A system for mirroring dropped packets by extending port mirroring. Networking devices, such as firewalls and routers drop some packets during data transmission due to various security issues, congestion and errors in the packets. The dropped packets are mirrored at a user-specified destination port by extending port mirroring. The mirrored packets can then be further analyzed by external traffic analyzers. The analysis can be helpful in finding out any mismatch between firewall rules and security policies at firewalls. Moreover, the analysis can also be helpful in finding out the extent of loss of useful data in dropped packets at forwarding devices such as routers, bridges, switches, firewalls etc.