CISSPGOALCISSPGOAL Member Posts: 27 ■□□□□□□□□□

Is DNS reside in Session Layer or Application Layer?

Thank You.


  • goktangoktan Registered Users Posts: 4 ■□□□□□□□□□
    Although I've seen some debates about this, I believe the correct answer should be Application layer for the exam. Also wikipedia says so;
    List of network protocols (OSI model) - Wikipedia, the free encyclopedia

    Moreover, I've found similar discussion on this forum happened years ago, check if you want to see what others said then;

    hope this helps,
  • mochaaddictmochaaddict Member Posts: 42 ■■□□□□□□□□
    I have always known dns to be layer 7. What rationale do you have to think it may be a session layer protocol?
  • Justin-Justin- Member Posts: 300
    Application layer. I agree with the user above. Why you think it's session?
  • CISSPGOALCISSPGOAL Member Posts: 27 ■□□□□□□□□□
    Saw CISSP Notes that say it is a session layer :).
  • tchokitchoki Banned Posts: 11 ■□□□□□□□□□
    Session layer as with all directory services such as LDAP , X.500 . Also radius, tacacs+ , diameter, SMB , CIFS,NIS, NFS, SQL,RPC,Netbios, all work at the session layer . ISC2 says it clearly in its seminar book.
  • JDMurrayJDMurray MSIT InfoSec, CISSP, SSCP, GSEC, EnCE, C|EH, CySA+, PenTest+, CASP+, Security+ Surf City, USAAdmin Posts: 11,895 Admin
    DNS really does not use session control. The 53/udp function is just a call and response with no preserved state information. The 53/tcp function is basically a file information transfer, like FTP, that uses one TCP connection per transfer. If DNS could do multiple, independent, simultaneous zone transfers over a single TCP connection then I'd say DNS used the OSI session layer.
  • papadocpapadoc Member Posts: 154
    One of the things I learned from the SANS MGT414 course was they teach you how to think in the "ISC2" world. I would go with what tchoki said --the ISC2 - Official Guide to the CBK - Third Edition.
Sign In or Register to comment.