IPv4 Resource Library
Your comprehensive guide to IPv4 addressing, subnetting, transfers, and market intelligence. Educational resources for network professionals and IT decision-makers.
IP Subnet Cheat Sheet & Calculator
A comprehensive reference for IPv4 subnet sizes, masks, usable hosts, and wildcard masks. Understanding CIDR notation is essential when buying or leasing IPv4 address blocks. The /24 block (256 addresses) is the most commonly traded size on the secondary market.
| CIDR | Subnet Mask | Total IPs | Usable Hosts | Wildcard | Description |
|---|---|---|---|---|---|
| /32 | 255.255.255.255 | 1 | 1 | 0.0.0.0 | Host Route |
| /31 | 255.255.255.254 | 2 | 2 | 0.0.0.1 | Point-to-Point |
| /30 | 255.255.255.252 | 4 | 2 | 0.0.0.3 | Point-to-Point |
| /29 | 255.255.255.248 | 8 | 6 | 0.0.0.7 | Smallest Multi-Host |
| /28 | 255.255.255.240 | 16 | 14 | 0.0.0.15 | Small Office |
| /27 | 255.255.255.224 | 32 | 30 | 0.0.0.31 | Small Network |
| /26 | 255.255.255.192 | 64 | 62 | 0.0.0.63 | Medium Network |
| /25 | 255.255.255.128 | 128 | 126 | 0.0.0.127 | Large Subnet |
| /24 | 255.255.255.0 | 256 | 254 | 0.0.0.255 | Class C |
| /23 | 255.255.254.0 | 512 | 510 | 0.0.1.255 | 2x Class C |
| /22 | 255.255.252.0 | 1,024 | 1,022 | 0.0.3.255 | 4x Class C |
| /21 | 255.255.248.0 | 2,048 | 2,046 | 0.0.7.255 | 8x Class C |
| /20 | 255.255.240.0 | 4,096 | 4,094 | 0.0.15.255 | 16x Class C |
| /19 | 255.255.224.0 | 8,192 | 8,190 | 0.0.31.255 | 32x Class C |
| /18 | 255.255.192.0 | 16,384 | 16,382 | 0.0.63.255 | 64x Class C |
| /17 | 255.255.128.0 | 32,768 | 32,766 | 0.0.127.255 | 128x Class C |
| /16 | 255.255.0.0 | 65,536 | 65,534 | 0.0.255.255 | Class B |
| /15 | 255.254.0.0 | 131,072 | 131,070 | 0.1.255.255 | 2x Class B |
| /14 | 255.252.0.0 | 262,144 | 262,142 | 0.3.255.255 | 4x Class B |
| /13 | 255.248.0.0 | 524,288 | 524,286 | 0.7.255.255 | 8x Class B |
| /12 | 255.240.0.0 | 1,048,576 | 1,048,574 | 0.15.255.255 | 16x Class B |
Most Traded Block
/24 (256 IPs) is the most commonly traded block size on the IPv4 secondary market, ideal for small to medium deployments.
Minimum Transfer Size
Most RIRs require a minimum /24 block for transfers. ARIN, RIPE, and APNIC all use /24 as the minimum transferable unit.
Enterprise Blocks
Blocks /20 and larger are typically used by ISPs, cloud providers, and large enterprises. IPv4 Depot regularly handles blocks up to /12.
Need Expert Guidance?
Our team has 15+ years of experience in IPv4 address management. Let us help you navigate the market.