FAQ 

Is this extension IPv6 compatible? 

Yes, it is. It uses the GeneralUtility::cmpIP() method, which can validate both IPv4 and IPv6 addresses.

What about "Logout"? 

Ah yeah, that is funny. Visitors with a matching IP address are authenticated on every single request. You cannot log out: if you press "Logout" the page reloads, a new request is made, and you are logged in again right away.

Can I configure more than one IP address per fe_user? 

Yes. Add as many entries as you like to the IP addresses field of a fe_users record. The visitor is logged in automatically if their remote address matches any one of them.