In the Infor CRM SLX 9.0 Implementation Guide, Infor has included the specific ports which need to be opened on the interior and exterior firewalls in the case of the web server hosting the Infor CRM SLX web client being placed in a DMZ. This is mentioned in Appendix F Advanced Web Host Configuration in the Implementation Guide that comes on the Infor CRM SLX 9.0 install media. Since this is a fairly common setup, and since it highlights many of the port that would need to open in other situations as well, I wanted to post about it. (See here for information about ports that might need to be open in other configurations.)
For a web server set up in the DMZ, Infor shows that ports ports 1433, 1706, and 11211 need to be open on the interior firewall. The first two are for the database connection, the last one for the caching server. On the exterior firewall, Infor suggests having port 1025 open, as well as whatever port your web client is using (likely 80 or 443). Port 1025 is used by ping, and is sometimes used to establish an initial connection to a website.
If you are using the Synchronization server, and have the Documents and Library folder inside the SyncLogs folder on the web server, there are a few more ports you will need to open on the interior firewall to make those folders work properly. You will certainly need ports 138 (UDP) and 139 (TCP) open. If you are using DNS, you will need ports 135 (TCP/UDP), 137 (TCP), and 445 (TCP/UDP) open on the interior firewall as well.