Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Trying to setup Time Capsule, how do i fix status that says "double NAT", preventing wifi from working?

In setting up Time Capsule, it won't connect to wifi. In the status pop up of the Time Capsule under the Airport Utility it says "Double NAT". I dont' know how to fix that.

Thanks.

MACBOOK PRO 15.4", Mac OS X (10.6.2), IPHONE 3G

Posted on Dec 3, 2012 2:35 PM

Reply
18 replies

Dec 3, 2012 4:04 PM in response to mcpo1234

This is one goofy modem that acts as if it is a router, so that is why the Double NAT issue is appearing.


There are two ways to tackle this:


1) If everything seems to be working OK, you have the option to click to "Ignore" the Double NAT error in AirPort Utility and the Status light will turn green.


Double NAT is usually not too serious of an error on a simple home network, but it will be a deal killer if you have an online gaming console and want to play games interactively on the Internet.


Your connection will slow slightly because of the multiple NAT firewall layers the signal must pass through, but you will likely not notice this in normal browsing, email, etc.


2) Reconfigure the modem to act in "bridge mode" only and then change the method that the Time Capsule uses to connecf from Ethernet to PPPoE service. There will be no NAT errors this way and this is what AT&T recommends....see link below.....but we are talking about some major surgery here.


http://www.att.com/esupport/article.jsp?sid=KB401764&cv=801,902&title=Connecting +a+non-AT%26T+provided+router+to+your+AT%26T+Internet+connection#fbid=kfca5LRlzv D

Dec 3, 2012 4:36 PM in response to mcpo1234

I tried a few popular routers / modem-routers. Only Time Capsule and AirPort series give me "double-NAT" problem!


mcpo1234, your situation is easy to fix. Just turn off the DHCP and NAT features from your modem (i.e. using "bridge" mode) and let your Time Capsule be the DHCP and NAT server.


In my case, it's complicated because the Internet is being provided as an private WAN which I cannot turn off their DHCP and NAT. Thus "double-NAT" error appears and my Time Capsule cannot connect to the Internet under "DHCP Only", or "DHCP and NAT" modes. But when I use "Bridge" mode, the Intranet only provides me one IP address and each time I can only EITHER use my Mac, OR my iPhone, NOT together.


My work-around will be: I connect the private WAN to my Time Capsule and from my Time Capsule to cascade another router (e.g. D-Link, Belkin or NetGear which supports double-NAT). Why do I do this? Becasue the WiFi network provided behind DHCP and NAT is well-secured. Under "Bridge" mode, my WiFi network is sharing the same wireless network behind, and thus unsecure! But the problem is: the Time Capsule drive (though password protected) is fully exposed in the WAN network because it's only bridged, not protected by DHCP and NAT. Did Apple's network engineers think about it?

Dec 3, 2012 4:57 PM in response to Ivan H

mcpo1234, your situation is easy to fix. Just turn off the DHCP and NAT features from your modem (i.e. using "bridge" mode) and let your Time Capsule be the DHCP and NAT server.


That is the "major surgery" that I was referring to in the previous post. At least it is "major" for most users. Pretty basic stuff for IT guys, but pretty intimidating to a user who is expecting plug and play.


mcpo1234 seems to not want to do this, if I read his response correctly.


Let's wait to see what he reports.

Trying to setup Time Capsule, how do i fix status that says "double NAT", preventing wifi from working?

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.