Netgear FVS318v1 – Prosafe Wireless N VPN Firewall Manual De Referencia

Virtual Private Networking

D-9

The SA contains all the information necessary for gateway A to negotiate a secure and encrypted 
communication stream with gateway B. This communication is often referred to as a “tunnel.” The 
gateways contain this information so that it does not have to be loaded onto every computer 
connected to the gateways.

Each gateway must negotiate its Security Association with another gateway using the parameters 
and processes established by IPSec. As illustrated below, the most common method of 
accomplishing this process is via the Internet Key Exchange (IKE) protocol which automates some 
of the negotiation procedures. Alternatively, you can configure your gateways using manual key 
exchange, which involves manually configuring each paramter on both gateways. 

1. The IPSec software on Host A initiates the IPSec process in an attempt to communicate 

with Host B. The two computers then begin the Internet Key Exchange (IKE) process.

VPN Tunnel

VPN Gateway

VPN Gateway

1) Communication

request sent to VPN Gateway

2) IKE Phase I authentication

3) IKE Phase II negotiation

4) Secure data transfer

5) IPSec tunnel termination