Reverse Traceroute

Rolf Winter rolf.winter at
Wed Feb 22 12:41:21 UTC 2023

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,

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