Double NAT Error

Discussion in 'Mac Accessories' started by Macnificant, Jul 31, 2017.

  1. Macnificant macrumors 6502a

    Joined:
    Feb 26, 2008
    #1
    I noticed the Double NAT error on my Airpoer Extreme this morning and was wondering what would cause this? I clicked on the error on my iMac and it went away.....should I be doing something else?
     
  2. BrianBaughn macrumors 601

    BrianBaughn

    Joined:
    Feb 13, 2011
    Location:
    Baltimore, Maryland
    #2
    Double NAT is usually caused by having two or more routers on the same network trying to provide network address translation (DHCP "on").

    Is that the situation?
     
  3. Macnificant thread starter macrumors 6502a

    Joined:
    Feb 26, 2008
    #3
    No I just have the AirPort Extreme and a Motorola modem
     
  4. chabig macrumors 68040

    Joined:
    Sep 6, 2002
    #4
    Both the Airport Extreme and the Motorola modem are acting as routers, assigning IP addresses to your local network. The easiest fix is to use Airport Utility to turn off DHCP on the Extreme as follows:
    1. Open Airport Utility and your settings
    2. Click on the Network tab
    3. Change the router mode to OFF (bridge mode)
     
  5. Fishrrman macrumors G4

    Joined:
    Feb 20, 2009
    #5
    Is your Motorola "modem" -ONLY- a modem, or is it a combined modem/router? (also called a "residential gateway")

    Look on the back. If it has more than one ethernet connection (there's usually a group of 4), then it's likely a combined modem/router.

    chabig has the correct solution in reply 4 above this one.
    Use Airport Utility to change the setup so that the Airport functions "in bridge mode".
    It works VERY well that way.
    I've been using an old (flat) Airport Extreme with a Uverse residential gateway for 7 years this way, with nary a hiccup...
     
  6. campyguy macrumors 68040

    Joined:
    Mar 21, 2014
    Location:
    Portland / Seattle
    #6
    OP, two bits. First, read my post here:
    https://forums.macrumors.com/posts/22951592/

    It's got two links that should address exactly what you're alluding two - . Supplementing my "9-month" non-issue period, I'm on 22 months now of no issues…

    Second, several ISPs (including Comcast and CenturyLink) notified users that extended maintenance periods would take place over the past few days - Comcast's was last night and CL was two days ago - with outages that would last 4-6 hours.
     
  7. Macnificant thread starter macrumors 6502a

    Joined:
    Feb 26, 2008
    #7
    I changed to router mode off and now Airport Utility says No configured Airport base stations have been found. Airport Utility will continue searching

    I have no idea what to do to get it back. Lol
     
  8. Taz Mangus macrumors 68040

    Taz Mangus

    Joined:
    Mar 10, 2011
    #8
    Is the double NAT causing you any issues on your network? I also have double NAT situation because I use a AT&T router from the ISP and I also use a AirPort Extreme base station. I simply set to ignore the double NAT on the AirPort Extreme. Does not cause any issues and I have been ignoring the double NAT for several years now. For me it is not an issue because my network uses 10 bases addressing and the AT&T uses 192 base addressing.
     

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