Monitoring constrained, low power and lossy networks is essential to many operations including troubleshooting, forensics, performance management. The main challenge for the monitoring plane in these networks is to efficiently cope with both frequently changing topologies and constrained resources. We present a novel algorithm and the supporting framework that improves a poller-pollee based architecture. We empower the poller-pollee placement decision process and operation by exploiting available routing data to monitor nodes status. In addition, monitoring data is efficiently embedded in any messages flowing through the network, drastically reducing monitoring overhead. Our approach is validated through both simulation, implementation and deployment on a 6LoWPAN-enabled network. Results demonstrate that our approach is less aggressive and less resource consuming than its competitors.