RFC 1918 Private IP Ranges
The three private IPv4 address blocks and their common uses.
RFC 1918 reserves three blocks of IPv4 address space for private internets: 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. Addresses in these ranges are not routable on the public internet and can be used freely inside any organization.
Choosing the right block depends on scale. The 10.0.0.0/8 range offers over 16 million addresses and is the standard choice for enterprise networks; 172.16.0.0/12 is common in mid-size networks and is the default for AWS VPCs; 192.168.0.0/16 is the familiar choice for SMB, branch, and home networks.
| CIDR | Range Start | Range End | Hosts | Common Use |
|---|---|---|---|---|
| 10.0.0.0/8 | 10.0.0.0 | 10.255.255.255 | 16,777,216 | Large enterprise networks |
| 172.16.0.0/12 | 172.16.0.0 | 172.31.255.255 | 1,048,576 | Mid-size networks, AWS VPC default |
| 192.168.0.0/16 | 192.168.0.0 | 192.168.255.255 | 65,536 | SMB, home networks, branch offices |
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