PPTP dd-wrt
From BTGuard Wiki
PLEASE READ THROUGH THIS WHOLE ARTICLE!
You risk breaking your router when using a custom firmware!
Proceed carefully and make sure your router is compatible!
REQUIREMENTS
These instructions are ONLY for people who already have a dd-wrt compatible router flashed with the latest version.
In this tutorial, a DIR-825 rev. B2 was used. Firmware: DD-WRT v24-sp2 (05/27/13) std.
If you're having issues with OpenVPN, please try the OpenVPN method.