If your data source is in the same location as the main file, you can use a relative external data source location. Just follow the example at the bottom of the "Edit Data Source" dialog window.
You may have to work with DNS for this...
Also because with custom SSL certificates becoming more mainstream, the connection to the server should done by its fully qualified domain name, not the IP address otherwise the SSL connection can not be validated.
I am having an issue with my DNS. I cannot get FileMaker to resolve the new name. I tried to run the deploy assistant but it comes back unable to communicate.
I put the new DNS name into the bindings of the IIS FMWebSite but I just can't seem to connect to it. If I re-install FileMaker Server, it recreates the website without the bindings.