I tried setting up Ignition with Docker as described in the IU session:

Elective Studies, Ignition with Docker, Creating a Testing Environment, Adding Ignition Gateways.

This worked fine when I followed the example and used Ignition 8.21. If I try to use 8.3 however, the gateway network does not connect.

Not sure where to work this out, somehow I ended up posting about it here.