u/Scienceman57

Edit: Solved! The bottleneck was Docker NAT.

It was my (very limited) understanding that IPv4 vs IPv6 has a limited performance impact in a LAN. So I am a little suprised at why I see a 15% performance uplift in one direction on my self hosted speed test. The server end of the connection is a cheap USB 2.5 GbE NIC which has been struggling to reach full upload speed in this particular test. Is it possible that the IPv6 path is more optimized on this dongle or would it be more related to this particular speedtest software (openspeedtest in docker).