Ipv6 neighbor discovery protocol, Address resolution – H3C Technologies H3C SecPath F1000-E User Manual

Page 706

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On a tunnel interface
The lower 32 bits of the EUI-64 address-based interface identifier are the source IPv4 address of
the tunnel interface. The higher 32 bits of the EUI-64 address-based interface identifier of an
ISATAP tunnel interface are 0000:5EFE, whereas those of other tunnel interfaces are all zeros. For

more information about tunnels, see VPN Configuration Guide.

On an interface of another type
The EUI-64 address-based interface identifier is generated randomly by the firewall.

IPv6 neighbor discovery protocol

The IPv6 Neighbor Discovery (ND) protocol 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 84

lists the types and functions of ICMPv6 messages used by the ND protocol.

Table 84 ICMPv6 messages used by ND

ICMPv6 message

Type

Function

Neighbor Solicitation (NS)
message

135

Acquires the link-layer address of a neighbor.

Verifies whether a neighbor is reachable.

Detects duplicate addresses.

Neighbor Advertisement
(NA) message

136

Responds to an NS message.

Notifies the neighboring nodes of link layer changes.

Router Solicitation (RS)
message

133

Requests for an address prefix and other configuration
information for autoconfiguration after startup.

Router Advertisement (RA)
message

134

Responds to an RS message.

Advertises information such as the Prefix Information options and
flag bits.

Redirect message

137

Informs the source host of a better next hop on the path to a
particular destination when certain conditions are satisfied.

Address resolution

This function is similar to the ARP function in IPv4. An IPv6 node acquires the link-layer addresses of

neighboring nodes on the same link through NS and NA message exchanges.

Figure 355

shows how

Host A acquires the link-layer address of Host B on a single link.

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