I am trying to log on to a computer that is hosted by my university for programming and have X windows sent to my computer, i.e.,
I ssh to remotehost.u.edu and I want to type "emacs" and have the window show up on my monitor.

However, the school does not support X forwarding through ssh, and when I set the DISPLAY variable on the remote host to my computer like such:
setenv DISPLAY mycomputer.ip.com:0.0
I then allow all connections on my local computer:
xhost +
Then I try and load the window:
emacs
It responds:
emacs: Cannot connect to X server c-24-12-167-131.client.comcast.net:0.0.
Check the DISPLAY environment variable or use `-d'.
Also use the `xhost' program to verify that it is set to permit
connections from your machine.

Also if I set the DISPLAY variable to mycomputer.ip.com:0.0 on my local computer, it STILL won't connect to the X server.

What could be going wrong?

If you just want to use emacs, simplest thing is to start it in a console with 'emacs -nw'. This stops it trying to open a window in the local machine, and it runs in the console instead. Since emacs was originally designed to run this way, there is not much loss of functionality.

Otherwise I think you do something called 'X11 forwarding'. See the tutorial at

http://www.aperiodic.net/phil/ssh/

for example, or search google for '"X11 forwarding" ssh linux' for lots more info.

I actually did end up using emacs without making a terminal window - but that's not what I want. I work faster if I can have more than one emacs window going at once, and there are other various reasons.

X forwarding using ssh works great, but unfortunately the computer I am ssh'ing into does not support this (i think i said this).

What's bothering me is that I SHOULD be able to do this the old fashioned way, but my computer seems to be refusing all connections -- I can't even locally say DISPLAY=myip.isp.com and have it work.

What besides xhost + and checking my hosts.deny and hosts.allow can I do to troubleshoot this problem? What could be happening?

-iw

Sorry - I realised after I posted that you had mentioned X forwarding.

There is another X access control thing called xauth, which I thought was supposed to be the successor to the xhost file. Don't know much about it, but it has a detailed man page.

Otherwise check /var/log/XFree86.0.log and anything else in /var/log that might be recording connection attempts??

No firewall blocking access??

Could try running tcpdump and watching for incoming connection attempts if you get desperate.

Just guessing.