> My claim that this website’s traceroute was the path your packets took to reach my server was a bit of a white lie. To calculate that, I would’ve had to be ab

> My claim that this website’s traceroute was the path your packets took to reach my server was a bit of a white lie. To calculate that, I would’ve had to be able to run a traceroute to my server from your computer. Instead, I ran the traceroute from my server to your computer and just reversed it. That’s also why the traceroute at the top seemingly loads in reverse order. I was wondering if we'd address this. That was my first thought - how can you do this without initiating ICMP from my side? > Does running a “reverse traceroute” sacrifice accuracy? A little, actually. > As I said when describing Internet routing, each device a packet traverses makes a decision about where to send the packet next until it reaches its final destination. If you send a packet in the other direction, the devices might make different routing decisions… and if one device makes one different decision, the rest of the path will certainly be different. > This reverse traceroute is still helpful. The paths will be roughly the same, likely differing only in terms of which specific routers see your packet. Sure... But it's pretty common for multi pathed AS' to traverse in all sorts of different ways. My experience (non residential) is that more often than not, the trace and reverse trace were different. Your upstreams and my upstreams have very different commercial agreements, and both peer and transit in multiple places. Still cool though, well done!