IP Subnet Cheet Sheet

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Below you will find a simple table of the most commonly used networks and netmask's. Further down you will find more detailed tables.
Cidr Hosts Netmask Subnets
/30    4    255.255.255.252    64
/29    8    255.255.255.248    32
/28    16    255.255.255.240    16
/27    32    255.255.255.224    8
/26    64    255.255.255.192    4
/25    128    255.255.255.128    2
/24    256    255.255.255.0    1
/23    512    255.255.254.0    2
/22    1024    255.255.252.0    4
/21    2048    255.255.248.0    8
/20    4096    255.255.240.0    16
/19    8192    255.255.224.0    32
/18    16384    255.255.192.0    64
/17    32768    255.255.128.0    128
/16    65536    255.255.0.0    256
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Guide to sub-class C blocks

/25 -- 2 Subnets -- 126 Hosts/Subnet
Network #IP RangeBroadcast
.0.1-.126.127
.128.129-.254.255
/30 -- 64 Subnets -- 2 Hosts/Subnet
Network #IP RangeBroadcast
.0.1-.2.3
.4.5-.6.7
.8.9-.10.11
.12.13-.14.15
.16.17-.18.19
.20.21-.22.23
.24.25-.26.27
.28.29-.30.31
.32.33-.34.35
.36.37-.38.39
.40.41-.42.43
.44.45-.46.47
.48.49-.50.51
.52.53-.54.55
.56.57-.58.59
.60.61-.62.63
.64.65-.66.67
.68.69-.70.71
.72.73-.74.75
.76.77-.78.79
.80.81-.82.83
.84.85-.86.87
.88.89-.90.91
.92.93-.94.95
.96.97-.98.99
.100.101-.102.103
.104.105-.106.107
.108.109-.110.111
.112.113-.114.115
.116.117-.118.119
.120.121-.122.123
.124.125-.126.127
.128.129-.130.131
.132.133-.134.135
.136.137-.138.139
.140.141-.142.143
.144.145-.146.147
.148.149-.150.151
.152.153-.154.155
.156.157-.158.159
.160.161-.162.163
.164.165-.166.167
.168.169-.170.171
.172.173-.174.175
.176.177-.178.179
.180.181-.182.183
.184.185-.186.187
.188.189-.190.191
.192.193-.194.195
.196.197-.198.199
.200.201-.202.203
.204.205-.206.207
.208.209-.210.211
.212.213-.214.215
.216.217-.218.219
.220.221-.222.223
.224.225-.226.227
.228.229-.230.231
.232.233-.234.235
.236.237-.238.239
.240.241-.242.243
.244.245-.246.247
.248.249-.250.251
.252.253-.254.255
/26 -- 4 Subnets -- 62 Hosts/Subnet
Network #IP RangeBroadcast
.0.1-.62.63
.64.65-.126.127
.128.129-.190.191
.192.193-.254.255
/27 -- 8 Subnets -- 30 Hosts/Subnet
Network #IP RangeBroadcast
.0.1-.30.31
.32.33-.62.63
.64.65-.94.95
.96.97-.126.127
.128.129-.158.159
.160.161-.190.191
.192.193-.222.223
.224.225-.254.255
/28 -- 16 Subnets -- 14 Hosts/Subnet
Network #IP RangeBroadcast
.0.1-.14.15
.16.17-.30.31
.32.33-.46.47
.48.49-.62.63
.64.65-.78.79
.80.81-.94.95
.96.97-.110.111
.112.113-.126.127
.128.129-.142.143
.144.145-.158.159
.160.161-.174.175
.176.177-.190.191
.192.193-.206.207
.208.209-.222.223
.224.225-.238.239
.240.241-.254.255
/29 -- 32 Subnets -- 6 Hosts/Subnet
Network #IP RangeBroadcast
.0.1-.6.7
.8.9-.14.15
.16.17-.22.23
.24.25-.30.31
.32.33-.38.39
.40.41-.46.47
.48.49-.54.55
.56.57-.62.63
.64.65-.70.71
.72.73-.78.79
.80.81-.86.87
.88.89-.94.95
.96.97-.102.103
.104.105-.110.111
.112.113-.118.119
.120.121-.126.127
.128.129-.134.135
.136.137-.142.143
.144.145-.150.151
.152.153-.158.159
.160.161-.166.167
.168.169-.174.175
.176.177-.182.183
.184.185-.190.191
.192.193-.198.199
.200.201-.206.207
.208.209-.214.215
.216.217-.222.223
.224.225-.230.231
.232.233-.238.239
.240.241-.246.247
.248.249-.254.255
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