Nope, normal ways what should work do not work from the office, this is puzzling. From home , using SciLinux58, I can use three methods and all work fine. Once I launch vncserver on the cluster at port 5906:
ssh -L 5906:localhost:5906 <email@example.com>
<login to cluster acct>
SciLinux58$ vncviewer [localhost] :6
or even simpler launching VNCViewer GUI client and entering ':6' into the address window.
Or without prior ssh:
SciLinux$ vncviewer -via <firstname.lastname@example.org> :6
which opens VNCViewer login dialog allowing me enter acct password and connect.
Nothing of the above works from the office. The outcome is the same - "Connection timeout" as if the address of local machine cannot be found or wrong. Or else.
I try to poke network traffic as recommended, may be I get some insights.