I have an instance of Channels DVR running in a Docker container on a small NAS server in my home. It accesses the internet through a Unifi Dream Machine Pro (UDM Pro). The threat management service on the UDM Pro has thrown several messages about outside IP addresses communicating to the channels DVR server port.
When I originally setup the Channels DVR, I was completely unaware that the default settings enable natpmp to create port forwards for outside traffic.
I’ve now disabled the “remote viewing” option in the DVR settings screen. I’m expecting that disables natpmp, and therefore eliminates the issue.
It seems that the remote viewing feature should be disabled by default, and should come with a big warning “this opens your dvr to the world, and the potential for malicious traffic. You will need to be vigilant about updating your dvr, to ensure you have the latest security patches”