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When monitoring Adj-RIB-Out, sometimes only a single peer needs to be monitored in a group of peers because they share the same egress policy. In the past we could simply include a peer-group name but now in current BGP implements, there are a ton of knobs that introduce multiple levels of inheritance at the afi/safi level. For this reason, instead of peer/af/session groups, an internal update-group is used to group same updates.

This update group is dynamic and not named. For this reason, we don't really want to convey the update-group number or name since it would be fairly meaningless, especially upon reload.

After reviewing JunOS and Cisco implementations, we believe two options would exist to support this ability while being multi-vendor/implementations agnostic.

1. Add a new administrative policy-group name to peers by afi/safi. This puts the onus on the operator to configure things correctly, but if configured correctly, a single afi/safi group name INFO TLV would suffice to convey the operator/administrator peer grouping.

2. Add a new afi/safi INFO TLV to convey each policy name that is in effect/applied. This would be one or more TLV's that contain the name of the policy (e.g. filter, export map, distribution list, prefix list, route-map, ...). The order could matter, in that the order which the policy is applied to the peer should be the same order as they are encoded. For example, map1, map2, map3 are used in that order for peer X.

In a way, the next-hop setting has to be treated as outbound policy setting because of the "nexthop-self" and "nexthop-unchanged" knobs. These are outbound policy settings that effect which next-hop is sent to the peer. Therefore, it needs to be classified as (Post) when doing next-hop self. In the case of EBGP, (Post) by default will in effect be nexthop-self unless the "nexthop-unchanged" knob has been configured. This means that (Pre) with EBGP should have the unchanged/existing next-hops and (Post) has the next-hops modified.

In the case of non-RR iBGP, routes wouldn't be selected for Adj-RIB-Out(Pre) since some routes cannot be reflected. Adj-RIB-Out should indicate that iBGP non-reflected routes are not considered post policy.