An MVPN belongs to a single sub-domain (SD). An SD is assigned to the PMSI of the MVPN, and forces the MVPN to resolve the BGP next-hop within that SD. Both I-PMSI and S-PMSI must be configured with the same SD. Different MVPNs can belong to different SDs. For example, mvpn-1 can belong to SD 0 which is an IPv4 unicast MT and mvpn-2 can belong to SD 1 which is an IPv4 multicast MT. This allows different MVPNs to be traffic engineered between different SDs or IS-IS MTs as needed.