Comcast, Netgear Run Into IPv6 Glitch

Last week a number of Comcast subscribers had a serious hardware problem on their hands. Netgear modems in California suddenly stopped working. Specifically, owners of the Netgear CMD31T lost Internet service, and subscribers were given a lot of confusing information about why they were being left out in the cold.

Industry analyst Mike Demler first reported the issue on EE Daily News, and noted that he was told by a Comcast technician that his Netgear model was not designed to work in California. Demler’s modem had been working for two straight months, however, and a quick search on the Internet found a data sheet saying the modem should work for all major providers except Time Warner. A trip to the local Frys Electronics store confirmed other Comcast subscribers were having the same problem, and Demler quickly escalated his investigation by reaching out to the PR departments at both Comcast and Netgear.

Fast forward to today, and it turns out that the faulty modem problem is an IPv6 issue. Here’s the statement from Comcast:

Comcast is in the process of deploying IPv6 nationally, as noted on this site in great detail. We recently identified that the retail NetGear CMD31T device ships with and runs an uncertified version of firmware that exacerbates a critical IPv6-related defect. To ensure Comcast customers with these devices will continue to have uninterrupted Internet service, we have rolled back IPv6 temporarily in some parts of our network to give NetGear more time to address the issue. Comcast anticipates NetGear will soon address the issue for their retail devices, which we will test and deploy on an emergency basis.

Of course the Comcast/Netgear problem makes one wonder what other glitches we’ll see as the IPv6 rollouts continue. Comcast plans to have IPv6 deployed in half of its network by the second half of this year. Here’s hoping the migration progresses as (relatively) smoothly as the digital TV transition. I had concerns then too, but ultimately the shift proved largely uneventful.

9 thoughts on “Comcast, Netgear Run Into IPv6 Glitch”

  1. Thanks Dave & Jon. Had been thinking of picking up a DOCSIS 3.0 Modem for a bit and based on the Comcast certified list I just ordered a Motorola Surfboard SB6121. I hear the initial setup is pretty easy.

  2. I wouldn’t change modems until mine dies, and Comcast completes the rollout.

    It’s Comcastic ………..

  3. A Netgear rep just reached out to let us know they’ve got firmware in the pipeline for Comcast to certify and deploy stating, “Resolving this issue for customers in a timely fashion is our number one priority and we are working closely with Comcast on the solution. But the broader question remains: What else could be impacted as Comcast and other choose migrate?

  4. I’m curious how many people will end up having to buy new routers. I know a lot of people out there who still have old linksys b/g equipment that probably has dated firmware that can’t handle IPv6.

    I wish i had an IPv6 net to play with. Do we know if it NATs to IPv4 on home networks? I can’t seem to find evidence if TiVo premieres (wired or wireless) support it.

    Glenn, I literally ordered the exact same modem after I posted that comment. $83 on Amazon, delivered tomorrow with Prime. Looking forward to speed improvements with docsis 3.0. I just got 20.4 Mbps down/3.49 Mbps up, lets see what tomorrow brings…

  5. Jon,

    Yeah, I had just talked to a friend the other day who told me about the speed boost he saw installing a DOCSIS 3.0 modem, and how easy it was (“we notice you’re using a new router, do you want us to update your records” or something like that). He had installed a Surfboard. And a while back Ryan Block had posted a query on gdgt that got a lot of follow up from people on the most reliable cable modem (pre-the redesign that has them focusing on reviews now). The feedback there was universally positive wrt the Surfboard modems. And of course the SB6121 shows up on the Comcast site with three stars… And yes I paid the extra $3.99 to get it in one day as well.

  6. Strange, buying a cable modem. In TW land (NY) they provide them.

    However my Linksys wrt610n died suddenly yesterday. I wonder if it had anything to do with some ipv6 shenanigans. The backup Netgear router worked…

    The 610 appeared to be working, but I was unable to get out and ping would not work to the router (wired). It gave an odd error Ping error Transmit failed. General failure. It just stopped working in the middle of the day.

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