When the recorder fails to find the camera, working through this list covers almost every case.

1. Same subnet? The recorder and camera defaults must sit on the same subnet (for example both 192.168.1.x). Across subnets the device simply is not discoverable without routing or re-addressing.
2. Cable and power: check the link LEDs on the switch and the device. No LED means fix the physical link first.
3. IP conflict: two devices on the same address knock each other offline, which shows up as intermittent discovery. Use the search tool to re-address them and avoid hand-allocating duplicates.
4. Protocol and credentials: third-party devices need ONVIF enabled on the camera and manual addition on the recorder, with correct credentials. Repeated wrong passwords can trigger a temporary lockout.
5. Port isolation: port isolation or VLAN segmentation on some switches blocks cross-port traffic. Disable isolation or place the devices in the same VLAN.

A useful pattern: if the vendor tool sees the camera but the recorder does not, suspect protocol or credentials. If neither sees it, suspect subnet, link or isolation.