No it's not an upgrade.
I tried to change the server.xml file to enable it to listen on port 443, it appears to be working, but not through the firewall, I've setup forwarding on the firewall using different ports, 8443, 2443, 8000, but each time I get the firewall's web managment interface with a url look like this
note what I typed in the url is this
https://xxx.xxx.xxx.xxx:8000
but I'm getting
http://xxx.xxx.xxx.xxx/zimbra?initMode=https
and it displays the firewall's login page, which listens on port 80/443
Many thanks,
- Yang