A hobby project by Andree Toonk (LinkedIn).
I have spent my career around Internet infrastructure, and I enjoy measuring it. This site is where that hobby lives: it continuously measures how much of the IPv4 Internet answers, country by country and network by network, and shows where that changes. Most days the map is boring. On the days it is not, you can watch a country, a city or an operator drop off and come back, minute by minute.
Everything on the site comes from lightweight, continuous measurements that the project makes itself, so what you see is what was actually observed, not an inference from someone else's data.
The responding counts are estimates of how many addresses answer, and they move with the time of day: offices and campuses switch on in the morning and off at night. An outage advisory means a place or a network lost at least half of its reachability for five consecutive minutes; the bar is deliberately high, so if something appears in the list it is significant. Every time on the site is UTC.