Network Working Group R. Rahman, Ed. Internet-Draft Cisco Systems Intended status: Standards Track L. Zheng, Ed. Expires: September 11, 2017 Huawei Technologies S. Pallagatti M. Jethanandani Cisco Systems G. Mirsky ZTE Corporation March 10, 2017 Yang Data Model for Bidirectional Forwarding Detection (BFD) draft-ietf-bfd-yang-05.txt Abstract This document defines a YANG data model that can be used to configure and manage Bidirectional Forwarding Detection (BFD). Requirements Language 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 RFC 2119 [RFC2119]. 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 September 11, 2017. Rahman, et al. Expires September 11, 2017 [Page 1] Internet-Draft BFD Yang March 2017 Copyright Notice Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Contributors . . . . . . . . . . . . . . . . . . . . . . 4 2. Design of the Data Model . . . . . . . . . . . . . . . . . . 4 2.1. Design of Configuration Model . . . . . . . . . . . . . . 4 2.1.1. Common BFD configuration parameters . . . . . . . . . 5 2.1.2. Single-hop IP . . . . . . . . . . . . . . . . . . . . 6 2.1.3. Multi-hop IP . . . . . . . . . . . . . . . . . . . . 6 2.1.4. MPLS Traffic Engineering Tunnels . . . . . . . . . . 7 2.1.5. MPLS Label Switched Paths . . . . . . . . . . . . . . 7 2.1.6. Link Aggregation Groups . . . . . . . . . . . . . . . 7 2.2. Design of Operational Model . . . . . . . . . . . . . . . 8 2.3. Notifications . . . . . . . . . . . . . . . . . . . . . . 8 2.4. RPC Operations . . . . . . . . . . . . . . . . . . . . . 9 2.5. BFD top level hierarchy . . . . . . . . . . . . . . . . . 9 2.6. BFD IP single-hop hierarchy . . . . . . . . . . . . . . . 9 2.7. BFD IP multi-hop hierarchy . . . . . . . . . . . . . . . 11 2.8. BFD over LAG hierarchy . . . . . . . . . . . . . . . . . 13 2.9. BFD over MPLS LSPs hierarchy . . . . . . . . . . . . . . 15 2.10. BFD over MPLS-TE hierarchy . . . . . . . . . . . . . . . 17 2.11. Examples . . . . . . . . . . . . . . . . . . . . . . . . 19 2.12. Interaction with other YANG modules . . . . . . . . . . . 19 2.12.1. Module ietf-interfaces . . . . . . . . . . . . . . . 19 2.12.2. Module ietf-ip . . . . . . . . . . . . . . . . . . . 19 2.12.3. Module ietf-mpls . . . . . . . . . . . . . . . . . . 20 2.12.4. Module ietf-te . . . . . . . . . . . . . . . . . . . 20 2.13. BFD top-level Yang Module . . . . . . . . . . . . . . . . 20 2.14. BFD IP single-hop Yang Module . . . . . . . . . . . . . . 32 2.15. BFD IP multi-hop Yang Module . . . . . . . . . . . . . . 35 2.16. BFD over LAG Yang Module . . . . . . . . . . . . . . . . 38 2.17. BFD over MPLS Yang Module . . . . . . . . . . . . . . . . 42 2.18. BFD over MPLS-TE Yang Module . . . . . . . . . . . . . . 45 Rahman, et al. Expires September 11, 2017 [Page 2] Internet-Draft BFD Yang March 2017 2.19. Security Considerations . . . . . . . . . . . . . . . . . 48 2.20. IANA Considerations . . . . . . . . . . . . . . . . . . . 48 2.21. Acknowledgements . . . . . . . . . . . . . . . . . . . . 48 3. References . . . . . . . . . . . . . . . . . . . . . . . . . 49 3.1. Normative References . . . . . . . . . . . . . . . . . . 49 3.2. Informative References . . . . . . . . . . . . . . . . . 50 Appendix A. Change log . . . . . . . . . . . . . . . . . . . . . 51 A.1. Changes between versions -04 and -05 . . . . . . . . . . 51 A.2. Changes between versions -03 and -04 . . . . . . . . . . 52 A.3. Changes between versions -02 and -03 . . . . . . . . . . 52 A.4. Changes between versions -01 and -02 . . . . . . . . . . 52 A.5. Changes between versions -00 and -01 . . . . . . . . . . 52 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 52 1. Introduction YANG [RFC6020] is a data definition language that was introduced to define the contents of a conceptual data store that allows networked devices to be managed using NETCONF [RFC6241]. YANG is proving relevant beyond its initial confines, as bindings to other interfaces (e.g RESTCONF [I-D.ietf-netconf-restconf]) and encodings other than XML (e.g JSON) are being defined. Furthermore, YANG data models can be used as the basis of implementation for other interfaces, such as CLI and programmatic APIs. This document defines a YANG data model that can be used to configure and manage Bidirectional Forwarding Detection (BFD)[RFC5880]. BFD is a network protocol which is used for liveness detection of arbitrary paths between systems. Some examples of different types of paths over which we have BFD: 1) Two systems directly connected via IP. This is known as BFD over single-hop IP [RFC5881] 2) Two systems connected via multiple hops [RFC5883] 3) Two systems connected via MPLS Label Switched Paths (LSPs) [RFC5884] 4) Two systems connected via pseudowires (PWs), this is known as Virtual Circuit Connectivity Verification (VCCV) [RFC5885] 5) Two systems connected via a Link Aggregation Group (LAG) interface [RFC7130] BFD typically does not operate on its own. Various control protocols, also known as BFD clients, use the services provided by BFD for their own operation [RFC5882]. The obvious candidates which Rahman, et al. Expires September 11, 2017 [Page 3] Internet-Draft BFD Yang March 2017 use BFD are those which do not have Hellos to detect failures, e.g. static routes, and routing protocols whose Hellos do not support sub- second failure detection, e.g. OSPF and IS-IS. 1.1. Contributors 2. Design of the Data Model Since BFD is used for liveliness detection of various forwarding paths, there is no uniform key to identify a BFD session. So the BFD data model is split in multiple YANG modules where each module corresponds to one type of forwarding path. For example, BFD for IP single-hop is in one YANG module and BFD for MPLS-TE is in another YANG module. The main difference between these modules is how a BFD session is uniquely identified, i.e the key for the list containing the BFD sessions for that forwarding path. To avoid duplication of BFD definitions, we have common types and groupings which are used by all the modules. A new control-plane protocol "bfdv1" is defined and a "bfd" container is created under control-plane-protocol as specified in [RFC8022]. This new "bfd" node is augmented by all the YANG modules for their respective specific information. Each BFD YANG module which augments the "bfd" node contains a "config" node and an "oper" node. BFD can operate in the following contexts: 1. Network devices as described in [I-D.ietf-rtgwg-device-model] 2. Logical Network Elements as described in [I-D.ietf-rtgwg-lne-model] 3. Network instances as described in [I-D.ietf-rtgwg-ni-model] The approach taken is to do a schema-mount (see [I-D.ietf-netmod-schema-mount]) of the BFD model in the appropriate locations. For example, if an implementation supports BFD IP multi- hop in network instances, the implementation would do schema-mount of the BFD IP multi-hop model in a mount-point which resides in a network instance. 2.1. Design of Configuration Model The configuration model consists mainly of the parameters specified in [RFC5880]. Some examples are desired minimum transmit interval, required minimum receive interval, detection multiplier, etc Rahman, et al. Expires September 11, 2017 [Page 4] Internet-Draft BFD Yang March 2017 Some implementations have BFD session configuration under the BFD clients. For example, BFD session configuration is under routing applications such as OSPF, IS-IS, BGP etc. Other implementations have BFD session configuration centralized under BFD, i.e. outside the multiple BFD clients. The BFD parameters of interest to a BFD client are mainly the multiplier and interval(s) since those parameters impact the convergence time of the BFD clients when a failure occurs. Other parameters such as BFD authentication are not specific to the requirements of the BFD client. To avoid splitting the BFD configuration between BFD clients and BFD, all the configuration is under BFD. The only BFD configuration under BFD clients should be an "enable" knob which makes those clients react to BFD liveliness detection events. 