What Does Neighbor Discovery Protocol (NDP) Mean?
Neighbor Discovery Protocol (NDP) is a part of the Internet Protocol suite used with IPv6. The IPv6 standard was developed by the Internet Engineering Task Force to help address the finite number of addresses assigned by the Internet Assigned Numbers Authority under IPv4.
The protocol performs functions that are similar to those addressed by the Address Resolution Protocol (ARP) and Internet Control Message Protocol (ICMP), as well as Router Discovery and Router Redirect protocols used in IPv4. NDP, however, has been improved compared to its IPv4 predecessors.