H3C Technologies H3C SecPath F1000-E - Manual (Page 106)

6
• Duplicate address detection
Router/prefix discovery and address autoconfiguration
NOTE:
•
In addition to an address prefix, the Prefix Information option also contains the preferred lifetime and
valid lifetime of the address prefix. Nodes update the preferred lifetime and valid lifetime accordingly
through periodic RA messages.
• An automatically generated address is applicable within the valid lifetime and is removed when the
valid lifetime expires.
• Redirection
Table 3 lists the types and functions of ICMPv6 messages used by the ND protocol.
Table 3 ICMPv6 messages used by ND
ICMPv6 message Type Function
Acquires the link-layer address of a neighbor.
Verifies whether a neighbor is reachable.
Neighbor Solicitation (NS)
message
135
Detects duplicate addresses.
Responds to an NS message.
Neighbor Advertisement
(NA) message
136
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.
Responds to an RS message.
Router Advertisement (RA)
message
134
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
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 3 shows how Host A acquires the
link-layer address of Host B on a single link.