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YANG Data Model for Bidirectional Forwarding Detection (BFD)
Xoriant Corporation
1248 Reamwood Ave
Sunnyvale
CA
United States of America
mjethanandani@gmail.com
Canada
reshad@yahoo.com
Huawei Technologies
China
veronique_cheng@hotmail.com
VMware
India
santosh.pallagatti@gmail.com
Ericsson
gregimirsky@gmail.com
Liveliness check
BGP
OSPF
IS-IS
TCP-AO
MD5
This document defines a YANG data model that can be used to configure
and manage Bidirectional Forwarding Detection (BFD).
The YANG modules in this document conform to the Network Management
Datastore Architecture (NMDA) (RFC 8342). This document updates "YANG Data Model for Bidirectional Forwarding Detection (BFD)" (RFC 9127).
Introduction
This document defines a YANG data model that can be used to configure
and manage Bidirectional Forwarding Detection (BFD)
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, as described in "Generic Application of Bidirectional Forwarding
Detection (BFD)" . The obvious
candidates that use BFD are those that 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.
The YANG modules in this document conform to the Network Management Datastore
Architecture (NMDA) . This means that the data models do not have
separate top-level or sibling containers for configuration data and
operational state data.
Tree Diagrams
This document uses the graphical representation of data models, as defined in
Design of the Data Model
Since BFD is used for liveness detection of various forwarding
paths, there is no uniform key to identify a BFD session. Therefore, the BFD
data model is split into 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 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 that 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 "A YANG Data Model for Routing
Management (NMDA Version)" . This new "bfd" container is augmented
by the following YANG modules for their respective specific information:
BFD can operate in the following contexts:
When used at the network device level, the BFD YANG data model is
used "as is". When the BFD YANG data model is used in an LNE or network instance, the BFD YANG data model augments
the mounted routing model for the LNE or network instance.
Design of the Configuration Model
The configuration model consists mainly of the parameters specified
in BFD -- for example, desired
minimum transmit interval, required minimum receive interval, and
detection multiplier.
BFD clients are applications that use BFD for fast detection of
failures. Some implementations have BFD session configuration under
the BFD clients -- for example, BFD session configuration under routing
applications such as OSPF, IS-IS, or BGP. Other implementations have
BFD session configuration centralized under BFD, i.e., outside the
multiple BFD clients.
The main BFD parameters of interest to a BFD client are those
related to 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. Configuration of BFD for all
clients should be centralized. However, this is a problem for BFD clients
that auto-discover their peers. For example, IGPs do not have the
peer address configured; instead, the IGP is enabled on an interface,
and the IGP peers are auto-discovered. So, for an operator to configure
BFD to an IGP peer, the operator would first have to determine the
peer addresses. And when a new peer is discovered, BFD configuration
would need to be added. To avoid this issue, we define the grouping
"client-cfg-parms" in
Common BFD Configuration Parameters
The basic BFD configuration parameters are as follows:
Although BFD
allows for different values for transmit and receive intervals, some
implementations allow users to specify just one interval that is
used for both transmit and receive intervals, or separate values for
transmit and receive intervals. The BFD YANG data 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 the
"base-cfg-parms" grouping (
For BFD authentication, we have the following:
Single-Hop IP
For single-hop IP, there is an augment of the "bfd" data node, as
described in
Multihop IP
For multihop IP, there is an augment of the "bfd" data node, as described in
Because of multiple paths, there could be multiple multihop IP
sessions between a source and a destination address. We identify
this set of sessions as a "session-group". The key for each "session-group" consists
of the following:
We use the configuration parameters defined in
This document also provides the following parameters:
MPLS Label Switched Paths
Here, we address MPLS LSPs whose
Forwarding Equivalence Class (FEC)
Since these LSPs are unidirectional, there is no LSP
configuration on the egress node.
The BFD parameters for the egress node are added under
"mpls".
Link Aggregation Groups
Per "Bidirectional
Forwarding Detection (BFD) on Link Aggregation Group (LAG)
Interfaces" , configuring BFD on a 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 data model that we can augment. So, a "lag" data node is
added to the "bfd" node; see
Design of the Operational State Model
The operational state model contains both the overall statistics for
the BFD sessions running on the device and the per-session operational
information.
The overall statistics for the BFD sessions consist of the number of BFD
sessions, the number of BFD sessions that are up, etc. This information is available
globally (i.e., for all BFD sessions) under the "bfd" node
(
For each BFD session, three main categories of operational state
data are shown.
For some path types, there may be more than one session on the
virtual path to the destination. For example, with IP multihop and
MPLS LSPs, there could be multiple BFD sessions from the source to the
same destination to test the various paths (ECMP) to the destination.
This is represented by having multiple "sessions" under each
"session-group".
Notifications
This YANG data model defines notifications to inform end users of
important events detected during the protocol operation. The
local discriminator identifies the corresponding BFD session on the
local system, and the remote discriminator identifies the BFD session
on the remote 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.
RPC Operations
None.
BFD Top-Level Hierarchy
At the "bfd" node under "control-plane-protocol", there is no
configuration data -- only operational state data. The operational state
data consists of overall BFD session statistics, i.e., for BFD on all
types of forwarding paths.
module: ietf-bfd
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol:
+--rw bfd
+--ro summary
+--ro number-of-sessions? yang:gauge32
+--ro number-of-sessions-up? yang:gauge32
+--ro number-of-sessions-down? yang:gauge32
+--ro number-of-sessions-admin-down? yang:gauge32
BFD IP Single-Hop Hierarchy
An "ip-sh" node is added under the "bfd" node in
"control-plane-protocol". The configuration data and operational state data
for each BFD IP single-hop session are under this "ip-sh" node.
module: ietf-bfd-ip-sh
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/bfd:bfd:
+--rw ip-sh
+--ro summary
| +--ro number-of-sessions? yang:gauge32
| +--ro number-of-sessions-up? yang:gauge32
| +--ro number-of-sessions-down? yang:gauge32
| +--ro number-of-sessions-admin-down? yang:gauge32
+--rw sessions
| +--rw session* [interface dest-addr]
| +--rw interface if:interface-ref
| +--rw dest-addr inet:ip-address
| +--rw source-addr? inet:ip-address
| +--rw local-multiplier? multiplier
| +--rw (interval-config-type)?
| | +--:(tx-rx-intervals)
| | | +--rw desired-min-tx-interval? uint32
| | | +--rw required-min-rx-interval? uint32
| | +--:(single-interval) {single-minimum-interval}?
| | +--rw min-interval? uint32
| +--rw demand-enabled? boolean
| | {demand-mode}?
| +--rw admin-down? boolean
| +--rw authentication! {authentication}?
| | +--rw key-chain? key-chain:key-chain-ref
| | +--rw meticulous? boolean
| +--ro path-type? identityref
| +--ro ip-encapsulation? boolean
| +--ro local-discriminator? discriminator
| +--ro remote-discriminator? discriminator
| +--ro remote-multiplier? multiplier
| +--ro demand-capability? boolean
| | {demand-mode}?
| +--ro source-port? inet:port-number
| +--ro dest-port? inet:port-number
| +--ro session-running
| | +--ro session-index? uint32
| | +--ro local-state? state
| | +--ro remote-state? state
| | +--ro local-diagnostic?
| | | iana-bfd-types:diagnostic
| | +--ro remote-diagnostic?
| | | iana-bfd-types:diagnostic
| | +--ro remote-authenticated? boolean
| | +--ro remote-authentication-type?
| | | iana-bfd-types:auth-type {authentication}?
| | +--ro detection-mode? enumeration
| | +--ro negotiated-tx-interval? uint32
| | +--ro negotiated-rx-interval? uint32
| | +--ro detection-time? uint32
| | +--ro echo-tx-interval-in-use? uint32
| | {echo-mode}?
| +--ro session-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? yang:counter32
| +--ro admin-down-count? yang:counter32
| +--ro receive-packet-count? yang:counter64
| +--ro send-packet-count? yang:counter64
| +--ro receive-invalid-packet-count? yang:counter64
| +--ro send-failed-packet-count? yang:counter64
+--rw interfaces* [interface]
+--rw interface if:interface-ref
+--rw authentication! {authentication}?
