Ingress LSR specific processing

VPLS supports failover and must preserve its forwarding state when the LDP tunnel is used to carry VPLS traffic until the GR has finished. LDP GR attempts to recover both the tunnel labels and the VC labels. In the case where a VC label cannot be recovered, the corresponding Pseudo Wire (PW) is brought down after GR has finished. In the case where the LDP tunnel cannot be recovered, all the PWs using the LDP tunnel is brought down due to tunnel down event.

LDP tunnels are preserved across failover and application can use them to provide hitless support.