Cannot display X apps from a remote UNIX
 

Hi.

I've been having this problem for a while. Hopefully some of you experts can shed some light on it.

I have CentOS 4.4 running on my local machine at work. Now on occasions I'd like to telnet into one of the corporate UNIX machines (i.e. HP-UX, Solaris and AIX) and run X applications there. On those remote machines, I have the DISPLAY variable correctly exported to point to "my_hostname:0.0". Yet I always get this error message:

I have both my firewall and SE Linux disabled, so I don't think they are the issues. I also run "xhost +" beforehand, but that does not seem to solve the problem.

Is there any local config settings that I need to change so that this will work?

Any help would be appreciated.

TIA,
Dai

Could there be other firewalls or ISP's intervening? X traffic is ordinarily sent on port 6000 for server :0. Have you tried the (better) option of using SSH with an X tunnel? On some setups, X runs with the -nolisten tcp option. SSH tunneling gets around this.

--- rod.

Hi Rod.

Thanks for the suggestion. As it turned out, it was an issue with the login manager (kdm, in my case). By default it does not allow any incoming TCP connection. Letting kdm allow it should solve the problem. The only remaining issue is, I have to figure out how to enable that with kdm. With gdm, I can set DisallowTCP to false, which probably gets rid of the "-nolisten tcp" option you mentioned above. I temporarily switched to use gdm for now. I will go back to kdm once I figure out how to enable that option there.

I agree that "ssh -X" would be a better alternative. Unfortunately, most of our UNIX hosts do not have ssh running. :(

[EDIT] Okay, I figured that out... In kdmrc, the kdm config file, there's a line that says:
All I had to do was remove that line and restart X. :)

Again, thanks for your help.

Dai