Corporate wireless LAN security 802.11 Wireless Local Area Network(WLAN have the ability to transmit data frames at one of four transmission rates lMb/s, 2Mb/s, 5. 5Mb/s and 1 lMb/s"( Sheu et al., 2003) Each transmission rate is dant on which version of 802. 11 the system is Wireless LANS are not competing with traditional Ethernet LANS. They are used to extend the existing corporate network to mobile clients. Therefore, if the security is lax on a company's wireless LAN, it compromises the security of the wired LaN Figure 2 shows how the wireless network connects to the existing wired LAn using an access point Figure 2 Wireless LAN extending Ethernet LAN Wireless LAN Ethernet LAN Mobile Client Authenticate adio trane ohr Mobil 3 Threats and attacks in corporate wireless LaN Wireless lans have the same risks and vulnerabilities that exist in a conventional wired network. There are numerous other types of Wlan threats and attacks that need to be aken into consideration if a WLan is to be kept free of hackers and crackers. Some of these threats and attacks are passive attacks, active attacks, loss of confidentiality, loss of integrity and loss of network availability 3. Passive attacks a passive attack occurs when an unauthorised party gains access within the network but does not modify the content. There are two types of passive attacks: eavesdropping and traffic analysis or monitoring Eavesdropping is when an attacker, usually from within the perimeter of the business, monitors transmissions for message content by listening to the transmission between two workstations. Nothing is touched physically, but information and privacy is invaded. On the other hand, traffic analysis is typically performed by an intruder that is outside the perimeter of the business, monitoring the transmissions for patterns of coCorporate wireless LAN security 269 802.11 Wireless Local Area Network (WLAN) have the ability to transmit data frames at one of four transmission rates 1Mb/s, 2Mb/s, 5.5Mb/s and 11Mb/s” (Sheu et al., 2003). Each transmission rate is dependant on which version of 802.11 the system is using. Wireless LANs are not competing with traditional Ethernet LANs. They are used to extend the existing corporate network to mobile clients. Therefore, if the security is lax on a company’s wireless LAN, it compromises the security of the wired LAN. Figure 2 shows how the wireless network connects to the existing wired LAN using an access point. Figure 2 Wireless LAN extending Ethernet LAN 3 Threats and attacks in corporate wireless LAN Wireless LANs have the same risks and vulnerabilities that exist in a conventional wired network. There are numerous other types of WLAN threats and attacks that need to be taken into consideration if a WLAN is to be kept free of hackers and crackers. Some of these threats and attacks are passive attacks, active attacks, loss of confidentiality, loss of integrity and loss of network availability. 3.1 Passive attacks A passive attack occurs when an unauthorised party gains access within the network but does not modify the content. There are two types of passive attacks: eavesdropping and traffic analysis or monitoring. Eavesdropping is when an attacker, usually from within the perimeter of the business, monitors transmissions for message content by listening to the transmission between two workstations. Nothing is touched physically, but information and privacy is invaded. On the other hand, traffic analysis is typically performed by an intruder that is outside the perimeter of the business, monitoring the transmissions for patterns of communication