More DoS information / a workaround

[mike-hostap at tiedyenetworks.com]

On Sun, 4 Apr 2004, Jouni Malinen wrote:

> On Wed, Mar 31, 2004 at 01:47:30PM -0800, mike-hostap at tiedyenetworks.com wrote:
> 
> Do you recognize that MAC address? It would be useful to know if it one
> of the known devices in the wired or wireless networks. That seems to be
> 3Com device.
> 

	Yes I do. All of the cases I have noted, are from the wired side. 
My testing shows this isn't in fact a DoS or being caused by received 
802.11 frames, there's just a screwey interaction with bridging going on 
here. So all that weird stuff I posted sooner wasn't anything more than a 
tcpdump hallucination.
> 
> > 	How is crimini's name could we get 573 packets per second???
> 
> This is clearly unwanted behavior from the driver, so I changed the
> current CVS snapshots to at least limit the rate of those messages.
> 

	That's probbly a good idea.

	I've done more testing and I can't seem to reproduce this problem 
with a single card version of my ap running the identical software load as 
my problem child. The problem child is an AP that has two cards (seano 200mw's both 
with 1.1.0/1.8.0 firmwares). Bridge 'br0' contains wlan0, wlan1 and eth0, 
and the messages always are about mac addresses on the eth0 side. The wlan 
interfaces each have different SSID's and wep keys (so there couldn't be 
any kind of loop on the wireless side) and neither interface is 
configured to associate as a client on the same channel, either. 

	Is it possible there could be a problem with having hostap drive 
two cards at the same time? I have an ap with dual cards running 0.1.2 but 
in that configuration (and for legacy reasons), I have wlan0,eth0 in a 
bridge, and wlan1,eth1 in a different bridge. 

	While writing this I just went into my problem child and
configured it the same way (different bridge groups for each wlan 
interface) and the problem still occurs. So I dunno....

More news later..


(I'm not rakin' on the software Jouni, thank you for all of your hard 
work)

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