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To: davidb@verisignlabs.com (David Blacka)
Cc: bmanning@isi.edu, scottr@antd.nist.gov, dnssec@cafax.se
From: Bill Manning <bmanning@isi.edu>
Date: Tue, 17 Sep 2002 13:00:38 -0700 (PDT)
In-Reply-To: <kofzw8s9fg.fsf@pinion.admin.cto.netsol.com> from David Blacka at "Sep 17, 2 03:28:03 pm"
Sender: owner-dnssec@cafax.se
Subject: Re: key length & fragmentation

% >>>>> "Bill" == Bill Manning <bmanning@isi.edu> writes:
% 
%  Bill> See the point above. If IDS/firewalls toss UDP fragments, we
%  Bill> loose.
% 
% My experience is that keeping DNSSEC messages (plus overhead) below a
% MTU of 1500 can be sort of difficult and too restrictive besides.
% 
% My opinion is that the firewall or router that drops UDP fragments is
% broken.

	broken or not, dnssec is a very -small- lever in getting
	ISP/customer hardware replaced.

% However, if clients behind such broken devices set their EDNS0 max
% buffer size to something that will fit in the MTU, everything will
% work.  Well, you will probably see a lot of TCP DNS traffic, but it
% will work.

	TCP has its own sets of performance issues but thats marginally
	better than random droppage. :)

	
% 
% -- 
% David Blacka    <davidb@verisignlabs.com> 
% Sr. Engineer    Verisign Applied Research
% 


-- 
--bill

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