This might be a stupid question, but I'm wondering how a network blocks a protocol like SSH even if the server is listening on port that isn't blocked, like 80. I've even tried port forwarding an non-blocked port to port 22 on the server side and I still get blocked. (This only affects external connections, SSH works just fine on local connections.)
I'm curious how exactly something like this is accomplished. This is definitely my weak area, so again sorry if it's a dumb question.