UCS Master (with dynamic IP) <-> UCS Backup/Slave connection

Hey Forum,
I have searched around but could not really find an answer to my question. My intended set-up is:

UCS Master as home server reachable from the internet via dyndns with (among others) installation of Nextcloud.
UCS Backup or Slave on a hosted (low price, low performance) vserver with installation of Kopano.

The idea is to have all my Nextcloud data at home and use the high availability of a hosted system for receival of emails. I simply don’t trust the reliability of our local ISP and the stability of my homebrew hardware, which is okay for nextcloud, but not for email.

Will this setup work, especially having a UCS Master whose ip is changing over time? How will the UCS Backup/Slave get to know the updated Master IP? I could not really find an answer to this in the docs or the forum

Thanks for you support!



well, at first you will need to have a VPN I would suggest. If not you will need proper port forwarding. Take care to only forward ports from the IP your Kopano server has! A least it helps a little bit.

Regarding the ports have a look here.

When I started with UCS (some time ago…) I was thinking of a similar setup but due to the high risk of loads of ports to open to my local net I decided against. My suggestion would be to “buy” a second machine on hosted environment using it as a VPN gateway for UCS. Might not be perfect and not as cheap as before but it will increase security a lot!

Just my thoughts…


Hey CV,
thanks for that. With the hint VPN, I found this: Openvpn Site to Site - Ports nur für vpn Verbindung öffnen
Let’s see if lebernd has found a final solution.