USRobotics NETServer/8, NETServer/16 manual Telnet Access Port

Note: You can also disable Telnet access to the !root account. For more information, see Telnet Access Port below.

Telnet Access Port

You can reach the command line interface by initiating a Telnet session and logging into the NETServer as !root. The Telnet Access Port identifies the specific TCP port number that the NETServer should listen to for incoming Telnet sessions. The default is 23, Telnet’s well-known port number.

The Telnet Access port number can range from 1 to 65536. Note that 10000 through 10100 are reserved for an internal filter used for host device port security. Use the following command:

set telnet <TCP port #>

Security Note: Some administrators consider using Telnet’s well-known port (23) for remote administration a security risk since anybody can get a login prompt simply by Telnetting to the NETServer. This allows a potential vandal to attempt to guess your !root password, possibly seizing control of the NETServer.

Changing to a non-standard port adds additional protection by making a potential vandal guess which port the NETServer is listening to.

Alternatively, you may disable Telnet administration altogether by setting this parameter to 0.

9-2 Administrative Tools