+--rw key-chain? key-chain:key-chain-ref
+--rw meticulous? boolean
notifications:
+---n singlehop-notification
+--ro local-discr? discriminator
+--ro remote-discr? discriminator
+--ro new-state? state
+--ro state-change-reason? iana-bfd-types:diagnostic
+--ro time-of-last-state-change? yang:date-and-time
+--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
BFD IP Multihop Hierarchy
An "ip-mh" node is added under the "bfd" node in
"control-plane-protocol". The configuration data and operational state data
for each BFD IP multihop session are under this "ip-mh" node. In the
operational state model, we support multiple BFD multihop sessions per
remote address (ECMP); the local discriminator is used as the key.
module: ietf-bfd-ip-mh
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/bfd:bfd:
+--rw ip-mh
+--ro summary
| +--ro number-of-sessions? yang:gauge32
| +--ro number-of-sessions-up? yang:gauge32
| +--ro number-of-sessions-down? yang:gauge32
| +--ro number-of-sessions-admin-down? yang:gauge32
+--rw session-groups
+--rw session-group* [source-addr dest-addr]
+--rw source-addr inet:ip-address
+--rw dest-addr inet:ip-address
+--rw local-multiplier? multiplier
+--rw (interval-config-type)?
| +--:(tx-rx-intervals)
| | +--rw desired-min-tx-interval? uint32
| | +--rw required-min-rx-interval? uint32
| +--:(single-interval) {single-minimum-interval}?
| +--rw min-interval? uint32
+--rw demand-enabled? boolean
| {demand-mode}?
+--rw admin-down? boolean
+--rw authentication! {authentication}?
| +--rw key-chain? key-chain:key-chain-ref
| +--rw meticulous? boolean
+--rw tx-ttl? bfd-types:hops
+--rw rx-ttl bfd-types:hops
+--ro sessions* []
+--ro path-type? identityref
+--ro ip-encapsulation? boolean
+--ro local-discriminator? discriminator
+--ro remote-discriminator? discriminator
+--ro remote-multiplier? multiplier
+--ro demand-capability? boolean {demand-mode}?
+--ro source-port? inet:port-number
+--ro dest-port? inet:port-number
+--ro session-running
| +--ro session-index? uint32
| +--ro local-state? state
| +--ro remote-state? state
| +--ro local-diagnostic?
| | iana-bfd-types:diagnostic
| +--ro remote-diagnostic?
| | iana-bfd-types:diagnostic
| +--ro remote-authenticated? boolean
| +--ro remote-authentication-type?
| | iana-bfd-types:auth-type {authentication}?
| +--ro detection-mode? enumeration
| +--ro negotiated-tx-interval? uint32
| +--ro negotiated-rx-interval? uint32
| +--ro detection-time? uint32
| +--ro echo-tx-interval-in-use? uint32
| {echo-mode}?
+--ro session-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?
| yang:counter32
+--ro admin-down-count?
| yang:counter32
+--ro receive-packet-count?
| yang:counter64
+--ro send-packet-count?
| yang:counter64
+--ro receive-invalid-packet-count?
| yang:counter64
+--ro send-failed-packet-count?
yang:counter64
notifications:
+---n multihop-notification
+--ro local-discr? discriminator
+--ro remote-discr? discriminator
+--ro new-state? state
+--ro state-change-reason? iana-bfd-types:diagnostic
+--ro time-of-last-state-change? yang:date-and-time
+--ro dest-addr? inet:ip-address
+--ro source-addr? inet:ip-address
+--ro session-index? uint32
+--ro path-type? identityref
BFD-over-LAG Hierarchy
A "lag" node is added under the "bfd" node in
"control-plane-protocol". The configuration data and operational state data
for each BFD LAG session are under this "lag" node.
module: ietf-bfd-lag
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/bfd:bfd:
+--rw lag
+--rw micro-bfd-ipv4-session-statistics
| +--ro summary
| +--ro number-of-sessions? yang:gauge32
| +--ro number-of-sessions-up? yang:gauge32
| +--ro number-of-sessions-down? yang:gauge32
| +--ro number-of-sessions-admin-down? yang:gauge32
+--rw micro-bfd-ipv6-session-statistics
| +--ro summary
| +--ro number-of-sessions? yang:gauge32
| +--ro number-of-sessions-up? yang:gauge32
| +--ro number-of-sessions-down? yang:gauge32
| +--ro number-of-sessions-admin-down? yang:gauge32
+--rw sessions
+--rw session* [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? multiplier
+--rw (interval-config-type)?
| +--:(tx-rx-intervals)
| | +--rw desired-min-tx-interval? uint32
| | +--rw required-min-rx-interval? uint32
| +--:(single-interval) {single-minimum-interval}?
| +--rw min-interval? uint32
+--rw demand-enabled? boolean
| {demand-mode}?
+--rw admin-down? boolean
+--rw authentication! {authentication}?
| +--rw key-chain? key-chain:key-chain-ref
| +--rw meticulous? boolean
+--rw use-ipv4? boolean
+--rw use-ipv6? boolean
+--ro member-links* [member-link]
+--ro member-link if:interface-ref
+--ro micro-bfd-ipv4
| +--ro path-type? identityref
| +--ro ip-encapsulation? boolean
| +--ro local-discriminator? discriminator
| +--ro remote-discriminator? discriminator
| +--ro remote-multiplier? multiplier
| +--ro demand-capability? boolean
| | {demand-mode}?
| +--ro source-port? inet:port-number
| +--ro dest-port? inet:port-number
| +--ro session-running
| | +--ro session-index? uint32
| | +--ro local-state? state
| | +--ro remote-state? state
| | +--ro local-diagnostic?
| | | iana-bfd-types:diagnostic
| | +--ro remote-diagnostic?
| | | iana-bfd-types:diagnostic
| | +--ro remote-authenticated? boolean
| | +--ro remote-authentication-type?
| | | iana-bfd-types:auth-type
| | | {authentication}?
| | +--ro detection-mode? enumeration
| | +--ro negotiated-tx-interval? uint32
| | +--ro negotiated-rx-interval? uint32
| | +--ro detection-time? uint32
| | +--ro echo-tx-interval-in-use? uint32
| | {echo-mode}?
| +--ro session-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?
| | yang:counter32
| +--ro admin-down-count?
| | yang:counter32
| +--ro receive-packet-count?
| | yang:counter64
| +--ro send-packet-count?
| | yang:counter64
| +--ro receive-invalid-packet-count?
| | yang:counter64
| +--ro send-failed-packet-count?
| yang:counter64
+--ro micro-bfd-ipv6
+--ro path-type? identityref
+--ro ip-encapsulation? boolean
+--ro local-discriminator? discriminator
+--ro remote-discriminator? discriminator
+--ro remote-multiplier? multiplier
+--ro demand-capability? boolean
| {demand-mode}?
