lkml.org 
[lkml]   [2001]   [Oct]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Other computers HIGHLY degrading network performance (DoS?)
From
Date
I think this is what QoS and the like are for.

Jeffrey H. Ingber (jhingber _at_ ix.netcom.com)

On Thu, 2001-10-25 at 22:43, Anuradha Ratnaweera wrote:
>
> This is not a direct kernel issse. However, it is a serious threat for the
> network performance of our Linux boxes, therefore I thought of posting it here.
>
> There is a popular software that runs on MS platform called "download
> accelerator". This opens several threads for a download job (each one
> downloading a portion of the file), sometimes even using mirror sites.
> However, it not only grabs whole bandwidth, but makes it hard for other
> machines to even ping each other the return time being around 5-10 seconds on a
> 100 Mbps network! The download process is getting only 64 kbps from the
> Internet. Internet access is virtually impossible for the other machines.
>
> This program can run with a `normal download' mode and this doesn't cause a
> big problem.
>
> I monitored network traffic with tcpdump, and noticed that those packets don't
> have tcp timestamps and tcp sack. I turned them off on my Linux box using
> sysctl, and also tried turning on ECN without success.
>
> This is of course a DoS in disguise, and is there a way to stop it?
>
> I am thinking of setting up a firewall with netfilter and transparent proxy as
> a workaround.
>
> Thanks in advance.
>
> Regards,
>
> Anuradha
>
> --
>
> Debian GNU/Linux (kernel 2.4.13)
>
> History books which contain no lies are extremely dull.
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:18    [W:0.075 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site