Today I installed my first Edge Transport server into an Exchange 2007 environment. The Edge Transport Server role should be installed on a server that is not part of the Active Directory domain in the DMZ. After installation I attempted to complete the post-installation tasks. This involves generating an XML file from the Edge Transport server and importing it on the Hub Transport server as an Edge Subscription.
After the XML is imported, I needed to start the Edge Synhronization using the command:
start-edgesynchronization
This command failed on my Hub transport server with the error - Could not connect and "The LDAP server is unavailable".
After some Google searches it seems the problem is DNS. I had checked all this by pointing my Edge Transport Server to my internal DNS servers. I had created a Forward Lookup zone for the Workgroup the Edge Transport server was in etc etc. The problem it turned out was that the DNS/DC/GC server did not have a reverse lookup PTR record! Once this was created the Edge Synchroniztion completed successfully!
