Yup, I believe it is. DNS isn't "part" of the group of protocols that are modeled with the OSI model, it's a service that runs for the benefit of wetware (that'd be us single-core, easily crashable humans).
bighornsheep, you're using Meyers' Network+ Passport, right? Check pages 141-142; DNS is an application layer service that uses UDP, which is part of the TCP/IP stack.
Oh, have I confused you? You are familiar with the OSI 7 layered model, as you know? On ther other hand, TCP/IP 4 layered model doesn't touch any on its application layer: application, presentation, and session layers in OSI, assuming application itself works on.
So, my understanding is, in terms of application, say, FTP works atop in either OSI or TCP/IP model. In terms of protocol, FTP works in the transport layer, TCP 20 for data flow, 21 for session control.
Note: HTTP is tricky. HTTP applications work atop but its protocol works in the presentaion layer.
Oh, have I confused you? You are familiar with the OSI 7 layered model, as you know? On ther other hand, TCP/IP 4 layered model doesn't touch any on its application layer: application, presentation, and session layers in OSI, assuming application itself works on.
So, my understanding is, in terms of application, say, FTP works atop in either OSI or TCP/IP model. In terms of protocol, FTP works in the transport layer, TCP 20 for data flow, 21 for session control.
Note: HTTP is tricky. HTTP applications work atop but its protocol works in the presentaion layer.
Thank you all for helping me clear that up. I was at Borders Bookstore yesterdsay and read from a Network Plus book that DNS was mapped to the session Layer of the OSI model.
Thanks again
"A lot of fellows nowadays have a B.A., M.D., or Ph.D. Unfortunately, they don't have a J.O.B."
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Let it never be said that I didn't do the very least I could do.
UDP port 53 for name resolution for clients
TCP port 53 for zone transfer for secondary (and trinary, if any) DNS server
hmm..I am a little confused...is layer 7 also part of TCP/IP?
So, my understanding is, in terms of application, say, FTP works atop in either OSI or TCP/IP model. In terms of protocol, FTP works in the transport layer, TCP 20 for data flow, 21 for session control.
Note: HTTP is tricky. HTTP applications work atop but its protocol works in the presentaion layer.
So, my understanding is, in terms of application, say, FTP works atop in either OSI or TCP/IP model. In terms of protocol, FTP works in the transport layer, TCP 20 for data flow, 21 for session control.
Note: HTTP is tricky. HTTP applications work atop but its protocol works in the presentaion layer.
Below may help on DNS.
http://www.soi.wide.ad.jp/soi-asia/pkg2/materials/01.pdf
Thanks again
Fats Domino