IPv6/DD-WRT

Every now and the we hear the doomsday is near and the last IPv4 address has been assigned. But sometimes I have to wonder why the ISPs are not providing more information on how configure the router with IPv6. It took me quite a while to figure out why my configuration did not work. This tutorial is for DD-WRT with at the time of the this writing latest and greatest release DD-WRT v24-sp2 (11/11/14) giga.

Prerequisites

• DD-WRT router with IPv6 stack
• ISP with DHCP6 and providing a block of addresses

Howto

• Open a web browser and open the configuration page of your DD-WRT router.
• Navigate to [Setup] -> [IPv6]
  • Set IPv6 to Enable
  • Select [DHCPv6 with Prefix Delegation] under IPv6 Type
  • Press [Apply Settings]
• Navigate to [Administration] -> [Commands]
  • In the Commands box enter ->

ip6tables -I INPUT 2 -m udp -p udp --dport 546 -j ACCEPT;

• • Click on [Save Firewall]
• Navigate to [Administration] -> [Management]
  • Scroll to the very bottom and click [Reboot Router]

Confirmation

After the reboot navigate to [Administration] -> [Commands]. In the Commands box type:

ifconfig br0; ifconfig vlan2; 

There should be 2 different IPv6 prefixes listed. Note: depending on the router the interface names might be different.