PPTP VPN 계정관리 Radius + MySQL Caveats: MPPE encryption seems to be available with MS-CHAP authentication only. Not PAP and CHAP. This document assumes only MS-CHAP v2 is used. (As version 1 is totally broken securitywise.) PPP and kernel: Note: patching the kernel is only required if you are using a kernel version below 2.6.15-rc1 -- James Cameron, 2005-11-16. Patch your kernel sources with the mppeinstall.sh script in linux..