Application Support

The following describes how SR-ISIS IPv4 or IPv6 or a SR-OSPF IPv4 tunnels are resolved.

  1. When an SR-ISIS IPv4 or an SR-OSPF IPv4 tunnel is resolved to one or more RSVP-TE LSPs, then the following applications can resolve to the SR-ISIS or SR-OSPF tunnel 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)

    • next hop of a BGP LU IPv4 route

    • indirect next hop of IPv4 static routes

  2. When an SR-ISIS IPv6 tunnel is resolved to one or more RSVP-TE LSPs, then the following applications can resolve to the SR-ISIS tunnel in TTM:

    • L2 service FECs

    • next hop of VPN-IPv4 and VPN-IPv6 over a spoke SDP interface using the SR tunnel

    • indirect next hop of IPv6 static routes

  3. When an SR-ISIS IPv4 or an SR-OSPF IPv4 tunnel is resolved to one or more RSVP-TE LSPs, then the following applications cannot resolve in TTM to a SR-TE LSP that is using an SR-ISIS or SR-OSPF segment:

    • next hop of a BGP LU route

      Note:

      Next hops of BGP LU routes cannot resolve to LDP in TTM to a SR-TE LSP that is using an SR-ISIS or SR-OSPF segment 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-SRTE-over-RSVPTE a 4-level hierarchy. BGP keeps these BGP-LU routes unresolved.