OSI Model Question

[A7XBandJunkie]

Question asked: How does the session ID differ from the port number?

How I answered: The session ID is used to keep data streams separate while port numbers are used to identify protocols and logical host addresses.

 

My question: How do you all think about my answer and what might you add?

[Mira Yurizaki]

Port numbers don't always identify protocols. There are protocols and services that tend to use the same port number, such as 22 for SSH, but an SSH server can listen on any port number. In fact, it's a recommended security practice to have common services not listen to their commonly used port if you're exposing it the outside world.

[A7XBandJunkie]

22 minutes ago, Mira Yurizaki said:

Port numbers don't always identify protocols. There are protocols and services that tend to use the same port number, such as 22 for SSH, but an SSH server can listen on any port number. In fact, it's a recommended security practice to have common services not listen to their commonly used port if you're exposing it the outside world.

I never thought of that. That is a smart idea though. Thank for the input.