+--ro source-port? inet:port-number
+--ro dest-port? inet:port-number
+--ro session-running
| +--ro session-index? uint32
| +--ro local-state? state
| +--ro remote-state? state
| +--ro local-diagnostic?
| | iana-bfd-types:diagnostic
| +--ro remote-diagnostic?
| | iana-bfd-types:diagnostic
| +--ro remote-authenticated? boolean
| +--ro remote-authentication-type?
| | iana-bfd-types:auth-type
| | {authentication}?
| +--ro detection-mode? enumeration
| +--ro negotiated-tx-interval? uint32
| +--ro negotiated-rx-interval? uint32
| +--ro detection-time? uint32
| +--ro echo-tx-interval-in-use? uint32
| {echo-mode}?
+--ro session-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?
| yang:counter32
+--ro admin-down-count?
| yang:counter32
+--ro receive-packet-count?
| yang:counter64
+--ro send-packet-count?
| yang:counter64
+--ro receive-invalid-packet-count?
| yang:counter64
+--ro send-failed-packet-count?
yang:counter64
notifications:
+---n lag-notification
+--ro local-discr? discriminator
+--ro remote-discr? discriminator
+--ro new-state? state
+--ro state-change-reason? iana-bfd-types:diagnostic
+--ro time-of-last-state-change? yang:date-and-time
+--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
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 state model, we support multiple BFD
sessions per MPLS FEC (ECMP); the local discriminator is used as the key.
The "mpls" node can be used in a network device (top level) or can be
mounted in an LNE or network instance.
module: ietf-bfd-mpls
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/bfd:bfd:
+--rw mpls
+--ro summary
| +--ro number-of-sessions? yang:gauge32
| +--ro number-of-sessions-up? yang:gauge32
| +--ro number-of-sessions-down? yang:gauge32
| +--ro number-of-sessions-admin-down? yang:gauge32
+--rw egress
| +--rw enabled? boolean
| +--rw local-multiplier? multiplier
| +--rw (interval-config-type)?
| | +--:(tx-rx-intervals)
| | | +--rw desired-min-tx-interval? uint32
| | | +--rw required-min-rx-interval? uint32
| | +--:(single-interval) {single-minimum-interval}?
| | +--rw min-interval? uint32
| +--rw authentication! {authentication}?
| +--rw key-chain? key-chain:key-chain-ref
| +--rw meticulous? boolean
+--rw session-groups
+--rw session-group* [mpls-fec]
+--rw mpls-fec inet:ip-prefix
+--rw local-multiplier? multiplier
+--rw (interval-config-type)?
| +--:(tx-rx-intervals)
| | +--rw desired-min-tx-interval? uint32
| | +--rw required-min-rx-interval? uint32
| +--:(single-interval) {single-minimum-interval}?
| +--rw min-interval? uint32
+--rw demand-enabled? boolean
| {demand-mode}?
+--rw admin-down? boolean
+--rw authentication! {authentication}?
| +--rw key-chain? key-chain:key-chain-ref
| +--rw meticulous? boolean
+--ro sessions* []
+--ro path-type? identityref
+--ro ip-encapsulation? boolean
+--ro local-discriminator? discriminator
+--ro remote-discriminator? discriminator
+--ro remote-multiplier? multiplier
+--ro demand-capability? boolean {demand-mode}?
+--ro source-port? inet:port-number
+--ro dest-port? inet:port-number
+--ro session-running
| +--ro session-index? uint32
| +--ro local-state? state
| +--ro remote-state? state
| +--ro local-diagnostic?
| | iana-bfd-types:diagnostic
| +--ro remote-diagnostic?
| | iana-bfd-types:diagnostic
| +--ro remote-authenticated? boolean
| +--ro remote-authentication-type?
| | iana-bfd-types:auth-type {authentication}?
| +--ro detection-mode? enumeration
| +--ro negotiated-tx-interval? uint32
| +--ro negotiated-rx-interval? uint32
| +--ro detection-time? uint32
| +--ro echo-tx-interval-in-use? uint32
| {echo-mode}?
+--ro session-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?
| | yang:counter32
| +--ro admin-down-count?
| | yang:counter32
| +--ro receive-packet-count?
| | yang:counter64
| +--ro send-packet-count?
| | yang:counter64
| +--ro receive-invalid-packet-count?
| | yang:counter64
| +--ro send-failed-packet-count?
| yang:counter64
+--ro mpls-dest-address? inet:ip-address
notifications:
+---n mpls-notification
+--ro local-discr? discriminator
+--ro remote-discr? discriminator
+--ro new-state? state
+--ro state-change-reason? iana-bfd-types:diagnostic
+--ro time-of-last-state-change? yang:date-and-time
+--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
Interaction with Other YANG Modules
"Generic YANG Data Model for the Management
of Operations, Administration, and Maintenance (OAM) Protocols That
Use Connectionless Communications" describes how the
Layer-Independent OAM Management in the Multi-Layer Environment (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.
"ietf-interfaces" Module
The following boolean configuration is defined in "A YANG Data Model for Interface Management" :
"ietf-ip" Module
The following boolean configuration is defined in "A YANG Data Model for IP Management" :
"ietf-mpls" Module
The following boolean configuration is defined in "A YANG Data Model for MPLS Base" :
BFD Types YANG Module
This YANG module imports typedefs from
WG List:
Editor: Reshad Rahman
Editor: Lianshu Zheng
Editor: Mahesh Jethanandani
";
description
"This module contains a collection of BFD-specific YANG data type
definitions, as per RFC 5880, and also groupings that are common
to other BFD YANG modules.
Copyright (c) 2022 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 Revised BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 9314; see the
RFC itself for full legal notices.";
reference
"RFC 5880: Bidirectional Forwarding Detection (BFD)
RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
revision 2022-09-22 {
description
"This revision is not backwards compatible with the
previous version of this model.
This revision adds an 'if-feature' statement called
'client-base-cfg-parms' for client configuration parameters.
Clients expecting to use those parameters now need to
verify that the server declares support of the feature
before depending on the presence of the parameters.
