Exchange migration reusing the IP address of old server.

Question

I'm working with a client on exchange 2016-2019 migration under hybrid. Mailboxes have been moved to Office 365. They use the On-premise exchange server for MFC devices, scanners, and user management. I am planning to cut over to 2019 and decommission of 2016.
The client has many devices that use the IP of the old exchange 2016 server and would like to reuse that ip on the new 2019 server.
Before I run the Hybrid Config Wizard (HCW) and decommission the 2016 server, I would like to change the ip address of the new exchange 2019 server to that of the old 2016 server.

My plan was to to reuse the old ip address on the new exchange 2019 server then change the IP address of the exchange 2016 server to something different. After the ip address changes, run HCW and then decommission the exchange 2016

Is changing the ip addresses a horrible idea? is it possible without causing major issues?

Thoughts and suggestions?

Answer 1

As long as DNS is updated to point to the new host, it should be fine. Make sure any custom receive connectors on the 2016 are recreated on the 2019.