Comparison between DHCP-based and IEEE 802.1x Network Access Control Mechanisms

摘要

IEEE 802.11 Wireless Local Area Networks (WLANs) have been widely deployed in various "hotspots" with reduced time and cost of wiring. However, the current standard is known to lack any useful security mechanism. Therefore, IEEE 802.1 x aims to provide port-based network access control when used in conjunction with 802.11 and other IEEE 802 media. But two security problems, namely, session hijacking and man-in-the-middle attack, are found to be possible in 802.1 x and its combination with 802.11. In this paper, a DHCP (Dynamic Host Configuration Protocol) -based infrastructure for network access control was proposed. Through the enforcement of new DHCP options such as DHCP reconfigure extension, the resource allocation function of DHCP mechanism and the packet filtering feature of MAC (Medium Access Control) bridges such as Ethernet switches and wireless LAN access points can be integrated with minimum overhead. Comparison was also made between DHCP-based and IEEE 802.1 x network access control mechanisms.