ISA Server 2004 blocking Outlook

Posted on 2009-07-07
Last Modified: 2013-11-16
We have SBS2003 running Exchange2003 and ISA 2004. Yesterday I was playing with ISA (which I don't yet understand - but I never let ignorance stand in my way) trying to open addtional SSL ports using a free tool called ISA Server Tunnel Port Editor in order to allow Autodesk licensing software to function (on port 145) This was successful but once I'd finished I thought I'd better remove this port. Today no one can access Exchange and ISA appears to be blocking with the message Unidentified IP traffice (TCP:2700) Any ideas please?
Question by:RogerNZ
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 5
  • 3
LVL 51

Expert Comment

by:Keith Alabaster
ID: 24798557
Interesting stance - one view might be to never let ignorance stand in the way. An alternative view might be not to screw around with systems you haven't a clue about.

The tool is actually called tunnel port range extender (tpre).

So what SSl ports does tpre believe are still in place?
What results do you get from the BPA?


Author Comment

ID: 24798670
Hi Keith
You're right of course...

tpre lists SSL port 443. All other services appear to be functional.

Downloading Best Practices Analyzer now. I'll let you know the results.
LVL 29

Expert Comment

ID: 24798725
Why would that tool even have anything to do with Autrodesk licensing?
Anyway,...Outlook.  ISA does not block Outlook, ignores Outlook,..not quite the same thing.   In the Firewall Client Configuration in the ISA MMC you have to enable Outlook to be used by the Firewall Client Software.  Change the setting from "1" to "0" so that it reads  "outlook    disable=0"
After you get the SSL Port Config back the way it belongs (which I don't think is related to all your problems), fix ISA in general re-run the Internet Connection Wizard thing over again.  You have to use the Wizards for just about everything with SBS,...manually configuring individual things yourself usually makes a big mess.
Ready to trade in that old firewall?

Whether you need to trade-up to a shiny new Firebox or just ready to upgrade from whatever appliance you're using now, WatchGuard has the right appliance for you! Find your perfect Firebox today with appliance sizing tool!

LVL 29

Expert Comment

ID: 24798739
Outlook.  Outlook works fine if you use anonymous Access to outbound POP3/SMTP and the Client machine is working as a SecureNAT Client.
But if you want authentication you have to use the Firewall Client which requires the steps I described.

Author Comment

ID: 24798761
BPA says I have a problem "The secure channel to the domain controller could not be verified" Is this likely to be it? Also I have some certificate errors but I suspect they've been there a while. Our Blackberry users are still receiving mail.

Author Comment

ID: 24798784
Autodesk licensing is now a web based activity. To transfer a license from one workstation to another the license gets returned to Autodesk - then downloaded to the target workstation. No more license file transfers.
LVL 29

Expert Comment

ID: 24798798
Use the SBS Installation Program.
Remove ISA
Do not use Add/Remove Programs to do it.
Run the Internet Conenction Wizard contraption (sorry I don't rember the exact name/acronym for the thing).
Use the SBS Installtion Program again
Install ISA,...again.
The Internet Connection Wizard should automatically run itself at the end of that,...if it doesn't then do it yourself.

Author Comment

ID: 24799024
I tried changing outlook to disable:0 and it didn't work.

I'm not that keen to run the ISA wizard since changine ISA without understanding it is what got me into trouble in the first place. I'm a Mechanical Design Engineer who doubles as IT for around 40 users. Mostly this works well but sometimes I get out of my depth by doing things I shouldn't have...

I have included more information from the ISA monitoring:
Denied connection
Log Type: Firewall Service
Status: A non-SYN packet was dropped because it was sent by a source that does not have an established connection with the ISA server computer.
Source: Internal (
Destination: Local Host (
Protocol: Unidentified IP Traffic (TCP:2700)

Accepted Solution

RogerNZ earned 0 total points
ID: 24799645
Managed to get webmail working and noticed Remote access service is stopped message. Restarted now all is fine. Thanks for the help.

Featured Post

2017 Webroot Threat Report

MSPs: Get the facts you need to protect your clients.
The 2017 Webroot Threat Report provides a uniquely insightful global view into the analysis and discoveries made by the Webroot® Threat Intelligence Platform to provide insights on key trends and risks as seen by our users.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Find out what you should include to make the best professional email signature for your organization.
This article will help to fix the below errors for MS Exchange Server 2013 I. Certificate error "name on the security certificate is invalid or does not match the name of the site" II. Out of Office not working III. Make Internal URLs and Externa…
In this Micro Video tutorial you will learn the basics about Database Availability Groups and How to configure one using a live Exchange Server Environment. The video tutorial explains the basics of the Exchange server Database Availability grou…
This video demonstrates how to sync Microsoft Exchange Public Folders with smartphones using CodeTwo Exchange Sync and Exchange ActiveSync. To learn more about CodeTwo Exchange Sync and download the free trial, go to:…
Suggested Courses

626 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question