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Mysterious, Creepy Double NAT error...

Hi everyone, always seem to get the best tips from these Support Communities! So here's my latest issue, would appreciate any input... I've been using the same DSL router for several years without any problem, and have had it connected to my Airport Extreme for almost 3 years to create a wireless network in our home. No problems at all with this set up at all, and we have many devices connected to it intermittently -- two Macbooks, two iphones, an ipad and an Apple TV. We also have a separate Airport Express that is solely used for wireless music in a separate room, and that connects to the Airport Extreme wireless network so we can use Apple Remote, etc.


All of a sudden I get a pop-up alert today that I have a "Double NAT" issue, and have one of two choices to resolve it, see the screenshot below:

User uploaded file

Here's where things get really weird:


1) As I don't know anything about this type of error, I selected Bridge Mode, and when the Airport Extreme restarted, all of a sudden I saw multiple random airports (most likely my neighbors') appear in the Airport Utility. That definitely freaked me out.

2) I definitely need to maintain a Guest network, so from what I've been reading that basically eliminates the Bridge option anyway.

3) Here's where it gets super-weird -- a few weeks ago I had an IT guru friend do some troubleshooting on my network when the speeds were getting horribly slow. He suspected someone had managed to hack into my wireless network and was streaming a ton of data nonstop. I immediately changed the password and security settings, renamed the network and that fixed that problem.


I'm wondering if there's any relation between/among all these separate issues? Also from what I've been reading about Double NAT issues, I understand that the modem may be causing the problem, but as I mentioned earlier the modem has been in place for a long, long time, as has the Airport, both of them essentially undisturbed so my gut tells me it's unlikely the modem is causing the issue. Any thoughts, advice or input is much appreciated, thanks!

Posted on Dec 2, 2012 9:04 PM

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5 replies

Dec 4, 2012 8:46 PM in response to b5160519

I am not a network guru (You know more than I do), but I do have a tad bit of expierence on the "testing network security side". I will agree somebody probably has cracked your network. Since you have put protective measures in place you may have upset the individual.


It seems to me he maybe using attacks to try to provoke your network into giving up the 4 way handshake necessary to use "bruteforce" on a WPA/WPA2 security network. Put it this way...a 21 key alpha numeric password will take about 2 years to crack with 1 device. 12 key password...5-8 days maybe. oh and WEP Secure networks only take a few seconds to a few hours depending on network activity.


If I am right and you are being attacked, then if I were you, I would find a way to cripple my network speed for a few days and make it relitivly easy for him to come in. You could set your airport wireless card to passive mode and try to do some passive scanning to see if you can find him (Good luck). Kismac is still compatible with your OSX. However, If he knows what he's doing and you upset him he could make your life miserable. I do not by any means endorse using kismac for anything illeagle nor do I advise installing the software. However, Passive scanning and wardriving a leagle in the united states but check with your local officals first. Also just a question, when you perform a broadband speed test what are your results? somewhere in the 10-20 MBPS or above may attract suckers depending on where you live. Good luck


Disclaimer: I am not a pro at networking. I am just starting out (as of yesterday), so if I am totally wrong here please be a little considerate. Oh yea some speed test sites will try to offer Mackeeper stay the Heck away from Mackeeper.

Mysterious, Creepy Double NAT error...

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