ND (Neighbor Discovery) is similar to the ARP (Address Resolution Protocol) that uses for determining the link-layer address. ND is more complex mechanism that is defined in RFC 4861 as a fundamental part of IPv6. It primarily serves the following purposes:
ND uses the following types of ICMPv6 messages:
The SEND (Secure Neighbor Discovery) was defined to ensure the security of computer systems. RFC 3971 describes the SEND fundamentals. The goal of SEND is to provide a sufficient secure level of exchange of ICMPv6 messages.