Configuring DHCPv6 Relay Forwarding

DHCPv6 relay forwarding functions are configured on the inbound interface of DHCPv6 messages. You can specify the outbound interface, or destination DHCPv6 server address, or next-hop DHCPv6 relay agent address.

Context

To relay packets sent from DHCPv6 clients on a network segment, configure DHCPv6 relay forwarding on the DHCPv6 relay agent's interface that connects to the network segment. If multiple outbound interfaces or destination IPv6 addresses are specified, the DHCPv6 relay agent forwards one copy of packets to each outbound interface or destination IPv6 address. The destination IPv6 address can be an interface address on the next-hop DHCPv6 relay agent or the DHCPv6 server.

Procedure

Run system-view
The system view is displayed.
(Optional) Run dhcpv6 relay server group group-name
A DHCPv6 relay server group is configured, and the server group view is displayed.

If you want to enable DHCPv6 relay on multiple interfaces and specify the same DHCPv6 relay servers for these interfaces, configure a DHCPv6 relay server group to simplify the configuration.
(Optional) Run server server-addr
A server is added to the DHCPv6 relay server group.
Run quit
Return to the system view.
Run interface interface-type interface-number
The interface view is displayed.
Perform either of the following operations as required:
- To specify an outbound interface or destination IPv6 address for DHCPv6 messages on the interface, run the dhcpv6 relay { interface interface-type interface-number | destination ipv6-address } command.
- To bind the interface to a DHCPv6 relay server group, run the dhcpv6 relay binding server group group-name command.
(Optional) Run dhcpv6 relay link-address ipv6-address
A DHCPv6 relay gateway address is configured.

When a DHCPv6 relay agent is connected to a host, it needs to periodically send RA messages to the host. An RA message carries both the IPv6 address prefix and stateful address autoconfiguration flag. You can run the undo ipv6 nd ra halt command to enable the agent to send RA messages.
(Optional) For the DHCPv6 server that replies packets based on the source IP address, the DHCPv6 relay agent uses the IP address of the relay interface as the source IP address when forwarding a DHCP request packet from a DHCPv6 client. If the source IP address needs to be specified, perform either of the following operations:
- Run dhcpv6 relay source-ip-address ipv6-address
  The source IPv6 address is specified for DHCPv6 messages on the interface.
- Run dhcpv6 relay source-interface { interface-name | interface-type interface-num }
  The IPv6 address of a specified interface is configured as the source IPv6 address of DHCPv6 relay forwarding packets.
Both the dhcpv6 relay source-ip-address and dhcpv6 relay source-interface commands can specify the source IP address used by a DHCP relay agent to forward packets. These two commands are mutually exclusive. If both of the two commands are run on a DHCP relay interface, the latter configuration overrides the former one.
(Optional) Run dhcpv6 relay gateway-switch enable
Automatic DHCPv6 relay gateway switching is enabled.
- If the dhcpv6 relay link-address command has been run on an interface to configure a gateway address, the dhcpv6 relay gateway-switch enable command does not take effect.
- You must run the preceding commands in VXLAN distributed gateway scenarios.
Run quit
Return to the system view.
(Optional) Run dhcpv6 rate-limit { disable | rate-limit }
Global rate limiting is disabled for DHCPv6 messages or a rate limit is configured for DHCPv6 messages.
(Optional) Run dhcpv6 source-ip-address format adaptive enable
The source IPv6 address type of the response packets sent by the DHCPv6 relay to the DHCPv6 client is configured as link-local.
Run commit
The configuration is committed.