27
IKE Authentication
md5, sha1, sha256, sha384, or sha512
ESP Encryption
des, 3des, aes128, aes192, or aes256
ESP DH Group
none, modp768, modp1024, modp1536, modp2048, or modp4096
ESP Authentication
md5, sha1, sha256, sha384, or sha512
Left Identifier
1-28 characters
Right Identifier
1-28 characters
KeyLife
120-604800 seconds
IKELifeTime
120-604800 seconds
RekeyMargin
120-604800 seconds
Dpdaction
none, clear, hold, or restart
Dpddelay
1-300 seconds
Keyingtries
0 means forever
3.8.2 General VPN
The VPN > General VPN menu offers 3 configuration options: L2TP, PPTP, and GRE. Each is explained below.
3.8.2.1
L2TP
Layer 2 Tunneling Protocol (L2TP) is a computer networking protocol used by Internet Service Providers (ISP)
for VPN operations. Similar to Layer 2 Data Link layer in the OSI reference model, L2TP is a session layer
protocol which provides an unencrypted tunnel between the CPE and the VPN. All Internet traffic including
ISP services will pass through the VPN.
A User Datagram Protocol (UDP) port is used for L2TP communications. Because it does not provide any
security for the data traffic, such as encryption and confidentiality, an encryption protocol such as IPSec is
often used with L2TP.
To configure L2TP VPN settings, click on the check box next to
Enable
(Figure 45) and complete the
configuration per Table 12.
Figure 45: L2TP
