The value of tmnxOspfVpnDomainId specifies the OSPF VPN Domain.
This is exchanged using BGP in the extended community attribute
associated with a prefix. This object applies to VPRN instances
of OSPF only. An attempt to modify the value of this object will
result in an 'inconsistentValue' error when the vRtrID index for
this row entry is not a VPRN instance.