The change was introduced for clients that do not need
them and have to deviate to prevent them from being
included.";
reference
"RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD).";
}
revision 2021-10-21 {
description
"Initial revision.";
reference
"RFC 9127: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
}
/*
* Feature definitions
*/
feature single-minimum-interval {
description
"This feature indicates that the server supports configuration
of one minimum interval value that is used for both transmit
and receive minimum intervals.";
}
feature authentication {
description
"This feature indicates that the server supports BFD
authentication.";
reference
"RFC 5880: Bidirectional Forwarding Detection (BFD),
Section 6.7";
}
feature demand-mode {
description
"This feature indicates that the server supports BFD Demand
mode.";
reference
"RFC 5880: Bidirectional Forwarding Detection (BFD),
Section 6.6";
}
feature echo-mode {
description
"This feature indicates that the server supports BFD Echo
mode.";
reference
"RFC 5880: Bidirectional Forwarding Detection (BFD),
Section 6.4";
}
feature client-base-cfg-parms {
description
"This feature allows protocol models to configure BFD client
session parameters.";
reference
"RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD).";
}
/*
* Identity definitions
*/
identity bfdv1 {
base rt:control-plane-protocol;
description
"BFD protocol version 1.";
reference
"RFC 5880: Bidirectional Forwarding Detection (BFD)";
}
identity path-type {
description
"Base identity for the BFD path type. The path type indicates
the type of path on which BFD is running.";
}
identity path-ip-sh {
base path-type;
description
"BFD on IP single-hop.";
reference
"RFC 5881: Bidirectional Forwarding Detection (BFD)
for IPv4 and IPv6 (Single Hop)";
}
identity path-ip-mh {
base path-type;
description
"BFD on IP multihop paths.";
reference
"RFC 5883: Bidirectional Forwarding Detection (BFD) for
Multihop Paths";
}
identity path-mpls-te {
base path-type;
description
"BFD on MPLS Traffic Engineering.";
reference
"RFC 5884: Bidirectional Forwarding Detection (BFD)
for MPLS Label Switched Paths (LSPs)";
}
identity path-mpls-lsp {
base path-type;
description
"BFD on an MPLS Label Switched Path.";
reference
"RFC 5884: Bidirectional Forwarding Detection (BFD)
for MPLS Label Switched Paths (LSPs)";
}
identity path-lag {
base path-type;
description
"Micro-BFD on LAG member links.";
reference
"RFC 7130: Bidirectional Forwarding Detection (BFD) on
Link Aggregation Group (LAG) Interfaces";
}
identity encap-type {
description
"Base identity for BFD encapsulation type.";
}
identity encap-ip {
base encap-type;
description
"BFD with IP encapsulation.";
}
/*
* Type definitions
*/
typedef discriminator {
type uint32;
description
"BFD Discriminator as described in RFC 5880.";
reference
"RFC 5880: Bidirectional Forwarding Detection (BFD)";
}
typedef state {
type enumeration {
enum adminDown {
value 0;
description
"'adminDown' state.";
}
enum down {
value 1;
description
"'Down' state.";
}
enum init {
value 2;
description
"'Init' state.";
}
enum up {
value 3;
description
"'Up' state.";
}
}
description
"BFD states as defined in RFC 5880.";
}
typedef multiplier {
type uint8 {
range "1..255";
}
description
"BFD multiplier as described in RFC 5880.";
}
typedef hops {
type uint8 {
range "1..255";
}
description
"This corresponds to Time To Live for IPv4 and corresponds to
the hop limit for IPv6.";
}
/*
* Groupings
*/
grouping auth-parms {
description
"Grouping for BFD authentication parameters
(see Section 6.7 of RFC 5880).";
container authentication {
if-feature "authentication";
presence "Enables BFD authentication (see Section 6.7
of RFC 5880).";
description
"Parameters for BFD authentication.";
reference
"RFC 5880: Bidirectional Forwarding Detection (BFD),
Section 6.7";
leaf key-chain {
type key-chain:key-chain-ref;
description
"Name of the 'key-chain' as per RFC 8177.";
}
leaf meticulous {
type boolean;
description
"Enables a meticulous mode as per Section 6.7 of
RFC 5880.";
}
}
}
grouping base-cfg-parms {
description
"BFD grouping for base configuration parameters.";
leaf local-multiplier {
type multiplier;
default "3";
description
"Multiplier transmitted by the local system.";
}
choice interval-config-type {
default "tx-rx-intervals";
description
"Two interval values or one value used for both transmit and
receive.";
case tx-rx-intervals {
leaf desired-min-tx-interval {
type uint32;
units "microseconds";
default "1000000";
description
"Desired minimum transmit interval of control packets.";
}
leaf required-min-rx-interval {
type uint32;
units "microseconds";
default "1000000";
description
"Required minimum receive interval of control packets.";
}
}
case single-interval {
if-feature "single-minimum-interval";
leaf min-interval {
type uint32;
units "microseconds";
default "1000000";
description
"Desired minimum transmit interval and required
minimum receive interval of control packets.";
}
}
}
}
grouping client-cfg-parms {
description
"BFD grouping for configuration parameters
used by BFD clients, e.g., IGP or MPLS.";
leaf enabled {
type boolean;
default "false";
description
"Indicates whether BFD is enabled.";
}
uses base-cfg-parms {
if-feature "client-base-cfg-parms";
}
}
grouping common-cfg-parms {
description
"BFD grouping for common configuration parameters.";
uses base-cfg-parms;
leaf demand-enabled {
if-feature "demand-mode";
type boolean;
default "false";
description
"To enable Demand mode.";
}
leaf admin-down {
type boolean;
default "false";
description
"Indicates whether the BFD session is administratively
down.";
}
uses auth-parms;
}
grouping all-session {
description
"BFD session operational information.";
leaf path-type {
type identityref {
base path-type;
}
config false;
description
"BFD path type. This indicates the path type that BFD is
running on.";
}
leaf ip-encapsulation {
type boolean;
config false;
description
"Indicates whether BFD encapsulation uses IP.";
}
leaf local-discriminator {
type discriminator;
config false;
description
"Local discriminator.";
}
leaf remote-discriminator {
type discriminator;
config false;
description
"Remote discriminator.";
}
leaf remote-multiplier {
type multiplier;
config false;
description
"Remote multiplier.";
}
leaf demand-capability {
if-feature "demand-mode";
type boolean;
config false;
description
"Local Demand mode capability.";
}
leaf source-port {
when "../ip-encapsulation = 'true'" {
description
"Source port valid only when IP encapsulation is used.";
}
type inet:port-number;
config false;
description
"Source UDP port.";
}
leaf dest-port {
when "../ip-encapsulation = 'true'" {
description
"Destination port valid only when IP encapsulation
is used.";
}
type inet:port-number;
config false;
description
"Destination UDP port.";
}
container session-running {
config false;
description
"BFD 'session-running' information.";
leaf session-index {
type uint32;
description
"An index used to uniquely identify BFD sessions.";
}
leaf local-state {
type state;
description
"Local state.";
}
leaf remote-state {
type state;
description
"Remote state.";
}
leaf local-diagnostic {
type iana-bfd-types:diagnostic;
description
"Local diagnostic.";
}
leaf remote-diagnostic {
type iana-bfd-types:diagnostic;
description
"Remote diagnostic.";
}
leaf remote-authenticated {
type boolean;
description
"Indicates whether incoming BFD control packets are
authenticated.";
}
leaf remote-authentication-type {
when "../remote-authenticated = 'true'" {
description
"Only valid when incoming BFD control packets are
authenticated.";
}
if-feature "authentication";
type iana-bfd-types:auth-type;
description
"Authentication type of incoming BFD control packets.";
}
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 {
type uint32;
units "microseconds";
description
"Negotiated transmit interval.";
}
leaf negotiated-rx-interval {
type uint32;
units "microseconds";
description
"Negotiated receive interval.";
}
leaf detection-time {
type uint32;
units "microseconds";
description
"Detection time.";
}
leaf echo-tx-interval-in-use {
when "../../path-type = 'bfd-types:path-ip-sh'" {
description
"Echo is supported for IP single-hop only.";
}
if-feature "echo-mode";
type uint32;
units "microseconds";
description
"Echo transmit interval in use.";
}
}
container session-statistics {
config false;
description
"BFD per-session statistics.";
leaf create-time {
type yang:date-and-time;
description
"Time and date when this session was created.";
}
leaf last-down-time {
type yang:date-and-time;
description
"Time and date of the last time this session went down.";
}
leaf last-up-time {
type yang:date-and-time;
description
"Time and date of the last time this session went up.";
}
leaf down-count {
type yang:counter32;
description
"The number of times this session has transitioned to the
'down' state.";
}
leaf admin-down-count {
type yang:counter32;
description
"The number of times this session has transitioned to the
'admin-down' state.";
}
leaf receive-packet-count {
type yang:counter64;
description
"Count of received packets in this session. This includes
valid and invalid received packets.";
}
leaf send-packet-count {
type yang:counter64;
description
"Count of sent packets in this session.";
}
leaf receive-invalid-packet-count {
type yang:counter64;
description
"Count of invalid received packets in this session.";
}
leaf send-failed-packet-count {
type yang:counter64;
description
"Count of packets that failed to be sent in this session.";
}
}
}
grouping session-statistics-summary {
description
"Grouping for session statistics summary.";
container summary {
config false;
description
"BFD session statistics summary.";
leaf number-of-sessions {
type yang:gauge32;
description
"Number of BFD sessions.";
}
leaf number-of-sessions-up {
type yang:gauge32;
description
"Number of BFD sessions currently in the 'Up' state
(as defined in RFC 5880).";
}
leaf number-of-sessions-down {
type yang:gauge32;
description
"Number of BFD sessions currently in the 'Down' or 'Init'
state but not 'adminDown' (as defined in RFC 5880).";
}
leaf number-of-sessions-admin-down {
type yang:gauge32;
description
"Number of BFD sessions currently in the 'adminDown' state
(as defined in RFC 5880).";
}
}
}
grouping notification-parms {
description
"This group describes common parameters that will be sent
as part of BFD notifications.";
leaf local-discr {
type discriminator;
description
"BFD local discriminator.";
}
leaf remote-discr {
type discriminator;
description
"BFD remote discriminator.";
}
leaf new-state {
type state;
description
"Current BFD state.";
}
leaf state-change-reason {
type iana-bfd-types:diagnostic;
description
"Reason for the BFD state change.";
}
leaf time-of-last-state-change {
type yang:date-and-time;
description
"Calendar time of the most recent previous state change.";
}
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 path-type;
}
description
"BFD path type.";
}
}
}
]]>
BFD Top-Level YANG Module
This YANG module imports and augments
"/routing/control-plane-protocols/control-plane-protocol" from
WG List:
Editor: Reshad Rahman
Editor: Lianshu Zheng
Editor: Mahesh Jethanandani
";
description
"This module contains the YANG definition for BFD parameters as
per RFC 5880.
