Introduction To Ipv6 Neighbor Discovery Protocol - 3Com 4500 Configuration Manual

Introduction to IPv6 Neighbor Discovery Protocol

The IPv6 Neighbor Discovery Protocol (NDP) uses five types of ICMPv6 messages to implement the
following functions:
Address resolution
Neighbor unreachability detection
Duplicate address detection
Router/prefix discovery
Address autoconfiguration
Redirection
Table 1-3 lists the types and functions of ICMPv6 messages used by the NDP.
Table 1-3 Types and functions of ICMPv6 messages
Neighbor solicitation (NS) message
Neighbor advertisement (NA) message
Router solicitation (RS) message
Router advertisement (RA) message
Redirect message
The 3com switch 4500 does not support the RS, RA, or Redirect message.
Of the above mentioned IPv6 NDP functions, 3com switches 4500 support the following three
functions: address resolution, neighbor unreachability detection, and duplicate address detection.
The subsequent sections present a detailed description of these three functions and relevant
configuration.
The NDP mainly provides the following functions:
ICMPv6 message
Used to acquire the link-layer address of a
neighbor
Used to verify whether the neighbor is reachable
Used to perform a duplicate address detection
Used to respond to a neighbor solicitation
message
When the link layer address changes, the local
node initiates a neighbor advertisement
message to notify neighbor nodes of the change.
After started, a host sends a router solicitation
message to request the router for an address
prefix and other configuration information for the
purpose of autoconfiguration.
Used to respond to a router solicitation message
With the RA message suppression disabled, the
router regularly sends a router advertisement
message containing information such as
address prefix and flag bits.
When a certain condition is satisfied, the default
gateway sends a redirect message to the source
host so that the host can reselect a correct next
hop router to forward packets.
1-6
Function