
48 n Handbook of IPv4 to IPv6 Transition
Protocol [SIP] proxies, H.323 gatekeepers, etc.) make use of ND to discover neigh-
boring routers, addresses, address prefixes, and other configuration parameters.
Routers make use of ND to advertise their presence, host configuration param
-
eters, and on-link prefixes. Routers also use ND to inform hosts of a better next-
hop address to forward PDUs for a specific destination. Nodes make use of ND
to resolve the link-layer address of a neighboring node to which an IPv6 PDU is
being forwarded. Nodes also use ND to determine when the link-layer address of a
neighboring node has changed and whether IPv6