BGP multihoming for VPLS inter-domain resiliency

BGP MH for VPLS can be used to provide resiliency between different VPLS domains. An example of a multihoming topology is shown in Figure 1.

Figure 1. BGP MH used in an HVPLS topology

LDP VPLS domains are interconnected using a core VPLS domain, either BGP VPLS or LDP VPLS. The gateway PEs, for example PE2 and PE3, are running BGP multihoming where one MH site is assigned to each of the pseudowires connecting the access PE, PE7, and PE8 in this example.

Alternatively, the MH site can be associated with multiple access pseudowires using an access SHG. The configure service vpls site failed-threshold command can be used to indicate the number of pseudowire failures that are required for the MH site to be declared down.