АМАТЕК AN-SGM28P24-400 [315/322] Ipv6 neighbor discovery protocol

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Figure 1-2 conversion process from MAC

address to EUI-64 format interface identifier

27.1.3 IPv6 neighbor discovery protocol

IPv6 neighbor discovery protocol using ICMPv6 message five types, some functions to

achieve the following: address resolution, verification of neighbors is reachable, duplicate address

detection, router discovery / prefix discovery, address auto configuration and redirection.。

The type and role of ICMPv6 messages used by neighbor discovery protocols are shown in

table 1-3。

Table 1-3 the type and role of ICMPv6 messages used in neighbor discovery protocols

The main functions of neighbor discovery protocol are as follows：

1 Address resolution

The link layer address of the neighbor node of the same chain is obtained (the same as the

ARP function of IPv4), which is implemented by neighbor request message NS and neighbor

notification message NA. As shown in Figure 1-3, node A is required to obtain the link layer

address of node B。

Schematic diagram of address resolution in Figure 1-3

(1) Node A sends NS messages in multicast mode. The source address of the NS message is

the interface IPv6 address of the node A, and the destination address is the multicast address of the

requested node of the node B. The message content contains the link layer address of the node A。

(2) After the node B receives the NS message, it determines whether the destination address

of the message is the multicast address of the requested node corresponding to its own IPv6

address. If it is, then the node B can learn the link layer address of the node A and return the NA

message in unicast mode, which contains its own link layer address。

(3) The node A obtains the link layer address of the node B from the received NA message。