We currently use Windows Firewall to restrict RDS access to a hosted server by IP address on port 3389. We use Server 2008 Enterprise and it's really our only option since it's hosted by a 3rd party.
We need to allow authenticated bypass rules for non-domain computers and domain users, but I don't know how to set it up or if it's even feasible.
If it is, my question is what is Microsoft's recommended method of securing a non-domain computer / domain user authenticated bypass rule over the internet?