I have exchange 5.5 on an NT 4.0 PDC with OWA on W2K server in the DMZ but am not sure that i have the corect ports open. I have allowed just http and ssl to the external adrress of OWA server and from the OWA to Exchange internal is ports 135 and i have mapped the directory service and the information store ports to 1225 and 1226 and opened them as it says in http://support.microsoft.com/default.aspx?scid=kb;en-us;259240
. I have also allowed 1024 through 65535 from exchange to OWA.
However it does not always work with this configuration. Do i need to open any other ports? i sometimes get the "There are currently no logon servers available to service the logon request." I notice in q259240 there is a bit at the bottom that says "NOTE: The OWA server must also be a member of the domain where the mailboxes reside. For additional information about how to configure that access, click the article number below to view the article in the Microsoft Knowledge Base: 179442 How to Configure a Firewall for Domains and Trusts" This involves opening a lot of Netbios ports. When i open these (137,138, 139) it works every time but is a lot less secure.
So do i need to open any other ports, i.e the net bios, and how come it is working imtermittently? I am using checkpoint FW-1 4.1