Comcast messed up my wi-fi Time Capsule

Discussion in 'Mac Accessories' started by zenpop, Aug 22, 2014.

  1. zenpop macrumors newbie

    Nov 30, 2011
    My internet connection was down to a crawl for days. Did all the usual attempts to fix with the modem and Time Capsule (rebooting, etc.) Nothing changed.

    Called Comcast. Tech comes out. Diddles with my set up for a half hour and then declares:

    "It was weird there was no signal at all coming through our modem but because Apple products are designed a certain way it allowed some sort of signal to get through. I have the modem working again and you have good speeds."

    Me: "Great, but now Time Capsule has gone amber and won't allow for back ups."

    Comcast: "Oh we didn't set up this wifi arrangement so you'll have to deal with whoever set that up to fix it."

    Me: "But it's been working fine, for 3 years, until you came today."

    Comcast: "I don't know what to tell you."


    My Time Capsule, as the main router, goes out to an Airport Expresses and Airport Extreme in the house, and those are all showing green connection lights, on the router, my Time Capsule stays yellow and gives this error:

    "Status: Double Nat."

    And then when I click on that it says to 'change to bridge mode' but when I do that the entire systems goes insane and I have to struggle to get it back to the Double Nat status.

    Somehow I have connectivity to the internet, probably with what's coming through the Extreme, but can't get Time Capsule back to normal.

    Any ideas how to remedy this?

    Thanks so much
  2. zenpop thread starter macrumors newbie

    Nov 30, 2011
    Uhm, wierd. I tooled around some more with the alert field, and next to where it showed the error, I clicked the IGNORE option, and then Time Capsule turned green.

    Jesus, that makes me even crazier, (not knowing why THAT worked) but at least it is working.

  3. Richdmoore macrumors 68000


    Jul 24, 2007
    Troutdale, OR
    Did you subscribe to the Comcast/Xfinity x1 service?

    I had it installed a few weeks ago, and discovered you can't turn off the router portion of the cable modem, unlike every other modem I have ever had. Comcast simply doesn't allow consumers to use their own router, they require you to use their router for their triple play service.

    My time capsule turned amber with the double NAT error, so I had to put it in bridge mode. After that it works again, but the comcast modem is doing all the work, all the time capsule does now is provide the time capsule disk drive and output the AC wifi signal (Comcast router is only a N router.) All the routing and DNS service is done using the comcast router.

    Because of the change, I had some issues with my eyetv mobile software not being able to connect to my computer. I fixed it by going into the comcast router and turned on upnp. I have not tried other remote login software yet, I may have to deal with opening ports for the back to my mac service.

    Anyway, the first step is to see if you can turn off the router portion of the comcast modem, and let the time machine handle the routing function. If you can't, then you have to configure the time machine to bridge mode. That will resolve the double NAT error. Simply ignoring it may make the light go green on the time capsule, but it does not fix the underlying issue.
  4. zenpop thread starter macrumors newbie

    Nov 30, 2011
    No, I don't have that service Rich. Just basic connection of the modem for internet and my landline.

    God, what you're describing sounds like a nightmare. Should I still be concerned even though all is working fine and Time Capsule is backing up as it should?

  5. troy14 macrumors 6502a

    Mar 25, 2008
    Las Vegas (Summerlin), NV

    Not true. It goes by market area but the majority of markets allow you to purchase your own modem and use that (and not pay their monthly fee!) I know this because it's what I did. I purchased an Arris TM822G and use it with my time capsule, AirPort Extreme and express with no problems.

    You can also call Comcast and tell them you want your gateway to be put into bridge mode. Most of the tech support understands this and is willing to do it remotely for you
  6. Richdmoore, Aug 23, 2014
    Last edited: Aug 23, 2014

    Richdmoore macrumors 68000


    Jul 24, 2007
    Troutdale, OR
    Ok. If it matters, when I was told that I couldn't use my own modem, it was in Beaverton, Oregon, and it was because I was installing the x1 dvr service with the triple play. (I had a 3.0 cable modem already, but it had no phone jack on it unlike the comcast modem.). There is no cable modem/router rental fee.