2.1.1. Common BFD configuration parameters The basic BFD configuration parameters are: local-multiplier This is the detection time multiplier as defined in [RFC5880]. desired-min-tx-interval This is the Desired Min TX Interval as defined in [RFC5880]. required-min-rx-interval This is the Required Min RX Interval as defined in [RFC5880]. Although [RFC5880] allows for different values for transmit and receive intervals, some implementations allow users to specify just one interval which is used for both transmit and receive intervals or separate values for transmit and receive intervals. The BFD YANG model supports this: there is a choice between "min-interval", used for both transmit and receive intervals, and "desired-min-tx- interval" and "required-min-rx-interval". This is supported via a grouping which is used by the YANG modules for the various forwarding paths. There are also intervals for the echo function (if supported): desired-min-echo-tx-interval This is the minimum interval that the local system would like to use when transmitting BFD echo packets. If 0, the echo function as defined in [RFC5880] is disabled. required-min-echo-rx-interval Rahman, et al. Expires September 11, 2017 [Page 5] Internet-Draft BFD Yang March 2017 This is the Required Min Echo RX Interval as defined in [RFC5880]. For BFD authentication we have: key-chain This is a reference to key-chain defined in [I-D.ietf-rtgwg-yang-key-chain]. The keys, cryptographic algotihms, key lifetime etc are all defined in the key-chain model. replay-protection This specifies meticulous v/s non-meticulous mode as per [RFC5880]. 2.1.2. Single-hop IP For single-hop IP, there is an augment of the "bfd" data node in Section 2. We have a list of IP single-hop sessions where each session is uniquely identified by the interface and destination address pair. For the configuration parameters we use what is defined in Section 2.1.1 2.1.3. Multi-hop IP For multi-hop IP, there is an augment of the "bfd" data node in Section 2. We have a list for BFD sessions over multi-hop IP. The key consists of: source address Address belonging to the local system as per [RFC5883] destination address Address belonging to the remote system as per [RFC5883] For the configuration parameters we use what is defined in Section 2.1.1 Here are some extra parameters: tx-ttl TTL of outgoing BFD control packets. rx-ttl Minimum TTL of incoming BFD control packets. Rahman, et al. Expires September 11, 2017 [Page 6] Internet-Draft BFD Yang March 2017 2.1.4. MPLS Traffic Engineering Tunnels For MPLS-TE tunnels, BFD is configured under the MPLS-TE tunnel since the desired failure detection parameters is a property of the MPLS-TE tunnel. This is achieved by augmenting the MPLS-TE data model in [I-D.ietf-teas-yang-te]. For BFD parameters which are specific to the TE application, e.g. whether to tear down the tunnel in the event of a BFD session failure, these parameters will be defined in the YANG model of the MPLS-TE application. On top of the usual BFD parameters, we have the following per MPLS-TE tunnel: encap Encapsulation for the BFD packets: choice between IP, G-ACh and IP with G-ACh as per [RFC5586] For general MPLS-TE data, "mpls-te" data node is added under the "bfd" node in Section 2. Since some MPLS-TE tunnels are uni- directional there is no MPLS-TE configuration for these tunnels on the egress node (note that this does not apply to bi-directional MPLS-TP tunnels). The BFD parameters for the egress node are added under "mpls-te". 2.1.5. MPLS Label Switched Paths Here we address MPLS LSPs whose FEC is an IP address. The "bfd" node in Section 2 is augmented with "mpls" which contains a list of sessions uniquely identified by an IP address. Since these LSPs are uni-directional there is no LSP configuration on the egress node. The BFD parameters for the egress node are added under "mpls". 2.1.6. Link Aggregation Groups Per [RFC7130], configuring BFD on LAG consists of having micro-BFD sessions on each LAG member link. Since the BFD parameters are an attribute of the LAG, they should be under the LAG. However there is no LAG YANG model which we can augment. So a "lag" data node is added to the "bfd" node in Section 2, the configuration is per-LAG: we have a list of LAGs. The destination IP address of the micro-BFD sessions is configured per-LAG and per address-family (IPv4 and IPv6) Rahman, et al. Expires September 11, 2017 [Page 7] Internet-Draft BFD Yang March 2017 2.2. Design of Operational Model The operational model contains both the overall statistics of BFD sessions running on the device and the per session operational information. The overall statistics of BFD sessions consist of number of BFD sessions, number of BFD sessions up etc. This information is available globally (i.e. for all BFD sessions) under the "bfd" node in Section 2 and also per type of forwarding path. For each BFD session, mainly three categories of operational items are shown. The fundamental information of a BFD session such as the local discriminator, remote discriminator and the capability of supporting demand detect mode are shown in the first category. The second category includes a BFD session running information, e.g. the remote BFD state and the diagnostic code received. Another example is the actual transmit interval between the control packets, which may be different from the desired minimum transmit interval configured, is shown in this category. Similar examples are actual received interval between the control packets and the actual transmit interval between the echo packets. The third category contains the detailed statistics of the session, e.g. when the session transitioned up/down and how long it has been in that state. For some session types, there may be more than 1 session on the virtual path to the destination. For example, with IP multi-hop there could be multiple BFD sessions from the source to the same destination to test the various paths (ECMP) to the destination. Each of the BFD sessions on the same virtual path is uniquely identified by the local discriminator. 2.3. Notifications This YANG model defines notifications to inform clients of BFD of important events detected during the protocol operation. Pair of local and remote discriminator identifies a BFD session on local system. Notifications also give more important details about BFD sessions; e.g. new state, time in previous state, network-instance and the reason that the BFD session state changed. The notifications are defined for each type of forwarding path but use groupings for common information. Rahman, et al. Expires September 11, 2017 [Page 8] Internet-Draft BFD Yang March 2017 2.4. RPC Operations TBD 2.5. BFD top level hierarchy At the "bfd" node under control-plane-protocol, there is no configuration data, only operational data. The operational data consist of overall BFD session statistics, i.e. for BFD on all types of forwarding paths. The "bfd" node under control-plane-protocol can be mounted in a network device (top-level), in an LNE or in a network instance. module: ietf-bfd augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol: +--rw bfd +--rw config +--ro oper +--ro bfd-session-statistics +--ro session-count? uint32 +--ro session-up-count? uint32 +--ro session-down-count? uint32 +--ro session-admin-down-count? uint32 2.6. BFD IP single-hop hierarchy An "ip-sh" node is added under "bfd" node in control-plane-protocol. The configuration and operational data for each BFD IP single-hop session is under this "ip-sh" node. The "ip-sh" node can be mounted in a network device (top-level), in an LNE or in a network instance. module: ietf-bfd-ip-sh augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/bfd:bfd: +--rw ip-sh +--rw config | +--rw session-cfg | +--rw sessions* [interface dest-addr] | +--rw interface if:interface-ref | +--rw dest-addr inet:ip-address | +--rw source-addr? inet:ip-address | +--rw local-multiplier? bfd-multiplier | +--rw (interval-config-type)? | | +--:(tx-rx-intervals) | | | +--rw desired-min-tx-interval uint32 | | | +--rw required-min-rx-interval uint32 | | +--:(single-interval) Rahman, et al. Expires September 11, 2017 [Page 9] Internet-Draft BFD Yang March 2017 | | +--rw min-interval uint32 | +--rw demand-enabled? boolean | +--rw admin-down? boolean | +--rw authentication-parms! {bfd-authentication}? | | +--rw key-chain? kc:key-chain-ref | | +--rw replay-protection? identityref | +--rw desired-min-echo-tx-interval? uint32 | +--rw required-min-echo-rx-interval? uint32 +--ro oper +--ro bfd-session-statistics | +--ro session-count? uint32 | +--ro session-up-count? uint32 | +--ro session-down-count? uint32 | +--ro session-admin-down-count? uint32 +--ro sessions* [interface dest-addr] +--ro interface if:interface-ref +--ro dest-addr inet:ip-address +--ro source-addr? inet:ip-address +--ro path-type? identityref +--ro local-discriminator? bfd-discriminator +--ro