I've got a server running Windows Server 2012 R2, using ESET 5.X on the server and about 20 workstations, using ERA to push install.
I migrated to Server 2012 from a 32-bit 2003 R2 server, using a second machine as an intermediary.
Following the migration, and after installing the ESET stuff, I discovered that no user machines could connect to the server unless I disabled the server's Windows Firewall for the domain. Looking at the firewall rules, I saw a bunch of rules, as you can see in the attachment, which appear to be ESET rules, and which I suspect are the source of my problem.