Cisco IPv6 Training IPv6 DHCPv6 RR and DR Identification

How is the DHCPv6 Requesting Router (RR) and Delegating Router (DR) Identified?

By Charles Ross CCNP #CSCO10444244

Lately, I’ve been receiving a lot of emails in regards to the question “What is an IPv6 DUID?”

Well, an IPv6 DUID is actually a DHCP for IPv6 Unique Identifier (DUID). It is used by the Requesting Router (RR) and the Delegating Router (DR) for identification. The DUID is unique to every RR and DR device, the DUID is actually formed (created) automatically from the layer 2 MAC address of the lowest-numbered interface on each type of RR or DR device or a network administrator can configure it manually with the help of ISP information.

The reason why the DUID is used for RR and DR identification is because the DUID is actually permanently assigned to the RR or DR device; which means even after the RR or DR device has been rebooted, the DUID for that particular RR or DR will remain unchanged (Some would say the DUID is a Stable Identifier).

The DUID plays an important role in the overall DHCP-Prefix Delegation (DHCP-PD) protocol message exchanges between a RR (the DHCP-Client) and a DR (the DHCP-Server).

To your success,

Charles Ross

CCNP #CSCO10444244