The Tapo C200 cameras insist on contacting public NTP servers to sync their clock. If you block them from reaching the Internet (a good idea for security), the cameras will slowly drift out of sync because they ignore the DHCP-provided NTP option. The solution is simple: run an NTP server on your OpenWrt router and transparently redirect the cameras’ NTP traffic to it. Step 1 — Enable NTP on OpenWrt Make sure your router itself syncs time and provides it to LAN devices. ...