Using IPSec

What is IPSec?

IPSec is a set of IP extensions developed by IETF (Internet Engineering Task Force) to provide security services compatible with the existing IP standard (IPv.4) and also the upcoming one(IPv.6). In addition, IPSec can protect any protocol that runs on top of IP, for instance TCP, UDP, and ICMP. IPSec is truly the most extensible and complete network security solution.

IPSec which is based on modern cryptographic technologies enables end-to-end security so that every single piece of information sent to or from a computer can be secured. It can also be deployed inside a network to form Virtual Private Networks (VPNs) where two distincts and disparate networks become one by connecting them with a tunnel secured by IPSec.

Tunnel mode

IPSec in tunnel mode is normally used when the ultimate destination of the packet is different from the security termination point. We introduce two tunnel mode examples:

> - Secure Gateway to Secure Gateway
> - Secure Gateway to PC

Network Diagram Key

In our network diagram figures, a dotted line indicates a logical connection (i.e., the two devices are not physically attached), a solid line indicates a physical connection (i.e., there is a physical link between the two devices and they are directly attached), and a pipe indicates a secure connection between two devices.