Using link RTT to passively detect unapproved wireless nodes

Rogue Access Points (APs) produce security vulnerabilities in enterprise/campus networks by circumventing security mechanisms. We propose to use network traffic Round Trip Time (RTT) coupled with standard wireless network policies to distinguish between wired nodes, authorised APs, and rogue APs. Further, this approach has the following advantages: independent of wireless technology (802.11a/b/g); resilient to increases in capacity for wired and wireless links; scalable; resilient to effects of multiple hops; independent of rouge AP signal range. Our experimental results show that we can quickly classify the nodes as wired or wireless with 80-100% accuracy.