On Mon, 19 Dec 2005 21:03:11 -0500 (EST) [EMAIL PROTECTED] wrote: > I believe DNS lookups will ordinarily use UDP but may use TCP for larger > transfers (like the 20 addresses returned for yahoo.com).
> It is my understanding (and experience) that DNS requires both UDP 53 and > TCP 53 open through a firewall to avoid problems. A quick look at RFC 1034 & 1035 shows how DNS works. Most setups (I'd say 99%) will need both of these ports open, assuming you want the world to access services running within your domain that rely on DNS & Bind (which is like 99% of them).
