action { type ttl-action-definition; description "The label TTL action."; } } } } }
grouping route-attributes { description "Route attributes."; leaf route-preference { type uint32; mandatory true; description "ROUTE_PREFERENCE: This is a numerical value that allows for comparing routes from different protocols. Static configuration is also considered a protocol for the purpose of this field. It is also known as administrative-distance. The lower the value, the higher the preference."; } leaf local-only { type boolean; mandatory true; description "Indicate whether the attribute is local only."; } container address-family-route-attributes { description "Address-family-related route attributes."; choice route-type { description "Address-family-related route attributes. Future documents should specify these attributes by augmenting the cases in this choice."; case ip-route-attributes { } case mpls-route-attributes { } case ethernet-route-attributes {
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} } } }
container routing-instance { description "A routing instance, in the context of the RIB information model, is a collection of RIBs, interfaces, and routing parameters."; leaf name { type string; description "The name of the routing instance. This MUST be unique across all routing instances in a given network device."; } list interface-list { key "name"; description "This represents the list of interfaces associated with this routing instance. The interface list helps constrain the boundaries of packet forwarding. Packets coming on these interfaces are directly associated with the given routing instance. The interface list contains a list of identifiers with each identifier uniquely identifying an interface."; leaf name { type if:interface-ref; description "A reference to the name of a network-layer interface."; } } leaf router-id { type yang:dotted-quad; description "Router ID: The 32-bit number in the form of a dotted quad."; } leaf lookup-limit { type uint8; description "A limit on how many levels of a lookup can be performed."; } list rib-list { key "name"; description "A list of RIBs that are associated with the routing instance.";
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leaf name { type string; mandatory true; description "A reference to the name of each RIB."; } leaf address-family { type address-family-definition; mandatory true; description "The address family of a RIB."; } leaf ip-rpf-check { type boolean; description "Each RIB can be optionally associated with a ENABLE_IP_RPF_CHECK attribute that enables Reverse Path Forwarding (RPF) checks on all IP routes in that RIB. An RPF check is used to prevent spoofing and limit malicious traffic."; } list route-list { key "route-index"; description "A list of routes of a RIB."; uses route; } // This is a list that maintains the nexthops added to the RIB. uses nexthop-list; } }
//RPC Operations
rpc rib-add { description "To add a RIB to an instance"; input { leaf name { type string; mandatory true; description "A reference to the name of the RIB that is to be added."; } leaf address-family { type address-family-definition; mandatory true;
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description "The address family of the RIB."; } leaf ip-rpf-check { type boolean; description "Each RIB can be optionally associated with an ENABLE_IP_RPF_CHECK attribute that enables RPF checks on all IP routes in that RIB. An RPF check is used to prevent spoofing and limit malicious traffic."; } } output { leaf result { type boolean; mandatory true; description "Return the result of the rib-add operation. true - success; false - failed"; } leaf reason { type string; description "The specific reason that caused the failure."; } } }
rpc rib-delete { description "To delete a RIB from a routing instance. After deleting the RIB, all routes installed in the RIB will be deleted as well."; input { leaf name { type string; mandatory true; description "A reference to the name of the RIB that is to be deleted."; } } output { leaf result { type boolean; mandatory true;
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description "Return the result of the rib-delete operation. true - success; false - failed"; } leaf reason { type string; description "The specific reason that caused failure."; } } }
grouping route-operation-state { description "Route operation state."; leaf success-count { type uint32; mandatory true; description "The numbers of routes that are successfully added/deleted/updated."; } leaf failed-count { type uint32; mandatory true; description "The numbers of the routes that fail to be added/deleted/updated."; } container failure-detail { description "The failure detail reflects the reason why a route operation fails. It is an array that includes the route index and error code of the failed route."; list failed-routes { key "route-index"; description "The list of failed routes."; leaf route-index { type uint32; description "The route index of the failed route."; } leaf error-code { type uint32; description "The error code that reflects the failure reason.
