Re: [squid-users] SYN flooding

From: Henrik Nordstrom <henrik@dont-contact.us>
Date: Tue, 20 Jun 2006 21:48:12 +0200

tis 2006-06-20 klockan 13:30 +0200 skrev Emilio Casbas:

> you can need a iptables script and see the 'limit' module in iptables.

Don't do that. It causes more damage than good leaving your system
easily vulnerable to DoS by SYN-Flooding. syn cookies alone solves the
SYN-flood problem very nicely and efficiently.

The log message should be taken more as a hint that you may want to
investigate the current network traffic as there maybe is something
broken (bad cable or similar) OR someone actually trying to SYN-flood
you. But it could also simply be that the server is overloaded. So it's
a hint that the traffic may need to be looked into, not a rule or even a
strong indication of problem.

Regards
Henrik

Received on Tue Jun 20 2006 - 13:48:23 MDT

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