Simply put, IPsec is a framework for providing reliable and secure communication between hosts. This additional protection is provided at the IP layer of the OSI model. IPsec is based on Internet Key Exchange (IKE), Authentication Header (AH), and Encapsulating Security Payload (ESP). These protocols work together to provide secure tunnels between a pair of hosts that are IPsec capable. The list of potential hosts includes but is not limited to firewalls, VPN concentrators, routers, cellular phones, PDAs, workstations, laptops, and servers. Let’s examine each of these protocols individually.
• Internet Key Exchange (IKE)
Handles the negotiation of security associations (SAs).
Communications occur using ...