The value of tmnxCpmVprnNwExceptions specifies whether the MPLS
exception messages are allowed to be received on all VPRN instances.
When the value of tmnxCpmVprnNwExceptions is set to 'true', the MPLS
exception messages are allowed to be received on all VPRN instances
in the system from all network interfaces.
When the value of tmnxCpmVprnNwExceptions is set to 'false', the MPLS
exception messages are not allowed to be received on all VPRN
instances in the system from all network interfaces.