December 07,2016.
According to ISP, Tel Aviv, Israel Dotcom-Monitor server is under DDOS attack. We’re working with ISP on resolution.
As attacks are not constant, location can be online periodically and can provide failures in monitoring. We would recommend to exclude it from devices till the issue is resolved.
Check wiki articles below for editing locations for device(s):
https://www.dotcom-monitor.com/wiki/device-manager/editing-locations-for-multiple-devices-at-once/
https://www.dotcom-monitor.com/wiki/getting-started/setting-up-monitoring-agent-locations/