IP inquiry if I want to change Portal UME data source

Hi masters,

I have this scenario:

My portal are currently using server-A as single-sign-on(SSO) UME data source.

I want to switch my portal's UME data source from server-A to server-B.

I notice that the IP address for server-A is publish to the web.

My question is that if I want to switch UME data source from server-A to server-B, do I need to publish the IP address for server-B to the web? Or would Netweaver portal accept an local intranet-based IP for UME data source?

Thank you.