Add multicast-focused AFTs by bewing · Pull Request #1468 · openconfig/public

bewing · 2026-04-02T21:24:08Z

As an operator, I need a standard way to monitor the current forwarding behavior of multicast on my network, across multiple vendor types.

Most(?) platforms forward multicast under a input interface / OIL model, keyed by various FECs. This change attempts to provide an initial implementation for IPv4, IPv6, and MPLS forwarding of multicast traffic.

Change Scope

Add multicast-focused AFTs
This change only adds new AFTs, and should be backwards compatible with existing implementations of AFT

Platform Implementations

Implementation A: Arista
Implementation B: Cisco
Implementation C: Linux

Tree View

--- /home/bewing/old-tree.txt   2026-05-05 09:50:50.188072742 -0500
+++ /home/bewing/new-tree.txt   2026-05-05 11:21:49.942691210 -0500
@@ -3829,200 +3829,252 @@
         |  |        +--rw next-hop* [index]
         |  |           +--rw index     -> ../config/index
         |  |           +--rw config
         |  |           |  +--rw index?   -> ../../../../../../next-hops/next-hop/index
         |  |           +--ro state
         |  |              +--ro index?   -> ../../../../../../next-hops/next-hop/index
         |  +--rw next-hops
         |     +--rw next-hop* [index]
         |        +--rw index            -> ../config/index
         |        +--rw config
         |        |  +--rw index?                                     string
         |        |  +--rw next-hop?                                  union
         |        |  +--rw recurse?                                   boolean
         |        |  +--rw metric?                                    uint32
         |        |  +--rw preference?                                uint32
         |        |  +--rw wecmp-weight?                              union
         |        |  +--rw oc-loc-rt-netinst:next-network-instance?   -> /oc-ni:network-instances/network-instance/config/name
         |        |  +--rw oc-loc-rt-netinst:nh-network-instance?     -> /oc-ni:network-instances/network-instance/config/name
         |        +--ro state
         |        |  +--ro index?                                     string
         |        |  +--ro next-hop?                                  union
         |        |  +--ro recurse?                                   boolean
         |        |  +--ro metric?                                    uint32
         |        |  +--ro preference?                                uint32
         |        |  +--ro wecmp-weight?                              union
         |        |  +--ro oc-loc-rt-netinst:next-network-instance?   -> /oc-ni:network-instances/network-instance/config/name
         |        |  +--ro oc-loc-rt-netinst:nh-network-instance?     -> /oc-ni:network-instances/network-instance/config/name
         |        +--rw encap-headers
         |           +--rw encap-header* [index]
         |              +--rw index     -> ../config/index
         |              +--rw config
         |              |  +--rw index?   uint8
         |              |  +--rw type?    oc-aftt:encapsulation-header-type
         |              +--ro state
         |              |  +--ro index?   uint8
         |              |  +--ro type?    oc-aftt:encapsulation-header-type
         |              +--rw udp-v4
         |              |  +--rw config
         |              |  |  +--rw src-ip?         oc-inet:ipv4-address
         |              |  |  +--rw dst-ip?         oc-inet:ipv4-address
         |              |  |  +--rw dscp?           oc-inet:dscp
         |              |  |  +--rw src-udp-port?   oc-inet:port-number
         |              |  |  +--rw dst-udp-port?   oc-inet:port-number
         |              |  |  +--rw ip-ttl?         uint8
         |              |  +--ro state
         |              |     +--ro src-ip?         oc-inet:ipv4-address
         |              |     +--ro dst-ip?         oc-inet:ipv4-address
         |              |     +--ro dscp?           oc-inet:dscp
         |              |     +--ro src-udp-port?   oc-inet:port-number
         |              |     +--ro dst-udp-port?   oc-inet:port-number
         |              |     +--ro ip-ttl?         uint8
         |              +--rw gre
         |              |  +--rw config
         |              |  |  +--rw src-ip?   oc-inet:ip-address
         |              |  |  +--rw dst-ip?   oc-inet:ip-address
