The options at the bottom of the page can be used to enable the MPPE encryption and MS-CHAP authentication protocols used by default by Windows clients. MPPE adds security to PPTP connections, but requires that both the PPP daemon and the operating system kernel support it. PPPd versions 2.4.2 and above have native MPPE support, while a patch exists for older versions. However, the actual configuration file options differ between these two PPPd versions. This module will always use the correct options though.