ZyXEL Communications 5 Series User Manual

Page of 824
 Chapter 19 IPSec VPN
ZyWALL 5/35/70 Series User’s Guide
359
Figure 207   Gateway and Network Policies 
This figure helps explain the main fields in the VPN setup.
Figure 208   IPSec Fields Summary 
Negotiation Mode
It takes several steps to establish an IKE SA. The negotiation mode determines the number of 
steps to use. There are two negotiation modes--main mode and aggressive mode. Main mode 
provides better security, while aggressive mode is faster.
"
Both routers must use the same negotiation mode.
These modes are discussed in more detail in 
Negotiation Mode on page 391
. Main mode is 
used in various examples in the rest of this section.
IP Addresses of the ZyWALL and Remote IPSec Router
In the ZyWALL, you have to specify the IP addresses of the ZyWALL and the remote IPSec 
router to establish an IKE SA.