What Is the Campus?

For campus security, it is helpful first to understand what the campus is. As used in this book, the term campus network refers to all the internal connectivity within a single location. Internal network is another term folks use. The important thing to realize is that we aren't referring only to networks at educational institutions here but rather to the internal connectivity of any organization. The campus connects to the edge through one or more connections. Housed within most campus networks are the following components:

• Client hosts End-user PCs, workstations, and so on
• Department servers Servers and applications only accessible by a limited set of users in the campus (accounting systems, HR, department fileservers, and so on)
• Central servers Servers and applications accessible by all users (e-mail, DNS, internal web applications, central file stores, and so on)
• Management devices Any device principally concerned with enabling the smooth running or monitoring of other systems (SNMP managers, AAA servers, Syslog servers, security event monitors, and so on)
• Switched/routed network infrastructure The routers, Layer 2/Layer 3 (L2/L3) Ethernet switches, and associated infrastructure that enables communication within the campus, with the edge network, and with external networks