9.4.6 Using X over TCP/IP

Because a remote TCP/IP socket connection without encryption is prone to an eavesdropping attack, the default setting for X in recent Debian versions disables the TCP/IP socket. Consider using ssh for a remote X connection (see Connecting to a remote X server – ssh, Section 9.4.8).

The method described here is not encouraged unless one is in a very secure environment behind a good firewall system with only trusted users present. Use the following command to verify your current X server setting for the TCP/IP socket:

     # find /etc/X11 -type f -print0 | xargs -0 grep nolisten
     /etc/X11/xinit/xserverrc:exec /usr/bin/X11/X -dpi 100 -nolisten tcp

Remove -nolisten to restore TCP/IP listening on the X server.