Draytek Vigor2950 Series User Manual page 118

IKE Authentication Method This usually applies to those are remote dial-in user or node
IPSec Security Method
108
(LAN-to-LAN) which uses dynamic IP address and
IPSec-related VPN connections such as L2TP over IPSec
and IPSec tunnel.
Certificate for Dial in -When the client executes remote
dial-in with IPSec mode, the router will transfer the
certificate to the client based on the setting selected here.
Please use the drop down list to choose one of the
certificates configured in Certificate Management>>Local
Certificate.
Pre-Shared Key- Currently only support Pre-Shared Key
authentication. Specify a key for IKE authentication
Confirm Pre-Shared Key-Confirm the pre-shared key.
Medium - Authentication Header (AH) means data will be
authenticated, but not be encrypted. By default, this option is
active.
High - Encapsulating Security Payload (ESP) means
payload (data) will be encrypted and authenticated. You may
select encryption algorithm from Data Encryption Standard
(DES), Triple DES (3DES), and AES.
Vigor2950 Series User's Guide