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[fw-wiz] TCP syncookies - firewall or host?

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Subject: [fw-wiz] TCP syncookies - firewall or host?
From: Florin Andrei <florin@andrei.myip.org>
Date: Tue, 03 Apr 2007 13:13:56 -0700
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Speaking about SYN flood - where would you handle it, at the firewall 
level, or at the host level?

Practical example:
A PIX-515E running v7.2.2, 128MB RAM
About 16 servers running Red Hat Enterprise 4, 8 GB RAM each, 4 CPU 
cores (recent AMD64 CPUs), all of them behind the firewall

syncookies can be enabled either at the firewall level, or at the host 
level. Also, all kinds of TCP parameters can be tweaked on the firewall 
(intercept and connection limits) but also on the servers via the /proc 
filesystem.

This sounds like a job for the firewall, but on the other hand all those 
servers are very fast, there's a lot of them, and usually they're mostly 
idle. So I'm very tempted to dump that task on the servers.

Pros and cons?

-- 
Florin Andrei

http://florin.myip.org/
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