What public IP adress

Hello,
i installed Jitsi on an Ubuntu 20.04 server and have a problem understanding Domain of your server and set up DNS i am hosting the server in Virtualbox on a windows system. The Ubuntu Server has a bridged adapter and should be able to connect to all devices in my network. I do not have my own dns server where i can add addtitional records too as far as i know.

I am not sure which IP adress to use here, should it be the ip address i get when i look up my ip adress on my windows Host System with https://www.what-is-my-ipv4.com/en ?
i added the following into /etc/hosts
127.0.0.1 localhost
192.168.178.73 meet.pat.org meet
But thats the privat ip adress in my network and did not work
then i changed it to the ip adress i got from the website mentioned above because i thought thats my routers public ip, and it still did not work.

What IP Adress do i have to use when my videobridge system is in a Virtualbox Ubuntu server and how do i test from my host system browser if my Videobridge installation is working?
Do i have to set up an own DNS server before i can use Video bridge?

Will the participants be local, remote or mixed?

The Participants are planned to be remote users outside of the Network.

Then you should use the router public IP address but using an FQDN which points to this address will be a better way

what is “this address” ? And how do i create the FQDN so that everyone can connect then?

the router public IP address

First you need to buy a domain name from a registerer

and if i want to use it in an intern network to test some things? can i use the private IP adress?

it’s needed to set an address during the installation. This address may be an FQDN or an IP. Many settings depends on this address and the default system only works with this address.

Therefore you can’t use two different addresses for internal and external participants in the default situation. And a TLS certificate is needed to run a Jitsi system, You can’t get a trusted TLS certificate for an internal IP and you can’t force the participants to use your self-signed certificate,

If you setup the system with an FQDN and if you have a trusted TLS certificate, external and internal participants can connect to your server if the routing rules are OK