Hey there Mark,
Is this for 13 or 14? 13 is limited to just using 80 and 443, but 14 gives you the option to choose your ports during installation (you will need to uninstall/reinstall to change them).
Hope that helps.
Their IT guy just sent me this:
It will still look like 80 and 443 to the OC-FM server, it will just be redirected from the outside using PAT. Will this make any difference?
Is this OK?
I believe as long as FileMaker Server is the only application using 80 and 443 on the device, and that server still thinks it's accepting traffic via those ports, but the router is handling any port translation, you should be fine.