I use tn3270-X (v3.1.1) to logon to an IBM mainframe
through a Virtual Private Network (CISCO VPN) across the Internet.
I'm running on a Mac G4 with OS 10.2.6 and I connect
to the Internet via cable-modem service (Comcast).
This arrangement has been working just fine but now I
have a requirement to define a second session with a different
host name from what I normally use.  Since the only thing
different (that I know of) about this other mainframe is
the IP address, I used a copy of the settings from my
existing working session and just changed the IP address
(and the descriptive session name).  Every time I attempt
to establish this new session it fails to connect and times
out after about a minute.  I tried pinging the IP address
from the Mac 'Terminal' window and, surprisingly, that works.
The old session still connects successfully to the original
mainframe, and I know the 2nd mainframe is working because
I can get to it from my PC at work (but with completely
different software).
So from this I have two questions:
(1) What are some possible explanations for this problem?
(2) What tools are available to diagnose this problem in
     more detail?

   Bruce Christopher
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