From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jason Opperisano <opie@817west.com>
Subject: Re: Prevent traceroutes
Date: Thu, 19 May 2005 19:33:47 -0400
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On Thu, May 19, 2005 at 07:23:14PM -0400, Jason Opperisano wrote:
>   # standard UDP ports used by traceroute
>   iptables -A INPUT -p udp --dport 33434:33523 -j DROP
>   iptables -A FORWARD -p udp --dport 33434:33523 -j DROP
> 
>   # ICMP echo-req's w/ low TTL
>   iptables -A INPUT -p icmp --icmp-type 8 -m ttl --ttl-lt 5 -j DROP
>   iptables -A FORWARD -p icmp --icmp-type 8 -m ttl --ttl-lt 5 -j DROP

looking at that response--there's a situation screaming for a custom
chain:

  iptables -N DROP_TRACE
  iptables -A DROP_TRACE -p udp --dport 33434:33523 -j DROP
  iptables -A DROP_TRACE -p icmp --icmp-type 8 -m ttl --ttl-lt 5 -j DROP

  iptables -A INPUT -j DROP_TRACE
  iptables -A FORWARD -j DROP_TRACE

-j

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