The value of vRtrPimNgAFGenMvpnUMHSelection specifies the
selection mechanism to use for selecting Upstream Multicast Hop(UMH).
When the value of vRtrPimNgAFGenMvpnUMHSelection is set to 'highestip',
the highest IP Address is selected as UMH. When the value is set to
'hashbased', UMH selection is based on the hash based procedures. When
the value is set to 'tunnelstatus', UMH selection is based on the
state of the tunnel as well as the available unicast routes through the
tunnel.
UMH selection is supported only with RSVP-TE PMSI. Its value cannot be
modified without shutting down the MVPN instance.