MVPN upstream UMH fast failover is supported for P2MP SR PMSI, as illustrated in
Figure 1. The upstream
PE failure detection uses the Unidirectional Forwarding Detection (UFD) method. A
downstream PE (receiver PE) supports fast upstream failover using the capability:
- to select two UMH nodes
- to monitor the upstream PE health using UFD
The tunnel status is monitored using the UFD session status received over the
P-tunnel; the C-flow source is declared to be active based on this monitoring
information. If multiple nodes are sourcing C-flows, the receiver PE node can choose to
receive traffic from a primary and a standby source, but forwards only the multicast
stream received from the primary source. If the detected P-tunnel status is down, the
multicast receiver PE forwards the traffic received over the standby P-tunnel.
Figure 1. Example of MVPN upstream PE fast failover
