Re: [lwip-users] portscan

[address@hidden]

Bernhard 'Gustl' Bauer wrote:
> Simon Goldschmidt schrieb:
>   
> > In the past, stalls like this have often been driver bugs: a portscan
> > is like a stress situation to your driver, maybe it leaves interrupts
> > disabled or something like that, so the device cannot receive any
> > packets?
> >     
>
> I enabled the stats of my driver (CS8900). What I get during a portscan 
> is a lot of misses and collisions. Could this crash TCP or ping?
>
>   

I shouldn't crash TCP: if a packet is not received correctly by a remote 
host, TCP retransmits it eventualy, so your connections should go back 
to normal after the portscan has finished. During the portscan, however, 
it could well be that your device is not fast enough to process all the 
packets sent by the PC, so TCP connections might stall and ping might 
fail while the portscan is active. That's perfectly normal for a device 
that cannot handle received packets as fast as they can be sent on the 
wire (which most embedded devices can't).

Simon