ECMP is supported for EVPN route next hops that are resolved to EVPN-MPLS destinations as follows:
ECMP for Layer 2 unicast traffic on Epipe and VPLS services for EVPN-MPLS destinations
This is enabled by the configure service epipe/vpls bgp-evpn mpls auto-bind-tunnel ecmp number command and allows the resolution of an EVPN-MPLS next hop to a group of ECMP tunnels of type RSVP-TE, SR-TE or BGP.
ECMP for Layer 3 unicast traffic on R-VPLS services with EVPN-MPLS destinations
This is enabled by the configure service vpls bgp-evpn mpls auto-bind-tunnel ecmp and configure service vpls allow-ip-int-bind evpn-mpls-ecmp commands.
The VPRN unicast traffic (IPv4 and IPv6) is sprayed among ‟m” paths, with ‟m” being the lowest value of (16,n), where ‟n” is the number of ECMP paths configured in the configure service vpls bgp-evpn mpls auto-bind-tunnel ecmp command.
CPM originated traffic is not sprayed and picks up the first tunnel in the set.
This feature is limited to FP3 and above systems.
ECMP for Layer 3 multicast traffic on R-VPLS services with EVPN-MPLS destinations
This is enabled by the configure service vpls allow-ip-int-bind ip-multicast-ecmp and configure service vpls bgp-evpn mpls auto-bind-tunnel ecmp commands. The VPRN multicast traffic (IPv4 and IPv6) are sprayed among up to ‟m” paths, with ‟m” being the lowest value of (16,n), and ‟n” is the number of ECMP paths configured in the configure service vpls bgp-evpn mpls auto-bind-tunnel ecmp command.
In all of these cases, the configure service epipe/vpls bgp-evpn mpls auto-bind-tunnel ecmp number command determines the number of Traffic Engineering (TE) tunnels that an EVPN next hop can resolved to. TE tunnels refer to RSVP-TE or SR-TE types. For shortest path tunnels, such as, ldp, sr-isis, sr-ospf, udp, and so on, the number of tunnels in the ECMP group are determined by the configure router ecmp command.
In addition, weighted ECMP for Layer 2 unicast traffic on Epipe and VPLS services for EVPN-MPLS destinations is also supported. When the bgp-evpn>mpls>auto-bind-tunnel>weighted-ecmp command is configured, packets are sprayed across Traffic Engineering (TE) LSPs in the ECMP set according to the outcome of the hash algorithm and the configured load balancing weight of each LSP.