Saturday 10 July 2010

Remote Graphical Desktop on RHEL-5 , XDMCP and Xwindows

Sometimes ,it happens that nothing works for you. You struggle and struggle again for a task which seems very very easy for you.
It happened to me few days ago when i was trying to do some graphical installation on my VMWare based RHEL-5 and was not able to do see graphical screen properly due to some resolution issues.

So after trying for hours and hours to fix this resolution issue, i finally decided to try some remote desktop software ( which are commonly as xwindows software ) on my windows machine .

It was a hard selection as nowadays so many xwindows software available on internet. Off course ideas was to use some freely available software so i selected cygwin/X for this purpose.
Cygwin/X installation/download was pretty simple however main trick was to select specific packages from x11 category. I took help from cygwin/x installation/user guide and installed this siftware very easily.

Then next step was to start cygwin bash shell and on this bash shell i tried

xwin -query 192.168.1.234 ( which was IP address of my RHEL-5), but no success.

i was sure that xwin command was right , as all cygwin manuals point to same command. After hours and hours effort , i concluded that Linux is not opening any remote graphical sessions from cygwin , as due to new RHEL-5 security standards XDCMP protocol is disabled by default.
So then i modified the file /etc/gdm/custom.conf and under the [xdmcp] section, added this line: Enable=true

Finally restarted GDM by using command gdm-restart

and then tried same xwin command from cygwin ,,,, Ahh it was successfull and finally i got graphical remote desktop on my windows machine connecting to Linux server.Thanks google again!!!

1 comment:

  1. Thank you for this!! Attempting to use Cygwin/X from Windows 7 to a RHEL5 box and all I could see was a black screen. After a minute or two a fat "X" cursor would show up, but no login screen.
    adding Enable=true under the [xdmcp] key then restarting gdm was part of the solution. The other part was to disable the firewall with
    service iptables stop
    Thanks for posting this!!

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