IPGadget is a small calculator for verifying IPv4 address information. IPGadget is particularly useful when designing IPv4 networks. The prefix-size popup menu makes it easy to verify route aggregation or summarization masks, and the stepper quickly recalculates the address field for the next or previous subnet in sequence. You choose whether to impose classful or classless rules. For example, sometimes it\'s simpler to skip all-zeroes or all-ones subnets rather than waste time explaining Classless Inter-Domain Routing (CIDR) to people who should know better. Alternatively, if legacy devices in your network preclude you from using CIDR, IPGadget\'s online help includes an example explaining the classic rules. IPGadget also provides a handy reference to address-class ranges, the ranges reserved for use in private LANs, and the link-local range.Here are some key features of \"IPGadget\":