Airport Extreme not getting IP

Discussion in 'Mac OS X Server, Xserve, and Networking' started by abeasom, Feb 13, 2018.

  1. abeasom macrumors member

    Joined:
    Dec 31, 2013
    #1
    Yesterday I tried to update my Xfinity gateway to the newest model that has DOCSIS 3.1. I think it's the XB6 model. I hooked it up, enabled bridge mode on it, and power cycled the AE. When it came back online, my internal network was working fine (security cameras, printer, Roomba etc..) but I couldn't get to any outside websites. Upon closer look, I noticed that my AE was still showing the old IP address from the older Xfinity gateway. I would assume it should be getting a new IP from a new Modem/Gateway device. I tried to Renew DHCP in the AP utility app and it wouldn't work. I powered cycled things numerous times and even spoke with Comcast tier-2 networking support and we just couldn't get the AE to get an IP from the new gateway. I ended up hooking back up the older gateway and it worked just fine; as it used the same IP it had before. Not sure if the Gateway or the AE is to blame. Anyone have any thoughts?
     
  2. techwarrior macrumors 65816

    techwarrior

    Joined:
    Jul 30, 2009
    Location:
    Colorado
    #2
    Did you contact Comcast to have them authorize your new gear?

    Any modem or modem\router that is used on their network needs to be registered in their systems. Kind of like EMEI on phones, the network only allows devices it is aware of on the network, to avoid people getting free service.
     
  3. BrianBaughn macrumors 603

    BrianBaughn

    Joined:
    Feb 13, 2011
    Location:
    Baltimore, Maryland
    #3
    The XB6 in bridge mode wouldn't provide DHCP, would it?

    Comcast/Xfinity might have a different idea of what "bridge mode" is and that idea may depend on what service you have and what equipment they provide. Also, having a dynamic IP address, if that is the case, throws a wrench in the works.

    First, have you tried the new Comcast AC modem/router to see if it is possibly better (wifi-wise) than your AE?

    Second, did you consider saving some money in the not-so-long-run by purchasing your own compatible Docsis 3.1 modem? You can log into Xfinity.com and visit My Device Info to see models that are acceptable. This is actually what I advise as it removes their equipment and firmware from your home and thus from the equation.

    Third, did their support ever ask you for the ethernet (MAC) address of your AE?
     
  4. belvdr, Feb 13, 2018
    Last edited: Feb 13, 2018

    belvdr macrumors 603

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    #4
    I have Spectrum and when I purchased my own cable modem, I had to give them that MAC address but I never gave them the MAC of my router, even when I replaced it with another vendor. That made me wonder if they are doing authorization on their cable modem. I would hope a tech could figure that out, but we all know how well that goes.

    Also, per the DOCSIS standard, the cable company controls the firmware of the cable modem, even if you own it.
     
  5. abeasom thread starter macrumors member

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    Dec 31, 2013
    #5
    I need a DOCSIS 3.1 gateway that does both internet and telephone. We use a home phone line because we live in a valley and do not get very good cell service, if at all. I have never seen a DOCSIS 3.1 with voice and internet for sale. Also, my wife works for Comcast Spotlight so we receive a substantial discount on all of Xfinity's services.
    Perhaps the new Comcast gateway would be better than the AE, however I have a ton of port forwarding setup for cameras and a bunch of DHCP reservations too that I was trying not to have to setup again and would rather just use AE. Their support never did ask me for the AE mac address. Maybe they should have?
    I do not want the XB6 to provide DHCP. I want to control that with the AE. What I need is the XB6 to pass it's IP address onto the AE. That is the problem I am having. When it's connected and the Gateway is bridged, the AE still shows the old IP address it received from the old Xfinity Gateway. It's like either the AE won't refresh and grab the new IP from the Gateway, or the Gateway is not passing along the IP address to the AE.
    --- Post Merged, Feb 13, 2018 ---
    Yes sir. They actually activated it and put it on my account when I picked it up from the Xfinity store. That immediately shut off the old Gateway.
     
  6. BrianBaughn macrumors 603

    BrianBaughn

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    Feb 13, 2011
    Location:
    Baltimore, Maryland
    #6
    Good, specific info there.

    If you haven't seen this thread give it a look.

    In my experience, changing equipment with Comcast sometimes takes a while to "settle in". You shouldn't have to change anything on the AE as I'm sure you were just getting the WAN IP on the AE via DHCP.

    Do you have a computer that you can connect directly to the XB6?
     
  7. abeasom thread starter macrumors member

    Joined:
    Dec 31, 2013
    #7
    I do. I'm going to exchange the Gateway tomorrow and get another one, just in case there actually was something wrong with it. After I get it up and running, I'll give plugging a computer directly into the modem a try before enabling bridge mode to see if it gives that computer an IP address.
     
  8. BrianBaughn macrumors 603

    BrianBaughn

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    Feb 13, 2011
    Location:
    Baltimore, Maryland
    #8
    If you plug in before bridge mode is enabled you'll get a local IP. After bridge mode, you should get the WAN IP.
     
  9. belvdr macrumors 603

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    #9
    Good point. When I have to power up my gear, I plug in the cable modem and wait a minute or so _after_ all the lights are normal. I then power up the router.
     

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8 February 13, 2018