DNS UDP or TCP?

[Brad Knowles]

At 4:32 PM -0700 9/26/01, Chris Parker wrote:

>  Are DNS queries UDP or TCP?

	Depends.  By default, DNS queries use UDP, but if there is a 
truncation in the response (i.e., it won't fit into a 512-byte UDP 
packet), then the server is responsible for retrying the query using 
TCP.  TCP is also used for zone transfers.  And for any particular 
query, you can specify if you want to use TCP instead of UDP (for 
whatever reason).

-- 
Brad Knowles, <brad.knowles at skynet.be>

H4sICIFgXzsCA2RtYS1zaWcAPVHLbsMwDDvXX0H0kkvbfxiwVw8FCmzAzqqj1F4dy7CdBfn7
Kc6wmyGRFEnvvxiWQoCvqI7RSWTcfGXQNqCUAnfIU+AT8OZ/GCNjRVlH0bKpguJkxiITZqes
MxwpSucyDJzXxQEUe/ihgXqJXUXwD9ajB6NHonLmNrUSK9nacHQnH097szO74xFXqtlbT3il
wMsBz5cnfCR5cEmci0Rj9u/jqBbPeES1I4PeFBXPUIT1XDSOuutFXylzrQvGyboWstCoQZyP
dxX4dLx0eauFe1x9puhoi0Ao1omEJo+BZ6XLVNaVpWiKekxN0VK2VMpmAy+Bk7ZV4SO+p1L/
uErNRS/qH2iFU+iNOtbcmVt9N16lfF7tLv9FXNj8AiyNcOi1AQAA



-- Binary/unsupported file stripped by Listar --
-- Type: application/ms-tnef
-- File: winmail.dat