13 Jun
2008
13 Jun
'08
6:19 p.m.
On Fri, 13 Jun 2008 14:14:55 EDT, Jon Kibler said:
UDP is used for queries.
TCP is used for zone transfers.
It's also sometimes used if a reply doesn't fit in the 512 bytes for a UDP answer and EDNS0 isn't in effect. You get a truncated UDP packet back and re-ask the query over TCP.