even queries beyond a certain size (I think 512bytes) will go on TCP.
http://www.maradns.org/dnstcp_security.html

rkt

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:Leonard.Ong@;nokia.com]
Sent: Thursday, October 31, 2002 5:51 PM
To: [EMAIL PROTECTED]
Subject: RE: TCP DNS requests


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


Regards,
Leonard Ong
Network Security Specialist, APAC
NOKIA

Email.  [EMAIL PROTECTED]
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.

--Daniel

> We are reporting TCP based DNS requests to one of our DNS servers
coming
> 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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