This paper provides a balanced comparison of 802.1X and IPsec. If your customers are considering deploying these security technologies, the paper is helpful in that it provides an objective review of the capabilities of both technologies. It lays out for the reader why/when one might consider implementing one, the other, or both solutions in combination for an end-to-end defense in depth.
"Microsoft Windows Server 2003 and Windows XP support both the IEEE 802.1X standard for wired networks and the Internet Protocol security (IPsec) Internet standard. The IEEE 802.1X standard for wired networks provides authentication and authorization protection at the network edge where a host attaches to the network. IPsec provides peer authentication and cryptographic protection of IP traffic from end-to-end. This white paper describes the security and capabilities of 802.1X for wired networks and IPsec based on industry standards and their support in Windows Server 2003 and Windows XP, and provides comparison information when evaluating deployment of these security technologies."