Putty works, but VNC doesn't

[Geerlings, Mark]

I'm trying to get my home desktop (WindowsXP Home Edition) to connect to
two Linux servers that I manage at work that have VNC server running.
With my laptop from work (which runs WindowsXP Professional) I can
connect to the VNC server on either of the two Linux servers with no
problem.  And I can do this either when I have my laptop connected to
the LAN at work, or via a VPN from home.  My home desktop can ping the
two Linux servers via the VPN, and I can use Putty to establish a
command-line session to the two Linux servers via the VPN, but VNC
viewer refuses to connect from my home desktop.



I first tried VNC viewer 3.3.3.2 (which works just fine on my WindowsXP
Professional laptop) on my home desktop.  But that never gave me a
password prompt for VNC.  I then installed the latest version of the VNC
viewer (version 4 something, but I'm not at home now so I can't confirm
the exact version).  When I tried that, I just got a "Connecting..."
window that never succeeded or gave an error.



Do you know what might be preventing VNC viewer from connecting when
ping and Putty can both connect?