Weird Extranet problem

[Stacy Pober]

First, thanks to those of you who offered suggestions regarding my 
numeric/alpha IP question.  Since writing the post asking for help, 
it's become clear that the problem is more complicated than I thought.  

Just as a quick overview:  We get several databases via an Extranet 
connection to our library.  We also have access to a campus Internet 
connection - MOST of the time.   However, we've been having frequent 
Internet outages, and now we find that one of the vendors (UMI's ProQuest 
Direct service) we get via Extranet is apparently not coming through the 
Extranet at all.  I had assumed this was due to a lack of DNS when the 
campus Internet connection was down.  However, I was wrong.

I had the opportunity to do some testing this week when the campus 
Internet connection went down again.  Incidentally, UMI has oddly chosen 
to block block ping and tracert -- but only from Extranet sites -- NOT 
for the rest of the internet.  This is one of the reasons that 
diagnosing this problem is such a pain.   The following pattern of error 
messages points to an odd failure of the Extranet, in that we are able to 
get through to the needed IP, but we are NOT able to get through to the 
needed subdirectory on that server:  

Using the URL:  http://www.umi.com/pqdauto the error message is:
"Netscape is unable to locate the server www.umi.com.  Please check the
server name and try again."

Using the numeric URL that is the equivalent of the above address
(http://192.195.245.135/pqdauto) the error message is:
"Netscape is unable to locate the server proquest.umi.com.  Please check
the server name and try again."

Using the numeric IP:  http://192.195.245.140 we can get to a generic UMI
page, but again, the links on that  page do not work to allow our site
access to the ProQuest service, and trying them just gets the same server
errors saying that "Nestcape is unable to locate proquest.umi.com"

Using the numeric URL:  http://192.195.245.135  (note - no file or
directory specified) we do get through to  UMI, but it goes to UMI
homepage, not to ProQuest Direct.  The user can access information about
UMI products and can click through some menu items, but if we try to get to
the IP recognition page for ProQuest Direct, the same message is displayed
-  that Netscape cannot locate the server.  This is despite the fact that 
the link on the UMI server is a *numeric* link (the same one as above:
http://192.195.256.135/pqdauto).

As I understand it, this indicates that it is not a DNS problem, since a
numeric IP address should not need a  Domain Name Server - the IP is
already "resolved".

This is puzzling.  It seems as if our library can connect with UMI's
general information pages using the Extranet, but cannot connect
specifically to the ProQuest Direct service.  Even when numeric URLs are
used,  we cannot connect to the /pqdauto subdirectory.

Anyone have any ideas about this?  I spoke to a UMI tech support person, 
but have not heard back from UMI as yet regarding this problem.  I think I 
have them stumped...and since tracert is blocked, I don't know of any 
other diagnostics I can try.   We have no problem connecting to ProQuest 
when the campus Internet connection is working, but there have been 
frequent network outages  lately, and I fear more are coming.   BTW, the 
other databases we get through the Extranet do work whether the campus 
Internet connection is up or down.


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Stacy Pober                   mailto: spober at manhattan.edu
Information Alchemist         http://www.manhattan.edu/library/
Manhattan College Libraries   Voice: 718-862-7166
Riverdale, NY 10471           Fax:   718-862-7995
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