Reverse Traceroute

Christopher Morrow morrowc.lists at
Wed Feb 22 17:19:52 UTC 2023

Didn't ethan's project:

end with usable code/etc?

On Wed, Feb 22, 2023 at 8:09 AM Rolf Winter <rolf.winter at> wrote:
> Dear NANOG folks,
> As you know, traceroute is unable to enumerate routers on the reverse
> path. Given that paths through the public internet are usually
> asymmetric, knowing the reverse path would be beneficial e.g. for
> troubleshooting purposes (
> We have implemented a reverse traceroute tool
> (, both client and server
> for both IPv4 and IPv6. We are also in the process of specifying the
> protocol at the IETF
> (
> We also gave a talk on reverse traceroute at DENOG14
> (
> If you would like to play with reverse traceroute, the easiest option is
> to work with the client and use one of the public server instances
> ( If
> you would be willing to host a public server instance yourself, please
> reach out to us. Also, if you find this work useful, please start
> discussing the work at the IntArea WG at the IETF.
> If you have any questions or comments, just drop us a line, file an
> issue on github and/or use the IntArea mailing list.
> Thanks a bunch,
> Rolf

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