Duke's WLAN pummeled by 'misbehaving' iPhones - report
The Wi-Fi implementation within Apple's new iPhone handset appears to be the source of a big headache for network administrators at Duke University, according to a published report.
"Misbehaving iPhones" are reportedly flooding the access points with up to 18,000 address requests per second, or nearly 10Mbps of bandwidth. As a result, the access points show up as "out of service" for 10-15 minutes at a time, in which there's no way to communicate with them, said Kevin Miller, assistant director, communications infrastructure, with Dukeâs Office of Information Technology.
âBecause of the time of year for us, itâs not a severe problem,â Miller said. âBut from late August through May, our wireless net is critical. My concern is how many students will be coming back in August with iPhones?"
Duke's network team is reported to have identified the Apple handsets as the cause of the issue after capturing wireless traffic for analysis. Cox said the requests are for what is, at least for Dukeâs network, an invalid router address. However, the source of the bad router addresses have not yet been isolated.
"Devices use the Address Resolution Protocol (ARP) to request the MAC address of the destination node, for which it already has the IP address," he wrote. "When it doesnât get an answer, the iPhone just keeps asking."
Duke's IT department is said to have filed a help desk ticket with Apple over the matter but so far communication with iPhone maker has been "one-way," Cox added.
While Apple is reported to have "escalated" the university's help request, it hadn't yet provided anything substantive as of Monday afternoon.
48 Comments
Ah, it sounds like the network is doing something wrong, it is getting a valid request for a MAC address and it appears to be ignoring it. They probably set up their network to do this since they only allow authorized systems to make a request and get on the network.
Since their network configuration is essentially now ignoring the request and the Iphone sees a valid network and keeps making the request it is the phones problem?
I think they should look at their network and fix the problem with the equipment timing out for probably security reason to keep hackers from compromising the network.
If the phone was misbehaving and just flooding a network, I believe this would have shown up elsewhere especial on Apple's own campus.
Ah, it sound like the network is doing something wrong, it get a valid request for a MAC address and it appears to be ignoring it, They probably set up their network to do this since they only allow authorized systems to make a request and get in the network.
While it's possible that the iPhone can be optimized to not send requests as frequently, the fact that routers are being knocked off line by an unintentional DoS attack is the fault of the network administrators.
Ayup, this is the only network reporting this.
At UNC, just down the road, the *entire network* is one giant flat space. Flat. Think about that for a moment. Every machine, in every dorm, in every office, in every WiFi spot (which is the entire campus). It. Is. Insane. (The CS Dept is reviled among campus IT for being 'different' and not 'playing ball'... they realized how dumb that was, and made their own network. Guess which departmental network is the one that *doesn't* go down more often than a $5 hooker during Fleet Week?)
Since Duke is known for playing catch-up to UNC, I wouldn't be surprised if they followed suit.
My 'sources' at Cisco are pretty sure that's what's happening - Duke has a too-flat network, and have been relying on more or less static device behavior. Now that assumption is broken, and they're paying the price for their configuration. Me? I have no opinion or speculation, I just pass along the expert opinion.
Ayup, this is the only network reporting this.
At UNC, just down the road, the *entire network* is one giant flat space. Flat. Think about that for a moment. Every machine, in every dorm, in every office, in every WiFi spot (which is the entire campus). It. Is. Insane. (The CS Dept is reviled among campus IT for being 'different' and not 'playing ball'... they realized how dumb that was, and made their own network. Guess which departmental network is the one that *doesn't* go down more often than a $5 hooker during Fleet Week?)
Since Duke is known for playing catch-up to UNC, I wouldn't be surprised if they followed suit.
My 'sources' at Cisco are pretty sure that's what's happening - Duke has a too-flat network, and have been relying on more or less static device behavior. Now that assumption is broken, and they're paying the price for their configuration. Me? I have no opinion or speculation, I just pass along the expert opinion.
They should be thanking Apple for highlighting they have a poor set up.
I'm just impressed the little iPhone can generate 10Mbps of traffic!