How to get a Comcast IPv6 address with everyday gear and a few mouse clicks

ipv6logoThe last time I tinkered with IPv6, it involved tunneling and a custom router. Since that time World IPv6 Day has come and gone, meaning internet service providers have had plenty of time to get a handle on the next generation IP addressing scheme. Seeing as Comcast is one of those major ISPs, Time Warner Cable acquisition or not, and happens to be the one plugged in at my present location, I ventured to find out if the beast could be roused. Without jumping through all the previous hoops.

Long story short … the findings were resoundingly positive. So what follows is the how-to, which has been outlined while running Apple networking gear but does not preclude possible tweaks for other hardware.

First you need to check if Comcast is serving IPv6 to your connection. Open your browser and head to


If the result says “Your CMTS is ready for IPv6” then you can proceed. If it doesn’t grab a whiskey. Better yet, grab a whiskey regardless (even if you are using an entirely different ISP). Check your modem for compatibility – most DOCSIS 3.0 compliant ones are. If it isn’t, make that a double.

Router Time

Next, open up Airport Utility. Click on the image of your router, and then the edit button on the popup …


Then hit the “Internet Options” button, at which point you should be staring at this screen …


For “Configure IPv6” select “Automatically”; for “IPv6 Mode” you’ll go with “Native”. “Enable IPv6 Connection sharing” should be checked.

Hit “Save” and then “Update”. Note that your network will go down while the router is doing its thing, so make sure you are not streaming Justified, The Americans, Vikings, Game of Thrones or The X-Files.

Once Airport Utility shows a green light for the router you can close the program. The router is likely set, but you are not quite.

Computer Time

Go to System Preferences and click the Network icon.


Then hit the Advanced button …


Here you will select the TCP/IP tab. Next to “Configure IPv6” select “Automatically”. You will hit the Save button on the present screen and the Apply button on the next.

Time to test! Go back to, and if you are lucky you will get the message that says “Congrats!” along with the IPv6 address you are coming from.


If you’d like to do an IPv6 readiness test, go to


Why did I do all this? Well, I was preparing this very site for IPv6, and the best way to test it was to have the right connection. While I won’t get into those details just yet, if you open a terminal window and type ping6 you should get conclusive results.

MG signing off (because that wasn’t so hard, was it?)

UPDATE 02/24/14: Dan York says don’t wait for the announcement – IPv6 is happening now.

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