Monitoring DHCP Hosts
This interface is monitoring DHCP hosts. Please consider changing the Local Broadcast Domain Hosts Identifier preference to "MAC Address".
Emergency Notifications
No recipient configured for Emergency Alerts (alerts with Emergency severity), please configure it to receive important notifications!
Host 172.20.0.2 cannot be found. Very likely it is expired and ntopng has purged it from memory. You can set purge idle timeout settings from the Preferences.