Help with exporting DISPLAY from Linux to Windows XP

Linux and Unix-Like Red Hat
1

Hi Experts,

I am using Cygwin and Xming server to bring back the display from Linux to a Windows machine.

I am following the below steps :-

  1. Close down all X Servers
  2. Run XMing � XLaunch
  3. Select Multiple
  4. Select Start no clients
  5. Tick No Access Control box
  6. Click Finish
  7. X Server starts and you should see icon in tray
  8. Run Putty/SSH in Cygwin
  9. SSH to server you want to connect to
  10. Enter: export DISPLAY=192.168.0.1:0.0 (replace 192.168.0.1 with your IP)
  11. Run dbca.

On using similar steps i can bring back the display from some Linux servers, but not from others, can you please let me know what the problem is and what things i need to verify.

I am not getting any error, some of the last lines from the message in the log states :-

winProcEstablishConnection - winInitClipboard returned.
winMultiWindowXMsgProc - XOpenDisplay () returned and successfully opened the display.
winClipboardProc - Hello
DetectUnicodeSupport - Windows XP
winClipboardProc - DISPLAY=127.0.0.1:0.0
winInitMultiWindowWM - XOpenDisplay () returned and successfully opened the display.
winClipboardProc - XOpenDisplay () returned and successfully opened the display.

I did a grep X11 /etc/ssh/* the result is as following :-

/etc/ssh/ssh_config:ForwardX11 yes
grep: can't open /etc/ssh/ssh_host_dsa_key
grep: can't open /etc/ssh/ssh_host_rsa_key
/etc/ssh/sshd_config:# X11 tunneling options
/etc/ssh/sshd_config:X11Forwarding yes
/etc/ssh/sshd_config:X11DisplayOffset 10
/etc/ssh/sshd_config:X11UseLocalhost yes

Your help wud be highly appreciated...

2

Are some of these servers on your local network and others not?

192.168.0.1 is not your internet IP address, just your local, internal address, because you're behind NAT. Anything that's not on the same local net as you won't have any idea where 192.168.0.1 is. You'd need to forward the appropriate ports on your router to you, and export the router's address.

3

192.168.0.1 was just an example, i am exporting it to a different ip.

I believe there are some more settings on the Linux machine (maybe the firewall) which are not allowing me to forward the display, so i would want to know what... as there are some servers in my network from which i can bring back the display

4

I still don't know for sure you have a real, external IP address, just that you don't have that particular internal IP address. That could explain some things if it isn't. If it's 192.168.x.x, 172.16.x.x, or 10.x.x.x, then it's internal.

How the firewall is configured varies from distro to distro and program to program, though it's all iptables in the end. iptables-dump as root should print the current firewall configuration. Usually though, a firewall would be more diligent in preventing things from connecting to the server than stopping the server from connecting to arbitrary things. A really paranoid firewall could do both of course.

5

ok, my ip is 192.168.99.73 i can definately send over the result for iptables-dump but tomm as m home at the moment, but i m really thankful to u for looking into this as i need to resolve the issue at the earliest...

Thanks a ton.

6

192.168.99.73 is also an internal IP address as stated above. You didn't need to obscure it, it started obscure, nothing except things on your local network know what it is. So, for servers that aren't, you need to

1) have things connect to your external ip address, i.e. your router's WAN address
2) have your router forward the appropriate port to the internal address 192.168.99.73

You may also want to make sure the router's set to always give you 192.168.99.73, otherwise, the port forwarding might break every time you get a new address.

7

Going Further, I would want to state that my Windows XP IP is 192.168.99.73 and the ip for the Linux box is 192.168.104.34, they are on the same network but different sub net.

The thing is that there is another Linux machine again on a different subnet but I can very easily export my Display onto the same Windows XP machine. If still the solution might be as what you say, could you please let me know how I can go about it.

8

Please post the ip addr, netmask, and default gateway for each computer on your local network. It's impossible to see whats going on unless all the networking information is available to troubleshoot.

A simple /sbin/ifconfig on each box will do. Label the one your having an issue with. Also the output of route on each machine may shed some light on this too.

Also, if you think the firewall is an issue, just temporarily turn it off to check if that is what is causing it.

service iptables save
service iptables stop
  --test out the X11 forwording--
service iptables start