Copyright (c) 2022 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 Revised BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 9314; see the
RFC itself for full legal notices.";
reference
"RFC 5880: Bidirectional Forwarding Detection (BFD)
RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
revision 2022-09-22 {
description
"Updating reference to RFC 9314.";
reference
"RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD).";
}
revision 2021-10-21 {
description
"Initial revision.";
reference
"RFC 9127: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol" {
when "derived-from-or-self(rt:type, 'bfd-types: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.";
uses bfd-types:session-statistics-summary;
}
}
}
]]>
BFD IP Single-Hop YANG Module
This YANG module imports "interface-ref" from
WG List:
Editor: Reshad Rahman
Editor: Lianshu Zheng
Editor: Mahesh Jethanandani
";
description
"This module contains the YANG definition for BFD IP single-hop
as per RFC 5881.
Copyright (c) 2022 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 Revised BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 9314; see the
RFC itself for full legal notices.";
reference
"RFC 5881: Bidirectional Forwarding Detection (BFD)
for IPv4 and IPv6 (Single Hop)
RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
revision 2022-09-22 {
description
"Updating reference to RFC 9314.";
reference
"RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD).";
}
revision 2021-10-21 {
description
"Initial revision.";
reference
"RFC 9127: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
}
/*
* Augments
*/
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.";
uses bfd-types:session-statistics-summary;
container sessions {
description
"BFD IP single-hop sessions.";
list session {
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 IP address.";
}
uses bfd-types:common-cfg-parms;
uses bfd-types:all-session;
}
}
list interfaces {
key "interface";
description
"List of interfaces.";
leaf interface {
type if:interface-ref;
description
"BFD information for this interface.";
}
uses bfd-types:auth-parms;
}
}
}
/*
* Notifications
*/
notification 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-types:notification-parms;
leaf interface {
type if:interface-ref;
description
"Interface to which this BFD session belongs.";
}
leaf echo-enabled {
type boolean;
description
"Indicates whether Echo was enabled for BFD.";
}
}
}
]]>
BFD IP Multihop YANG Module
This YANG module imports typedefs from
WG List:
Editor: Reshad Rahman
Editor: Lianshu Zheng
Editor: Mahesh Jethanandani
";
description
"This module contains the YANG definition for BFD IP multihop
as per RFC 5883.
Copyright (c) 2022 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 Revised BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 9314; see the
RFC itself for full legal notices.";
reference
"RFC 5883: Bidirectional Forwarding Detection (BFD) for
Multihop Paths
RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
revision 2022-09-22 {
description
"Updating reference to RFC 9314.";
reference
"RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD).";
}
revision 2021-10-21 {
description
"Initial revision.";
reference
"RFC 9127: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
}
/*
* Augments
*/
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/bfd:bfd" {
description
"BFD augmentation for IP multihop.";
container ip-mh {
description
"BFD IP multihop top-level container.";
uses bfd-types:session-statistics-summary;
container session-groups {
description
"BFD IP multihop session groups.";
list session-group {
key "source-addr dest-addr";
description
"Group of BFD IP multihop sessions (for ECMP). A
group of sessions is between one source and one
destination. Each session has a different field
in the UDP/IP header for ECMP.";
leaf source-addr {
type inet:ip-address;
description
"Local IP address.";
}
leaf dest-addr {
type inet:ip-address;
description
"IP address of the peer.";
}
uses bfd-types:common-cfg-parms;
leaf tx-ttl {
type bfd-types:hops;
default "255";
description
"Hop count of outgoing BFD control packets.";
}
leaf rx-ttl {
type bfd-types:hops;
mandatory true;
description
"Minimum allowed hop count value for incoming BFD
control packets. Control packets whose hop count is
lower than this value are dropped.";
}
list sessions {
config false;
description
"The multiple BFD sessions between a source and a
destination.";
uses bfd-types:all-session;
}
}
}
}
}
/*
* Notifications
*/
notification multihop-notification {
description
"Notification for BFD multihop session state change. An
implementation may rate-limit notifications, e.g., when a
session is continuously changing state.";
uses bfd-types:notification-parms;
}
}
]]>
BFD-over-LAG YANG Module
This YANG module imports "interface-ref" from
WG List:
Editor: Reshad Rahman
Editor: Lianshu Zheng
Editor: Mahesh Jethanandani
";
description
"This module contains the YANG definition for BFD-over-LAG
interfaces as per RFC 7130.
Copyright (c) 2022 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 Revised BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 9314; see the
RFC itself for full legal notices.";
reference
"RFC 7130: Bidirectional Forwarding Detection (BFD) on
Link Aggregation Group (LAG) Interfaces
RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
revision 2022-09-22 {
description
"Updating reference to RFC 9314.";
reference
"RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD).";
}
revision 2021-10-21 {
description
"Initial revision.";
reference
"RFC 9127: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
}
/*
* Augments
*/
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/bfd:bfd" {
description
"BFD augmentation for a LAG.";
container lag {
description
"BFD-over-LAG top-level container.";
container micro-bfd-ipv4-session-statistics {
description
"Micro-BFD IPv4 session counters.";
uses bfd-types:session-statistics-summary;
}
container micro-bfd-ipv6-session-statistics {
description
"Micro-BFD IPv6 session counters.";
uses bfd-types:session-statistics-summary;
}
container sessions {
description
"BFD-over-LAG sessions.";
list session {
key "lag-name";
description
"List of BFD-over-LAG sessions.";
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-types:common-cfg-parms;
leaf use-ipv4 {
type boolean;
description
"Using IPv4 micro-BFD.";
}
leaf use-ipv6 {
type boolean;
description
"Using IPv6 micro-BFD.";
}
list member-links {
key "member-link";
config false;
description
"Micro-BFD over a 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 a member link.";
uses bfd-types:all-session;
}
container micro-bfd-ipv6 {
when "../../use-ipv6 = 'true'" {
description
"Needed only if IPv6 is used.";
}
description
"Micro-BFD IPv6 session state on a member link.";
uses bfd-types:all-session;
}
}
}
}
}
}
/*
* Notifications
*/
notification 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-types:notification-parms;
leaf lag-name {
type if:interface-ref;
description
"LAG interface name.";
}
leaf member-link {
type if:interface-ref;
description
"Member link on which BFD is running.";
}
}
}
]]>
BFD-over-MPLS YANG Module
This YANG module imports typedefs from
WG List:
Editor: Reshad Rahman
Editor: Lianshu Zheng
Editor: Mahesh Jethanandani
";
description
"This module contains the YANG definition for BFD parameters for
MPLS LSPs as per RFC 5884.