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0 - Reserved 1 - Trying to add a repeat route 2 - Trying to delete or update a route that does not exist 3 - Malformed route attributes"; } } } }
rpc route-add { description "To add a route or a list of routes to a RIB"; input { leaf return-failure-detail { type boolean; default "false"; description "Whether to return the failure detail. true - return the failure detail false - do not return the failure detail The default is false."; } leaf rib-name { type string; mandatory true; description "A reference to the name of a RIB."; } container routes { description "The routes to be added to the RIB."; list route-list { key "route-index"; description "The list of routes to be added."; uses route-prefix; container route-attributes { uses route-attributes; description "The route attributes."; } container route-vendor-attributes { if-feature "route-vendor-attributes"; uses route-vendor-attributes; description "The route vendor attributes."; }
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container nexthop { uses nexthop; description "The nexthop of the added route."; } } } } output { uses route-operation-state; } }
rpc route-delete { description "To delete a route or a list of routes from a RIB"; input { leaf return-failure-detail { type boolean; default "false"; description "Whether to return the failure detail. true - return the failure detail false - do not return the failure detail The default is false."; } leaf rib-name { type string; mandatory true; description "A reference to the name of a RIB."; } container routes { description "The routes to be added to the RIB."; list route-list { key "route-index"; description "The list of routes to be deleted."; uses route-prefix; } } } output { uses route-operation-state; } }
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grouping route-update-options { description "Update options: 1. update the nexthop 2. update the route attributes 3. update the route-vendor-attributes"; choice update-options { description "Update options: 1. update the nexthop 2. update the route attributes 3. update the route-vendor-attributes"; case update-nexthop { container updated-nexthop { uses nexthop; description "The nexthop used for updating."; } } case update-route-attributes { container updated-route-attr { uses route-attributes; description "The route attributes used for updating."; } } case update-route-vendor-attributes { container updated-route-vendor-attr { uses route-vendor-attributes; description "The vendor route attributes used for updating."; } } } }
rpc route-update { description "To update a route or a list of routes of a RIB. The inputs: 1. The match conditions, which could be: a. route prefix, b. route attributes, or c. nexthop. 2. The update parameters to be used: a. new nexthop, b. new route attributes, or c. nexthop.
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Actions: 1. update the nexthop 2. update the route attributes The outputs: success-count - the number of routes updated failed-count - the number of routes fail to update failure-detail - the detail failure info "; input { leaf return-failure-detail { type boolean; default "false"; description "Whether to return the failure detail. true - return the failure detail false - do not return the failure detail The default is false."; } leaf rib-name { type string; mandatory true; description "A reference to the name of a RIB."; } choice match-options { description "Match options."; case match-route-prefix { description "Update the routes that match the route prefix(es) condition."; container input-routes { description "The matched routes to be updated."; list route-list { key "route-index"; description "The list of routes to be updated."; uses route-prefix; uses route-update-options; } } } case match-route-attributes { description "Update the routes that match the route attributes condition."; container input-route-attributes {
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description "The route attributes are used for matching."; uses route-attributes; } container update-parameters { description "Update options: 1. update the nexthop 2. update the route attributes 3. update the route-vendor-attributes"; uses route-update-options; } } case match-route-vendor-attributes { if-feature "route-vendor-attributes"; description "Update the routes that match the vendor attributes condition"; container input-route-vendor-attributes { description "The vendor route attributes are used for matching."; uses route-vendor-attributes; } container update-parameters-vendor { description "Update options: 1. update the nexthop 2. update the route attributes 3. update the route-vendor-attributes"; uses route-update-options; } } case match-nexthop { description "Update the routes that match the nexthop."; container input-nexthop { description "The nexthop used for matching."; uses nexthop; } container update-parameters-nexthop { description "Update options: 1. update the nexthop 2. update the route attributes 3. update the route-vendor-attributes"; uses route-update-options; }
