What's wrong with IP filtering?

• Effectively eliminates off-campus access
  • Distance education students, staff and faculty with off-campus workplaces, users who are travelling, and home users (unless your institution provides dial-in Internet access).
• Thwarts the "Information Anywhere" promise of the Internet by tying access to specific network nodes.

If it's so bad, why is it so prevalent? Because it's relatively easy to set up (if not to maintain), difficult to circumvent, and has a negligible performance cost. When combined with proxy servers, IP filtering is an important part of a healthy license enforcement system.