BGP Shortcut Using Segment Routing Tunnel

The user enables the resolution of IPv4 prefixes using SR tunnels to BGP next-hops in TTM with the following command:

config>router>bgp>next-hop-resolution
        — shortcut-tunnel
            — [no] family {ipv4}
                — resolution {any | disabled | filter}
                — resolution-filter
                    — [no] sr-isis
                    — [no] sr-ospf
                — [no] disallow-igp
                — exit
            — exit
        — exit

When resolution is set to any, any supported tunnel type in BGP shortcut context is selected following TTM preference. The following tunnel types are supported in a BGP shortcut context and in order of preference: RSVP, LDP, Segment Routing and BGP.

When the sr-isis or sr-ospf value is enabled, an SR tunnel to the BGP next-hop is selected in the TTM from the lowest preference IS-IS or OSPF instance. If many instances have the same lowest preference from the lowest numbered IS-IS or OSPF instance.

See the BGP chapter for more details.