         |              |  |  +--rw ttl?      uint8
         |              |  +--ro state
         |              |     +--ro src-ip?   oc-inet:ip-address
         |              |     +--ro dst-ip?   oc-inet:ip-address
         |              |     +--ro ttl?      uint8
         |              +--rw mpls
         |                 +--rw config
         |                 |  +--rw traffic-class?   oc-mplst:mpls-tc
         |                 |  +--rw label?           oc-mplst:mpls-label
         |                 +--ro state
         |                    +--ro traffic-class?   oc-mplst:mpls-tc
         |                    +--ro label?           oc-mplst:mpls-label
         +--rw afts
         |  +--ro ipv4-unicast
         |  |  +--ro ipv4-entry* [prefix]
         |  |     +--ro prefix    -> ../state/prefix
         |  |     +--ro state
         |  |        +--ro prefix?                                     oc-inet:ipv4-prefix
         |  |        +--ro counters
         |  |        |  x--ro packets-forwarded?          oc-yang:counter64
         |  |        |  x--ro octets-forwarded?           oc-yang:counter64
         |  |        |  x--ro packets-forwarded-backup?   oc-yang:counter64
         |  |        |  x--ro octets-forwarded-backup?    oc-yang:counter64
         |  |        +--ro entry-metadata?                             binary
         |  |        +--ro origin-protocol?                            identityref
         |  |        +--ro decapsulate-header?                         oc-aftt:encapsulation-header-type
         |  |        +--ro oc-aftni:next-hop-group?                    -> /oc-ni:network-instances/network-instance/afts/next-hop-groups/next-hop-group/state/id
         |  |        +--ro oc-aftni:next-hop-group-network-instance?   oc-ni:network-instance-ref
         |  |        +--ro oc-aftni:origin-network-instance?           oc-ni:network-instance-ref
         |  +--ro ipv6-unicast
         |  |  +--ro ipv6-entry* [prefix]
         |  |     +--ro prefix    -> ../state/prefix
         |  |     +--ro state
         |  |        +--ro prefix?                                     oc-inet:ipv6-prefix
         |  |        +--ro counters
         |  |        |  x--ro packets-forwarded?          oc-yang:counter64
         |  |        |  x--ro octets-forwarded?           oc-yang:counter64
         |  |        |  x--ro packets-forwarded-backup?   oc-yang:counter64
         |  |        |  x--ro octets-forwarded-backup?    oc-yang:counter64
         |  |        +--ro entry-metadata?                             binary
         |  |        +--ro origin-protocol?                            identityref
         |  |        +--ro decapsulate-header?                         oc-aftt:encapsulation-header-type
         |  |        +--ro oc-aftni:next-hop-group?                    -> /oc-ni:network-instances/network-instance/afts/next-hop-groups/next-hop-group/state/id
         |  |        +--ro oc-aftni:next-hop-group-network-instance?   oc-ni:network-instance-ref
         |  |        +--ro oc-aftni:origin-network-instance?           oc-ni:network-instance-ref
+        |  +--ro ipv4-multicast
+        |  |  +--ro ipv4-multicast-entry* [source-address group-address]
+        |  |     +--ro source-address    -> ../state/source-address
+        |  |     +--ro group-address     -> ../state/group-address
+        |  |     +--ro state
+        |  |        +--ro source-address?                             oc-inet:ipv4-address
+        |  |        +--ro group-address?                              oc-inet:ipv4-address
+        |  |        +--ro counters
+        |  |        |  x--ro packets-forwarded?   oc-yang:counter64
+        |  |        |  x--ro octets-forwarded?    oc-yang:counter64
+        |  |        +--ro entry-metadata?                             binary
+        |  |        +--ro origin-protocol?                            identityref
+        |  |        +--ro decapsulate-header?                         oc-aftt:encapsulation-header-type
+        |  |        +--ro rpf-discards?                               oc-yang:counter64
+        |  |        +--ro reverse-path-neighbor?                      oc-inet:ipv4-address
+        |  |        +--ro oc-aftni:next-hop-group?                    -> /oc-ni:network-instances/network-instance/afts/next-hop-groups/next-hop-group/state/id
+        |  |        +--ro oc-aftni:next-hop-group-network-instance?   oc-ni:network-instance-ref
+        |  +--ro ipv6-multicast
