In general a watchdog is a piece of equipment that supervises other systems and resets them in case it detects that those systems are failing, automating the process and increasing the reliability of the system. Network Watchdog is a simple watchdog for monitoring network connectivity and power cycle a device based on ICMP ping replies.
With it’s minimal power requirements, Network Watchdog can use the controlled device’s DC Power source (between 5 and 12 volts) to function, avoiding any additional power requirements. The following is an example setup: