The Neighbor Discovery Protocol (NDP), defined in RFC 4861, is the functional replacement for the Address Resolution Protocol (ARP) in IPv6. While ARP in IPv4 resolves IPv4 addresses to link-layer (MAC) addresses, NDP performs this same address resolution function for IPv6 using Neighbor Solicitation (NS) and Neighbor Advertisement (NA) messages. NDP is a more comprehensive protocol that also replaces other IPv4 functions like ICMP Router Discovery and ICMP Redirect, but its address resolution capability is the direct successor to ARP.

A. Duplicate address detection (DAD) is a function within NDP used to ensure an IPv6 address is unique on a link before use, a task not performed by ARP.

B. Router discovery is a function within NDP that allows hosts to locate routers, replacing the ICMP Router Discovery protocol from IPv4, not ARP.

D. Stateless address auto-configuration (SLAAC) allows hosts to generate their own addresses, a function more analogous to DHCP in IPv4, not ARP.

1. Nokia. (2021). 7450 ESS

7750 SR

7950 XRS

and VSR Router Configuration Guide

Release 21.10.R1. Section: IPv6 Neighbor Discovery. The guide states

"The Neighbor Discovery Protocol (NDP) is a protocol in the Internet Protocol Suite used with IPv6. It operates at the Network Layer of the Internet model and is responsible for address autoconfiguration of nodes

discovery of other nodes on the link

determining the link-layer addresses of other nodes (replaces ARP)

and duplicate address detection."

2. Narten

T.

Nordmark

E.

Simpson

W.

& Soliman

H. (2007). RFC 4861: Neighbor Discovery for IP version 6 (IPv6). IETF. Abstract. The document states

"This document specifies the Neighbor Discovery protocol for IP Version 6. 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... The protocol replaces the following IPv4 protocols: Address Resolution Protocol (ARP)

ICMP Router Discovery

and ICMP Redirect."