remote-discriminator? bfd-discriminator +--ro remote-multiplier? bfd-multiplier +--ro out-interface? if:interface-ref +--ro demand-capability? boolean +--ro source-port? inet:port-number +--ro dest-port? inet:port-number +--ro session-running | +--ro session-index? uint32 | +--ro local-state? bfd-state | +--ro remote-state? bfd-state | +--ro local-diagnostic? bfd-diagnostic | +--ro remote-diagnostic? bfd-diagnostic | +--ro detection-mode? enumeration | +--ro negotiated-tx-interval? uint32 | +--ro negotiated-rx-interval? uint32 | +--ro echo-tx-interval-in-use? uint32 | +--ro detection-time? uint32 +--ro sesssion-statistics +--ro create-time? yang:date-and-time +--ro last-down-time? yang:date-and-time +--ro last-up-time? yang:date-and-time +--ro down-count? uint32 +--ro admin-down-count? uint32 +--ro receive-packet-count? uint64 +--ro send-packet-count? uint64 +--ro receive-bad-packet? uint64 +--ro send-failed-packet? uint64 notifications: Rahman, et al. Expires September 11, 2017 [Page 10] Internet-Draft BFD Yang March 2017 +---n bfd-singlehop-notification +--ro local-discr? bfd-discriminator +--ro remote-discr? bfd-discriminator +--ro new-state? bfd-state +--ro state-change-reason? string +--ro time-in-previous-state? string +--ro dest-addr? inet:ip-address +--ro source-addr? inet:ip-address +--ro session-index? uint32 +--ro path-type? identityref +--ro interface? if:interface-ref +--ro echo-enabled? boolean 2.7. BFD IP multi-hop hierarchy An "ip-mh" node is added under the "bfd" node in cntrol-plane- protocol. The configuration and operational data for each BFD IP multi-hop session is under this "ip-mh" node. In the operational model we support multiple BFD multi-hop sessions per remote address (ECMP), the local discriminator is used as key. The "ip-mh" node can be mounted in a network device (top-level), in an LNE or in a network instance. module: ietf-bfd-ip-mh augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/bfd:bfd: +--rw ip-mh +--rw config | +--rw session-cfg | +--rw sessions* [source-addr dest-addr] | +--rw source-addr inet:ip-address | +--rw dest-addr inet:ip-address | +--rw local-multiplier? bfd-multiplier | +--rw (interval-config-type)? | | +--:(tx-rx-intervals) | | | +--rw desired-min-tx-interval uint32 | | | +--rw required-min-rx-interval uint32 | | +--:(single-interval) | | +--rw min-interval uint32 | +--rw demand-enabled? boolean | +--rw admin-down? boolean | +--rw authentication-parms! {bfd-authentication}? | | +--rw key-chain? kc:key-chain-ref | | +--rw replay-protection? identityref | +--rw tx-ttl? bfd:ttl | +--rw rx-ttl bfd:ttl +--ro oper +--ro bfd-session-statistics Rahman, et al. Expires September 11, 2017 [Page 11] Internet-Draft BFD Yang March 2017 | +--ro session-count? uint32 | +--ro session-up-count? uint32 | +--ro session-down-count? uint32 | +--ro session-admin-down-count? uint32 +--ro session-group* [source-addr dest-addr] +--ro source-addr inet:ip-address +--ro dest-addr inet:ip-address +--ro sessions* [local-discriminator] +--ro ttl? bfd:ttl +--ro path-type? identityref +--ro local-discriminator bfd-discriminator +--ro remote-discriminator? bfd-discriminator +--ro remote-multiplier? bfd-multiplier +--ro out-interface? if:interface-ref +--ro demand-capability? boolean +--ro source-port? inet:port-number +--ro dest-port? inet:port-number +--ro session-running | +--ro session-index? uint32 | +--ro local-state? bfd-state | +--ro remote-state? bfd-state | +--ro local-diagnostic? bfd-diagnostic | +--ro remote-diagnostic? bfd-diagnostic | +--ro detection-mode? enumeration | +--ro negotiated-tx-interval? uint32 | +--ro negotiated-rx-interval? uint32 | +--ro echo-tx-interval-in-use? uint32 | +--ro detection-time? uint32 +--ro sesssion-statistics +--ro create-time? yang:date-and-time +--ro last-down-time? yang:date-and-time +--ro last-up-time? yang:date-and-time +--ro down-count? uint32 +--ro admin-down-count? uint32 +--ro receive-packet-count? uint64 +--ro send-packet-count? uint64 +--ro receive-bad-packet? uint64 +--ro send-failed-packet? uint64 notifications: +---n bfd-multihop-notification +--ro local-discr? bfd-discriminator +--ro remote-discr? bfd-discriminator +--ro new-state? bfd-state +--ro state-change-reason? string +--ro time-in-previous-state? string +--ro dest-addr? inet:ip-address +--ro source-addr? inet:ip-address +--ro session-index? uint32 Rahman, et al. Expires September 11, 2017 [Page 12] Internet-Draft BFD Yang March 2017 +--ro path-type? identityref 2.8. BFD over LAG hierarchy A "lag" node is added under the "bfd" node in control-plane-protocol. The configuration and operational data for each BFD LAG session is under this "lag" node. The "lag" node can be mounted in a network device (top-level), in an LNE or in a network instance. module: ietf-bfd-lag augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/bfd:bfd: +--rw lag +--rw config | +--rw session-cfg | +--rw sessions* [lag-name] | +--rw lag-name if:interface-ref | +--rw ipv4-dest-addr? inet:ipv4-address | +--rw ipv6-dest-addr? inet:ipv6-address | +--rw local-multiplier? bfd-multiplier | +--rw (interval-config-type)? | | +--:(tx-rx-intervals) | | | +--rw desired-min-tx-interval uint32 | | | +--rw required-min-rx-interval uint32 | | +--:(single-interval) | | +--rw min-interval uint32 | +--rw demand-enabled? boolean | +--rw admin-down? boolean | +--rw authentication-parms! {bfd-authentication}? | +--rw key-chain? kc:key-chain-ref | +--rw replay-protection? identityref +--ro oper +--ro micro-bfd-ipv4-session-statistics | +--ro bfd-session-statistics | +--ro session-count? uint32 | +--ro session-up-count? uint32 | +--ro session-down-count? uint32 | +--ro session-admin-down-count? uint32 +--ro micro-bfd-ipv6-session-statistics | +--ro bfd-session-statistics | +--ro session-count? uint32 | +--ro session-up-count? uint32 | +--ro session-down-count? uint32 | +--ro session-admin-down-count? uint32 +--ro session-lag* [lag-name] +--ro lag-name if:interface-ref +--ro use-ipv4? boolean +--ro use-ipv6? boolean Rahman, et al. Expires September 11, 2017 [Page 13] Internet-Draft BFD Yang March 2017 +--ro member-links* [member-link] +--ro member-link if:interface-ref +--ro micro-bfd-ipv4 | +--ro path-type? identityref | +--ro local-discriminator? bfd-discriminator | +--ro remote-discriminator? bfd-discriminator | +--ro remote-multiplier? bfd-multiplier | +--ro out-interface? if:interface-ref | +--ro demand-capability? boolean | +--ro source-port? inet:port-number | +--ro dest-port? inet:port-number | +--ro session-running | | +--ro session-index? uint32 | | +--ro local-state? bfd-state | | +--ro remote-state? bfd-state | | +--ro local-diagnostic? bfd-diagnostic | | +--ro remote-diagnostic? bfd-diagnostic | | +--ro detection-mode? enumeration | | +--ro negotiated-tx-interval? uint32 | | +--ro negotiated-rx-interval? uint32 | | +--ro echo-tx-interval-in-use? uint32 | | +--ro detection-time? uint32 | +--ro sesssion-statistics | +--ro create-time? yang:date-and-time | +--ro last-down-time? yang:date-and-time | +--ro last-up-time? yang:date-and-time | +--ro down-count? uint32 | +--ro admin-down-count? uint32 | +--ro receive-packet-count? uint64 | +--ro send-packet-count? uint64 | +--ro receive-bad-packet? uint64 | +--ro send-failed-packet? uint64 +--ro micro-bfd-ipv6 +--ro path-type? identityref +--ro local-discriminator? bfd-discriminator +--ro remote-discriminator? bfd-discriminator +--ro remote-multiplier? bfd-multiplier +--ro out-interface? if:interface-ref +--ro demand-capability? boolean +--ro source-port? inet:port-number +--ro dest-port? inet:port-number +--ro session-running | +--ro session-index? uint32 | +--ro local-state? bfd-state | +--ro remote-state? bfd-state | +--ro local-diagnostic? bfd-diagnostic | +--ro remote-diagnostic? bfd-diagnostic | +--ro detection-mode? enumeration Rahman, et al. Expires September 11, 2017 [Page 14] Internet-Draft BFD Yang March 2017 | +--ro negotiated-tx-interval? uint32 | +--ro negotiated-rx-interval? uint32 | +--ro echo-tx-interval-in-use? uint32 | +--ro detection-time? uint32 +--ro sesssion-statistics +--ro create-time? yang:date-and-time +--ro last-down-time? yang:date-and-time +--ro last-up-time? yang:date-and-time +--ro down-count? uint32 +--ro admin-down-count? uint32 +--ro receive-packet-count? uint64 +--ro send-packet-count? uint64 +--ro receive-bad-packet? uint64 +--ro send-failed-packet? uint64 notifications: +---n bfd-lag-notification +--ro local-discr? bfd-discriminator +--ro remote-discr? bfd-discriminator +--ro