I'll provide a little more background here. We are running Terminal Services. We plan to have clients on our LAN and remote clients from home and on the road.
For convenience sake, we want users on our LAN to not require passwords to log into theserver (our applications require passwords of their own, so this isn't that big of a security issue).
Obviously, we don't want accounts without passwords accessible over the Internet. We statically assign private IP addresses here based on station number, so it would make the most sense (and be simplest) to set each user account on our local LAN so that it can only log in from a single private IP Address.
This way users on the local LAN wouldn't require a password, but remote users would, and local LAN accounts would not be usable outside the LAN.