Application support

The use of SR-TE IGP shortcuts is supported in the following applications:

  1. family ipv4 resolves IPv4 prefixes in RTM for the following:

    • IGP routes

    • indirect next hop of static routes

    • BGP next hop of BGP routes

    • LDP IPv4 prefix FEC

  2. family ipv6 resolves IPv6 prefixes in RTM for the following:

    • IGP routes

    • indirect next hop of static routes

    • BGP next hop of BGP routes

  3. When an LDP IPv4 FEC prefix is resolved to one or more SR-TE LSPs, the following applications can resolve to LDP in TTM:

    • L2 service FECs

    • BGP next hop of VPN IPv4 and IPv6 prefixes

    • BGP next hop of EVPN routes

    • BGP next hop of IPv4 prefixes

    • BGP next hop of IPv6 prefixes (6PE)

    • IGP IPv4 routes (LDP shortcut feature)

    • indirect next hop of IPv4 static routes

  4. When an LDP IPv4 FEC prefix is resolved to one or more SR-TE LSPs, next hops of BGP LU routes cannot resolve to LDP in TTM.

    Note: SR OS supports a 3-level hierarchy in the data path. Because SR-TE LSP is a hierarchical LSP already, this makes the BGP-over-LDP-over-SR-TE a 4-level hierarchy. Consequently, BGP keeps these BGP-LU routes unresolved.
Parent topic: IPv4 IGP shortcuts using SR-TE LSP feature configuration