There AND back - designing reverse traceroute

Rolf Winter

Playlists: 'denog14' videos starting here / audio

There are very few troubleshooting tools that work across the public internet reasonably reliably. Well, it really boils down to Ping and Traceroute. Of those two, the latter is sometimes referred to as the "the number one go-to tool" for troubleshooting problems on the internet [1]. That is not, because it provides all the information we need or would like to have but at least, for the most part, it is universally supported. Traceroute is however missing one important piece of information, and that is information about the return path, i.e. the path from the target towards the host that initiated the traceroute. In this talk, we look at why this would be useful, what people have worked on in the past to implement a reverse traceroute tool and recent work in the IETF that aims at defining a standard protocol for reverse traceroute [2].