The ping tool in Cisco IOS provides a few features that can help with troubleshooting:
Attaching an IP option
Specifying the MTU
With ping, you can specify to add an IP option such as timestamp or record route to the packet. If you add an IP option, all intermediate routers have to process-switch the IP packet. This can exclude problems in the fast path forwarding (CEF). Because ping allows you to specify the MTU value as the size of the packet, you debug certain MTU problems that might exist in the MPLS cloud. Ping lets you sweep, or use a variable packet size for the ping. You can specify a range of packet sizes and see which sized ping is lost.