I got what bittn2 said already, just now I misunderstood. He asked me to use the same IP address or change the firewall setting if using a new IP address.Which ip are you reffering?
get it, thanks for answering.He refer to the local ip of the server, this is already configured in the PBX. For example in V18 the local phones are provisioned to contact this local ip. If you migrate and change this local ip the phones will not be able to contact the server as they are already provisioned.
However the best option which is also required in V20 is the split DNS: https://www.3cx.com/docs/creating-fqdn-split-dns/
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