BGP Labeled Unicast Next Hop Self in Route-Map

Overview

The BGP-LU next-hop-self in route map feature provides the ability set the local BGP peer as the next-hop for select BGP-LU routes. When such a route map is applied to a BGP-LU neighbor in the outbound direction, the matched routes will be updated as below:

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The next-hop address is replaced with the local BGP peer address. Based on the BGP configuration, this is either the local interface address or the local loopback address

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The label is replaced with the local label allocated for the prefix

Feature Characteristics

BGP-LU routes permitted by the route-map and configured with set ip next-hop self are advertised with the local BGP peer address as the next-hop and the locally assigned label. BGP-LU routes permitted by the route-map without set next-hop self are advertised with their original next-hop and the label remains unchanged. The BGP-LU routes denied by the route-map are not advertised.

Limitations

The existing route-map CLIs to set next-hop, such as, set ip next-hop a.b.c.d or set ip next-hop peer-address are not recommended to be used for this feature and they can impact adversely.

Prerequisites

While deploying BGP labelled unicast, ensure that the allocate-label command is enabled under router bgp mode. This command is required for allocating labels to IPv4 prefixes.