On June 14th, 2011, Linksys released firmware update 1.0.02 (Build 13) for hardware version 1.0 of the Linksys E4200. This firmware contains the long awaited implementation of IPv6 for the E4200!

The good news is, it works! The bad news is, not with Comcast apparently. More on that later. First things first, here’s a screenshot of my current setup.

Linksys E4200 IPv6 Configuration Dialog

The first thing you’ll notice is that I had to disable the Automatic mode. That’s the “doesn’t work with Comcast” part. I put it in place, rebooted it a few times, released and renewed my IP, nothing. It could be my modem, but I doubt it. I’m using a DOCSIS 3.0 compliant surfboard which should be IPv6 compliant. Maybe it’s Comcast, but who knows?

In order to get this working, flip the “IPv6 – Automatic” toggle to Disabled, then put the “6rd Tunnel” to Manual Configuration. (The “Automatic Configuration” of the 6rd Tunnel didn’t work either.) Once you’re in Manual mode, you can head on over to tunnelbroker.net and create yourself a login and a new tunnel. (Note : You’ll have to enable ping in order for Tunnel Broker to work. Go to Security -> Firewall and clear the check box next to “Filter Anonymous Internet Requests“. This will allow ICMP requests to come through and Tunnel Broker will allow you to create a tunnel.) Once you have the tunnel created, enter the “Server IPv4 Address” from tunnel broker into the “Border Relay” field on the E4200. Now enter the “Routed /64” from tunnel broker into the “Prefix” on the E4200. (Note : You need to get rid of the “::/64″ off of the end of the field that tunnel broker gives you.) Put “64” into the Prefix Length and “32” into the IPv4 Address Mask and Save Settings.

Head over to Status -> Router and at the very bottom, you should see “Tunnel Status:  Connected“. If you don’t, hit the Connect button. One thing, I did have to release and renew my IPv4 address for some reason. Probably because I was fiddling with all of the tunnel configurations, trying to get this thing to work.

Good luck and if anyone has any luck connecting to Comcast in Automatic mode, let me know. I’d love to go native instead of tunneling!