37
User defines XATUTH
password
Multiple strategies available
Perfect Forward Secrecy
(PFS) (Advanced Option)
Select disable/Group 1/Group
2/Group 5
Disable (this needs to match
the server)
Link Detection Parameters (Advanced Option)
Set the timeout for dropped
packets.
Set ICMP detection server
Set ICMP detection local IP
Set ICMP Detection Interval
Set ICMP detection timeout
Set ICMP detection max.
retries
The security level of three encryption algorithms ranks successively: AES, 3DES, DES. The
implementation mechanism of encryption algorithm with stricter security is complex and slow
arithmetic speed. DES algorithm can satisfy the ordinary safety requirements.
3.6.3 GRE Tunnels
Generic Route Encapsulation (GRE) defines the encapsulation of any other network layer protocol
on a network layer protocol. GRE could be used as the L3TP of VPN to provide a transparent
transmission channel for VPN data. In simple terms, GRE is a tunneling technology which provides
a channel through which encapsulated data message could be transmitted and encapsulation and
decapsulation could be realized at both ends. GRE tunnel application networking shown as the
following figure: