I installed multi-server zimbra for mail system. I have 2 ldap, 2 mailbox, 2 MTA and 2 proxy servers in my cluster. The servers have LAN IP addresses but it serving with global IP and domain. I’m using Fortigate Virtual Server for load balancing and redirect. The system works exactly as I want. I haven’t any connection problem from accessing the global internet. But I have "connection timed out" error in LAN when trying to access the domain. I haven't figured out where I went wrong yet. Here is an example, my virtual server settings. Thanks for helping :)
Virtual Server (18X.XXX.XXX.XX6) mapped to Real Servers (1XX.XXX.XXX.XX0 and 1XX.XXX.XXX.XX1). Global access is OK but the server or client(in LAN) cannot access the virtual Server IP or domain.
This had happened to me in the past many, many years ago. I had to do some weird configuration to get it to work. If I can recall, I believe I made a policy from the inside LAN to the outside interface with the target destination the internal IP address. I know it looks stupid, but if I recall it did the trick. Give that a whirl.