Application Support

SR-TE IGP shortcuts can be used 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, then the following applications can resolve to LDP in TTM:

    • L2 service FECs

    • BGP next hop of VPN IPv4/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, then the following applications cannot resolve to LDP in TTM:

    • next hop of BGP LU routes

      Note:

      Next hops of BGP LU routes cannot resolve to LDP in TTM because SR OS supports three levels of hierarchy in the data path and, because SR-TE LSP is a hierarchical LSP already, this makes the BGP-over-LDP-over-SRTE a 4-level hierarchy. BGP keeps these BGP-LU routes unresolved.

Parent topic: IPv4 IGP Shortcuts using SR-TE LSP Feature Configuration