+        |  |  +--ro ipv6-multicast-entry* [source-address group-address]
+        |  |     +--ro source-address    -> ../state/source-address
+        |  |     +--ro group-address     -> ../state/group-address
+        |  |     +--ro state
+        |  |        +--ro source-address?                             oc-inet:ipv6-address
+        |  |        +--ro group-address?                              oc-inet:ipv6-address
+        |  |        +--ro counters
+        |  |        |  x--ro packets-forwarded?   oc-yang:counter64
+        |  |        |  x--ro octets-forwarded?    oc-yang:counter64
+        |  |        +--ro entry-metadata?                             binary
+        |  |        +--ro origin-protocol?                            identityref
+        |  |        +--ro decapsulate-header?                         oc-aftt:encapsulation-header-type
+        |  |        +--ro rpf-discards?                               oc-yang:counter64
+        |  |        +--ro reverse-path-neighbor?                      oc-inet:ipv6-address
+        |  |        +--ro oc-aftni:next-hop-group?                    -> /oc-ni:network-instances/network-instance/afts/next-hop-groups/next-hop-group/state/id
+        |  |        +--ro oc-aftni:next-hop-group-network-instance?   oc-ni:network-instance-ref
+        |  +--ro mpls-multicast
+        |  |  +--ro multicast-label-entry* [label]
+        |  |     +--ro label                      -> ../state/label
+        |  |     +--ro state
+        |  |     |  +--ro label?                                      oc-mplst:mpls-label
+        |  |     |  +--ro counters
+        |  |     |  |  x--ro packets-forwarded?   oc-yang:counter64
+        |  |     |  |  x--ro octets-forwarded?    oc-yang:counter64
+        |  |     |  +--ro entry-metadata?                             binary
+        |  |     |  +--ro origin-protocol?                            identityref
+        |  |     |  +--ro oc-aftni:next-hop-group?                    -> /oc-ni:network-instances/network-instance/afts/next-hop-groups/next-hop-group/state/id
+        |  |     |  +--ro oc-aftni:next-hop-group-network-instance?   oc-ni:network-instance-ref
+        |  |     +--ro decap-mpls-label-stacks
+        |  |        +--ro decap-mpls-label-stack* [id]
+        |  |           +--ro id       -> ../state/id
+        |  |           +--ro state
+        |  |              +--ro id?      uint8
+        |  |              +--ro label?   oc-mplst:mpls-label
         |  +--ro policy-forwarding
         |  |  +--ro policy-forwarding-entry* [index]
         |  |     +--ro index    -> ../state/index
         |  |     +--ro state
         |  |        +--ro index?                                      uint64
         |  |        +--ro ip-prefix?                                  oc-inet:ip-prefix
         |  |        +--ro mac-address?                                oc-yang:mac-address
         |  |        +--ro mpls-label?                                 oc-mplst:mpls-label
         |  |        +--ro mpls-tc?                                    oc-mplst:mpls-tc
         |  |        +--ro ip-dscp?                                    oc-inet:dscp
         |  |        +--ro ip-protocol?                                oc-pkt-match-types:ip-protocol-type
         |  |        +--ro l4-src-port?                                oc-inet:port-number
         |  |        +--ro l4-dst-port?                                oc-inet:port-number
         |  |        +--ro counters
         |  |        |  x--ro packets-forwarded?   oc-yang:counter64
         |  |        |  x--ro octets-forwarded?    oc-yang:counter64
         |  |        +--ro entry-metadata?                             binary
         |  |        +--ro oc-aftni:next-hop-group?                    -> /oc-ni:network-instances/network-instance/afts/next-hop-groups/next-hop-group/state/id
         |  |        +--ro oc-aftni:next-hop-group-network-instance?   oc-ni:network-instance-ref
         |  +--ro mpls
         |  |  +--ro label-entry* [label]
         |  |     +--ro label                      -> ../state/label
         |  |     +--ro state
         |  |     |  +--ro label?                                      oc-mplst:mpls-label
         |  |     |  +--ro counters
         |  |     |  |  x--ro packets-forwarded?   oc-yang:counter64
         |  |     |  |  x--ro octets-forwarded?    oc-yang:counter64
         |  |     |  +--ro entry-metadata?                             binary
