Mediatrace: A New Traceroute tool IOS 15.1(3)T

The classic traceroute tool has become an essential tool for network engineers. Traceroute is able to discover layer-3 nodes (routers) along the path towards a destination. This information provides operators with visibility about the path towards a destination.

However, there are limitations to traceroute such as issues with traceroute following the right path (as it’s IP source address might be different), no layer-2 (switches and bridges) discovery and really only a single piece of information is returned (IP address of the router).

With mediatrace, which shares the IP header of the flow you would like to trace, you can have much better path congruency—and confidence in the discovery. The mediatrace will also not only discover the routers (as with traceroute), but also switches that are only doing layer 2 forwarding.

Mediatrace does not need to be enabled on every hop. If it is not enabled on node, the mediatrace packet will simply be forwarded through that part of the network. This is exactly what would happen in the case of your traditional MPLS-VPN network.

Figure 1. Mediatrace tracing a flow while the operator chillaxes

Now for the best part! Mediatrace can dynamically engage the performance monitor feature we talked about a few weeks ago. This allows a dynamic surgical monitoring policy to be applied for the flow we are tracing that results in hop by hop performance measurements such as loss and jitter. As is the case with all mediatrace runs, the information is brought back into a single report where it can be quickly analyzed.

Figure 2. Mediatrace integration with performance monitor

Despite the name, mediatrace is not only for voice/video flows. It is able to trace any IP flow, and is even able to engage performance monitor to gather hop by hop TCP stats.

Mediatrace is a new tool that cisco released in IOS 15.1(3)T  for the ISR platforms as part of the medianet program.  Over the course of 2011, this feature will proliferate across cisco’s enterprise line of routers and switches.

Mediatrace Configuration Guide
http://www.cisco.com/en/US/docs/ios/media_monitoring/configuration/guide/mm_mediatrace.html