:PROPERTIES:
:ID:       98eade62-125a-40f1-b572-ff3e107ca4fa
:END:
#+title:  x11-forwarding
#+filetags: :system:basics:

[[id:aac10dba-6276-414e-a3ff-7887528c7918][X11]] forwarding is a mechanism that allows graphical interfaces of X11 programs running on a remote system to be displayed on a local client machine. For X11 forwarding the remote host does not need to have a full X11 system installed; however, it needs at least to have xauth installed. xauth is a utility that maintains Xauthority configurations used by [[id:f2b1d5af-1a7d-47a5-95c8-4a85d558419e][server]] and [[id:70899526-8b7d-4976-94fc-cc07c41e550a][client]] for authentication of X11 session (source).

Warning: X11 forwarding has important security implications which should be at least acknowledged by reading relevant sections of [[id:422e07f8-c888-460f-849e-76d451946045][ssh]](1), sshd_config(5), and ssh_config(5) manual pages. See also this StackExchange question.
* Setup
** install the xorg-xauth packages
** in /etc/ssh/sshd_config:
set X11Forwarding to yes
verify that Allow[[id:0fa93c0d-6741-48cf-8bea-f2519146e4dc][TCP]]Forwarding and X11UseLocalhost options are set to yes, and that X11DisplayOffset is set to 10 
** then restart the sshd daemon.