What is IPSec?

IPSec is a transparent standards-based security layer for TCP/IP that is commonly used to create and operate Virtual Private Networks (VPNs).

An IPSec VPN uses modern encryption and authentication technologies to keep the data that it carries private-hidden from public view and completely protected against unauthorized access or theft.

Think of the VPN as a group of related hosts that are carved out of the insecure Internet to safely extend your private network across the public Internet.

For hosts in the VPN this feature is transparent; tunneled traffic appears to be local and peer-to-peer, even if the datagrams themselves must travel across the public Internet in order to reach their destinations.

You are most likely to need IPSec if you own or work for an organization faced with one of these common needs:

• The need to migrate leased lines (e.g. Frame Relay) to a private network across the public Internet.
• The need to securely link networks or hosts at distant locations or branch offices
• The need to unify disparate IP address ranges into a single, more convenient address space
• The need to secure sensitive network communications from prying eyes
• The need to ensure the integrity of data being exchanged
• The need to provide telecommuters a secure path to the workplace network

IPSEC IS THE PREDOMINANT VPN STANDARD IPSec is the most common technology in use today for creating Virtual Private Networks. As an IPSec user, you'll be taking advantage of a range of robust technologies that are widely used by governments and businesses for secure communication and infrastructure deployment.