172.16.0.0/12 range is blocked as candidates

[daveagill]

I am creating this to mirror this issue: https://github.com/home-assistant/core/issues/143701

It would seem that because HomeAssistant uses go2rtc that when HA is hosted in the 172.16.0.0/12 range then webrtc streaming does not work and has to fall back on HLS.

This change indicates the range is blocked because of Docker.

I am not sure why that would be necessary but assuming it is: Docker uses the 172.17.0.0/16 range (by default), so I would propose a quick-fix is to block just that range rather than the whole class B private IP space (172.16.0.0/12) which is not uncommonly used in homelab setups.

[AlexxIT]

I need to test how much webrtc candidates on internal docker addresses harm the application.

I think there are fewer users of these rare IP addresses than there are Docker users.

[daveagill]

I would suggest an interim solution is to just block the Docker range (172.17.0.0/16) not the entire class B space (172.16.0.0/12).

At least this would constrain the problem down to being just a Docker issue rather than a class B private IP issue, which I believe would be more inline with the original intention of the change.

For HomeAssistant I imagine there might still be an issue if HomeAssistant is being run as a container itself but at least the interim solution would be a fix all other scenarios.