That would require a custom provider for just IP automatic login. Perhaps you could explain more about how you envision such a setup working as I can't see how it would really work. There are very few systems that use static IP addresses anymore and even though I do have one at home I can still see a potential problem. IE: You've got a provider that has my IP listed for automatic login but then my wife, daughter, or son visit the site from one of the other computers at home. They would be logged in automatically as me because the broadcasted internet IP is the same as mine.

I understand what you're trying to accomplish. In any case it's going to take a new provider to do what you're looking for. If I were going to try something similar I would use a combination of the DNN login provider and the IP range selection in the 01.00.03 version of the AD provider. On the settings screen (Admin->Authentication) I would have an area where I could input a single IP address or IP range and then select the user account to be associated with that IP. An httpModule would be needed so that the IP is checked when the site is loaded to see if the account should be logged in automatically or ignored.