Copyright (c) 2022 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 Revised BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 9314; see the
RFC itself for full legal notices.";
reference
"RFC 5884: Bidirectional Forwarding Detection (BFD)
for MPLS Label Switched Paths (LSPs)
RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
revision 2022-09-22 {
description
"Updates to use base-cfg-parms instead of client-cfg-parms,
and add the enabled flag.";
reference
"RFC 9314: YANG Data Model for Bidirectional Forwarding
Detection (BFD).";
}
revision 2021-10-21 {
description
"Initial revision.";
reference
"RFC 9127: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
}
/*
* Identity definitions
*/
identity encap-gach {
base bfd-types:encap-type;
description
"BFD with Generic Associated Channel (G-ACh) encapsulation
as per RFC 5586.";
reference
"RFC 5586: MPLS Generic Associated Channel";
}
identity encap-ip-gach {
base bfd-types:encap-type;
description
"BFD with IP and G-ACh encapsulation as per RFC 5586.";
}
/*
* Groupings
*/
grouping encap-cfg {
description
"Configuration for BFD encapsulation.";
leaf encap {
type identityref {
base bfd-types:encap-type;
}
default "bfd-types:encap-ip";
description
"BFD encapsulation.";
}
}
grouping mpls-dest-address {
description
"Destination address as per RFC 5884.";
reference
"RFC 5884: Bidirectional Forwarding Detection (BFD)
for MPLS Label Switched Paths (LSPs)";
leaf mpls-dest-address {
type inet:ip-address;
config false;
description
"Destination address as per RFC 5884.
Needed if IP encapsulation is used.";
}
}
/*
* Augments
*/
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.";
uses bfd-types:session-statistics-summary;
container egress {
description
"Egress configuration.";
leaf enabled {
type boolean;
default "false";
description
"Indicates whether BFD over MPLS is enabled.";
}
uses bfd-types:base-cfg-parms;
uses bfd-types:auth-parms;
}
container session-groups {
description
"BFD-over-MPLS session groups.";
list session-group {
key "mpls-fec";
description
"Group of BFD MPLS sessions (for ECMP). A group of
sessions is for one FEC. Each session has a different
field in the UDP/IP header for ECMP.";
leaf mpls-fec {
type inet:ip-prefix;
description
"MPLS FEC.";
}
uses bfd-types:common-cfg-parms;
list sessions {
config false;
description
"The BFD sessions for an MPLS FEC. The local
discriminator is unique for each session in the
group.";
uses bfd-types:all-session;
uses bfd-mpls:mpls-dest-address;
}
}
}
}
}
/*
* Notifications
*/
notification 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-types:notification-parms;
leaf mpls-dest-address {
type inet:ip-address;
description
"Destination address as per RFC 5884.
Needed if IP encapsulation is used.";
}
}
}
]]>
Data Model Examples
This section presents some simple and illustrative examples of how to
configure BFD.
The examples are represented in XML
IP Single-Hop
The following is an example configuration for a BFD IP single-hop
session. The desired transmit interval and the required receive
interval are both set to 10 ms.
<?xml version="1.0" encoding="UTF-8"?>
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
<interface>
<name>eth0</name>
<type xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">
ianaift:ethernetCsmacd
</type>
</interface>
</interfaces>
<routing xmlns="urn:ietf:params:xml:ns:yang:ietf-routing">
<control-plane-protocols>
<control-plane-protocol>
<type xmlns:bfd-types=
"urn:ietf:params:xml:ns:yang:ietf-bfd-types">
bfd-types:bfdv1
</type>
<name>name:BFD</name>
<bfd xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd">
<ip-sh xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-ip-sh">
<sessions>
<session>
<interface>eth0</interface>
<dest-addr>2001:db8:0:113::101</dest-addr>
<desired-min-tx-interval>
10000
</desired-min-tx-interval>
<required-min-rx-interval>
10000
</required-min-rx-interval>
</session>
</sessions>
</ip-sh>
</bfd>
</control-plane-protocol>
</control-plane-protocols>
</routing>
</config>
IP Multihop
The following is an example configuration for a BFD IP multihop
session group. The desired transmit interval and the required receive
interval are both set to 150 ms.
<?xml version="1.0" encoding="UTF-8"?>
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<routing xmlns="urn:ietf:params:xml:ns:yang:ietf-routing">
<control-plane-protocols>
<control-plane-protocol>
<type xmlns:bfd-types=
"urn:ietf:params:xml:ns:yang:ietf-bfd-types">
bfd-types:bfdv1
</type>
<name>name:BFD</name>
<bfd xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd">
<ip-mh xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-ip-mh">
<session-groups>
<session-group>
<source-addr>2001:db8:0:113::103</source-addr>
<dest-addr>2001:db8:0:114::100</dest-addr>
<desired-min-tx-interval>
150000
</desired-min-tx-interval>
<required-min-rx-interval>
150000
</required-min-rx-interval>
<rx-ttl>240</rx-ttl>
</session-group>
</session-groups>
</ip-mh>
</bfd>
</control-plane-protocol>
</control-plane-protocols>
</routing>
</config>
LAG
The following is an example of BFD configuration for a LAG session.
In this case, an interface named "Bundle-Ether1" of interface type
"ieee8023adLag" has a desired transmit interval and required receive interval
set to 10 ms.
<?xml version="1.0" encoding="UTF-8"?>
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
<interface>
<name>Bundle-Ether1</name>
<type xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">
ianaift:ieee8023adLag
</type>
</interface>
</interfaces>
<routing xmlns="urn:ietf:params:xml:ns:yang:ietf-routing">
<control-plane-protocols>
<control-plane-protocol>
<type xmlns:bfd-types=
"urn:ietf:params:xml:ns:yang:ietf-bfd-types">
bfd-types:bfdv1
</type>
<name>name:BFD</name>
<bfd xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd">
<lag xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-lag">
<sessions>
<session>
<lag-name>Bundle-Ether1</lag-name>
<ipv6-dest-addr>2001:db8:112::16</ipv6-dest-addr>
<desired-min-tx-interval>
10000
</desired-min-tx-interval>
<required-min-rx-interval>
10000
</required-min-rx-interval>
<use-ipv6>true</use-ipv6>
</session>
</sessions>
</lag>
</bfd>
</control-plane-protocol>
</control-plane-protocols>
</routing>
</config>
MPLS
The following is an example of BFD configured for an MPLS LSP. In
this case, the desired transmit interval and required receive interval
are both set to 250 ms.
