[isalist] Re: oh no, error 64 - network name no longer available

  • From: Jim Harrison <Jim@xxxxxxxxxxxx>
  • To: "isalist@xxxxxxxxxxxxx" <isalist@xxxxxxxxxxxxx>
  • Date: Fri, 4 Sep 2009 16:39:13 -0700

ISA and TMG give you this error when the TCP connection is broken unexpectedly.
If you get a network capture of this process, I'll bet the server or client 
close the connection before ISA expects it to.
 is a great tool for that task.


From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx] On 
Behalf Of Lars Hansen
Sent: Friday, September 04, 2009 10:38 AM
To: isalist@xxxxxxxxxxxxx
Subject: [isalist] oh no, error 64 - network name no longer available

One of our clients are getting this error when they go to one of the website 
that they have to go to.

We've tried the URL through 3 different ISA servers, and we're getting the same 
error through all three ISA servers. If we test this at sites not using ISA, we 
are having no issues with this URL. Configuring IE to use ISA as a proxy or not 
does not appear to make a difference; same error.

The actual error message on the firewall is this:
Log type: Web Proxy (Forward)
Status: 64 The specified network name is no longer available.
Rule: Allow all HTTP traffic from ISA Server to all networks (for CRL downloads)
Source: Local Host (
Destination: External (216-136-16-106.static.twtelecom.net
Request: GET http://www.refil.net/xap/refil/invlib/?customernumber=[redacted]
Filter information: Req ID: 174477d2
Protocol: http

So, here's the "funny" part. If I try http://www.refil.net/xap.refil/invlib, I 
get the correct login screen without any issues.
However, once the URL gets filled up with user ID information, it fails:

(actual userids and customer numbers changed, still get the same error)

I tried creating a special rule to pass everything going to refill.net through 
a special port-80 protocol without web filtering on it, but still no go. Also, 
the rule listed in the error message doesn't show on the firewall, so I can't 
edit and/or disable it. Even with a custom rule, this one always picks it up 
and throws the error.

During my google & bing searches, I noticed another gentleman had a similar 
issue, and someone pointed out the odd use of "/?", and  then he rewrote the 
app to use something else eliminating the "/?" and the issue went away. 
However, it works with /?customernumber=99999 as well as 
/?customernumber=99999&from=liebert, but when the URL grows bigger than that, 
ISA barfs all over it and suddenly throws the "error 64" message.

Any ideas?

Lars M. Hansen
Engineer II
MicroData Group, Inc.
100 Cummings Center, Suite 146N
Beverly, MA 01915
Voice 978.921.0990
Fax 978.921.0950


JPEG image

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