Operation Manual – IPv6 Management
H3C S3100 Series Ethernet Switches
Chapter 1 IPv6 Configuration
1-9
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.
III. Duplicate address detection
After a node acquires an IPv6 address, it should perform the duplicate address
detection to determine whether the address is being used by other nodes (similar to the
gratuitous ARP function). The duplication address detection is accomplished through
NS and NA messages.
Figure 1-4
shows the duplicate address detection procedure.
Figure 1-4
Duplicate address detection
The duplicate address detection procedure is as follows:
1)
Node A sends an NS message whose source address is the unassigned address ::
and the destination address is the corresponding solicited-node multicast address
of the IPv6 address to be detected. The NS message also contains the IPv6
address.
2) If node B uses this IPv6 address, node B returns an NA message. The NA
message contains the IPv6 address of node B.
3) Node A learns that the IPv6 address is being used by node B after receiving the
NA message from node B. Otherwise, node B is not using the IPv6 address and
node A can use it.
1.1.4 Introduction to IPv6 DNS
In the IPv6 network, a domain name system (DNS) supporting IPv6 converts domain
names into IPv6 addresses. Different from an IPv4 DNS, an IPv6 DNS converts domain
names into IPv6 addresses, instead of IPv4 addresses.
However, just like an IPv4 DNS, an IPv6 DNS also covers static domain name
resolution and dynamic domain name resolution. The function and implementation of
these two types of domain name resolution are the same as those of an IPv4 DNS. For
details, refer to
DNS
..
Usually, the DNS server connecting IPv4 and IPv6 networks contain not only A records
(IPv4 addresses) but also AAAA records (IPv6 addresses). The DNS server can