How would you implement IPSec to encrypt as much TCP/IP traffic as possible with minimum overhead?

Because of security concerns, an IPSec security policy is being evaluated for the company. The board of directors wants all communication between staff workstations and all servers encrypted. They also want to encrypt all communication between clients' computers and the servers. Client computers run various operating systems, including Windows 95, UNIX, Linux, Windows 2000, and Windows XP.

What is a VPN?

VPN is (Virtual Private Network) were first used by companies to enable their employees to securely access internal systems such as email remotely (e.g. from home or while on business trips). Today they are increasingly being used for personal use by individuals to protect their privacy while online in public places (e.g. when using the wi-fi connection in a cafe) or in a country where the internet is censored / blocked (e.g. China, Saudi Arabia��).