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Re: TCP windows shrinking



This is a fairly common error w/ 2.4.x.   Actually, error is the wrong
word; more like warning.  The only reason you're seeing it is because
TCP_DEBUG is defined.  If it's annoying, you can undefine it in 
linux/include/net/tcp.h.


On Fri, Apr 06, 2001 at 12:03:40PM -0400, Noah L. Meyerhans wrote:
> 
> This was logged by one of my servers the other day (potato, upgraded
> with the necessary packages to run kernel 2.4.2):
> 
> Mar 31 08:40:48 debian kernel: TCP: peer xxx.xx.xx.xx:41760/20 shrinks
> window 3735214707:8280:3735227987. Bad, what else can I say?
> 
> The IP address, obviously, has been replaced with x's here.  I haven't
> ever seen the message before.  I have heard of some vulnerabilities in
> various firewall code that allows bogus IP header 'offset' fields to be
> used to avoid firewall packet matching rules.  Might this be an attempt
> at something like that?  Might this merely have been a packet that got
> horribly mangled somewhere on the internet, completely unintentionally?
> 
> Any thoughts?
> 
> Thanks.
> noah
> 
> -- 
>  _______________________________________________________
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> 



-- 
"... being a Linux user is sort of like living in a house inhabited
by a large family of carpenters and architects. Every morning when
you wake up, the house is a little different. Maybe there is a new
turret, or some walls have moved. Or perhaps someone has temporarily
removed the floor under your bed." - Unix for Dummies, 2nd Edition
        -- found in the .sig of Rob Riggs, rriggs@tesser.com



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