What you are talking about here is what a lot of people are going through, as going from SBS to the new 2012 with virtualized servers is a big jump, but virtualization is far more powerful and scalable and allows easier backup and fault troubleshooting options.
You need two certificates:
1. e.g. remote.domain.com (for Essentials Anywhere Access and Direct Access)
2. e.g. mail.domain.com (if you use an SRV record through your domain hosts cpanel you can get away with a single name certificate as autodiscover is dealt with at external domain level (you will get a one-time warning as you connect outlook accounts to
allow the redirect), otherwise you will need a UCC certificate with at least mail.domain.com & autodiscover.domain.com for Exchange & essentials DNS to deal with it (you won't get a redirect warning)). This is all so autodiscover works when you connect
outlook accounts later.
What you do is is outlined below:
https://technet.microsoft.com/en-us/library/jj200172.aspx
So you install Windows Server 2012 R2 Standard (for eg) on your actual hardware box and only add the Hyper-V (and Windows Server Backup Role if you wish). This is your host. It is standalone and not part of the domain.
Then through Hyper V manager you create your two boxes (Essentials R2 (domain Controller) and Standard R2 with Exchange) then connect Exchange box to domain via usual methods via Hyper V VirtualSwitch.
So in essence you have three boxes running (one real and two virtual) Trick is to give each virtual box half each of your processors (ie 4 each if 8 core) and plenty of RAM. Ups the performance a lot I have seen a lot of installs stuck in first gear because
Admins forgot to assign more than one virtual processor to Vms. Like being stuck in first gear with a modern, multi core processor.
ARR 3.0 (Application Request Routing) is then used to "place" the exchange certificate into the Essentials IIS (for the specific purpose of proxying the info to the Exchange box), therefore allowing an SSL security checkpoint for Exchange on the
Essentials Server, which allows the mail to flow in and out of your other virtualized Windows Server 2012 R2 (Standard or Enterprise) with Exchange installed. This is where you use a single network adapter on your server as it all has to flow through port
443 and port 25.
Then OWA works as normal (through mail.domain.com, but routed through the Essentials IIS via ARR proxy)
You can then put direct access on the Essentials Server as well if you want (in addition to anywhere access which must be set up first to enable direct access):
https://technet.microsoft.com/en-us/library/jj204618.aspx
Its basically splitting the parts of the SBS box into separate parts via virtualization then it all joins to the Domain Controller (Essentials) to create similar functionality to what SBS used to (as i said tho with virtualization the sky is the limit SBS
was very restricted because everything ran on the same OS)
P.S The longest part of the above process (which is quite easy after you do it a few times) is, go figure, Windows Update. It takes ages as lot of updates for base RTMs of these Os's now even R2 .... :(
