SubnetOnline

SubnetOnline’s IP calculator takes an IPv4 address and dotted-decimal mask and returns the network, broadcast, host range and address sizes. Use that arithmetic to plan an allocation, then choose a separate connectivity tool when the question concerns a reachable host. The suite separates IPv4 and IPv6 calculators, conversions, DNS and remote probes. An address falling inside a calculated subnet does not establish that a device exists or that its service is reachable. Keep provider-origin ping or traceroute observations separate from local network conditions; this is a collection of tools with different inputs and viewpoints.