Upgrading Forefront TMG to Beta 3 - Modify the backup/export xml to enable import

For those of you who had installed a previous beta of Forefront TMG (yes, it's the new name for ISA Server) you might have had the pleasure of experiencing your TMG server going down after the 180+7 days grace period with the message "the evaluation period has expired" in the eventlog.

It's really hard to figure out the Forefront TMG version history, but currently (September 09) the latest one I've found is the Beta 3.

The upgrade path is based on backup (export) and restore (import) of your settings, so make sure you export your setup before you uninstall the previous version. After you've installed the new version you'll get some trouble importing again: "An XML DOM document object [...] could not be imported because its based on a newer build".

After some creative xml-file hacking we managed to get the import working. We upgraded the xml elements fpc4:Build and fpc4:Version to reflect the new version number 7.0.7509.100. That didn't do the trick, so the next step was to also alter the fpc4:IsaXmlVersion from 6.2 to 7.0. After that change the backup restored successfully.

After the import all our SSL based services seemed to work fine, but the regular http services didn't.

First hunch was to set up a log filter to see what went through the TMG server. A curious new behaviour from the prior beta to Beta 3 is that we used to be able to filter logs based on the Destination Host Name property. In Beta 3 it seems like this post has gone into effect with this field beeing empty.

After a lot of troubleshooting the problem was so elementary that it's almost embarrassing. The Beta 3 installer for Forefront TMG actually installs IIS7 and sets up an active default website on port 80, thus blocking all your traffic. You'll see indications of this in your eventlog with the message "The Web Proxy filter failed to bind its socket to 127.0.0.1 port 80". I.o.w. run inetmgr and stop the damn thing to get your HTTP traffic back online.