CIDR Trainer

CIDR Trainer trains users to perform network subnet calculations. It uses directed training drills while providing documentation to instruct users to perform each step of network subnetting calculations. CIDR Trainer includes IPv4 and IPv6 CIDR calculators. Version 1.1 includes the following categories of drills: 1-digit hexadecimal and binary drills 2-digit hexadecimal and binary drills IPv4 terminology drills IPv4 prefix-length drills IPv4 CIDR drills IPv6 Address Shortening and Lengthening Drills IPv6 Terminology Drills IPv6 CIDR Drills IPv4 and IPv6 CIDR Calculators You may try each training drill for free 20 times. After that you may try the other drills or purchase a permanent unlock of all training drills for a low price (see in-app purchases for the "forever full-unlock" price in your region). One purchase unlocks all versions of the app (iOS, iPadOS, and MacOS). CIDR Trainer uses iCloud to sync drill progress between your devices. Each training drill has a "help" button in the top-right which provides related documentation Full list of drills: (you may try them in any order) 1-digit hex -> decimal 1-digit decimal -> hex 1-digit hex -> binary Binary -> 1-digit hex 4-digit binary -> decimal Decimal -> 4-digit binary 1-bit AND 2-digit hexadecimal -> decimal (easy multiples of 16) Decimal -> 2-digit hexadecimal (easy multiples of 16) 2-digit hexadecimal -> binary binary -> 2-digit hexadecimal 2-digit hexadecimal -> decimal Decimal -> 2-digit hexadecimal 8-digit binary -> decimal Decimal -> 8-digit binary 8-bit AND Valid IPv4 address recognition IPv4 address types IPv4 prefix-length to binary netmask IPv4 binary netmask to prefix-length IPv4 prefix-length to hexadecimal netmask IPv4 hexadecimal netmask to prefix-length IPv4 prefix-length to dotted-decimal netmask IPv4 dotted-decimal netmask to prefix-length IPv4 CIDR Drills: Number of IPs in a CIDR Number of usable unicast IPs in a CIDR CIDR to network address in binary CIDR to network address in decimal Well-formed CIDR to broadcast address Well-formed CIDR to first usable IP address Well-formed CIDR to last usable IP address IPv6 Address Shortening and Lengthening Drills: IPv6 Hextet Shortening IPv6 Hextet Lengthening IPv6 Eight Hextet Shortening IPv6 Eight Hextet Lengthening IPv6 Double Colon Shortening IPv6 Double Colon Lengthening IPv6 Address Shortening IPv6 Address Lengthening IPv6 Address Types Valid IPv6 Sextets Valid IPv6 Addresses IPv6 CIDR (prefix / 16) drill IPv6 CIDR (prefix / 4) drill IPv6 CIDR (any prefix) drill IPv4 CIDR Calculator IPv6 CIDR Calculator