I was able to successfully sync an FMGo 16 iPhone instance with our FMS16 server-hosted database when all interactions were VPN/LAN based. But in setting up public WAN access, I encountered problems I cannot work around and did not find documentation to address.

We opened up our firewall to not require offline users to use VPN. Since we have redundant ISP, I used a hostname as the external address so users could connect over the secondary line if our primary was down. Each of our WAN connections has multiple public IPs, and the public IP assigned to the filemaker server does not match the public ip of the router.  When setting up the sync in MirrorSync Configuration java app, an error is reported that "The external sync address you have supplied (fms.company.com) does not match the actual address (x.x.x.154)." I chose to ignore the problem because fms.company.com successfully routes to x.x.x.156--FileMaker Pro, Go, web browsers, etc, have no issue getting to the server. When trying to sync FIleMaker Go, we now have an error and cannot sync: "Communication Error with Server. Error from server: user lacks privilege or object not found: SYNCCLIENT in statement [INSERT INTO SyncClient(timestamp, description, device_id, clone) VALUES (?,?,?,?)]

I'm hoping there's a setting that can be adjusted so I can use a domain name for remote WAN syncs.

UPDATE/RESOLVED

360Works support walked me through using the 360Works Admin.jar tool to stop and start the MirrorSync server to resolve this error. So, for the external server address, it seems to be fully possible to use a domain name whose public IP doesn't match the public IP of the router, and to ignore the IP-mismatch warning during configuration setup. But, you may need to restart MirrorSync to avoid errors caused by cached data.

Unrelated to this, if you update the internal IP of the hosting server, or update the filename of the database, you may need to make adjustments manually in the external data sources to match those changes.