Xming not connecting on Windows 7

Question

I have just installed Xming on a Windows 7 Ultimate system. I have another machine on the LAN running Ubuntu and am trying to have its X11 apps appear on the Windows system.

This has worked in the past but I have now reformatted the Windows system and the Linux machine cannot connect to it, despite Windows firewall having the necessary rules to permit connections.

1. On Windows, I start Xming - tray icon appears as expected
2. On the Linux machine, I run this from a terminal: DISPLAY=192.168.0.10:0 lxmusic & (where 192.168.0.10 is the IP of the Windows box)
3. I expect lxmusic to 'appear' on my Windows desktop, but instead I see (lxmusic:5645): Gtk-WARNING **: cannot open display: 172.20.52.5:0 on my terminal, and lxmusic exits

Things I have already tried: - I have verified that the IP stated is the correct IP for the Windows machine - I have tried adding the Xming rules for Windows firewall to different network profiles (Public, Home, etc), though Windows sees the LAN as its 'home' network

Having forgotten how I had this working before I cannot think what else to try.

(I am fully aware that sending X11 traffic over the network in the clear poses a security risk and am ignoring that risk.)

Answer 1

Found the answer.

I found that I could telnet from the Linux machine to the Windows machine no problem (telnet 192.168.0.10 6000), so I was looking in the wrong place, the problem was not with the firewall.

As mentioned here (under Access Control) Xming has its own access control to prevent unauthorised connections. By default Xming will only allow connections from localhost.

To correct this I simply added the IP address of my Linux machine to C:\Program Files (x86)\Xming\X0.hosts and now things work as expected. :-)