Draytek 5500 Series 用户手册

 

VigorPro5500 Series User’s Guide 

104

This submenu only applies to PPP-related VPN connections, such as PPTP, L2TP, L2TP 
over IPSec.   

 

Select this option to force the router to authenticate dial-in 
users with the PAP protocol. 

Selecting this option means the router will attempt to 
authenticate dial-in users with the CHAP protocol first. If the 
dial-in user does not support this protocol, it will fall back to 
use the PAP protocol for authentication. 

This option represents that the MPPE encryption method will 
be optionally employed in the router for the remote dial-in 
user. If the remote dial-in user does not support the MPPE 
encryption algorithm, the router will transmit “no MPPE 
encrypted packets”. Otherwise, the MPPE encryption scheme 
will be used to encrypt the data. 

 

Require MPPE (40/128bits) - Selecting this option will force 
the router to encrypt packets by using the MPPE encryption 
algorithm. In addition, the remote dial-in user will use 40-bit 
to perform encryption prior to using 128-bit for encryption.   
In other words, if 128-bit MPPE encryption method is not 
available, then 40-bit encryption scheme will be applied to 
encrypt the data. 
Maximum MPPE - This option indicates that the router will 
use the MPPE encryption scheme with maximum bits 
(128-bit) to encrypt the data. 

The Mutual Authentication function is mainly used to 
communicate with other routers or clients who need 
bi-directional authentication in order to provide stronger 
security, for example, Cisco routers. So you should enable 
this function when your peer router requires mutual 
authentication. You should further specify the User Name 
and Password of the mutual authentication peer. 

Enter a start IP address for the dial-in PPP connection. You 
should choose an IP address from the local private network.