How do I configure CDRouter for DHCPv6 prefix delegation?

CDRouter’s IPv6 expansion supports DHCPv6 Prefix Delegation (RFC 3633) on the WAN to dynamically assign an IPv6 prefix for the DUT to use on its LAN interfce(s).

DHCPv6 prefix delegation is enabled by setting dhcpv6WanEnablePD testvar to yes. IPv6 must also be enabled on the WAN interface (ie. ipv6WanMode must be set to DHCP, static, PPPoE, or autoconf).

The prefix and prefix length provided by CDRouter’s DHCPv6 server on the WAN are specified by the testvars dhcpv6WanAssignPrefix and dhcpv6WanAssignPrefixLen.

The testvar dhcpv6WanAssignNextPrefix specifies a free prefix on the WAN used for renumbering tests. The testvar dhcpv6PDLatency defines the amount of time, in seconds, it takes the DUT to update its LAN side IPv6 settings when a new IPv6 prefix is learned on the WAN.

Example Configuration

testvar dhcpv6WanEnablePD              yes 
testvar dhcpv6WanAssignPrefix          3001:dddd::
testvar dhcpv6WanAssignNextPrefix      3001:ddde::
testvar dhcpv6WanAssignPrefixLen       48 
testvar dhcpv6PDLatency                30

By default, the delegated prefix defined above may not include the DUT’s global WAN address. CDRouter will generate an error if the ipv6WanIspAssignIp testvar overlaps with the delegated prefix.

The DHCPv6 Prefix Exclude option (RFC 6603) specifically allows an exception to this rule and must be enabled in order for CDRouter to allow this configuration.

For more information and configuration examples, please see the IPv6 Addressing with Prefix Delegation article in our Knowledge Base.