[vox-tech] firewall question

Ted Deppner vox-tech@lists.lugod.org
Fri, 4 Jan 2002 15:11:00 -0800


On Thu, Jan 03, 2002 at 12:49:35PM -0800, Micah Cowan wrote:
> Doesn't DNS have a udp version?

yes, UDP port 53 is the primary DNS port.

AXFER (zone transfers) use port 53 (client and server, port 53 to port
53).  too-large DNS queries will also resort to TCP 53 outbound, but that
is usually rare, and can usually be turned off.

Unless you're serving DNS or allowing zone transfers, you don't need TCP
53 inbound at all.

-- 
Ted Deppner
http://www.psyber.com/~ted/