SnapGear 2.0.1 - Manual (Page 123)

Virtual Private Networking
119
Figure 9-13
Check the Enable IPSec checkbox.
Select the type of IPSec endpoint the CyberGuard SG appliance has on its Internet port.
The CyberGuard SG appliance can either have a static IP, dynamic IP or DNS
hostname address. If a dynamic DNS service is to be used or there is a DNS hostname
that resolves to the IP address on the Internet port, then the DNS hostname address
option should be selected. In this example, select dynamic IP address.
The Maximum Transmission Unit (MTU) of the IPSec interface can be configured by
checking the Set the IPSec MTU to be checkbox and filling in the desired MTU value.
For most applications this need not be configured, however if it is set, the MTU value
should be between 1400 and 1500. In this example leave the checkbox unchecked.
Click the Apply button to save the changes.