IPV6
Internet Protocol Version 6
Male IT Specialist Holds Laptop and Discusses Work with Female Server Technician. They're Standing in Data Center, Rack Server Cabinet is Open.
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Occasional Visitor

My IPv6 suddenly stopped working.

My IPv6 has been working for a year.

But it stopped working without warning a week ago.

I have rebooted the cable modem several times without helping.

I tried reaching Comcast with the support chat a couple of times,

but no resonse yet.
The cablemodem settings all look correct  (visible with browser to 10.1.10.1) .
But I cannot ping my ipv6 gateway 2603:3024:1aaf:2001 nor the ipv6 dns server 2001:558:feed::1, which always worked before. And of course I cannot use IPv6 with ssh or browsing. Maybe a routing table upstream at Comcast needs a kick?

(FYI the IPv4 connection is working.)

 

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6 REPLIES 6
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Official Employee

Re: My IPv6 suddenly stopped working.

Hi! Thanks for reaching out to Comcast over Forums and for your patience! I am sorry to learn that the IPV6 connection stopped working! You have reached the right place for help! I will certainly do everything possible to get this fixed as quickly as possible. To get started, please send us a private message with your first/last name, address, and account number or a phone number linked to the account so I can take a look at what’s going on.

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Occasional Visitor

Re: My IPv6 suddenly stopped working.

OK. I will reply directly to you. Thanks.

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Official Employee

Re: My IPv6 suddenly stopped working.

I appreciate your reply, Galt. Are you able to erase your pubic message for privacy and send over a private message? 

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Occasional Visitor

Re: My IPv6 suddenly stopped working.

I fixed my IPv6 routing problem.

I had earlier discovered that my /64 prefix

plus the ::1 address was acting as a gateway,

and I configured my server to use it.

Somehow, that address is no longer supported on the cable modem.

Instead, I found under the local profile a default global gateway address.

It looks somewhat random, but is probably stable and defined on the modem's MAC address.  So it should not change until I have to get a new modem someday.

After updating my default gateway on the outside ethernet on my linux server, my IPv6 network is working great.  I supposed that it would be handy if users could set the value themselves. But at least my ipv6 is working now!

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Official Employee

Re: My IPv6 suddenly stopped working.

Awesome, I am very excited that you are now able to use your IPv6 as needed. This is great news! We appreciate the update. This issue can be one of the most challenging for our customers to work with so Kudos! Do all you can to have a great night and if something else comes up please let us know. Take care 🙂 

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Forum Contributor

Re: My IPv6 suddenly stopped working.

If you have a static IPv4 than your IPv6 address will be static.  If you do not have a static IPv4 then your IPv6 is subjected to change.  You need to create a little script and have it check for that number and see if it changes and if it does then email you.

 

If you have your modem on a UPS then generally the IP addresses assigned to it won't change.  But if it takes a power failure for many hours in particular then it will often change.

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