<?xml version="1.0" encoding="UTF-8"?>
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<routing xmlns="urn:ietf:params:xml:ns:yang:ietf-routing">
<control-plane-protocols>
<control-plane-protocol>
<type xmlns:bfd-types=
"urn:ietf:params:xml:ns:yang:ietf-bfd-types">
bfd-types:bfdv1
</type>
<name>name:BFD</name>
<bfd xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd">
<mpls xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-mpls">
<session-groups>
<session-group>
<mpls-fec>2001:db8:114::/116</mpls-fec>
<desired-min-tx-interval>
250000
</desired-min-tx-interval>
<required-min-rx-interval>
250000
</required-min-rx-interval>
</session-group>
</session-groups>
</mpls>
</bfd>
</control-plane-protocol>
</control-plane-protocols>
</routing>
</config>
Security Considerations
The YANG modules specified in this document define a schema for data
that is designed to be accessed via network management protocols such
as NETCONF
The Network Configuration Access Control Model (NACM)
There are a number of data nodes defined in these YANG modules 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 from a write access perspective:
The YANG modules have writable data nodes that can be used for the
creation of BFD sessions and the modification of BFD session parameters. The
system should "police" the creation of BFD sessions to prevent new sessions
from causing existing BFD sessions to fail. In the case of BFD session
modification, the BFD protocol has mechanisms in place that allow for
in-service modification.
When BFD clients are used to modify BFD configuration (as described
in
Some of the readable data nodes in these YANG modules may be considered
sensitive or vulnerable in some network environments. It is thus
important to control read access (e.g., via get, get-config, or
notification) to these data nodes. These are the subtrees and data nodes
and their sensitivity/vulnerability from a read access perspective:
This document does not define any RPC operations.
IANA Considerations
This document registers the following namespace URIs in the "IETF XML Registry"
This document registers the following YANG modules in the "YANG Module Names"
registry
References
Normative References
Informative References
Extensible Markup Language (XML) 1.0 (Fifth Edition)
World Wide Web Consortium Recommendation REC-xml-20081126
Echo Function Configuration Example
As mentioned in
module: example-bfd-echo
augment /rt:routing/rt:control-plane-protocols
/rt:control-plane-protocol/bfd:bfd/bfd-ip-sh:ip-sh
/bfd-ip-sh:sessions:
+--rw echo {bfd-types:echo-mode}?
+--rw desired-min-echo-tx-interval? uint32
+--rw required-min-echo-rx-interval? uint32
Example YANG Module for BFD Echo Function Configuration
This appendix provides an example YANG module for
configuration of the BFD Echo function. It imports and augments
"/routing/control-plane-protocols/control-plane-protocol" from
WG List:
Editor: Reshad Rahman
Editor: Lianshu Zheng
Editor: Mahesh Jethanandani
";
description
"This module contains an example YANG augmentation for
configuration of the BFD Echo function.
Copyright (c) 2021 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 Revised BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC 9127; see the
RFC itself for full legal notices.";
revision 2021-10-21 {
description
"Initial revision.";
reference
"RFC 9127: YANG Data Model for Bidirectional Forwarding
Detection (BFD)";
}
/*
* Groupings
*/
grouping echo-cfg-parms {
description
"BFD grouping for Echo configuration parameters.";
leaf desired-min-echo-tx-interval {
type uint32;
units "microseconds";
default "0";
description
"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 BFD (RFC 5880) is
disabled.";
}
leaf required-min-echo-rx-interval {
type uint32;
units "microseconds";
default "0";
description
"This is the Required Min Echo RX Interval as defined in BFD
(RFC 5880).";
}
}
augment "/rt:routing/rt:control-plane-protocols/"
+ "rt:control-plane-protocol/bfd:bfd/bfd-ip-sh:ip-sh/"
+ "bfd-ip-sh:sessions" {
description
"Augmentation for the BFD Echo function.";
container echo {
if-feature "bfd-types:echo-mode";
description
"BFD Echo function container.";
uses echo-cfg-parms;
}
}
}
]]>
Updates since RFC 9127
This document updates the 'ietf-bfd-types' module
to define a new feature called 'client-base-cfg-parms and an
'if-feature' statement that conditionally includes definitions
of parameters, such as 'multiplier' or
'desired-min-tx-interval'. The feature statement allows
YANG implementations of protocols, such as OSPF, IS-IS, PIM,
and BGP, to support both a model where such parameters are
not needed, such as when multiple BFD sessions are supported
over a given interface, as well as when they need to be
defined per session. As a result, the BFD MPLS module has to
use the base-cfg-parms instead of client-cfg-parms to be able
to include all the parameters unconditionally.
The
iana-bfd-types module, created in RFC 9127, was delegated to
IANA for maintenance. No changes are requested from IANA as
part of this update.
Acknowledgments
We would like to thank
94089
- Two systems directly connected via IP. This is known as BFD over
single-hop IP, which is also known as
BFD for IPv4 and IPv6 . - Two systems connected via multiple hops as described in
"Bidirectional Forwarding Detection (BFD) for Multihop Paths" . - Two systems connected via MPLS Label Switched Paths (LSPs) as
described in
"Bidirectional Forwarding Detection (BFD) for MPLS Label Switched Paths (LSPs)" . - Two systems connected via a Link Aggregation Group (LAG) interface
as described in
"Bidirectional Forwarding Detection (BFD) on Link Aggregation Group (LAG) Interfaces" . - Two systems connected via pseudowires (PWs). This is known as
Virtual Circuit Connectivity Verification (VCCV) as described in
"Bidirectional Forwarding Detection (BFD) for the Pseudowire Virtual Circuit Connectivity Verification (VCCV)" . This scenario is not addressed in this document.
- The "ietf-bfd-ip-sh" module (
) augments "/routing/control-plane-protocols/control-plane-protocol/bfd/" with the "ip-sh" container for BFD sessions over IP single-hop. - The "ietf-bfd-ip-mh" module (
) augments "/routing/control-plane-protocols/control-plane-protocol/bfd/" with the "ip-mh" container for BFD sessions over IP multihop. - The "ietf-bfd-lag" module (
) augments "/routing/control-plane-protocols/control-plane-protocol/bfd/" with the "lag" container for BFD sessions over a LAG. - The "ietf-bfd-mpls" module (
) augments "/routing/control-plane-protocols/control-plane-protocol/bfd/" with the "mpls" container for BFD-over-MPLS LSPs.
- At the network-device level.
- In logical network elements (LNEs) as described in
"YANG Model for Logical Network Elements" . - In network instances as described in
"YANG Data Model for Network Instances" .
- local-multiplier
- This is the detection time multiplier as defined in
BFD . - desired-min-tx-interval
- This is the Desired Min TX Interval as defined in
BFD . - required-min-rx-interval
- This is the Required Min RX Interval as defined in
BFD .
- key-chain
- This is a reference to "key-chain" as defined in
"YANG Data Model for Key Chains" . The keys, cryptographic algorithms, key lifetime, etc. are all defined in the "key-chain" model. - meticulous
- This enables a meticulous mode as per
BFD .
- Configuration. This is suitable for an Echo function that
operates continuously. An example is provided in
. - RPC. This is suitable for an Echo function that operates on demand.
- Source address
- Address belonging to the local system as per
"Bidirectional Forwarding Detection (BFD) for Multihop Paths" . - Destination address
- Address belonging to the remote system as per
.
- tx-ttl
- TTL of outgoing BFD control packets.
- rx-ttl
- Minimum TTL of incoming BFD control packets.
- The first category includes fundamental information regarding a BFD session, such as the local discriminator, the remote discriminator, and the ability to support Demand mode.
- The second category includes 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 configured desired minimum transmit interval. Similar examples include the actual receive interval between the control packets and the actual transmit interval between the Echo packets.
- The third category contains the detailed statistics for the session, e.g., when the session transitioned up/down and how long it has been in that state.
- /if:interfaces/if:interface/if:enabled
- If this configuration is set to "false", no BFD packets can be transmitted or received on that interface.
- /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
- 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.
- /rt:routing/mpls:mpls/mpls:interfaces/mpls:interface/mpls:mpls-enabled
- If this configuration is set to "false", no BFD MPLS packets can be transmitted or received on that interface.
