ABSTRACT
Local area networks (LANs) have become the repository of mission-critical information at many major organizations, the information processing backbone at most large organizations, and the sole implementation avenue for IP efforts in smaller concerns. The growing importance of LANs — the integrity and confidentiality of data and programs on them, their availability for use — demands proper security, but LANs have historically been designed to facilitate sharing and access, and not for security. There is a growing pattern of interconnecting these networks, further increasing their vulnerabilities.