         |  |     |  x--ro popped-mpls-label-stack*                    oc-mplst:mpls-label
         |  |     |  +--ro oc-aftni:next-hop-group?                    -> /oc-ni:network-instances/network-instance/afts/next-hop-groups/next-hop-group/state/id
         |  |     |  +--ro oc-aftni:next-hop-group-network-instance?   oc-ni:network-instance-ref
         |  |     +--ro decap-mpls-label-stacks
         |  |        +--ro decap-mpls-label-stack* [id]
         |  |           +--ro id       -> ../state/id
         |  |           +--ro state
         |  |              +--ro id?      uint8
         |  |              +--ro label?   oc-mplst:mpls-label
         |  +--ro ethernet
         |  |  +--ro mac-entry* [mac-address]
         |  |     +--ro mac-address    -> ../state/mac-address
         |  |     +--ro state
         |  |        +--ro mac-address?                                oc-yang:mac-address
         |  |        +--ro counters
         |  |        |  x--ro packets-forwarded?   oc-yang:counter64
         |  |        |  x--ro octets-forwarded?    oc-yang:counter64
         |  |        +--ro entry-metadata?                             binary
         |  |        +--ro oc-aftni:next-hop-group?                    -> /oc-ni:network-instances/network-instance/afts/next-hop-groups/next-hop-group/state/id
         |  |        +--ro oc-aftni:next-hop-group-network-instance?   oc-ni:network-instance-ref
         |  +--ro state-synced
         |  |  +--ro state
         |  |     +--ro ipv4-unicast?   boolean
         |  |     +--ro ipv6-unicast?   boolean
         |  +--ro next-hop-groups
         |  |  +--ro next-hop-group* [id]
         |  |     +--ro id             -> ../state/id
         |  |     +--ro state
         |  |     |  +--ro id?                      uint64
         |  |     |  +--ro next-hop-group-name?     string
         |  |     |  +--ro programmed-id?           uint64
         |  |     |  +--ro color?                   uint64
         |  |     |  +--ro backup-next-hop-group?   -> ../../../next-hop-group/state/id
         |  |     |  +--ro backup-active?           boolean
         |  |     +--ro next-hops
         |  |     |  +--ro next-hop* [index]
         |  |     |     +--ro index    -> ../state/index
         |  |     |     +--ro state
         |  |     |        +--ro index?    -> ../../../../../../next-hops/next-hop/state/index
         |  |     |        +--ro weight?   uint64
         |  |     +--ro conditional
         |  |        +--ro condition* [id]
         |  |           +--ro id                  -> ../state/id
         |  |           +--ro state
         |  |           |  +--ro id?               uint64
         |  |           |  +--ro dscp*             oc-inet:dscp
         |  |           |  +--ro next-hop-group?   -> ../../../../../next-hop-group/state/id
         |  |           +--ro input-interfaces
         |  |              +--ro input-interface* [id]
         |  |                 +--ro id       -> ../state/id
         |  |                 +--ro state
         |  |                    +--ro id?             string
         |  |                    +--ro interface?      -> /oc-if:interfaces/interface/name
         |  |                    +--ro subinterface?   -> /oc-if:interfaces/interface[oc-if:name=current()/../interface]/subinterfaces/subinterface/index
         |  +--ro next-hops
         |  |  +--ro next-hop* [index]
         |  |     +--ro index            -> ../state/index
         |  |     +--ro state
         |  |     |  +--ro index?                       uint64
         |  |     |  +--ro programmed-index?            uint64
         |  |     |  +--ro ip-address?                  oc-inet:ip-address
         |  |     |  +--ro mac-address?                 oc-yang:mac-address
         |  |     |  +--ro pop-top-label?               boolean
         |  |     |  x--ro pushed-mpls-label-stack*     oc-mplst:mpls-label
         |  |     |  +--ro encapsulate-header?          oc-aftt:encapsulation-header-type
         |  |     |  +--ro decapsulate-header?          oc-aftt:encapsulation-header-type
         |  |     |  +--ro origin-protocol?             identityref
         |  |     |  +--ro lsp-name?                    string
         |  |     |  +--ro counters
         |  |     |  |  x--ro packets-forwarded?   oc-yang:counter64
         |  |     |  |  x--ro octets-forwarded?    oc-yang:counter64
         |  |     |  +--ro vni-label?                   oc-evpn-types:evi-id

