H3C MSR 2600 Series, Configuration Manual

Page: 225 / 288

210
client against the subnets of all address pools, and selects the address pool with the
longest-matching subnet.
To avoid wrong address allocation, keep the subnet used for dynamic assignment consistent with
the subnet where the interface of the DHCPv6 server or DHCPv6 relay agent resides.
IPv6 address/prefix allocation sequence
The DHCPv6 server selects an IPv6 address/prefix for a client in the following sequence:
1. IPv6 address/prefix statically bound to the client's DUID and IAID and expected by the client.
2. IPv6 address/prefix statically bound to the client's DUID and IAID.
3. IPv6 address/prefix statically bound to the client's DUID and expected by the client.
4. IPv6 address/prefix statically bound to the client's DUID.
5. IPv6 address/prefix that was ever assigned to the client.
6. Assignable IPv6 address/prefix in the address pool/prefix pool expected by the client.
7. Assignable IPv6 address/prefix in the address pool/prefix pool.
8. IPv6 address/prefix that was a conflict or passed its lease duration. If no IPv6 address/prefix is
assignable, the server does not respond.
If a client moves to another subnet, the DHCPv6 server selects an IPv6 address/prefix from the address
pool that matches the new subnet.
Configuration task list
Tasks at a glance
(Optional.) Perform the following tasks:
•
Configuring IPv6 prefix assignment
•
Configuring IPv6 address assignment
•
Configuring network parameters assignment
(Required.) Configuring the DHCPv6 server on an interface
(Optional.) Setting the DSCP value for DHCPv6 packets sent by the DHCPv6 server
Configuring IPv6 prefix assignment
Use the following methods to configure IPv6 prefix assignment:
•
Configure a static IPv6 prefix binding in an address pool —If you bind a DUID and an IAID to an
IPv6 prefix, the DUID and IAID in a request must match those in the binding before the DHCPv6
server can assign the IPv6 prefix to the DHCPv6 client. If you only bind a DUID to an IPv6 prefix, the
DUID in the request must match the DUID in the binding before the DHCPv6 server can assign the
IPv6 prefix to the DHCPv6 client.
•
Apply a prefix pool to an address pool —The DHCPv6 server dynamically assigns an IPv6 prefix
from the prefix pool in the address pool to a DHCPv6 client.