(Optional) Configuring the Function of Inserting the Option79 Field into DHCPv6 Messages

The MAC address is used to identify the DHCPv4 client on the IPv4 network and the DUID is used to identify the DHCPv6 client on the IPv6 network. In an IPv4 and IPv6 dual-stack service deployment scenario, the administrator wants to establish connections between clients' MAC addresses and IPv4 or IPv6 addresses obtained by the clients and perform unified management over dual-stack clients based on the MAC address. However, the MAC address of the DHCPv6 client cannot be identified using the DUID currently.

As defined in RFC, a DHCPv6 relay agent can fill the link address and link type of a client into the Option79 field. When a device functions as a DHCPv6 relay agent, you can run the dhcpv6 relay option79 insert enable command to insert the Option79 field into DHCPv6 messages for enabling the DHCPv6 server to obtain the clients' MAC addresses. When this command is run and the DHCPv6 relay agent receives a Request message from a client, it inserts the Option79 field into the Request message and forwards the message to the DHCPv6 server. The DHCPv6 server then obtains the MAC address of the client by parsing the Option79 field.

• Only the first-hop DHCPv6 relay agent supports this function.
• This function takes effect for all interfaces if it is configured in the system view, and takes effect for a specified interface if it is configured in the view of the interface. If this command is configured in both the interface view and system view, the configuration in the interface view takes effect.

Prerequisites

• The DHCPv6 function has been enabled in the system view.
• The DHCPv6 relay function has been enabled in the interface view.