DNS = regular DNS resolutions = UDP 53

DNS = zone transfers (happen between DNS servers themselves ) = TCP 53 .

For exam , the question should be clear or you can ask the proctor.

Since it is security CCIE lab group, i would advice to define both tcp and udp, 
as firewall and IPS are involved, hope you can think of possible variations to 
the questions as well !

good day!



Kamran Shakil 
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-----Original Message-----
From: [email protected] on behalf of Eugene Pefti
Sent: Mon 3/12/2012 2:48 AM
To: [email protected]
Subject: [OSL | CCIE_Security] Ports for DNS traffic
 
Guys,
Just a generic question. Would it be prudent to include a TCP port 53 as well 
if the question in the task asks about DNS traffic to be allowed through the 
firewall ? Or we should assume that hosts behind the firewall will do only UDP 
based queries ?

Eugene

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