Wi-Fi

Tech Tip: Beware of wireless network security concerns and traffic leakage


Providing mobile IT pros with remote access to all business apps may put a company's vital information at risk. Read Security in the Wireless Revolution to find out about today’s available wireless systems and the type of security you need to avoid costly and dangerous security concerns.

Jonathan Yarden

Wireless networks have many advantages over wired networks, especially when it comes to the ease of installation. However, this easy implementation has resulted in countless wireless networks being installed in areas where information security should have been the first concern.

It's scary, but I've seen hospitals, banks, and even government buildings running insecure wireless networks. In addition to the security holes, self-installed or economical wireless network gear has resulted in an increase in IP traffic leakage.

In the context of wireless networks, Wired Equivalent Privacy (WEP) is a contradiction. WEP is designed to provide a wireless local area network with the same level of security and privacy that's provided by a wired LAN. But most self-installed or economical wireless network gear doesn't even enable WEP.

So if you've set up a wireless network in an office, it's possible for the person across the hall to purchase a wireless network card and immediately access your network. This itself is a problem, but it gets even worse when you've installed a wireless network and you accidentally end up connecting to someone else's wireless network. The result is network problems that seem to defy explanation.

Interference between wireless access points of different networks will occur if the wireless access points are within range of each other. In one incident I discovered, a dental office using the same building as a hospital experienced problems when network traffic from the hospital's wireless network and the dental office's network "leaked" into both networks.

The dentist's office used a wireless bridge connected to a DSL line, but both the hospital and the dental office were using the same private network numbers and netmask. This resulted in bizarre problems for both the hospital and the dental office until both networks were secured with WEP.

While WEP can fix the bulk of the network traffic leakage issues, WEP won't make your network secure. Anyone who wants to poach network access can simply run a copy of the open source Airsnort program, decode the WEP keys for a network, and gain access.

As more companies implement wireless networks, traffic leakage issues and security flaws will become more of a concern. And the continued availability of low-cost, self-installed wireless network equipment won't make the problem any simpler to fix.

Jonathan Yarden is the senior UNIX system administrator, network security manager, and senior software architect for a regional ISP.

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