3Com MSR 50 Series Configuration Manual page 661

Figure 196 Address resolution
Host A
ICMP type = 135
Src = A
Dst = solicited-node multicast address of B
Data = link layer address of A
The address resolution procedure is as follows:
1 Node A multicasts an NS message. The source address of the NS message is the
IPv6 address of an interface of node A and the destination address is the
solicited-node multicast address of node B. The NS message contains the link-layer
address of node A.
2 After receiving the NS message, node B judges whether the destination address of
the packet corresponds to the solicited-node multicast address. If yes, node B can
learn the link-layer address of node A, and then unicast an NA message containing
its link-layer address.
3 Node A acquires the link-layer address of node B from the NA message. After that,
node A and node B can communicate.
Neighbor reachability detection
After node A acquires the link-layer address of its neighbor node B, node A can
verify whether node B is reachable according to NS and NA messages.
1 Node A sends an NS message whose destination address is the IPv6 address of
node B.
2 If node A receives an NA message from node B, node A considers that node B is
reachable. Otherwise, node B is unreachable.
Duplicate address detection
After node A acquires an IPv6 address, it will perform duplicate address detection
(DAD) to determine whether the address is being used by other nodes (similar to
the gratuitous ARP function of IPv4). DAD is accomplished through NS and NA
messages. Figure 196
Host B
NS
ICMP type = 136
NA
Src = B
Dst = A
Data = link layer address of B
shows the DAD procedure.
IPv6 Overview 661