3Com 4210 PWR Configuration Manual page 532

530 C 46: IP 6 M
HAPTER V
n
C
ANGEMENT ONFIGURATION
Table 385 Types and functions of ICMPv6 messages
ICMPv6 message
Neighbor advertisement (NA)
message
Router solicitation (RS)
message
Router advertisement (RA)
message
Redirect message
3Com Switch 4210 Family do not support RS, RA, or Redirect message.
■
Of the above mentioned IPv6 NDP functions, 3Com Switch 4210 Family
■
support the following three functions: address resolution, neighbor
unreachability detection, and duplicate address detection. The subsequent
sections present a detailed description of these three functions and relevant
configuration.
The NDP mainly provides the following functions:
Address resolution
Similar to the ARP function in IPv4, a node acquires the link-layer address of
neighbor nodes on the same link through NS and NA messages. Figure 191 shows
how node A acquires the link-layer address of node B.
Figure 191 Address resolution
A
ICMP type=135
Src =A
Dst=solicited - node multicast 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 the interface of node A and the destination address is the
Function
Used to respond to a neighbor solicitation message
When the link layer address changes, the local node initiates a
neighbor advertisement message to notify neighbor nodes of
the change.
After started, a host sends a router solicitation message to
request the router for an address prefix and other configuration
information for the purpose of autoconfiguration.
Used to respond to a router solicitation message
With the RA message suppression disabled, the router regularly
sends a router advertisement message containing information
such as address prefix and flag bits.
When a certain condition is satisfied, the default gateway sends
a redirect message to the source host so that the host can
reselect a correct next hop router to forward packets.
NS
ICMP type=136
Src=B
NA
Dst=A
Data=link- layer address of B
B