[98106] in North American Network Operators' Group
Re: iPhone and Network Disruptions ...
daemon@ATHENA.MIT.EDU (Marshall Eubanks)
Tue Jul 24 21:08:54 2007
In-Reply-To: <4AA193E2-28A5-4DD0-B776-24426533482C@muada.com>
Cc: "Prof. Robert Mathews (OSIA)" <mathews@hawaii.edu>,
North American Network Operators Group <Nanog@merit.edu>
From: Marshall Eubanks <tme@multicasttech.com>
Date: Tue, 24 Jul 2007 20:00:25 -0400
To: Iljitsch van Beijnum <iljitsch@muada.com>
Errors-To: owner-nanog@merit.edu
On Jul 24, 2007, at 5:34 PM, Iljitsch van Beijnum wrote:
>
> On 24-jul-2007, at 15:27, Prof. Robert Mathews (OSIA) wrote:
>
>> Looking at this issue with an 'interoperability lens,' I remain
>> puzzled by a personal observation that at least in the publicized
>> case of Duke University's Wi-Fi net being effected, the "ARP
>> storms" did not negatively impact network operations UNTIL the
>> presence of iPhones on campus. The nagging point in my mind
>> therefore, is: why have other Wi-Fi devices (laptops, HPCs/PDAs,
>> Smartphones etc.,) NOT caused the 'type' of ARP flooding, which
>> was made visible in Duke's Wi-Fi environment?
>
> Reading the Cisco document the conclusion seems obvious: the iPhone
> implements RFC 4436 unicast ARP packets which cause the problem.
>
> I don't have an iPhone on hand to test this and make sure, though.
>
> The difference between an iPhone and other devices (running Mac OS
> X?) that do the same thing would be that an iPhone is online while
> the user moves around, while laptops are generally put to sleep
> prior to moving around.
>
But I know that I have walked around IETF meetings with my laptop
open, and I know others do too, and I don't recall
ever hearing about this problem at an IETF meeting from Jim Martin
and the other NOC volunteers.
Regards
Marshall
