Configuring DHCPv6 Relay
When a DHCPv6 client and a DHCPv6 server reside on different links, configure a DHCPv6 relay agent to relay DHCPv6 messages between the client and server.
Usage Scenario
On the network shown in Figure 1, DHCPv6 clients reside on Network A, and the DHCPv6 server resides on Network B. A DHCPv6 relay agent must be configured to relay DHCPv6 messages between the clients and server so that the clients can apply for IPv6 addresses from the server.
Pre-configuration Tasks
Before configuring DHCPv6 relay, complete the following tasks:
- Configure a DHCPv6 server.
- Configure a DHCPv6 relay interface.
- Configure a route on the DHCPv6 server destined for the DHCPv6 relay interface.
- Enable DHCPv6
- DHCPv6 provides client, relay, and server functions.
- 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.
- (Optional) Configuring DHCPv6 PD Relay Functions
- A DHCPv6 relay agent can be configured to advertise DHCPv6 PD routes, limit the maximum number of access DHCPv6 clients, and check the physical information of DHCPv6 packets.
- (Optional) Configuring DHCPv6 Relay Dual-Device Hot Standby
- DHCPv6 relay dual-device hot standby can be enabled to back up user entries between devices. If a network node or link fails, a rapid user service switchover is triggered, improving service reliability.
- (Optional) Configuring DHCPv6 Relay Options
- DHCPv6 relay options include the Interface-ID option, Remote-ID option, and Subscriber-ID option. These options carry detailed user information for address assignment and parameter configuration.
- (Optional) Configuring IPsec on a DHCPv6 Relay Agent
- To defend against DoS attacks, configure IPsec on a DHCPv6 relay agent so that IPsec can be implemented on packets exchanged between DHCPv6 relay agents or between the DHCPv6 relay agent and DHCPv6 server.
- (Optional) Configuring CAR for Whitelisted DHCPv6 Sessions
- You can configure an aging time and bandwidth parameters for CAR for whitelisted DHCPv6 sessions to flexibly isolate the sessions.
- Verifying the Configuration of DHCPv6 Relay
- After configuring DHCPv6 relay on a host or router, verify the configuration.