bewing · 2026-04-02T21:29:00Z

FWIW, I swear I had opened a similar PR/ticket back in 2018....ish, but I can't find it now.

edit: found it

#197

gemini-code-assist

Code Review

This pull request introduces support for multicast forwarding tables (AFT) within the OpenConfig model, specifically adding submodules for IPv4, IPv6, and MPLS P2MP multicast forwarding. It defines new groupings for multicast outgoing interface states and structural lists, which are integrated into the main AFT module. Review feedback recommends utilizing existing common groupings in the new IPv4 and IPv6 submodules to ensure consistency and minimize code duplication.

bewing · 2026-05-05T14:55:08Z

Pushed a new changeset based on feedback received.

Using the existing NHG pattern has the side effect of removing RPF information from the model. This is important information to have (traffic received on the non-RPF interface isn't forwarded, usually punted to CPU/control plane). Where is the right place to put this information? Should it just be a leaf in the mc-entry/state grouping? Somewhere in the AFT-common tree?

bewing · 2026-05-05T14:58:23Z

Just noticed I need to incorporate some recent changes in the MPLS modeling into this change, working on that now.

bewing · 2026-05-05T15:41:42Z

Additional question - unicast MPLS AFT doesn't include aft-common-install-protocol in grouping aft-mpls-entry-state - is this an oversight in that AFT? oc-mpls:signaling-protocols seems like the likely reference here.

github-project-automation Bot added this to OC Operator Review Apr 2, 2026

bewing requested a review from a team as a code owner April 2, 2026 21:24

gemini-code-assist Bot reviewed Apr 2, 2026

View reviewed changes

Comment thread release/models/aft/openconfig-aft-ipv4-multicast.yang Outdated

Comment thread release/models/aft/openconfig-aft-ipv6-multicast.yang Outdated

dplore assigned ElodinLaarz Apr 3, 2026

dplore moved this to Ready to discuss in OC Operator Review Apr 3, 2026

akalluru1 reviewed Apr 7, 2026

View reviewed changes

Comment thread release/models/aft/openconfig-aft-ipv4-multicast.yang Outdated

bewing force-pushed the feat/mft branch 2 times, most recently from d5ccef2 to fd48ac6 Compare May 5, 2026 14:51

bewing requested a review from akalluru1 May 5, 2026 14:57

bewing force-pushed the feat/mft branch from fd48ac6 to b8b9100 Compare May 5, 2026 15:07

bewing force-pushed the feat/mft branch from b8b9100 to 632029b Compare May 5, 2026 16:13

Add multicast-focused AFTs

50c70f7

bewing force-pushed the feat/mft branch from 632029b to 50c70f7 Compare May 5, 2026 16:22

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Add multicast-focused AFTs#1468

Add multicast-focused AFTs#1468
bewing wants to merge 1 commit into
openconfig:masterfrom
bewing:feat/mft

bewing commented Apr 2, 2026 •

edited

Loading

Uh oh!

bewing commented Apr 2, 2026 •

edited

Loading

Uh oh!

gemini-code-assist Bot left a comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

bewing commented May 5, 2026

Uh oh!

bewing commented May 5, 2026

Uh oh!

bewing commented May 5, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

Conversation

bewing commented Apr 2, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Change Scope

Platform Implementations

Tree View

Uh oh!

bewing commented Apr 2, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

gemini-code-assist Bot left a comment

Choose a reason for hiding this comment

Code Review

Uh oh!

Uh oh!

Uh oh!

Uh oh!

bewing commented May 5, 2026

Uh oh!

bewing commented May 5, 2026

Uh oh!

bewing commented May 5, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

bewing commented Apr 2, 2026 •

edited

Loading

bewing commented Apr 2, 2026 •

edited

Loading