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, 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, 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, next hops of BGP LU routes cannot resolve in TTM to a SR-TE LSP that is using an SR-ISIS or SR-OSPF segment.

   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 a 3-level 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.