    For what it is worth, the installer said that all of comcast is switching to the new x1 system, and everyone will be required to use a comcast provided modem. Of course, he could be misinformed.

    I thought of trying to go up the chain and get them to turn off the router function on comcast's end (can't be switched off by the customer) but after reading lots of info on DSLreports some customers find it gets turned back on at every firmware update, which makes a vicious circle of calling again to get the routing corrected. Again, I just read it on dslreports, I haven't called to verify it myself.

    One more ugly thing. The comcast router made an xfinity wifi public login, so my neighbors could piggy back off of my connection using their unique Comcast login! I can also log into my neighbors public wifi (xfinity said) using my id. It's a public hotspot "feature" I am not wild about. The only way I found to kill it was to disable the wifi. Since I wanted to use the time capsule ac wifi instead of the comcast n wifi, that solution worked well for me.

    Anyway, at the end of the day bridging the time capsule (and turning on the comcast upnp) was the best solution for me.

    Edit: I will try to find some links talking about these new modem/routers.

    Xfinity wifi FAQ:
  7. Rettogo macrumors newbie

    Oct 16, 2012
    --- Post Merged, May 29, 2016 ---
    I'm in an X1 market and have an Arris telephony modem that I purchased the last time I was with Comcast. They said I could use the modem but they wouldn't support getting my router and everything going so I chose not to then. I do intend to contact them and see if I can get a tech support person with a brain to help me get it up and running hopefully without the double NAT requiring bridge mode. I'll post here the outcome if/when I can get that person with a brain.
  8. Richdmoore macrumors 68000


    Jul 24, 2007
    Troutdale, OR
    My understanding is that a firmware update happened that now allows a customer to turn off the router portion via an internet page. I think the change happened over a year ago.

    I have since dumped the modem/cable box and use an old surfboard modem that I already own.
  9. havokalien macrumors 6502a


    Apr 27, 2006
    Kelso, Wa
    Comcast supports a lot of cable modems, and of course its always a good idea to seperate wifi from the router for trouble shooting and replacement of course. The double nat probably has alot to do with a hard reset he did on the modem that changed something other than the IP. Its why ignoring it with your time capsule probably made it work.

    In most areas cable is just the best speed/value for internet since its been run for decades more than DSL. Any company is going to have their downfalls. Those installers/repair guys get like a 6 hour class to do a job. You have probably had your computer network longer than he has been installing it.

    I dont have many issues, but when I do I call them because its on their end.
  10. Ries macrumors 68020

    Apr 21, 2007
  11. Richdmoore macrumors 68000


    Jul 24, 2007
    Troutdale, OR
  12. hallux macrumors 68030


    Apr 25, 2012
    Not a Comcast customer but I do seem to recall reading that the hotspot traffic doesn't count against any caps (if applicable) and I would HOPE your own traffic is prioritized. I have heard others reporting that when this feature was enabled at their home it caused some confusion with their devices if they had connected to a hotspot elsewhere.

    I would hope they make a change to that feature that allows people to opt out (though they'll probably tie it to your ability to use hotspots when roaming). It seems silly to enable it in a residential neighborhood where the airwaves are likely saturated as it is. I'm a TWC customer (soon to be Spectrum I guess), I can see 11 other networks within range as I sit outside (I'm in a sprawling apartment complex, 4 units to a building).
  13. campyguy macrumors 68040

    Mar 21, 2014
    Read my post from a few weeks ago, which contains a couple links to my earlier posts on this matter:

    I own my own modems, since my "fix" I've had zero issues in 9 months since I figured it out and canned my dimwit IT guy (who just couldn't figure it out and keep my offices running) - no need for bridge mode, no more double NAT, no more timeouts, just working internet with Comcast in 5 markets and I'm setting up another office tomorrow morning. There's background, an explanation, and the fix in those two posts. Cheers, and good luck...

Share This Page

12 August 22, 2014