IPv4 Subnet Mask Cheat Sheet

AddressesNetmaskAmount 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

 

 

 

 

 

 

 

 

 

/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

 

 

 

 

 

 

 

 

 

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

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.

SubnetAddressesAmount 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
/10416,777,216This is equivalent to an IPv4 Internet or IPv4 /8
/10333,554,432
/10267,108,864
/101134,217,728
/100268,435,456
/99536,870,912
/981,073,741,824
/972,147,483,648
/964,294,967,296
/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