If you want to monitor sites, DNS fo rmultiple sites and even set up failover so never down again get DNSMAdeEasy and run it on a home computer to monitor all your sites. Youll need a server or more somewhere else than the servers you are monitoring and a machine to run the monitor on but worth it.
If ip goes down, check however many minutes you set, it will dynamically switch DNS to elsewhere where you have a backup or even just a splash page set up explaining the problem

For $89 per license is worth ever penny, Im in process of setting up the secondary reuirements now, like the server elsewhere form my datacenter