I have an application running in my corporate environment, which users access through SSH. All the users within the corporate network as that of the server are able to access this application over SSH.
However, all of a sudden users from a different network outside our corporate network, for whom necessary firewall rules are in place, are unable to access this application over SSH. From a machine on the external network, we are able to do a telnet to port 22 of the server successfully. However, when we try to establish a SSH connection to the server on the corporate network, we get a message saying that the "Server Closed the connection".
Have been hanging around this issue for 2 weeks now. But unable to get a solution. When one can do telnet to port 22, does that mean the client and the server can communicate successfully over SSH without any restrictions or does the ability to telnet not imply full SSH 2 way communication between client and server ? Is there a way of testing between the client and server If SSH connection will work among them, other than telnet ?