Building Better Branch-Office WirelessOne rogue access point at a remote site can make for a potentially huge security mess. The answer? Extend the corporate wireless LAN safely and efficiently. We'll show you how.
Remote users can feel marginalized if they don't have the same technology amenities that employees at headquarters enjoy, and they won't take design complexity, management overhead, or security risk as an excuse. A prime example is a branch office that deems itself underserved because "everyone else has wireless." Employees might just pitch in to buy a $50 access point and believe they're doing the corporate IT folks a favor by solving the "problem" themselves.
Of course, security is only as strong as its weakest link, so that $50 rogue access point could neutralize thousands of dollars' worth of sophisticated, layered access controls. Put simply, an open AP connected to the corporate network is tantamount to placing an Ethernet jack in the parking lot. Even when the device is configured with Wired Equivalent Privacy, it's vulnerable. Armed with a high-gain antenna and a proximate location to the target, an attacker can inject and/or collect 802.11 data frames and recover static WEP keys and passphrases used by the "helpful" employee who's attempting to secure his unauthorized device.
To make matters worse, once someone gains access to the remote office's network and obtains a valid IP address, the intruder could appear, at least from a network perspective, to be an authorized corporate user. Unless you have network access control or core firewalling in place, the attacker may well gain access to all local and WAN-connected corporate assets via the branch-office connection.
With the advent of enterprise-class 802.11n systems, the remote WLAN equation becomes even more complex. The upside is that 802.11n will greatly increase the throughput rates of each AP radio while enhancing IT's ability to identify rogue devices. The downside--besides the enormous cost premium that 11n gear commands--is that it will be even easier for wireless users to saturate available WAN bandwidth.
THE N FACTOR
Don't give in to irrational exuberance over the latest Wi-Fi standard. Cold, hard calculations are called for.
The best answer for geographically diverse organizations may be to provide enterprise-class 802.11 WLAN coverage at branch offices. While you could just stick lightweight access points at remote sites, link them to the controller at your main office, and call it a day, problems with subpar connectivity and bandwidth hogging make this a poor choice. Better are scaled-down WLAN controller appliances from companies such as Aruba Networks, Cisco Systems, and Motorola-Symbol that can support as many as six access points while providing many of the sophisticated capabilities available in controllers that scale to well over 1,000 APs.
Alternately, manufacturers such as Aruba and Cisco offer enhanced systems designed to extend corporate WLAN standards to branch offices while addressing the bandwidth constraints inherent in WAN connectivity. Aruba's Remote Access Points and Cisco's Hybrid Remote Edge Access Points use standard lightweight APs loaded with specialized firmware that integrates seamlessly with centralized WLAN controllers, letting branch offices enjoy the functionality and security provided to headquarters without the need to deploy local WLAN controllers--or have advanced IT resources on site to maintain them.
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