Reference Manual for the ProSafe Wireless 802.11g VPN Firewall Model FVG318
7-2 Advanced Virtual Private Networking
v1.0, October 2005
• IKE Policies: Define the authentication scheme and automatically generate the encryption 
keys. As an alternative option, to further automate the process, you can create an IKE policy 
that uses a trusted certificate authority to provide the authentication while the IKE policy still 
handles the encryption.
• VPN Policies: Apply the IKE policy to specific traffic that requires a VPN tunnel. Or, you can 
create a VPN policy that does not use an IKE policy but in which you manually enter all the 
authentication and key parameters.
Since VPN policies use IKE policies, you define the IKE policy first. The FVG318 also allows you 
to manually input the authentication scheme and encryption key values. In the case of manual key 
management there will not be any IKE policies.  
In order to establish secure communication over the Internet with the remote site you need to 
configure matching VPN policies on both the local and remote FVG318 wireless VPN firewalls. 
The outbound VPN policy on one end must match to the inbound VPN policy on other end, and 
vice versa.
When the network traffic enters into the FVG318 from the LAN network interface, if there is no 
VPN policy found for a type of network traffic, then that traffic passes through without any 
change. However, if the traffic is selected by a VPN policy, then the IPSec authentication and 
encryption rules are applied to it as defined in the VPN policy.
By default, a new VPN policy is added with the least priority, that is, at the end of the VPN policy 
table. 
Using Automatic Key Management
The most common configuration scenarios will use IKE policies to automatically manage the 
authentication and encryption keys. Based on the IKE policy, some parameters for the VPN tunnel 
are generated automatically. The IKE protocols perform negotiations between the two VPN 
endpoints to automatically generate required parameters. 
Some organizations will use an IKE policy with a Certificate Authority (CA) to perform 
authentication. Typically, CA authentication is used in large organizations that maintain their own 
internal CA server. This requires that each VPN gateway have a certificate from the CA. Using 
CAs reduces the amount of data entry required on each VPN endpoint.