Avaya 4524GT, Руководство по настройке

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• Parameter discovery: host and routers discover link parameters such as the link MTU or
the hop limit value placed in outgoing packets.
• Address autoconfiguration: nodes configure an address for an interface with address
autoconfiguration.
• Duplicate address detection: hosts and nodes determine if an address is assigned to
another router or a host.
• Address resolution: hosts determine link layer addresses (MAC for Ethernet) of the local
neighbors (attached on the local network), provided the IP address is known.
• Next-hop determination: hosts determine how to forward local or remote traffic with next-
hop determination. The next hop can be a local or remote router.
• Neighbor unreachability detection: hosts determine if the neighbor is unreachable, and
address resolution must be performed again to update the database. For neighbors you
use as routers, hosts attempt to forward traffic through alternate default routers.
• Redirect: routers inform the host of more efficient routes with redirect messages.
Neighbor discovery uses three components:
• host-router discovery
• host-host communication component
• redirect
For more information, see Figure 8: Neighbor discovery components on page 35 for the ND
components.
Figure 8: Neighbor discovery components
ND messages
The following table shows new ICMPv6 message types.
Table 6: IPv4 and IPv6 neighbor discovery comparison
IPv4 neighbor function IPv6 neighbor function Description
ARP Request message Neighbor solicitation
message A node sends this message
to determine the link-layer
address of a neighbor or to
IPv6 management
Configuration — System April 2011 35