The value of vRtrLdpNgGenRetentionMode specifies the label retention mode used. If the value of this object is 'conservative', then advertised label mappings are retained only if they will be used to forward packets, i.e. if the label came from a valid next hop. Label bindings received from non-nexthops for each FEC are discarded. If the value of this object is 'liberal', then all advertised label mappings are retained whether they are from a valid next hop or not. When vRtrLdpNgGenDistMethod has a value of 'downstreamUnsolicited', a LSR may receive label bindings for the same destination for all its neighbors. Labels for the non-nexthops for the FECs are retained in the software but not used. When a network topology change occurs where a non-nexthop becomes a true next hop, the label received earlier is then used.