The value of vRtrLdpTunIfRootNode specifies if the given ldp-p2mp
tunnel interface instance is a root-node for that tunnel interface.
The value of this object must be specified when the row is created and
cannot be changed while 'vRtrLdpTunIfRowStatus' is 'active'. An
'inconsistentValue' error is returned if an attempt is made to set
this object individually.