I moved a Docker container to a different Linux box and it couldn’t work. I eventually determined ffmpeg was failing with an rtsp authorization. It ran fine on the previous Linux box. After much futzing around the only difference I could find was the Linux machine it failed on used a network bridge. I deleted the bridge (easy) but the ethernet port stayed disconnected. Thirty minutes later I found how to fix that and voila ffmepg works. No idea why a bridge would break it’s rstp auth. 😖