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Date: Sun, 10 Feb 2013 14:48:08 +0200
From: Janne Snabb <snabb@epipe.com>
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To: khatfield@socllc.net
Subject: Re: FreeBSD DDoS protection
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On 2013-02-10 03:57, khatfield@socllc.net wrote:
> Deny all ICMP (drop I mean) and UDP except where specifically required.

Please do not drop all ICMP unless you understand what you are doing. By
doing that you are creating a path MTU discovery blackhole.

See for example the following sites for more information:

http://www.phildev.net/mss/
https://supportforums.cisco.com/docs/DOC-5839
http://www.cymru.com/Documents/icmp-messages.html
http://packetlife.net/blog/2008/oct/09/disabling-unreachables-breaks-pmtud/

-- 
Janne Snabb / EPIPE Communications
snabb@epipe.com - http://epipe.com/