IPv4 Subnet Mask Cheat Sheet


HostsNetmaskAmount of a Class C
/312255.255.255.2541/128
/304255.255.255.2521/64
/298255.255.255.2481/32
/2816255.255.255.2401/16
/2732255.255.255.2241/8
/2664255.255.255.1921/4
/25128255.255.255.1281/2
/24256255.255.255.01
/23512255.255.254.02
/221024255.255.252.04
/212048255.255.248.08
/204096255.255.240.016
/198192255.255.224.032
/1816384255.255.192.064
/1732768255.255.128.0128
/1665536255.255.0.0256
/15131072255.254.0.0512
/14262144255.252.0.01024
/13524288255.248.0.02048
/121048576255.240.0.04096
/112097152255.224.0.08192
/104194304255.192.0.016384
/98388608255.128.0.032768
/816777216255.0.0.065536

Guide to IPv4 subnets

/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

IPv6 Subnet Cheat Sheet


IPv6 is a complete and different animal as far as subnetting goes. Please note the yellow rows as
each has special common use or notes. If there is nothing in the "Amount of a /64" column that means
it is to miniscule or to massive to justify calculation. Not much is the same with IPv6 compared to IPv4.
Route aggregation and purpose drive subnetting is something which every enterprise IPv6 deployment will make
use of, or it will fail miserably. As I put together more resources I will link them on the main site here


SubnetHostsAmount of a /64
/1281
/1272
/1264
/1258
/12416
/12332
/12264
/121128
/120256
/119512
/1181,024
/1172,048
/1164,096
/1158,192
/11416,384
/11332,768
/11265,536
/111131,072
/110262,144
/109524,288
/1081,048,576
/1072,097,152
/1064,194,304
/1058,388,608
/10416,777,216
/10333,554,432
/10267,108,864
/101134,217,728
/100268,435,456
/99536,870,912
/981,073,741,824
/972,147,483,648
/964,294,967,296This is equivalent to an IPv4 Internet or IPv4 /8
/958,589,934,592
/9417,179,869,184
/9334,359,738,368
/9268,719,476,736
/91137,438,953,472
/90274,877,906,944
/89549,755,813,888
/881,099,511,627,776
/872,199,023,255,5521/8,388,608
/864,398,046,511,1041/4,194,304
/858,796,093,022,2081/2,097,152
/8417,592,186,044,4161/1,048,576
/8335,184,372,088,8321/524,288
/8270,368,744,177,6641/262,144
/81140,737,488,355,3281/131,072
/80281,474,976,710,6561/65,536
/79562,949,953,421,3121/32,768
/781,125,899,906,842,6201/16,384
/772,251,799,813,685,2401/8,192
/764,503,599,627,370,4901/4,096
/759,007,199,254,740,9901/2,048
/7418,014,398,509,481,9001/1,024
/7336,028,797,018,963,9001/512
/7272,057,594,037,927,9001/256
/71144,115,188,075,855,0001/128
/70288,230,376,151,711,0001/64
/69576,460,752,303,423,0001/32
/681,152,921,504,606,840,0001/16
/672,305,843,009,213,690,0001/8
/664,611,686,018,427,380,0001/4
/659,223,372,036,854,770,0001/2
/6418,446,744,073,709,500,000This is the standard end user allocation
/6336,893,488,147,419,100,0002
/6273,786,976,294,838,200,0004
/61147,573,952,589,676,000,0008
/60295,147,905,179,352,000,00016
/59590,295,810,358,705,000,00032
/581,180,591,620,717,410,000,00064
/572,361,183,241,434,820,000,000128
/564,722,366,482,869,640,000,000256
/559,444,732,965,739,290,000,000512
/5418,889,465,931,478,500,000,0001,024
/5337,778,931,862,957,100,000,0002,048
/5275,557,863,725,914,300,000,0004,096
/51151,115,727,451,828,000,000,0008,192
/50302,231,454,903,657,000,000,00016,384
/49604,462,909,807,314,000,000,00032,768
/481,208,925,819,614,620,000,000,00065,536 This is the standard business allocation
/472,417,851,639,229,250,000,000,000131,072
/464,835,703,278,458,510,000,000,000262,144
/459,671,406,556,917,030,000,000,000524,288
/4419,342,813,113,834,000,000,000,0001,048,576
/4338,685,626,227,668,100,000,000,0002,097,152
/4277,371,252,455,336,200,000,000,0004,194,304
/41154,742,504,910,672,000,000,000,0008,388,608
/40309,485,009,821,345,000,000,000,00016,777,216
/39618,970,019,642,690,000,000,000,00033,554,432
/381,237,940,039,285,380,000,000,000,00067,108,864
/372,475,880,078,570,760,000,000,000,000134,217,728
/364,951,760,157,141,520,000,000,000,000268,435,456
/359,903,520,314,283,040,000,000,000,000536,870,912
/3419,807,040,628,566,000,000,000,000,0001,073,741,824
/3339,614,081,257,132,100,000,000,000,0002,147,483,648
/3279,228,162,514,264,300,000,000,000,0004,294,967,296 This is the standard ISP Allocation
/31158,456,325,028,528,000,000,000,000,0008,589,934,592
/30316,912,650,057,057,000,000,000,000,00017,179,869,184
/29633,825,300,114,114,000,000,000,000,00034,359,738,368
/281,267,650,600,228,220,000,000,000,000,00068,719,476,736
/272,535,301,200,456,450,000,000,000,000,000
/265,070,602,400,912,910,000,000,000,000,000
/2510,141,204,801,825,800,000,000,000,000,000
/2420,282,409,603,651,600,000,000,000,000,000
/2340,564,819,207,303,300,000,000,000,000,000
/2281,129,638,414,606,600,000,000,000,000,000
/21162,259,276,829,213,000,000,000,000,000,000
/20324,518,553,658,426,000,000,000,000,000,000
/19649,037,107,316,853,000,000,000,000,000,000
/181,298,074,214,633,700,000,000,000,000,000,000
/172,596,148,429,267,410,000,000,000,000,000,000
/165,192,296,858,534,820,000,000,000,000,000,000
/1510,384,593,717,069,600,000,000,000,000,000,000
/1420,769,187,434,139,300,000,000,000,000,000,000
/1341,538,374,868,278,600,000,000,000,000,000,000
/1283,076,749,736,557,200,000,000,000,000,000,000
/11166,153,499,473,114,000,000,000,000,000,000,000
/10332,306,998,946,228,000,000,000,000,000,000,000
/9664,613,997,892,457,000,000,000,000,000,000,000
/81,329,227,995,784,910,000,000,000,000,000,000,000