Double NAT Error

Macnificant

macrumors 6502a
Original poster
Feb 26, 2008
539
95
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?
 

BrianBaughn

macrumors 604
Feb 13, 2011
6,822
1,108
Baltimore, Maryland
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?
 

Macnificant

macrumors 6502a
Original poster
Feb 26, 2008
539
95
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?
No I just have the AirPort Extreme and a Motorola modem
 

chabig

macrumors 604
Sep 6, 2002
6,660
3,828
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)
 
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Fishrrman

macrumors Core
Feb 20, 2009
19,146
6,576
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...
 

campyguy

macrumors 68040
Mar 21, 2014
3,413
950
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.
 

Macnificant

macrumors 6502a
Original poster
Feb 26, 2008
539
95
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
 

Taz Mangus

macrumors 68040
Mar 10, 2011
3,742
504
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
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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