HP 5920 Series Configuration Manual page 125

Table 8 ICMPv6 messages used by ND
ICMPv6 message
Neighbor Solicitation (NS)
Neighbor Advertisement
(NA)
Router Solicitation (RS)
Router Advertisement (RA)
Redirect
Address resolution
This function is similar to ARP in IPv4. An IPv6 node acquires the link-layer addresses of neighboring
nodes on the same link through NS and NA messages.
link-layer address of Host B on the same link.
Figure 52 Address resolution
The address resolution procedure is as follows:
Host A multicasts an NS message. The source address of the NS message is the IPv6 address of the
1.
sending interface of Host A and the destination address is the solicited-node multicast address of
Host B. The NS message body contains the link-layer address of Host A and the target IPv6
address.
After receiving the NS message, Host B determines whether the target address of the packet is its
2.
IPv6 address. If yes, Host B learns the link-layer address of Host A, and then unicasts an NA
message containing its link-layer address.
Host A acquires the link-layer address of Host B from the NA message.
3.
Neighbor reachability detection
After Host A acquires the link-layer address of its neighbor Host B, Host A can use NS and NA messages
to test reachability of Host B as follows:
Host A sends an NS message whose destination address is the IPv6 address of Host B.
1.
Type Function
Acquires the link-layer address of a neighbor.
135 Verifies whether a neighbor is reachable.
Detects duplicate addresses.
Responds to an NS message.
136
Notifies the neighboring nodes of link layer changes.
Requests an address prefix and other configuration information
133
for autoconfiguration after startup.
Responds to an RS message.
134
Advertises information, such as the Prefix Information options
and flag bits.
Informs the source host of a better next hop on the path to a
137
particular destination when certain conditions are satisfied.
116
Figure 52 shows how Host A acquires the