3 The preferred solution

Starlink now recommends that users use the Secure Shell login command (ssh or its alias slogin) between machines which support it (all the Starlink Unix computers and even Microsoft Windows systems using additional software – see your Site Manager). This uses sophisticated means to authenticate that the remote machine is the correct one and encrypts all data traffic over the network.

An additional benefit is that ssh on Unix automatically creates an encrypted-channel X11 device on the remote computer, points the DISPLAY environment variable towards this and sets up local X11 authentication to allow remote access from this machine. The setting of DISPLAY must be left under the control of ssh to use this facility and it is important to check login files (such as .login) to ensure that these do not alter this environment variable.