On many operating systems, you start a terminal session from the command line with a combination of the protocol to be used and the IP address to connect to. There may be deviations depending on the protocol or client. For the precise syntax, refer to the relevant system or program documentation.
The following contains some of the common commands for various protocols and systems:
Telnet
From the Windows command line or the Linux terminal, start a Telnet session with the command telnet <host>. Telnet establishes an (unencrypted) connection to the device with the IP address entered. After entering the password (assuming one has been set to protect the configuration) all of the configuration commands are available to you.
SSH
Windows does not feature an SSH client by default. On Linux systems, use the command ssh <login-name>@<host> to set up an encrypted connection to the device and thus prevent the data being transferred during configuration from being intercepted within the network.