OSI layer

[Dineshkumar]

can some one help me to understand what will happen in OSI layers, while we trying to connect a switch in telnet .....?

[Mark Malone]

It works from Layer 1 up right to layer 7 as its a user app

so initiate the telnet it will check physical layer then the frame at layer 2 , check the src and destination ip at network layer 3 , then layer 4 telnet is a TCP protocol so it will use that , as its an application it goes all the way to layer 7 app layer

each specific layer has a part , you can see in more details what each layer does here
http://www.techexams.net/technotes/ccna/osimodel.shtml

[Richard Burts]

This same question was posted in the Other Infrastructure Subjects forum where I posted a reply

https://supportforums.cisco.com/t5/other-network-infrastructure/can-see-the-neighbors-but-cant-telnet-or-ping/m-p/452717#M148380

HTH

Rick