Configuring Neighbor Discovery; Overview - Juniper IGP - CONFIGURATION GUIDE V11.1.X Configuration Manual

Chapter 3

Configuring Neighbor Discovery

Overview

This chapter describes how to configure Neighbor Discovery (ND) on your E Series
router; it contains the following sections:
Overview on page 193
Platform Considerations on page 194
References on page 194
Before You Configure Neighbor Discovery on page 194
Configuring Neighbor Discovery on page 195
Configuring Proxy Neighbor Advertisements on page 200
Configuring Duplicate Address Detection Attempts on page 201
Monitoring Neighbor Discovery on page 202
Though not a true protocol, routers and hosts (nodes) use Neighbor Discovery (ND)
messages to determine the link-layer addresses of neighbors that reside on attached
links and to overwrite invalid cache entries. Hosts also use ND to find neighboring
routers that can forward packets on their behalf.
In addition, nodes use ND to actively track the ability to reach neighbors. When a
router (or the path to a router) fails, nodes actively search for alternatives to reach
the destination.
IPv6 Neighbor Discovery corresponds to a number of the IPv4 protocols
ICMP Router Discovery, and ICMP Redirect. However, Neighbor Discovery provides
many improvements over the IPv4 set of protocols. These improvements address
the following:
Router discovery How a host locates routers residing on an attached link.
Prefix discovery How a host discovers address prefixes for destinations residing
on an attached link. Nodes use prefixes to distinguish between destinations that
reside on an attached link and those destinations that it can reach only through
a router.
Parameter discovery How a node learns various parameters (link parameters
or Internet parameters) that it places in outgoing packets.
Address resolution How a node uses only a destination IPv6 address to
determine a link-layer address for destinations on an attached link.
ARP,
193
Overview