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} } } output { uses route-operation-state; } } rpc nh-add { description "To add a nexthop to a RIB. Inputs parameters: 1. rib-name 2. nexthop Actions: Add the nexthop to the RIB Outputs: 1. Operation result: true - success false - failed 2. nexthop identifier"; input { leaf rib-name { type string; mandatory true; description "A reference to the name of a RIB."; } uses nexthop; } output { leaf result { type boolean; mandatory true; description "Return the result of the rib-add operation: true - success false - failed"; } leaf reason { type string; description "The specific reason that caused the failure."; } leaf nexthop-id { type uint32; description "A nexthop identifier that is allocated to the nexthop."; }
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} }
rpc nh-delete { description "To delete a nexthop from a RIB"; input { leaf rib-name { type string; mandatory true; description "A reference to the name of a RIB."; } uses nexthop; } output { leaf result { type boolean; mandatory true; description "Return the result of the rib-add operation: true - success; false - failed"; } leaf reason { type string; description "The specific reason that caused the failure."; } } }
//Notifications
notification nexthop-resolution-status-change { description "Nexthop resolution status (resolved/unresolved) notification."; container nexthop { description "The nexthop."; uses nexthop; } leaf nexthop-state { type nexthop-state-definition; mandatory true; description "Nexthop resolution status (resolved/unresolved)
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notification."; } }
notification route-change { description "Route change notification."; leaf rib-name { type string; mandatory true; description "A reference to the name of a RIB."; } leaf address-family { type address-family-definition; mandatory true; description "The address family of a RIB."; } uses route-prefix; leaf route-installed-state { type route-installed-state-definition; mandatory true; description "Indicates whether the route got installed in the FIB."; } leaf route-state { type route-state-definition; mandatory true; description "Indicates whether a route is active or inactive."; } list route-change-reasons { key "route-change-reason"; description "The reasons that cause the route change. A route change may result from several reasons; for example, a nexthop becoming resolved will make a route A active, which is of better preference than a currently active route B, which results in the route A being installed"; leaf route-change-reason { type route-change-reason-definition; mandatory true; description "The reason that caused the route change."; } }
This document registers a URI in the "ns" registry within the "IETF XML Registry" [RFC3688]:
------------------------------------------------------------------- URI: urn:ietf:params:xml:ns:yang:ietf-i2rs-rib Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. -------------------------------------------------------------------
This document registers a YANG module in the "YANG Module Names" registry [RFC7950]:
The YANG module specified in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446].
The NETCONF access control model [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content.
The YANG module defines information that can be configurable in certain instances, for example, a RIB, a route, a nexthop can be created or deleted by client applications; the YANG module also defines RPCs that can be used by client applications to add/delete RIBs, routes, and nexthops. In such cases, a malicious client could attempt to remove, add, or update a RIB, a route, or a nexthop by creating or deleting corresponding elements in the RIB, route, and
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nexthop lists, respectively. Removing a RIB or a route could lead to disruption or impact in performance of a service; updating a route may lead to suboptimal path and degradation of service levels as well as possibly disruption of service. For those reasons, it is important that the NETCONF access control model is vigorously applied to prevent misconfiguration by unauthorized clients.
There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have a negative effect on network operations. These are the subtrees and data nodes and their sensitivity/vulnerability:
o RIB: A malicious client could attempt to remove a RIB from a routing instance, for example, in order to sabotage the services provided by the RIB or to add a RIB to a routing instance (hence, to inject unauthorized traffic into the nexthop).
o route: A malicious client could attempt to remove or add a route from/to a RIB, for example, in order to sabotage the services provided by the RIB.
o nexthop: A malicious client could attempt to remove or add a nexthop from/to RIB, which may lead to a suboptimal path, a degradation of service levels, and a possible disruption of service.
[RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger, L., Sridhar, T., Bursell, M., and C. Wright, "Virtual eXtensible Local Area Network (VXLAN): A Framework for Overlaying Virtualized Layer 2 Networks over Layer 3 Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014, <https://www.rfc-editor.org/info/rfc7348>.
The authors would like to thank Chris Bowers, John Scudder, Tom Petch, Mike McBride, and Ebben Aries for their review, suggestions, and comments to this document.
Contributors
The following individuals also contributed to this document.