new-state? bfd-state +--ro state-change-reason? string +--ro time-in-previous-state? string +--ro dest-addr? inet:ip-address +--ro source-addr? inet:ip-address +--ro session-index? uint32 +--ro path-type? identityref +--ro lag-name? if:interface-ref +--ro member-link? if:interface-ref 2.9. BFD over MPLS LSPs hierarchy An "mpls" node is added under the "bfd" node in control-plane- protocol. The configuration is per MPLS FEC under this "mpls" node. In the operational model we support multiple BFD sessions per MPLS FEC (ECMP), the local discriminator is used as key. The "mpls" node can be mounted in a network device (top-level), in an LNE or in a network instance. module: ietf-bfd-mpls augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/bfd:bfd: +--rw mpls +--rw config | +--rw egress | | +--rw local-multiplier? bfd-multiplier | | +--rw (interval-config-type)? | | | +--:(tx-rx-intervals) | | | | +--rw desired-min-tx-interval uint32 | | | | +--rw required-min-rx-interval uint32 Rahman, et al. Expires September 11, 2017 [Page 15] Internet-Draft BFD Yang March 2017 | | | +--:(single-interval) | | | +--rw min-interval uint32 | | +--rw authentication-parms! {bfd-authentication}? | | +--rw key-chain? kc:key-chain-ref | | +--rw replay-protection? identityref | +--rw session-cfg | +--rw sessions* [mpls-fec] | +--rw mpls-fec inet:ip-address | +--rw local-multiplier? bfd-multiplier | +--rw (interval-config-type)? | | +--:(tx-rx-intervals) | | | +--rw desired-min-tx-interval uint32 | | | +--rw required-min-rx-interval uint32 | | +--:(single-interval) | | +--rw min-interval uint32 | +--rw demand-enabled? boolean | +--rw admin-down? boolean | +--rw authentication-parms! {bfd-authentication}? | +--rw key-chain? kc:key-chain-ref | +--rw replay-protection? identityref +--ro oper +--ro bfd-session-statistics | +--ro session-count? uint32 | +--ro session-up-count? uint32 | +--ro session-down-count? uint32 | +--ro session-admin-down-count? uint32 +--ro session-group* [mpls-fec] +--ro mpls-fec inet:ip-address +--ro sessions* [local-discriminator] +--ro path-type? identityref +--ro local-discriminator bfd-discriminator +--ro remote-discriminator? bfd-discriminator +--ro remote-multiplier? bfd-multiplier +--ro out-interface? if:interface-ref +--ro demand-capability? boolean +--ro source-port? inet:port-number +--ro dest-port? inet:port-number +--ro session-running | +--ro session-index? uint32 | +--ro local-state? bfd-state | +--ro remote-state? bfd-state | +--ro local-diagnostic? bfd-diagnostic | +--ro remote-diagnostic? bfd-diagnostic | +--ro detection-mode? enumeration | +--ro negotiated-tx-interval? uint32 | +--ro negotiated-rx-interval? uint32 | +--ro echo-tx-interval-in-use? uint32 | +--ro detection-time? uint32 Rahman, et al. Expires September 11, 2017 [Page 16] Internet-Draft BFD Yang March 2017 +--ro sesssion-statistics | +--ro create-time? yang:date-and-time | +--ro last-down-time? yang:date-and-time | +--ro last-up-time? yang:date-and-time | +--ro down-count? uint32 | +--ro admin-down-count? uint32 | +--ro receive-packet-count? uint64 | +--ro send-packet-count? uint64 | +--ro receive-bad-packet? uint64 | +--ro send-failed-packet? uint64 +--ro mpls-dest-address? inet:ip-address notifications: +---n bfd-mpls-notification +--ro local-discr? bfd-discriminator +--ro remote-discr? bfd-discriminator +--ro new-state? bfd-state +--ro state-change-reason? string +--ro time-in-previous-state? string +--ro dest-addr? inet:ip-address +--ro source-addr? inet:ip-address +--ro session-index? uint32 +--ro path-type? identityref +--ro mpls-dest-address? inet:ip-address 2.10. BFD over MPLS-TE hierarchy The MPLS-TE YANG model [I-D.ietf-teas-yang-te] is augmented. BFD is configured per MPLS-TE tunnel, and BFD session operational data is provided per MPLS-TE LSP. module: ietf-bfd-mpls-te augment /rt:routing/rt:control-plane-protocols /rt:control-plane-protocol/bfd:bfd: +--rw mpls-te +--rw config | +--rw egress | +--rw local-multiplier? bfd-multiplier | +--rw (interval-config-type)? | | +--:(tx-rx-intervals) | | | +--rw desired-min-tx-interval uint32 | | | +--rw required-min-rx-interval uint32 | | +--:(single-interval) | | +--rw min-interval uint32 | +--rw authentication-parms! {bfd-authentication}? | +--rw key-chain? kc:key-chain-ref | +--rw replay-protection? identityref +--ro oper +--ro bfd-session-statistics Rahman, et al. Expires September 11, 2017 [Page 17] Internet-Draft BFD Yang March 2017 +--ro session-count? uint32 +--ro session-up-count? uint32 +--ro session-down-count? uint32 +--ro session-admin-down-count? uint32 augment /te:te/te:tunnels/te:tunnel/te:config: +--rw local-multiplier? bfd-multiplier +--rw (interval-config-type)? | +--:(tx-rx-intervals) | | +--rw desired-min-tx-interval uint32 | | +--rw required-min-rx-interval uint32 | +--:(single-interval) | +--rw min-interval uint32 +--rw demand-enabled? boolean +--rw admin-down? boolean +--rw authentication-parms! {bfd-authentication}? | +--rw key-chain? kc:key-chain-ref | +--rw replay-protection? identityref +--rw encap? identityref augment /te:te/te:lsps-state/te:lsp: +--ro path-type? identityref +--ro local-discriminator? bfd-discriminator +--ro remote-discriminator? bfd-discriminator +--ro remote-multiplier? bfd-multiplier +--ro out-interface? if:interface-ref +--ro demand-capability? boolean +--ro source-port? inet:port-number +--ro dest-port? inet:port-number +--ro session-running | +--ro session-index? uint32 | +--ro local-state? bfd-state | +--ro remote-state? bfd-state | +--ro local-diagnostic? bfd-diagnostic | +--ro remote-diagnostic? bfd-diagnostic | +--ro detection-mode? enumeration | +--ro negotiated-tx-interval? uint32 | +--ro negotiated-rx-interval? uint32 | +--ro echo-tx-interval-in-use? uint32 | +--ro detection-time? uint32 +--ro sesssion-statistics | +--ro create-time? yang:date-and-time | +--ro last-down-time? yang:date-and-time | +--ro last-up-time? yang:date-and-time | +--ro down-count? uint32 | +--ro admin-down-count? uint32 | +--ro receive-packet-count? uint64 | +--ro send-packet-count? uint64 | +--ro receive-bad-packet? uint64 | +--ro send-failed-packet? uint64 Rahman, et al. Expires September 11, 2017 [Page 18] Internet-Draft BFD Yang March 2017 +--ro mpls-dest-address? inet:ip-address notifications: +---n bfd-mpls-te-notification +--ro local-discr? bfd-discriminator +--ro remote-discr? bfd-discriminator +--ro new-state? bfd-state +--ro state-change-reason? string +--ro time-in-previous-state? string +--ro dest-addr? inet:ip-address +--ro source-addr? inet:ip-address +--ro session-index? uint32 +--ro path-type? identityref +--ro mpls-dest-address? inet:ip-address +--ro tunnel-name? string 2.11. Examples 2.12. Interaction with other YANG modules [I-D.ietf-lime-yang-connectionless-oam] describes how the LIME connectionless OAM model could be extended to support BFD. Also, the operation of the BFD data model depends on configuration parameters that are defined in other YANG modules. 2.12.1. Module ietf-interfaces The following boolean configuration is defined in the "ietf- interfaces" YANG module [RFC7223]: /if:interfaces/if:interface/if:enabled If this configuration is set to "false", no BFD packets can be transmitted or received on that interface. 2.12.2. Module ietf-ip The following boolean configuration is defined in the "ietf-ip" YANG module [RFC7277]: /if:interfaces/if:interface/ip:ipv4/ip:enabled If this configuration is set to "false", no BFD IPv4 packets can be transmitted or received on that interface. /if:interfaces/if:interface/ip:ipv4/ip:forwarding If this configuration is set to "false", no BFD IPv4 packets can be transmitted or received on that interface. /if:interfaces/if:interface/ip:ipv6/ip:enabled Rahman, et al. Expires September 11, 2017 [Page 19] Internet-Draft BFD Yang March 2017 If this configuration is set to "false", no BFD IPv6 packets can be transmitted or received on that interface. /if:interfaces/if:interface/ip:ipv6/ip:forwarding If this configuration is set to "false", no BFD IPv6 packets can be transmitted or received on that interface. 2.12.3. Module ietf-mpls The following boolean configuration is defined in the "ietf-mpls" YANG module [I-D.ietf-mpls-base-yang]: /rt:routing/mpls:mpls/mpls:interface/mpls:config/mpls:enabled If this configuration is set to "false", no BFD MPLS packets can be transmitted or received on that interface. 