# RFC 4681

RFC 4681 - Neighbor Discovery for IP version 6 - specifies the [Neighbor Discovery protocol](/glossary/n/ndp) for [IPv6](/glossary/i/ipv6).

IPv6 nodes on the same link use Neighbor Discovery to discover each other's presence, to determine each other's link-layer addresses, to find routers, and to maintain reachability information about the paths to active neighbors.


## More information

[https://tools.ietf.org/html/rfc4681](https://tools.ietf.org/html/rfc4681)