The document proposes a scheme called Link Scanner (LS) for detecting faulty links in wireless sensor networks. LS operates passively by collecting hop count data from probe flooding processes. It analyzes mismatches between expected and received hop counts to infer which links may be faulty. Having a blacklist of potential faulty links allows further analysis and recovery, including adjusting routing strategies, identifying root causes of observed network issues, and providing spare link options. The scheme aims to not only detect currently faulty links but also evaluate unused links, to help guide rerouting for better performance. It was tested on a 60-node sensor network and in simulation and found to accurately detect faulty links with low overhead.