2.12.4. Module ietf-te The following configuration is defined in the "ietf-te" YANG module [I-D.ietf-teas-yang-te]: /ietf-te:te/ietf-te:tunnels/ietf-te:tunnel/ietf-te:config/ietf- te:admin-status If this configuration is not set to "state-up", no BFD MPLS packets can be transmitted or received on that tunnel. 2.13. BFD top-level Yang Module file "ietf-bfd@2017-03-07.yang" module ietf-bfd { namespace "urn:ietf:params:xml:ns:yang:ietf-bfd"; // replace with IANA namespace when assigned prefix "bfd"; import ietf-interfaces { prefix "if"; } import ietf-inet-types { prefix "inet"; } import ietf-yang-types { prefix "yang"; } import ietf-routing { prefix "rt"; Rahman, et al. Expires September 11, 2017 [Page 20] Internet-Draft BFD Yang March 2017 } import ietf-key-chain { prefix "kc"; } organization "IETF BFD Working Group"; contact "WG Web: WG List: WG Chair: Jeff Haas WG Chair: Reshad Rahman Editor: Lianshu Zheng and Reshad Rahman"; description "This module contains the YANG definition for BFD parameters as per RFC5880. Copyright (c) 2017 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 2017-03-07 { description "Initial revision."; reference "RFC XXXX: A YANG data model for BFD"; } // RFC Ed.: replace XXXX with actual RFC number and remove this // note identity bfdv1 { base "rt:control-plane-protocol"; description "BFD protocol version 1 as per RFC5880."; } typedef bfd-discriminator { type uint32 { range 1..4294967295; Rahman, et al. Expires September 11, 2017 [Page 21] Internet-Draft BFD Yang March 2017 } description "BFD discriminator"; } typedef bfd-diagnostic { type enumeration { enum none { value 0; description "None"; } enum controlExpiry { value 1; description "Control timer expiry"; } enum echoFailed { value 2; description "Echo failure"; } enum nborDown { value 3; description "Neighbor down"; } enum fwdingReset { value 4; description "Forwarding reset"; } enum pathDown { value 5; description "Path down"; } enum concPathDown { value 6; description "Concatenated path down"; } enum adminDown { value 7; description "Admin down"; } enum reverseConcPathDown { value 8; description "Reverse concatenated path down"; } } description "BFD diagnostic"; } typedef bfd-state { type enumeration { Rahman, et al. Expires September 11, 2017 [Page 22] Internet-Draft BFD Yang March 2017 enum adminDown { value 0; description "admindown"; } enum down { value 1; description "down"; } enum init { value 2; description "init"; } enum up { value 3; description "up"; } } description "BFD state"; } typedef bfd-multiplier { type uint8 { range 1..255; } description "Multiplier"; } typedef ttl { type uint8 { range 1..255; } description "Time To Live"; } identity bfd-path-type { description "Base identity for BFD path type. The session type indicates the type of path on which BFD is running"; } identity bfd-path-ip-sh { base bfd-path-type; description "BFD on IP single hop"; } identity bfd-path-ip-mh { base bfd-path-type; description "BFD on IP multi hop"; } identity bfd-path-mpls-te { Rahman, et al. Expires September 11, 2017 [Page 23] Internet-Draft BFD Yang March 2017 base bfd-path-type; description "BFD on MPLS Traffic Engineering"; } identity bfd-path-mpls-lsp { base bfd-path-type; description "BFD on MPLS Label Switched Path"; } identity bfd-path-lag { base bfd-path-type; description "Micro-BFD on LAG member links"; } identity bfd-encap-type { description "Base identity for BFD encapsulation type."; } identity bfd-encap-ip { base bfd-encap-type; description "BFD with IP encapsulation."; } feature bfd-authentication { description "BFD authentication supported"; } identity bfd-auth-replay-protection { description "Base identity for BFD authentication replay protection"; } identity bfd-auth-replay-protection-non-meticulous { base bfd-auth-replay-protection; description "Non-meticulous (see RFC5880)"; } identity bfd-auth-replay-protection-meticulous { base bfd-auth-replay-protection; description "Meticulous (see RFC5880)"; } grouping bfd-auth-parms { description "Grouping for BFD authentication parameters (see section 6.7 of RFC5880)."; container authentication-parms { if-feature bfd-authentication; presence "Enables BFD authentication (see section 6.7 of RFC5880)."; description "Parameters for BFD authentication"; Rahman, et al. Expires September 11, 2017 [Page 24] Internet-Draft BFD Yang March 2017 leaf key-chain { type kc:key-chain-ref; description "Name of key-chain"; } leaf replay-protection { type identityref { base bfd-auth-replay-protection; } description "Protection against replays"; } } } grouping bfd-grouping-base-cfg-parms { description "BFD grouping for base config parameters"; leaf local-multiplier { type bfd-multiplier; default 3; description "Multiplier transmitted by local system"; } choice interval-config-type { description "Two interval values or 1 value used for both tx and rx"; case tx-rx-intervals { leaf desired-min-tx-interval { type uint32; units microseconds; mandatory true; description "Desired minimum transmit interval of control packets"; } leaf required-min-rx-interval { type uint32; units microseconds; mandatory true; description "Required minimum receive interval of control packets"; } } case single-interval { leaf min-interval { type uint32; units microseconds; mandatory true; Rahman, et al. Expires September 11, 2017 [Page 25] Internet-Draft BFD Yang March 2017 description "Desired minimum transmit interval and required " + "minimum receive interval of control packets"; } } } } grouping bfd-grouping-common-cfg-parms { description "BFD grouping for common config parameters"; uses bfd-grouping-base-cfg-parms; leaf demand-enabled { type boolean; default false; description "To enable demand mode"; } leaf admin-down { type boolean; default false; description "Is the BFD session administratively down"; } uses bfd-auth-parms; } grouping bfd-grouping-echo-cfg-parms { description "BFD grouping for echo config parameters"; leaf desired-min-echo-tx-interval { type uint32; units microseconds; default 0; description "Desired minumum transmit interval for echo"; } leaf required-min-echo-rx-interval { type uint32; units microseconds; default 0; description "Required minimum receive interval for echo"; } } grouping bfd-client-base-cfg-parms { description "BFD grouping which could be used by a protocol which Rahman, et al. Expires September 11, 2017 [Page 26] Internet-Draft BFD Yang March 2017 is a client of BFD to enable its use of BFD"; container bfd-cfg { description "BFD configuration"; leaf enabled { type boolean; default false; description "True if BFD is enabled"; } } } grouping bfd-all-session { description "BFD session operational information"; leaf path-type { type identityref { base bfd-path-type; } description "BFD session type, this indicates the path type that BFD is running on"; } leaf local-discriminator { type bfd-discriminator; description "Local discriminator"; } leaf remote-discriminator { type bfd-discriminator; description "Remote discriminator"; } leaf remote-multiplier { type bfd-multiplier; description "Remote multiplier"; } leaf out-interface { type if:interface-ref; description "Outgoing physical interface name"; } leaf demand-capability { type boolean; description "Local demand mode capability"; } leaf source-port { type inet:port-number; description "Source UDP port"; } leaf dest-port { type inet:port-number; Rahman, et al. Expires September 11, 2017 [Page 27] Internet-Draft BFD Yang March 2017 description "Destination UDP port"; } container session-running { description "BFD session running information"; leaf session-index { type uint32; description "An index used to uniquely identify BFD sessions"; } leaf local-state { type bfd-state; description "Local state"; } leaf remote-state { type bfd-state; description "Remote state"; } leaf local-diagnostic { type bfd-diagnostic; description "Local diagnostic"; } leaf remote-diagnostic { type bfd-diagnostic; description "Remote diagnostic"; } leaf detection-mode { type enumeration { enum async-with-echo { value "1"; description "Async with echo"; } enum async-without-echo { value "2"; description "Async without echo"; } enum demand-with-echo { value "3"; description "Demand with echo"; } enum demand-without-echo { value "4"; description "Demand without echo"; } } description "Detection mode"; } leaf negotiated-tx-interval { Rahman, et al. Expires September 11, 2017 [Page 28] Internet-Draft BFD Yang March 2017 type uint32; units microseconds; description "Negotiated transmit interval"; } leaf negotiated-rx-interval { type uint32; units microseconds; description "Negotiated receive interval"; } leaf echo-tx-interval-in-use { when "../../path-type = 'bfd-path-ip-sh'" { description "Echo is supported for IP single-hop only."; } type uint32; units microseconds; description "Echo transmit interval in use"; } leaf detection-time { type uint32; units microseconds; description "Detection time"; } } container sesssion-statistics { description "BFD per-session statistics"; leaf create-time { type yang:date-and-time; description "Time and date when session was created"; } leaf last-down-time { type yang:date-and-time; description "Time and date of last time the session went down"; } leaf last-up-time { type yang:date-and-time; description "Time and date of last time the session went up"; } leaf down-count { type uint32; description "Session Down Count"; } leaf admin-down-count { Rahman, et al. Expires September 11, 2017 [Page 29] Internet-Draft BFD Yang March 2017 type uint32; description "Session Admin-Down Count"; } leaf receive-packet-count { type uint64; description "Received Packet Count"; } leaf send-packet-count { type uint64; description "Sent Packet Count"; } leaf receive-bad-packet { type uint64; description "Received bad packet count"; } leaf send-failed-packet { type uint64; description "Packet Failed to Send Count"; } } } grouping bfd-session-statistics { description "Grouping for session counters"; container bfd-session-statistics { description "BFD session counters"; leaf session-count { type uint32; description "Number of sessions"; } leaf session-up-count { type uint32; description "Count of sessions which are up"; } leaf session-down-count { type uint32; description "Count of sessions which are down"; } leaf session-admin-down-count { type uint32; description "Count of sessions which are admin-down"; } } } grouping bfd-notification-parms { description "This group describes common parameters that will be sent " + Rahman, et al. Expires September 11, 2017 [Page 30] Internet-Draft BFD Yang March 2017 "as part of BFD notification"; leaf local-discr { type bfd-discriminator; description "BFD local discriminator"; } leaf remote-discr { type bfd-discriminator; description "BFD remote discriminator"; } leaf new-state { type bfd-state; description "Current BFD state"; } leaf state-change-reason { type string; description "BFD state change reason"; } leaf time-in-previous-state { type string; description "How long the BFD session was in the previous state"; } leaf dest-addr { type inet:ip-address; description "BFD peer address"; } leaf source-addr { type inet:ip-address; description "BFD local address"; } leaf session-index { type uint32; description "An index used to uniquely identify BFD sessions"; } leaf path-type { type identityref { base bfd-path-type; } description "BFD path type"; Rahman, et al. Expires September 11, 2017 [Page 31] Internet-Draft BFD Yang March 2017 } } augment "/rt:routing/rt:control-plane-protocols/" + "rt:control-plane-protocol" { when "rt:type = 'bfd:bfdv1'" { description "This augmentation is only valid for a control-plane protocol instance of BFD (type 'bfdv1')."; } description "BFD augmentation."; container bfd { description "BFD top level container"; container config { description "BFD configuration container"; } container oper { config "false"; description "BFD operational container."; uses bfd-session-statistics; } } } } 2.14. BFD IP single-hop Yang Module file "ietf-bfd-ip-sh@2017-03-07.yang" module ietf-bfd-ip-sh { namespace "urn:ietf:params:xml:ns:yang:ietf-bfd-ip-sh"; // replace with IANA namespace when assigned prefix "bfd-ip-sh"; import ietf-bfd { prefix "bfd"; } import ietf-interfaces { prefix "if"; } import ietf-inet-types { prefix "inet"; } Rahman, et al. Expires September 11, 2017 [Page 32] Internet-Draft BFD Yang March 2017 import ietf-routing { prefix "rt"; } organization "IETF BFD Working Group"; contact "WG Web: WG List: WG Chair: Jeff Haas WG Chair: Reshad Rahman Editor: Lianshu Zheng and Reshad Rahman"; description "This module contains the YANG definition for BFD IP single-hop as per RFC5881. Copyright (c) 2017 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 2017-03-07 { description "Initial revision."; reference "RFC XXXX: A YANG data model for BFD IP single-hop"; } // RFC Ed.: replace XXXX with actual RFC number and remove this // note augment "/rt:routing/rt:control-plane-protocols/" + "rt:control-plane-protocol/bfd:bfd" { description "BFD augmentation for IP single-hop"; container ip-sh { description "BFD IP single-hop top level container"; container config { description "BFD IP single-hop configuration container"; container session-cfg { description "BFD IP single-hop session configuration"; Rahman, et al. Expires September 11, 2017 [Page 33] Internet-Draft BFD Yang March 2017 list sessions { key "interface dest-addr"; description "List of IP single-hop sessions"; leaf interface { type if:interface-ref; description "Interface on which the BFD session is running."; } leaf dest-addr { type inet:ip-address; description "IP address of the peer"; } leaf source-addr { type inet:ip-address; description "Local address"; } uses bfd:bfd-grouping-common-cfg-parms; uses bfd:bfd-grouping-echo-cfg-parms; } } } container oper { config "false"; description "BFD IP single-hop operational container"; uses bfd:bfd-session-statistics; list sessions { key "interface dest-addr"; description "BFD IP single-hop sessions"; leaf interface { type if:interface-ref; description "Interface on which the BFD session is running."; } leaf dest-addr { type inet:ip-address; description "BFD peer address"; } leaf source-addr { type inet:ip-address; description "BFD source address"; } uses bfd:bfd-all-session; Rahman, et al. Expires September 11, 2017 [Page 34] Internet-Draft BFD Yang March 2017 } } } } notification bfd-singlehop-notification { description "Notification for BFD single-hop session state change. An " + "implementation may rate-limit notifications, e.g. when a" + "session is continuously changing state."; uses bfd:bfd-notification-parms; leaf interface { type if:interface-ref; description "Interface to which this BFD session belongs to"; } leaf echo-enabled { type boolean; description "Was echo enabled for BFD"; } } } 2.15. BFD IP multi-hop Yang Module file "ietf-bfd-ip-mh@2017-03-07.yang" module ietf-bfd-ip-mh { namespace "urn:ietf:params:xml:ns:yang:ietf-bfd-ip-mh"; // replace with IANA namespace when assigned prefix "bfd-ip-mh"; import ietf-bfd { prefix "bfd"; } import ietf-inet-types { prefix "inet"; } import ietf-routing { prefix "rt"; } organization "IETF BFD Working Group"; Rahman, et al. Expires September 11, 2017 [Page 35] Internet-Draft BFD Yang March 2017 contact "WG Web: WG List: WG Chair: Jeff Haas WG Chair: Reshad Rahman Editor: Lianshu Zheng and Reshad Rahman"; description "This module contains the YANG definition for BFD IP multi-hop as per RFC5883. Copyright (c) 2017 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 2017-03-07 { description "Initial revision."; reference "RFC XXXX: A YANG data model for BFD IP multi-hop"; } // RFC Ed.: replace XXXX with actual RFC number and remove this // note augment "/rt:routing/rt:control-plane-protocols/" + "rt:control-plane-protocol/bfd:bfd" { description "BFD augmentation for IP multi-hop"; container ip-mh { description "BFD IP multi-hop top level container"; container config { description "BFD IP multi-hop configuration container"; container session-cfg { description "BFD IP multi-hop session configuration"; list sessions { key "source-addr dest-addr"; description "List of IP multi-hop sessions"; leaf source-addr { Rahman, et al. Expires September 11, 2017 [Page 36] Internet-Draft BFD Yang March 2017 type inet:ip-address; description "Local IP address"; } leaf dest-addr { type inet:ip-address; description "IP address of the peer"; } uses bfd:bfd-grouping-common-cfg-parms; leaf tx-ttl { type bfd:ttl; default 255; description "TTL of outgoing BFD control packets"; } leaf rx-ttl { type bfd:ttl; mandatory true; description "Minimum allowed TTL value for incoming BFD control packets"; } } } } container oper { config "false"; description "BFD IP multi-hop operational container"; uses bfd:bfd-session-statistics; list session-group { key "source-addr dest-addr"; description "BFD IP multi-hop group of sessions. A group of " + "sessions is between 1 source and 1 destination, " + "each session has a different field in UDP/IP hdr for " + "ECMP."; leaf source-addr { type inet:ip-address; description "BFD source address"; } leaf dest-addr { type inet:ip-address; description "BFD peer