Windows Putty X11 forwarding to Xming

X11Forwarding-putty-xming.md

How to forward Linux X11 to Windows hosted X11 server

1. Linux sshd setup

1.1 Modify /etc/ssh/sshd_config and set:

X11Forwarding yes

1.2 Restart sshd:

[pkw@server1 ~]$ sudo systemctl restart sshd

1.3 Check whether xauth/xclock are available

[pkw@server1 ~]# which xauth xclock
/usr/bin/which: no xauth in (/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin)
/usr/bin/which: no xclock in (/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin)

Install missing pacakges, for Centos7 it is:

[pkw@server1 ~]# sudo yum install -y xorg-x11-xauth xorg-x11-apps

(for other distributions, use your favourite package manager)

2. X11 Server for Windows

2.1 Install Xming X Server for Windows

2.2 Run Xming

3. Putty

3.1 In Connection->SSH->X11 check "Enable X11 forwarding"

3.2 Log into remote host as non-root user

3.3 Check if DISPLAY is set and xclock works

[pkw@server1 ~]$ echo $DISPLAY
localhost:10.0
[pkw@server1 ~]$ xclock

4. root/other user X11 forwarding

In case you can't directly log into user account (e.g. root login over ssh disabled)

4.1 Get authorization string of a logged user

[pkw@server1 ~]$ xauth list
server1/unix:10  MIT-MAGIC-COOKIE-1  28726720a84442cff2e9eaac22945aa8

4.2 Switch to other user

[pkw@server1 ~]$ sudo su - root 
[root@server1 ~]# export DISPLAY=localhost:10.0
[root@server1 ~]# xauth add server1/unix:10  MIT-MAGIC-COOKIE-1  28726720a84442cff2e9eaac22945aa8

4.3 Run test app

[root@server1 ~]# xclock