Neighbor Discovery; Neighbor Discovery Overview - Lenovo RackSwitch G8264 Application Manual

Neighbor Discovery

Neighbor Discovery Overview

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G8264 Application Guide for ENOS 8.4
The switch uses Neighbor Discovery protocol (ND) to gather information about
other router and host nodes, including the IPv6 addresses. Host nodes use ND to
configure their interfaces and perform health detection. ND allows each node to
determine the link‐layer addresses of neighboring nodes and to keep track of each
neighbor's information. A neighboring node is a host or a router linked directly to
the switch. The switch supports Neighbor Discovery as described in RFC 4861.
Neighbor Discover messages allow network nodes to exchange information, as
follows:
 Neighbor Solicitations allow a node to discover information about other nodes.
Neighbor Advertisements are sent in response to Neighbor Solicitations. The

Neighbor Advertisement contains information required by nodes to determine
the link‐layer address of the sender, and the sender's role on the network.
 IPv6 hosts use Router Solicitations to discover IPv6 routers. When a router
receives a Router Solicitation, it responds immediately to the host.
Routers uses Router Advertisements to announce its presence on the network, and

to provide its address prefix to neighbor devices. IPv6 hosts listen for Router
Advertisements, and uses the information to build a list of default routers. Each
host uses this information to perform autoconfiguration of IPv6 addresses.
 Redirect messages are sent by IPv6 routers to inform hosts of a better first‐hop
address for a specific destination. Redirect messages are only sent by routers for
unicast traffic, are only unicast to originating hosts, and are only processed by
hosts.
ND configuration for general advertisements, flags, and interval settings, as well as
for defining prefix profiles for router advertisements, is performed on a
per‐interface basis using the following commands:
RS G8264(config)# interface ip <interface number>
RS G8264(config­ip­if)# [no] ipv6 nd ?
RS G8264(config­ip­if)# exit
To add or remove entries in the static neighbor cache, use the following command:
RS G8264(config)# [no] ip neighbors ?
To view the neighbor cache table, use the following command:
RS G8264(config)# show ipv6 neighbors ?
To view the neighbor cache counters, use the following command:
RS G8264(config)# show ipv6 neighbors counters