Private network
lastmod 2026-08-23created 2020-07-224 edits
A private network is a network that uses private IP address space in the Internet addressing architecture, conforming to the RFC 1918 and RFC 4193 standards. These addresses are used in home, office, and enterprise LANs.
Private IPv4 address space
The Internet Engineering Task Force (IETF) has directed IANA (the Internet Assigned Numbers Authority) to reserve the following IPv4 address ranges for private networks, as published in RFC 1918.
| RFC1918 name | IP address range | Number of addresses | Network class description | Largest CIDR block (subnet mask) | Host ID size |
| 24-bit block | 10.0.0.0 – 10.255.255.255 | 16,777,216 | Single class A | 10.0.0.0/8 (255.0.0.0) | 24 bits |
| 20-bit block | 172.16.0.0 – 172.31.255.255 | 1,048,576 | 16 contiguous class Bs | 172.16.0.0/12 (255.240.0.0) | 20 bits |
| 16-bit block | 192.168.0.0 – 192.168.255.255 | 65,536 | 256 contiguous class Cs | 192.168.0.0/16 (255.255.0.0) | 16 bits |