NAC helps with wireless LAN security at college

For Scott McCollum, IT services director at Sinclair Community College in Dayton, Ohio, network security can't mean one thing for the wired LAN and another for wireless connections.

After all, no matter their origin, security breaches can have serious ramifications for a school. "Security incidents can create intangible costs to the college, such as lost productivity or lack of customer satisfaction. In addition, they can create breaches of confidential information that could cause financial penalties for the college," he says.

Keeping wireless links secure can be particularly problematic. But shutting down wireless access wouldn't sit well with the school's 24,000 students and 1,000 faculty members or with the thousands of users of the conference and banquet center. "Users expect the network to be everywhere and available at all times, but they expect it to be secure as well. Every person that uses the network develops an opinion about it that contributes to the college's reputation as an educational institution, which ultimately impacts enrollment and funding," McCollum says.

To address the college's needs for secure access from anywhere across the 20-building campus, McCollum rolled wireless and wired LAN security into a master project called the Secure LAN Strategy. "It's a road map for the implementation of network authentication for all computers that connect to the Sinclair network,"he says. This comprehensive, integrated view of wireless and wired LAN security earns Sinclair a 2007 Enterprise All-Star Award.

Two plus three

For the project, launched in 2005, McCollum created a tiered-policy architecture and applied two-factor authentication -- by device and user, in all instances. On the wireless side, as soon as a device -- for example, a laptop, smart phone or PDA -- attempts a connection, it must authenticate using 802.1X.

The wireless controller switch passes the request to a RADIUS-based Microsoft Internet Authentication Service (IAS) server. After IAS authenticates the device, it checks with Active Directory to authenticate the user. Once the user and the device are authenticated, the user can access the network, including applications and databases, based on preset rights. This Level One access, the highest available, applies to faculty, staff and student employees using school computers, including those in the laboratories.

If the device cannot be authenticated, it is quarantined on a virtual LAN (VLAN). From the VLAN, IAS authenticates the user, and Cisco NAC Appliance (formerly Cisco Clean Access) checks for virus definitions and patches, and requires remediation before letting the machine proceed. Once cleared, the device is allowed Web-only access to the Sinclair network. Like Level One, this Level Two access applies to faculty, staff and student employees. In this case, however, they are attempting network access using their own devices.

If the user and the device -- for example, a guest lecturer with a laptop -- are unknown, Level Three -- basic Web access -- applies. These users are sent to an Internet connection used exclusively for this purpose, McCollum says.

In tandem with tiered authentication, McCollum uses Enterasys Networks' NetSight Automated Security Manager and Dragon intrusion-detection system to make sure all machines on the network have an acceptable level of security and comply with use policies.

"Even though we trusted you, if we see that your computer is spewing out bad code, we can shut down your policy rights," McCollum says. So far, so good, he adds. "We've kept machines clean and unauthorized traffic off the network."

Cost-cutting scheme

Partnering with a wireless ISP for Level Three guest access helped keep project costs to a modest US$197,000, McCollum says. In exchange for supplying all wireless access points and controllers for public areas, HarborLink Network gets to display pop-up advertising to guest users. The tiered approach, which builds intelligence into the network devices and prevents them from forwarding unauthorized communications, makes this possible, he says. Otherwise, data leakage would be a concern.

Gittlen is a freelance technology writer. She can be reached at sgittlen@charter.net.

• Tweet