Note: This article was originally published in 2011. Some steps, commands, or software versions may have changed. Check the current Infrastructure documentation for the latest information.
The reserved IP ranges for private networks are the following:
- 10.0.0.1/8 through 10.255.255.254/8
- 172.16.0.1/12 through 172.31.255.254/12
- 192.168.0.1/16 through 192.168.255.254/16
| This information is very useful specially when working with routing tables as you may want to know what subnet mask to use when and the size of your private network based on its address class, etc. Below is a little table with more information on the network prefixes and what is the default length of the subnet / mask to better aid you: Network Prefix Length Subnet Masking Address Class | Subnet Mask in Binary | Network Prefix with Decimal Equivalent |
|---|---|---|
| Class A | **11111111 **00000000 00000000 00000000 | /8 = 255.0.0.0 |
| Class B | **11111111 11111111 **00000000 00000000 | /16 = 255.255.0.0 |
| Class C | **11111111 11111111 11111111 **00000000 | /24 = 255.255.255.0 |