Free download · PDF
The subnetting cheat sheet
Two A4 pages with everything you look up when planning or troubleshooting an IP network. Print it, pin it, or keep it open beside your design.
- Every IPv4 prefix from /8 to /32: mask, wildcard, addresses, usable hosts and block size
- Private, CGNAT, documentation and other special ranges
- A four-step method to subnet any address, with a worked example
- Sizing for N hosts, VLSM planning and route summarisation
- IPv6 prefix sizes, address types and how to write addresses
