The value of vRtrMvpnCMcastImportRT indicates C-multicast Import
Route that uniquely identifies a VRF.
vRtrMvpnCMcastImportRT controls imports of C-multicast routes into
a particular VRF. A PE that has sites of a given MVPN connected to it
needs to communicate the value of the C-multicast Import RT associated
with the VRF of that MVPN on the PE to all other PEs that have sites of
that MVPN. A PE that originates a (unicast) route to VPN-IP addresses
must include in the BGP Update message the value of the C-multicast
Import RT of the VRF associated with the route.