In this chapter, you saw how to troubleshoot problems in the forwarding or data path of MPLS networks. Tools such as the well-known traceroute and ping are useful in pinpointing a problem, but you must be aware how to use them and how to interpret the data. This chapter reviewed specific MPLS commands that have a relationship with tracerouting. It covered other typical MPLS issues, such as MTU problems and load balancing of labeled packets. Finally, it explained MPLS-aware Netflow and indicated how it could help you in troubleshooting certain forwarding problems. Chapter 14 covers MPLS operation and maintenance (OAM)-specific tools that you can use to troubleshoot problems in the MPLS network.