Wireless users are accustomed to the ritual of providing login information before they connect to a local network. The IEEE 802.1X standard [1] defines a technique for port-based network access control that is used with most wireless access points.

Many admins don't realize IEEE 802.1X can also provide access control for conventional (wired) networks. The IEEE 802.1X authentication scheme actually offers several advantages over alternatives such as MAC-based port authentication, which is easily sniffed and often difficult to manage.

In the age of netbooks, an unauthorized laptop can plug in from almost anywhere on the network. Wary admins looking for better protection can use IEEE 802.1X to stop unauthorized access before the intruder reaches a browser window or login screen.

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