IPsec VPNs

IPsec is a security architecture, based on standardized norms, that allows two entities to establish secure communication. The objectives of the IPsec protocol are: confidentiality; data integrity; authentication and antireplay protection. The three main components of IPsec are AH; ESP and Internet Key Exchange (IKE). An IPsec frame contains five basic elements that must be configured to ensure a secured connection. They are IPsec protocol; confidentiality; integrity; authentication and Diffie‐Hellman. An IPsec Security Association (SA) makes it possible to specify the security settings associated with a communication. There are two modes in which IPsec can be used: transport mode and tunnel mode. IKE is a protocol used to dynamically negotiate the security settings associated with IPSec communication. It is the combination of three protocols, namely: ISAKMP, SKEME and Oakley. A site‐to‐site VPN connects two remote LANs in order to securely share resources via the internet.