User Tips for the CGM Lab

WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!

Secure Shell will emit the following warning if you try to connect to a system whose host key has changed.

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@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
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IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
The reason for the change could be nasty (an attacker trying to eavesdrop on your session) or innocuous (the administrator of the remote system has changed the host key). SSH is warning you to decide between the two possibilities.

The recommended course of action is to contact the administrator of the remote site (the one to which you are trying to login) and ask whether the host key has changed. If so, you simply let the connection go through. If SSH does not continue, but instead shows a message similar to

RSA host key for 132.230.37.128 has changed and you have requested strict
checking.
Host key verification failed.
then you can re-run ssh using the option -o StrictHostKeyChecking=ask.

Error: Can't open display:

Can't open a tool after logging into a remote machine with ssh or slogin? The above message indicates that the DISPLAY variable is not set. SSH allows you to forward the graphics data over the encrypted session, which is a good idea as it prevents a malicious person from capturing your keystrokes. You enable this using the -X option with ssh: ssh -X toro.cs.mcgill.ca, for example. Some implementations of ssh use +x instead of -X.

I try to open Netscape, but Mozilla appears instead

Yes, I find this irritating, too. The quick workaround is this: open netscape (type netscape& in an xterm if you have to), and leave it running (iconize it if you like).

At logon, Adobe Reader starts to open (splash screen pops up) and then stays there for the entire session

Perhaps you had it running in the previous session? It will re-start on the same document each session. The behaviour you describe -- only the intro window -- happens when that document has vanished. I find this happens usually on documents viewed via the browser: they get copied to a temporary file then deleted when the browser exits.

The only fix I know of here is to hunt down the process (use ps -x|grep acro) and kill it. Also: be sure to quit all acrobat processes before logging out, to avoid the problem recurring.


Last modified: Wed Oct 2 21:41:10 EDT 2002