Draytek Vigor2912 Series User Manual page 279

Available settings are explained as follows:
Item
User account and
Authentication
Allowed Dial-In Type
Description
Enable this account - Check the box to enable this
function.
Idle Timeout- If the dial-in user is idle over the limitation
of the timer, the router will drop this connection. By
default, the Idle Timeout is set to 300 seconds.
PPTP - Allow the remote dial-in user to make a PPTP VPN
connection through the Internet. You should set the User
Name and Password of remote dial-in user below.
IPsec Tunnel - Allow the remote dial-in user to make an
IPsec VPN connection through Internet.
L2TP with IPsec Policy - Allow the remote dial-in user to
make a L2TP VPN connection through the Internet. You
can select to use L2TP alone or with IPsec. Select from
below:
None - Do not apply the IPsec policy. Accordingly,
the VPN connection employed the L2TP without
IPsec policy can be viewed as one pure L2TP
connection.
Nice to Have - Apply the IPsec policy first, if it is
applicable during negotiation. Otherwise, the dial-in
VPN connection becomes one pure L2TP
connection.
Must -Specify the IPsec policy to be definitely
269 Vigor2912 Series User's Guide