Problem of DNS and Double-NAT

[visioneye]

I just bought a Time Capsule 500GB which I do not yet know all the tricks and in particular the operation of the network of guests. Here I would like to create a network of guests, I connected by Ethernet to the TC, on which I turned off the wifi. Then I started the network configuration utility with guests airport. Once done, the TC was flashing amber and ever showed me a utility problem of "double NAT". I read that to solve the problem he had to pass the TC in "bridge" but with this configuration, it is impossible to create a network of guests. I understood that the double NAT problem was that the TC was played to determine which of the two was the router. If anyone has an idea to fix this, it would be grateful.

[Spyrus]

Generally, an AirPort Extreme warns you if it is a double NAT situation. The AirPort Utility emits a message such as "Double NAT" or "incompatible DHCP address range, and the status light blinks amber. The AirPort Utility can suggest you go off the bridge. To solve the problem, you can disable NAT on the router, so that the IP address provided by your Internet Service Provider (ISP) is assigned to the AirPort Extreme. The AirPort Extreme can then use NAT to assign IP addresses to all connected computers.

[Milton.J]

If it is not possible to disable NAT on the modem Internet, then according to me using an AirPort Extreme in bridge mode can be the better alternative :

1. First you will have to Open AirPort Utility.
2. Then click on the Internet tab.
3. Now you will have to note your current settings.
4. Then change the settings which is shown as follows:
   
   • Connecting via Ethernet
   • Configure IPv4: Using DHCP
   • Connection Sharing: Off (Bridge Mode)
5. Later you will have to click on an Update.
6. Confirm that you can still connect to the Internet (in a web browser for example).
7. Try to use Back to My Mac again.

[Big Fish]

I was having the similar issue. In fact, I can create a guest network, but after seeing the flashing orange and TC airport utility tells me there is this double NAT I have to configure the TC to bridge mode. However, with this configuration option "guest network" disappears. I went directly asked for advice apple store and was told that the double NAT is an indication and does not pose a problem to run the network. So I tried and it works well indeed. Just click "ignore" in the Windows operating status of TC Utility airport to stop the flashing orange TC. Well I'm still not really capture what it represents "double NAT", but at least it works.

[Shen]

Although each network configuration is different, here is a simple way to determine if your computer runs on a network "Double NAT".

1. In Finder, Go menu, select Utilities.
2. Open Network Utility.
3. Click Traceroute.
4. In the field, enter "www.mac.com"
5. Click on Plot.

After starting the trace, look for the line beginning with number 2.

[Sanith]

Although each network configuration is different, there is a very easy to tell if your computer is on a network "Double NAT" :

1. In Finder, Go menu, choose Utilities.
2. Open the Network Utility.
3. Click traceroute.
4. In the field, enter www.mac.com.
5. Click traceroute.

If the direction of that line is an IP address in any of the following ranges:

• 10.xxx
• 192.168.xx

[Otto]

When I purchased the PAP2 probe to connect to my WRT54G, which is a client of another router via WIFI, but there was no way to connect to the server Peoplecall with a NAT if it works, but with two or mapping ports on both routers, or mapping in the former and activating the DMZ for the ip of the PAP2 in the WRT or anything, there was no way. I tried Peoplecall technical service and they told me it was for double NAT, but I got no solution, no clue to fix it. After many turns, configurations, and testing, I decided to try the DD-WRT v23 firmware, and specifically the special version for VoIP. And that worked for me.