PWNLOGS

Note: You are ssh-ing from hostA to hostB in all the following cases except case 4. In case 4, you ssh from hostB to hostA.

Case 1

Case 2

Case 3

Case 4 (SSH Host B ↦ Host A)

Case 5

Case 6

ssh -R 4001:127.0.0.1:2001 -g -v root@hostB socat tcp-listen:4002,fork,bind=0.0.0.0 tcp:localhost:4001

Courtesy:

Thanks to Paul Turner for the excellent explanations in his/her/their YouTube video.
Watch Paul Turner's youtube video on SSH port forwarding.