The vRtrMplsFSGroupTable has an entry for each group that is
a part of the fate sharing database configured for the virtual
router in the system.
A fate sharing group is used to define a group of links and
nodes in the network that share common risk attributes. To
minimize a single point of failure, backup paths can be created
that not only avoid the nodes and links of the primary path but
also any other nodes and links that share risk with the nodes
and links of the primary path.