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Date: Tue, 04 Feb 2003 00:41:51 -0800 (PST)
Message-Id: <20030204.004151.22906189.davem@redhat.com>
To: greearb@candelatech.com
Cc: john@grabjohn.com, cfriesen@nortelnetworks.com, ahu@ds9a.nl,
       linux-kernel@vger.kernel.org
Subject: Re: problems achieving decent throughput with latency.
From: "David S. Miller" <davem@redhat.com>
In-Reply-To: <3E3F7CDA.9020701@candelatech.com>
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	<20030203.233948.53493107.davem@redhat.com>
	<3E3F7CDA.9020701@candelatech.com>
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   From: Ben Greear <greearb@candelatech.com>
   Date: Tue, 04 Feb 2003 00:42:02 -0800
   
   Am I correct that if I have 10k clients doing their worst tricks, and
   3 * (80k, my default according to the kernel) == 240k, then I have at most
   2.4MB denial of service?  Assuming 60k clients, that is only about 15MB
   of DoS?  If true, that is a fairly small time DoS considering the RAM available
   on today's machines.

Add in the struct sk_buff for each packet as well, which is dependant
upon MSS.  Thus you could make the clients use a super-small MSS to
get more per-packet struct sk_buff overhead.  The list goes on and on.
At least Linux, unlike BSD, makes an attempt to account for the
sk_buff overhead in the limits :-)
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