Enterprises continue to battle the installation of unauthorised, or rogue, wireless LAN access points (AP) on corporate networks by employees who install the increasingly cheap devices unmindful of the security risks, according to speakers here Palm Desert, California on Wednesday at Computerworld's Mobile and Wireless Conference.

Tom Dillon, manager for mobile and wireless at Hilton Hotels in Beverly Hills, California, said the management of a Hilton hotel he recently visited assured him that the property's network had in operation only six authorised WLAN APs. Dillon said he fired up sniffer software and quickly detected 15 APs at the hotel, which he declined to identify.

That, he said, clearly illustrates the continued proliferation of rogue APs, which he said IT managers need to battle with strict policies. He also called on companies to institute strong authentication policies to ensure that only authorised users can gain access to wireless networks carrying sensitive business information. That's absolutely necessary, he said, for businesses such as hotels that operate both public and private WLANs in the same space.

He also said enterprises need to govern the use of WLAN client devices, which can be used in an insecure mode on home or public-access WLAN systems. He said Hilton now requires that WLAN clients, such as cards in laptop computers, be disabled when the laptop is connected to the wired enterprise LAN to prevent injection of Trojan horses picked up when the laptop was hooked up to a home network.

Joe Przeporia, an IT manager at Cargill in Wayzatya, Minnesota, said his company's many business units, including manufacturing plants, use such a variety of WLAN and fixed wireless technologies "that we are not [yet] equipped with it at a corporate level." But, Przeporia said, Cargill has started to develop high-level corporate policies to deal with WLAN security, including rogue access points.

Overall, WLAN use and security policies will remain a paramount concern for business as high-speed, over-the-air network systems continue to gain market share. Gartner (US) estimates that sales of WLAN chip sets (used in both APs and client devices) totalled 18 million units in 2002, and it predicts that sales will hit 50 million units by 2006.

Richard Stone, mobility solutions manager for the HP Americas division of Hewlett-Packard, said his company has scrambled to come up with policies governing the use of HP wireless networks by guests visiting company facilities. The policy includes subjecting guest users on HP WLAN networks to the same Internet filtering policies applied to HP users for "moral and legal reasons."

Allan Thompson, CEO of Senforce Technologies, said his company has developed "location-aware" security software that automatically configures security settings to protect wireless PC users from unauthorised access to vulnerable, confidential data on mobile devices when they use public-access WLAN "hot spots."

Dave Sankey, director for process and technology development at Sears, Roebuck and Co., said his company has added software to the 10,000 WLAN-equipped notebook computers it has fielded to its service technicians that blocks them from using public-access hot spots. Sankey said Sears intends to install private hot spots at company stores and facilities so technicians can access training materials.