How using an iPhone 4S can kill your entire network (true story)

Summary:Nah, it couldn't be, could it? It couldn't be my branny-new iPhone killing my network. Could it? Really?

Shortly after I got my iPhone 4S, I decided I wanted to check out this AirPlay thing. I have an Apple TV, I now had a phone modern enough to be AirPlay compatible, and I thought it'd be neat to see what all the shouting was about.

See also: The two reasons I avoided Android and finally upgraded to the relatively boring iPhone 4S

So, I fired up my iPhone 4S, enabled AirPlay, saw my iPhone screen connect to the Apple TV, and, then...

...nothing...

And, by nothing, I mean nothing. No Internet. No internal connectivity. No shares.

Nothing.

Weird, well, okay, I'll do the time tested thing of rebooting the router, and if that didn't work, I expected to reboot the cable modem. One router cycle later and everything was back. Deep sigh of relief.

Okay, so where was I? Oh, yeah, I was playing with AirPlay. I fired up my iPhone 4S, enabled AirPlay, saw my iPhone screen connect to the Apple TV, and, then...

...nothing...

And, by nothing, I mean nothing. No Internet. No internal connectivity. No shares.

Nothing. Again?

Nah, it couldn't be, could it? It couldn't be my branny-new iPhone killing my network. Could it? Really? Fine, let's be scientific about this. Let's try it again. I fired up my iPhone 4S, enabled AirPlay, saw my iPhone screen connect to the Apple TV, and, then...

...nothing...

And, by nothing, I mean nothing. No Internet. No internal connectivity. No shares.

Nothing.

Wow, apparently my iPhone was killing my entire network. Next question: was it just me? As it turns out, the answer to that is no. There is, according to the nice people on the Cisco Home Community Forum what you might call a problem.

As it turns out, the Cisco E4200 router has some sort of incompatibility with AirPlay. When you run AirPlay, out of the box, with an unmodified router, AirPlay takes down the router.

For the record, I really like my E4200. I do hate the fact it doesn't have any indicator lights (apparently, the 140-character generation also doesn't like extraneous data that comes from indicator lights). The E4200 is the most robust router I've ever used for smashing large amounts of video across my GigE pipes here at Camp David.

It just can't handle AirPlay. At least until you apply a fix so generously described by user AdminLB. Here's what you do:

  • Login to your router
  • Click on Application and Gaming
  • Click on QOS
  • Disable WMM Support
  • Done

So, yes, using an iPhone 4S can kill your entire network. But it's a pretty easy fix to make it stop.

Topics: iPhone, Hardware, Mobility, Networking, Smartphones

About

In addition to hosting the ZDNet Government and ZDNet DIY-IT blogs, CBS Interactive's Distinguished Lecturer David Gewirtz is an author, U.S. policy advisor and computer scientist. He is featured in The History Channel special The President's Book of Secrets, is one of America's foremost cyber-security experts, and is a top expert on savi... Full Bio

zdnet_core.socialButton.googleLabel Contact Disclosure

Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.

Related Stories

The best of ZDNet, delivered

You have been successfully signed up. To sign up for more newsletters or to manage your account, visit the Newsletter Subscription Center.
Subscription failed.