The value of vRtrLabelMode specifies the mode of allocation of service
labels to the routes exported by the VPRN as BGP-VPN routes.
If the value of vRtrLabelMode is set to 'nexthop(2)', the service labels
are allocated per next-hop.
By default the value of vRtrLabelMode is set to 'vrf(1)' which means
the service labels are allocated per VRF(Virtual Routing and
Forwarding).