address"; } Rahman, et al. Expires September 11, 2017 [Page 37] Internet-Draft BFD Yang March 2017 list sessions { key "local-discriminator"; description "The BFD sessions between a source and a. " + "destination. Local discriminator is unique for " + "each session in the group."; leaf ttl { type bfd:ttl; description "TTL of outgoing packets"; } uses bfd:bfd-all-session; } } } } } notification bfd-multihop-notification { description "Notification for BFD multi-hop session state change. An " + "implementation may rate-limit notifications, e.g. when a" + "session is continuously changing state."; uses bfd:bfd-notification-parms; } } 2.16. BFD over LAG Yang Module file "ietf-bfd-lag@2017-03-07.yang" namespace "urn:ietf:params:xml:ns:yang:ietf-bfd-lag"; // replace with IANA namespace when assigned prefix "bfd-lag"; import ietf-bfd { prefix "bfd"; } import ietf-interfaces { prefix "if"; } import ietf-inet-types { prefix "inet"; } import ietf-routing { Rahman, et al. Expires September 11, 2017 [Page 38] Internet-Draft BFD Yang March 2017 prefix "rt"; } organization "IETF BFD Working Group"; contact "WG Web: WG List: WG Chair: Jeff Haas WG Chair: Reshad Rahman Editor: Lianshu Zheng and Reshad Rahman"; description "This module contains the YANG definition for BFD over LAG interfaces as per RFC7130. Copyright (c) 2017 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 2017-03-07 { description "Initial revision."; reference "RFC XXXX: A YANG data model for BFD over LAG"; } // RFC Ed.: replace XXXX with actual RFC number and remove this // note augment "/rt:routing/rt:control-plane-protocols/" + "rt:control-plane-protocol/bfd:bfd" { description "BFD augmentation for LAG"; container lag { description "BFD over LAG top level container"; container config { description "BFD over LAG configuration container"; container session-cfg { description "BFD over LAG session configuration"; list sessions { Rahman, et al. Expires September 11, 2017 [Page 39] Internet-Draft BFD Yang March 2017 key "lag-name"; description "A LAG interface on which BFD is running"; leaf lag-name { type if:interface-ref ; description "Name of the LAG"; } leaf ipv4-dest-addr { type inet:ipv4-address; description "IPv4 address of the peer, for IPv4 micro-BFD."; } leaf ipv6-dest-addr { type inet:ipv6-address; description "IPv6 address of the peer, for IPv6 micro-BFD."; } uses bfd:bfd-grouping-common-cfg-parms; } } } container oper { config "false"; description "BFD over LAG operational container."; container micro-bfd-ipv4-session-statistics { description "Micro-BFD IPv4 session counters"; uses bfd:bfd-session-statistics; } container micro-bfd-ipv6-session-statistics { description "Micro-BFD IPv6 session counters"; uses bfd:bfd-session-statistics; } list session-lag { key "lag-name"; description "A LAG interface on which BFD is running"; leaf lag-name { type if:interface-ref ; description "Name of the LAG"; } leaf use-ipv4 { type boolean; description "Using IPv4 micro-BFD."; } leaf use-ipv6 { type boolean; Rahman, et al. Expires September 11, 2017 [Page 40] Internet-Draft BFD Yang March 2017 description "Using IPv6 micro-BFD."; } list member-links { key "member-link"; description "Micro-BFD over LAG. This represents one member link"; leaf member-link { type if:interface-ref; description "Member link on which micro-BFD is running"; } container micro-bfd-ipv4 { when "../../use-ipv4 = 'true'" { description "Needed only if IPv4 is used."; } description "Micro-BFD IPv4 session state on member link"; uses bfd:bfd-all-session; } container micro-bfd-ipv6 { when "../../use-ipv6 = 'true'" { description "Needed only if IPv6 is used."; } description "Micro-BFD IPv6 session state on member link"; uses bfd:bfd-all-session; } } } } } } notification bfd-lag-notification { description "Notification for BFD over LAG session state change. " + "An implementation may rate-limit notifications, e.g. when a" + "session is continuously changing state."; uses bfd:bfd-notification-parms; leaf lag-name { type if:interface-ref; description "LAG interface name"; } Rahman, et al. Expires September 11, 2017 [Page 41] Internet-Draft BFD Yang March 2017 leaf member-link { type if:interface-ref; description "Member link on which BFD is running"; } } } 2.17. BFD over MPLS Yang Module file "ietf-bfd-mpls@2017-03-07.yang" module ietf-bfd-mpls { namespace "urn:ietf:params:xml:ns:yang:ietf-bfd-mpls"; // replace with IANA namespace when assigned prefix "bfd-mpls"; import ietf-bfd { prefix "bfd"; } import ietf-inet-types { prefix "inet"; } import ietf-routing { prefix "rt"; } organization "IETF BFD Working Group"; contact "WG Web: WG List: WG Chair: Jeff Haas WG Chair: Reshad Rahman Editor: Lianshu Zheng and Reshad Rahman"; description "This module contains the YANG definition for BFD parameters for MPLS LSPs as per RFC5884. Copyright (c) 2017 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 Rahman, et al. Expires September 11, 2017 [Page 42] Internet-Draft BFD Yang March 2017 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 2017-03-07 { description "Initial revision."; reference "RFC XXXX: A YANG data model for BFD over MPLS LSPs"; } // RFC Ed.: replace XXXX with actual RFC number and remove this // note identity bfd-encap-gach { base bfd:bfd-encap-type; description "BFD with G-ACh encapsulation as per RFC5586."; } identity bfd-encap-ip-gach { base bfd:bfd-encap-type; description "BFD with IP and G-ACh encapsulation as per RFC5586."; } grouping bfd-encap-cfg { description "Configuration for BFD encapsulation"; leaf encap { type identityref { base bfd:bfd-encap-type; } default bfd:bfd-encap-ip; description "BFD encapsulation"; } } grouping bfd-mpls-dest-address { description "Destination address as per RFC5884"; leaf mpls-dest-address { type inet:ip-address; config "false"; description "Destination address as per RFC5884. Needed if IP encapsulation is used"; } Rahman, et al. Expires September 11, 2017 [Page 43] Internet-Draft BFD Yang March 2017 } augment "/rt:routing/rt:control-plane-protocols/" + "rt:control-plane-protocol/bfd:bfd" { description "BFD augmentation for MPLS"; container mpls { description "BFD MPLS top level container"; container config { description "BFD MPLS configuration container"; container egress { description "Egress configuration"; uses bfd:bfd-grouping-base-cfg-parms; uses bfd:bfd-auth-parms; } container session-cfg { description "BFD MPLS session configuration"; list sessions { key "mpls-fec"; description "List of BFD MPLS sessions"; leaf mpls-fec { type inet:ip-address; description "MPLS FEC"; } uses bfd:bfd-grouping-common-cfg-parms; } } } container oper { config "false"; description "BFD MPLS operational container"; uses bfd:bfd-session-statistics; list session-group { key "mpls-fec"; description "BFD MPLS group of sessions. A group of sessions is" + "for 1 FEC, each session has a different field in " + "UDP/IP hdr for ECMP."; Rahman, et al. Expires September 11, 2017 [Page 44] Internet-Draft BFD Yang March 2017 leaf mpls-fec { type inet:ip-address; description "MPLS-FEC"; } list sessions { key "local-discriminator"; description "The BFD sessions for an MPLS FEC. Local " + "discriminator is unique for each session in the " + "group."; uses bfd:bfd-all-session; uses bfd-mpls:bfd-mpls-dest-address; } } } } } notification bfd-mpls-notification { description "Notification for BFD over MPLS FEC session state change. " + "An implementation may rate-limit notifications, e.g. when a" + "session is continuously changing state."; uses bfd:bfd-notification-parms; leaf mpls-dest-address { type inet:ip-address; description "Destination address as per RFC5884. Needed if IP encapsulation is used"; } } } 2.18. BFD over MPLS-TE Yang Module file "ietf-bfd-mpls-te@2017-03-07.yang" module ietf-bfd-mpls-te { namespace "urn:ietf:params:xml:ns:yang:ietf-bfd-mpls-te"; // replace with IANA namespace when assigned prefix "bfd-mpls-te"; import ietf-bfd { prefix "bfd"; Rahman, et al. Expires September 11, 2017 [Page 45] Internet-Draft BFD Yang March 2017 } import ietf-bfd-mpls { prefix "bfd-mpls"; } import ietf-te { prefix "te"; } import ietf-routing { prefix "rt"; } organization "IETF BFD Working Group"; contact "WG Web: WG List: WG Chair: Jeff Haas WG Chair: Reshad Rahman Editor: Lianshu Zheng and Reshad Rahman"; description "This module contains the YANG definition for BFD parameters for MPLS Traffic Engineering as per RFC5884. Copyright (c) 2017 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 2017-03-07 { description "Initial revision."; reference "RFC XXXX: A YANG data model for BFD over MPLS-TE"; } // RFC Ed.: replace XXXX with actual RFC number and remove this // note Rahman, et al. Expires September 11, 2017 [Page 46] Internet-Draft BFD Yang March 2017 augment "/rt:routing/rt:control-plane-protocols/" + "rt:control-plane-protocol/bfd:bfd" { description "BFD augmentation for MPLS-TE"; container mpls-te { description "BFD MPLS-TE top level container"; container config { description "BFD MPLS-TE configuration container"; container egress { description "Egress configuration"; uses bfd:bfd-grouping-base-cfg-parms; uses bfd:bfd-auth-parms; } } container oper { config "false"; description "BFD operational container"; uses bfd:bfd-session-statistics; } } } augment "/te:te/te:tunnels/te:tunnel/te:config" { description "BFD configuration on MPLS-TE tunnel."; uses bfd:bfd-grouping-common-cfg-parms; uses bfd-mpls:bfd-encap-cfg; } augment "/te:te/te:lsps-state/te:lsp" { when "/te:te/te:lsps-state/te:lsp/te:origin-type != 'transit'" { description "BFD information not needed at transit points"; } description "BFD state information on MPLS-TE LSP."; uses bfd:bfd-all-session; uses bfd-mpls:bfd-mpls-dest-address; } notification bfd-mpls-te-notification { description Rahman, et al. Expires September 11, 2017 [Page 47] Internet-Draft BFD Yang March 2017 "Notification for BFD over MPLS-TE session state change. " + "An implementation may rate-limit notifications, e.g. when a" + "session is continuously changing state."; uses bfd:bfd-notification-parms; uses bfd-mpls:bfd-mpls-dest-address; leaf tunnel-name { type string; description "MPLS-TE tunnel on which BFD was running."; } } } 2.19. Security Considerations The YANG module defined in this memo is 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]. The NETCONF access control model [RFC6536] provides the means to restrict access for particular NETCONF users to a pre-configured subset of all available NETCONF protocol operations and content. The YANG module has writeable data nodes which can be used for creation of BFD sessions and modification of BFD session parameters. The system should "police" creation of BFD sessions to prevent new sessions from causing existing BFD sessions to fail. For BFD session modification, the BFD protocol has mechanisms in place which allow for in service modification. 2.20. IANA Considerations The IANA is requested to as assign a new new namespace URI from the IETF XML registry. URI:TBD 2.21. Acknowledgements We would also like to thank Nobo Akiya and Jeff Haas for their encouragement on this work. We would also like to thank Rakesh Gandhi and Tarek Saad for their help on the MPLS-TE model. We would also like to thank Acee Lindem for his guidance. Rahman, et al. Expires September 11, 2017 [Page 48] Internet-Draft BFD Yang March 2017 3. References 3.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5586] Bocci, M., Ed., Vigoureux, M., Ed., and S. Bryant, Ed., "MPLS Generic Associated Channel", RFC 5586, DOI 10.17487/RFC5586, June 2009, . [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010, . [RFC5881] Katz, D. and D. Ward, "Bidirectional Forwarding Detection (BFD) for IPv4 and IPv6 (Single Hop)", RFC 5881, DOI 10.17487/RFC5881, June 2010, . [RFC5882] Katz, D. and D. Ward, "Generic Application of Bidirectional Forwarding Detection (BFD)", RFC 5882, DOI 10.17487/RFC5882, June 2010, . [RFC5883] Katz, D. and D. Ward, "Bidirectional Forwarding Detection (BFD) for Multihop Paths", RFC 5883, DOI 10.17487/RFC5883, June 2010, . [RFC5884] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow, "Bidirectional Forwarding Detection (BFD) for MPLS Label Switched Paths (LSPs)", RFC 5884, DOI 10.17487/RFC5884, June 2010, . [RFC5885] Nadeau, T., Ed. and C. Pignataro, Ed., "Bidirectional Forwarding Detection (BFD) for the Pseudowire Virtual Circuit Connectivity Verification (VCCV)", RFC 5885, DOI 10.17487/RFC5885, June 2010, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . Rahman, et al. Expires September 11, 2017 [Page 49] Internet-Draft BFD Yang March 2017 [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, . [RFC7130] Bhatia, M., Ed., Chen, M., Ed., Boutros, S., Ed., Binderberger, M., Ed., and J. Haas, Ed., "Bidirectional Forwarding Detection (BFD) on Link Aggregation Group (LAG) Interfaces", RFC 7130, DOI 10.17487/RFC7130, February 2014, . [RFC7223] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 7223, DOI 10.17487/RFC7223, May 2014, . [RFC7277] Bjorklund, M., "A YANG Data Model for IP Management", RFC 7277, DOI 10.17487/RFC7277, June 2014, . [RFC8022] Lhotka, L. and A. Lindem, "A YANG Data Model for Routing Management", RFC 8022, DOI 10.17487/RFC8022, November 2016, . 3.2. Informative References [I-D.ietf-lime-yang-connectionless-oam] Kumar, D., Wang, Z., Wu, Q., Rahman, R., and S. Raghavan, "Generic YANG Data Model for Connectionless Operations, Administration, and Maintenance(OAM) protocols", draft- ietf-lime-yang-connectionless-oam-04 (work in progress), February 2017. [I-D.ietf-mpls-base-yang] Raza, K., Gandhi, R., Liu, X., Beeram, V., Saad, T., Bryskin, I., Chen, X., Jones, R., and B. Wen, "A YANG Data Model for MPLS Base", draft-ietf-mpls-base-yang-02 (work in progress), March 2017. [I-D.ietf-netconf-restconf] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", draft-ietf-netconf-restconf-18 (work in progress), October 2016. [I-D.ietf-netmod-routing-cfg] Lhotka, L. and A. Lindem, "A YANG Data Model for Routing Management", draft-ietf-netmod-routing-cfg-25 (work in progress), November 2016. Rahman, et al. Expires September 11, 2017 [Page 50] Internet-Draft BFD Yang March 2017 [I-D.ietf-netmod-schema-mount] Bjorklund, M. and L. Lhotka, "YANG Schema Mount", draft- ietf-netmod-schema-mount-04 (work in progress), March 2017. [I-D.ietf-rtgwg-device-model] Lindem, A., Berger, L., Bogdanovic, D., and C. Hopps, "Network Device YANG Organizational Models", draft-ietf- rtgwg-device-model-01 (work in progress), October 2016. [I-D.ietf-rtgwg-lne-model] Berger, L., Hopps, C., Lindem, A., and D. Bogdanovic, "YANG Logical Network Elements", draft-ietf-rtgwg-lne- model-01 (work in progress), October 2016. [I-D.ietf-rtgwg-ni-model] Berger, L., Hopps, C., Lindem, A., and D. Bogdanovic, "YANG Network Instances", draft-ietf-rtgwg-ni-model-01 (work in progress), October 2016. [I-D.ietf-rtgwg-yang-key-chain] Lindem, A., Qu, Y., Yeung, D., Chen, I., Zhang, Z., and Y. Yang, "Routing Key Chain YANG Data Model", draft-ietf- rtgwg-yang-key-chain-15 (work in progress), February 2017. [I-D.ietf-teas-yang-te] Saad, T., Gandhi, R., Liu, X., Beeram, V., Shah, H., Bryskin, I., Chen, X., Jones, R., and B. Wen, "A YANG Data Model for Traffic Engineering Tunnels and Interfaces", draft-ietf-teas-yang-te-05 (work in progress), October 2016. Appendix A. Change log RFC Editor: Remove this section upon publication as an RFC. A.1. Changes between versions -04 and -05 o "bfd" node in augment of control-plane-protocol as per [RFC8022]. o Removed augment of network-instance. Replaced by schema-mount. o Added information on interaction with other YANG modules. Rahman, et al. Expires September 11, 2017 [Page 51] Internet-Draft BFD Yang March 2017 A.2. Changes between versions -03 and -04 o Updated author information. o Fixed YANG compile error in ietf-bfd-lag.yang which was due to incorrect when statement. A.3. Changes between versions -02 and -03 o Fixed YANG compilation warning due to incorrect revision date in ietf-bfd-ip-sh module. A.4. Changes between versions -01 and -02 o Replace routing-instance, which has been removed from [I-D.ietf-netmod-routing-cfg], with network-instance from [I-D.ietf-rtgwg-ni-model] A.5. Changes between versions -00 and -01 o Remove BFD configuration parameters from BFD clients, all BFD configuration parameters in BFD o YANG module split in multiple YANG modules (one per type of forwarding path) o For BFD over MPLS-TE we augment MPLS-TE model o For BFD authentication we now use key-chain in [I-D.ietf-rtgwg-yang-key-chain] Authors' Addresses Reshad Rahman (editor) Cisco Systems Canada Email: rrahman@cisco.com Lianshu Zheng (editor) Huawei Technologies China Email: vero.zheng@huawei.com Rahman, et al. Expires September 11, 2017 [Page 52] Internet-Draft BFD Yang March 2017 Santosh Pallagatti India Email: santosh.pallagatti@gmail.com Mahesh Jethanandani Cisco Systems Email: mjethanandani@gmail.com Greg Mirsky ZTE Corporation Email: gregimirsky@gmail.com Rahman, et al. Expires September 11, 2017 [Page 53]