* Jon Kibler: >>>From what I have read, public DNS servers should support both UDP and >> TCP queries. TCP queries are often used when a UDP query fails, or if >> the answer is over a certain length. >> > > UDP is used for queries. > > TCP is used for zone transfers.
I've seen such claims countless times. 8-( However, you can perform zone file transfers over UFP in some cases (using IXFR), and TCP fallback may happen even if you never respond with packets with the TC bit set.
