Help with DNS

[ARam]

I ran into a question among my training material that asked which protocol DNS used. I was under the impression DNS used both TCP and UDP. Both these options were listed, but separately. Was i wrong in thinking DNS used both TCP and UDP ? Thanks for the help...

[Jared H]

It does. One is for name look ups, the other for zone transfers. Was the question specific about what function in DNS?

[ARam]

The question did not specify... it was very vague. I'm going to pencil it off as a typo.... everyone else has also indicated DNS uses both tcp and udp. What I DIDN"T know was that one was for zone transfer and the other for name lookup. Thanks for the response!

[Jared H]

Here is a link that talks about the protocols being used for various functions.

http://en.wikipedia.org/wiki/Domain_Name_System

[samol]

One is for name lookup and another for zone transfer,so which one use TCP ?


Samol

[See Chun Siong]

For name query, it will use UDP while for zone transfer, it will use TCP.

[Scott Morris]

Many operating systems will do regualr queries via tcp as well if the response time takes too long. So you may see some variety in there. But GENERALLY, it's as listed above!

You just have to understand what each process (and protocol) gives you. UDP is for quick and easy things. TCP is for things you want acknoeledgements or larger chunks of transfers (zones).


Cheers,
Scott