- /routing/control-plane-protocols/control-plane-protocol/bfd/ip-sh/sessions:
-
This list specifies the IP single-hop BFD sessions. Data nodes "local-multiplier", "desired-min-tx-interval", "required-min-rx-interval", and "min-interval" all impact the BFD IP single-hop session. The "source-addr" and "dest-addr" data nodes can be used to send BFD packets to unwitting recipients. describes how BFD mitigates such threats. Authentication data nodes "key-chain" and "meticulous" impact the security of the BFD IP single-hop session. - /routing/control-plane-protocols/control-plane-protocol/bfd/ip-mh/session-group:
-
This list specifies the IP multihop BFD session groups. Data nodes "local-multiplier", "desired-min-tx-interval", "required-min-rx-interval", and "min-interval" all impact the BFD IP multihop session. The "source-addr" and "dest-addr" data nodes can be used to send BFD packets to unwitting recipients. describes how BFD mitigates such threats. Authentication data nodes "key-chain" and "meticulous" impact the security of the BFD IP multihop session. - /routing/control-plane-protocols/control-plane-protocol/bfd/lag/sessions:
-
This list specifies the BFD sessions over a LAG. Data nodes "local-multiplier", "desired-min-tx-interval", "required-min-rx-interval", and "min-interval" all impact the BFD-over-LAG session. The "ipv4-dest-addr" and "ipv6-dest-addr" data nodes can be used to send BFD packets to unwitting recipients. describes how BFD mitigates such threats. Authentication data nodes "key-chain" and "meticulous" impact the security of the BFD-over-LAG session. - /routing/control-plane-protocols/control-plane-protocol/bfd/mpls/session-group:
-
This list specifies the session groups for BFD over MPLS. Data nodes "local-multiplier", "desired-min-tx-interval", "required-min-rx-interval", and "min-interval" all impact the BFD-over-MPLS-LSPs session. Authentication data nodes "key-chain" and "meticulous" impact the security of the BFD-over-MPLS-LSPs session. - /routing/control-plane-protocols/control-plane-protocol/bfd/mpls/egress:
- Data nodes "local-multiplier", "desired-min-tx-interval", "required-min-rx-interval", and "min-interval" all impact the BFD-over-MPLS-LSPs sessions for which this device is an MPLS LSP egress node. Authentication data nodes "key-chain" and "meticulous" impact the security of the BFD-over-MPLS-LSPs sessions for which this device is an MPLS LSP egress node.
- /routing/control-plane-protocols/control-plane-protocol/bfd/ip-sh/summary:
- Access to this information discloses the number of BFD IP single-hop sessions that are in the "up", "down", or "admin-down" state. The counters include BFD sessions for which the user does not have read access.
- /routing/control-plane-protocols/control-plane-protocol/bfd/ip-sh/sessions/session/:
- Access to data nodes "local-discriminator" and "remote-discriminator" (combined with the data nodes in the authentication container) provides the ability to spoof BFD IP single-hop packets.
- /routing/control-plane-protocols/control-plane-protocol/bfd/ip-mh/summary:
- Access to this information discloses the number of BFD IP multihop sessions that are in the "up", "down", or "admin-down" state. The counters include BFD sessions for which the user does not have read access.
- /routing/control-plane-protocols/control-plane-protocol/bfd/ip-mh/session-groups/session-group/sessions:
- Access to data nodes "local-discriminator" and "remote-discriminator" (combined with the data nodes in the session group's authentication container) provides the ability to spoof BFD IP multihop packets.
- /routing/control-plane-protocols/control-plane-protocol/bfd/lag/micro-bfd-ipv4-session-statistics/summary:
- Access to this information discloses the number of micro-BFD IPv4 LAG sessions that are in the "up", "down", or "admin-down" state. The counters include BFD sessions for which the user does not have read access.
- /routing/control-plane-protocols/control-plane-protocol/bfd/lag/sessions/session/member-links/member-link/micro-bfd-ipv4:
- Access to data nodes "local-discriminator" and "remote-discriminator" (combined with the data nodes in the session's authentication container) provides the ability to spoof BFD IPv4 LAG packets.
- /routing/control-plane-protocols/control-plane-protocol/bfd/lag/micro-bfd-ipv6-session-statistics/summary:
- Access to this information discloses the number of micro-BFD IPv6 LAG sessions that are in the "up", "down", or "admin-down" state. The counters include BFD sessions for which the user does not have read access.
- /routing/control-plane-protocols/control-plane-protocol/bfd/lag/sessions/session/member-links/member-link/micro-bfd-ipv6:
- Access to data nodes "local-discriminator" and "remote-discriminator" (combined with the data nodes in the session's authentication container) provides the ability to spoof BFD IPv6 LAG packets.
- /routing/control-plane-protocols/control-plane-protocol/bfd/mpls/summary:
- Access to this information discloses the number of BFD sessions over MPLS LSPs that are in the "up", "down", or "admin-down" state. The counters include BFD sessions for which the user does not have read access.
- /routing/control-plane-protocols/control-plane-protocol/bfd/mpls/session-groups/session-group/sessions:
- Access to data nodes "local-discriminator" and "remote-discriminator" (combined with the data nodes in the session group's authentication container) provides the ability to spoof BFD-over-MPLS-LSPs packets.
- URI:
- urn:ietf:params:xml:ns:yang:ietf-bfd-types
- Registrant Contact:
- The IESG.
- XML:
- N/A; the requested URI is an XML namespace.
- URI:
- urn:ietf:params:xml:ns:yang:ietf-bfd
- Registrant Contact:
- The IESG.
- XML:
- N/A; the requested URI is an XML namespace.
- URI:
- urn:ietf:params:xml:ns:yang:ietf-bfd-ip-sh
- Registrant Contact:
- The IESG.
- XML:
- N/A; the requested URI is an XML namespace.
- URI:
- urn:ietf:params:xml:ns:yang:ietf-bfd-ip-mh
- Registrant Contact:
- The IESG.
- XML:
- N/A; the requested URI is an XML namespace.
- URI:
- urn:ietf:params:xml:ns:yang:ietf-bfd-lag
- Registrant Contact:
- The IESG.
- XML:
- N/A; the requested URI is an XML namespace.
- URI:
- urn:ietf:params:xml:ns:yang:ietf-bfd-mpls
- Registrant Contact:
- The IESG.
- XML:
- N/A; the requested URI is an XML namespace.
- Name:
- ietf-bfd-types
- Namespace:
- urn:ietf:params:xml:ns:yang:ietf-bfd-types
- Prefix:
- bfd-types
- Reference:
- RFC 9314
- Name:
- ietf-bfd
- Namespace:
- urn:ietf:params:xml:ns:yang:ietf-bfd
- Prefix:
- bfd
- Reference:
- RFC 9314
- Name:
- ietf-bfd-ip-sh
- Namespace:
- urn:ietf:params:xml:ns:yang:ietf-bfd-ip-sh
- Prefix:
- bfd-ip-sh
- Reference:
- RFC 9314
- Name:
- ietf-bfd-ip-mh
- Namespace:
- urn:ietf:params:xml:ns:yang:ietf-bfd-ip-mh
- Prefix:
- bfd-ip-mh
- Reference:
- RFC 9314
- Name:
- ietf-bfd-lag
- Namespace:
- urn:ietf:params:xml:ns:yang:ietf-bfd-lag
- Prefix:
- bfd-lag
- Reference:
- RFC 9314
- Name:
- ietf-bfd-mpls
- Namespace:
- urn:ietf:params:xml:ns:yang:ietf-bfd-mpls
- Prefix:
- bfd-mpls
- Reference:
- RFC 9314