Multisite, mapped doamin SSL

Sub domain install with domain mapping. How would I secure a mapped site with an SSL. I’m still pondering this myself, just wondering if any one has done this. I’m pretty good with multisite, I have switched from sub folder to domain install.

I see the Value of running a sub folder install with a cheap SSL. If you domain mapped and wanted the mapped domain secured with an SSL It would be the same senerio of how to assign a dedicated IP to the mapped domain.