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RE: TCP DNS requests
From: "Royans Tharakan" <RTharakan () ingenuity com>
Date: Fri, 1 Nov 2002 10:40:28 -0800

even queries beyond a certain size (I think 512bytes) will go on TCP.


-----Original Message-----
From: Leonard.Ong () nokia com [mailto:Leonard.Ong () nokia com]
Sent: Thursday, October 31, 2002 5:51 PM
To: security-basics () securityfocus com
Subject: RE: TCP DNS requests

Yes, I am confirming this. Zone transfer uses TCP/53, while queries use UDP/53.

Leonard Ong
Network Security Specialist, APAC

Email.  Leonard.Ong () nokia com
Mobile. +65 9431 6184
Phone.  +65 6723 1724
Fax.    +65 6723 1596

-----Original Message-----
From: ext Daniel Miessler [mailto:danielrm26 () hotmail com]
Sent: Friday, November 01, 2002 1:20 AM
To: 'Carl R Diliberto'; 'security-basics'
Subject: RE: TCP DNS requests

Zone Transfers use TCP instead of UDP on port 53.  That is most likely
what you are seeing.


We are reporting TCP based DNS requests to one of our DNS servers
from internal, client IP addresses.  My manager would like to block
the TCP
packets.  What or why would their be random TCP packets?  We monitored
several clients and it appears it only needs UDP.

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