What ports are used by Secure Shell (SSH)?

Secure Shell (SSH) uses port 22 as its default communication port. This port is specifically designated for securing remote login and other secure network services over an unsecured network. The primary goal of SSH is to provide a secure channel over an unsecured network by using encryption, which ensures that any data sent over this connection is protected from eavesdropping, spoofing, or other types of attacks.

Using this standard port allows systems and network administrators to manage secure connections easily since SSH clients typically attempt to connect to port 22 by default. While it is possible to configure SSH to use a different port for added security through obscurity, port 22 remains the widely recognized and used port for SSH communications.

In contrast, the other options relate to different protocols: ports 20 and 21 are associated with FTP, ports 161 and 162 are used for SNMP, and ports 989 and 990 are designated for FTPS. Each of these protocols serves distinct purposes and has its own security mechanisms different from those employed by SSH.