From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dan Egli <dan@shortcircuit.dyndns.org>
Subject: Re: Use netfilter to block DoS
Date: Sun, 27 Apr 2003 12:16:35 -0600
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Peter Bi wrote:

>Hi,
>
>I have two questions related to Denial of Service:
>
>1) If I want to set up a syn-flood protection, based on 1 per second (bursts
>5), should I use
>
>iptables -A INPUT -p tcp --syn -m limit --limit 1/s -j DROP
>or
>iptables -A INPUT -p tcp --syn -m limit --limit 1/s -j ACCEPT
>
>The first one seems to drop those which EXCEED 1 per second
>  
>
I have a similiar rule, and I use ACCEPT.  I have my system configured 
to allow up to 5 ICMP messages per second. Beyond that they are dropped.
iptables -A INPUT -p icmp -m limit --limit 5/sec -j ACCEPT