Re: TCP DNS requests

[Douglas K. Fischer]

At 08:46 AM 10/30/2002, Carl R Diliberto wrote:

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.

DNS will use TCP if the response is > 512 bytes. It is perfectly valid for an internal client system to receive a TCP DNS response in such a case.

Doug


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