Introduction To Ipv6 Neighbor Discovery Protocol - H3C S5120-EI Series Operation 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 reachability detection
Duplicate address detection
Router/prefix discovery and 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
ICMPv6 message
Neighbor solicitation (NS)
message
Neighbor advertisement
(NA) message
Router solicitation (RS)
message
Router advertisement
(RA) message
Redirect message
The NDP mainly provides the following functions:
Address resolution
Similar to the ARP function in IPv4, a node acquires the link-layer addresses of neighbor nodes on the
same link through NS and NA messages.
of node B.
Number
Used to acquire the link-layer address of a neighbor
135
Used to verify whether the neighbor is reachable
Used to perform a duplicate address detection
Used to respond to an NS message
When the link layer changes, the local node initiates an
136
NA message to notify neighbor nodes of the node
information change.
After started, a node sends an RS message to request
133 the router for an address prefix and other configuration
information for the purpose of autoconfiguration.
Used to respond to an RS message
With the RA message suppression disabled, the router
134
regularly sends an RA message containing information
such as prefix information options and flag bits.
When a certain condition is satisfied, the default
gateway sends a redirect message to the source host
137
so that the host can reselect a correct next hop router
to forward packets.
Figure 1-3 shows how node A acquires the link-layer address
1-6
Function