IPv4 Subnet Cheat Sheet



128  64  32  16  8  4  2  1

1    128    10000000
2    192    11000000
3    224    11100000
4    240    11110000
5    248    11111000
6    252    11111100
7    254    11111110
8    255    11111111

CIRD to DDN
/12     8.4.0.0    255.240.0.0
/20     8.8.4.0    255.255.240.0
/28     8.8.8.4    255.255.255.240 

Private IP ranges
Class    Range of IPs                  Default CIRD
A        10.0.0.1 - 10.255.255.254      /8
B        172.16.0.1 - 172.31.255.254    /16
C        192.168.0.1 - 192.168.255.254  /24

CIDR   Subnet Mask          Total IPs
/32    255.255.255.255              1
/31    255.255.255.254              2
/30    255.255.255.252              4
/29    255.255.255.248              8
/28    255.255.255.240             16
/27    255.255.255.224             32
/26    255.255.255.192             64
/25    255.255.255.128            128
/24    255.255.255.0              256
/23    255.255.254.0              512
/22    255.255.252.0             1024
/21    255.255.248.0             2048
/20    255.255.240.0             4096
/19    255.255.224.0             8192
/18    255.255.192.0           16,384
/17    255.255.128.0           32,768
/16    255.255.0.0             65,536
/15    255.254.0.0            131,072
/14    255.252.0.0            262,144
/13    255.248.0.0            524,288
/12    255.240.0.0          1,048,576
/11    255.224.0.0          2,097,152
/10    255.192.0.0          4,194,304
/9     255.128.0.0          8,388,608
/8     255.0.0.0           16,777,216
/7     254.0.0.0           33,554,432
/6     252.0.0.0           67,108,864
/5     248.0.0.0          134,217,728
/4     240.0.0.0          268,435,456
/3     224.0.0.0          536,870,912
/2     192.0.0.0        1,073,741,824
/1     128.0.0.0        2,147,483,648



Published by

Ferdy Mañago

Portland, Oregon