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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Prefix/120
Addresses256
/64 networksPart of one
Network
2c19:dd:d9:dd:c25:c25:94de:6100/120
First address
2c19:dd:d9:dd:c25:c25:94de:6100
Last address
2c19:dd:d9:dd:c25:c25:94de:61ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:94de:6100
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
1.6.e.d.4.9.5.2.c.0.5.2.c.0.d.d.0.0.9.d.0.0.d.d.0.0.9.1.c.2.ip6.arpa
Split into smaller subnets/128
/121 (2)/122 (4)/123 (8)/124 (16)/127 (128)/128 (256)

2c19:dd:d9:dd:c25:c25:94de:6100/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:94de:6100/1282c19:dd:d9:dd:c25:c25:94de:6100
22c19:dd:d9:dd:c25:c25:94de:6101/1282c19:dd:d9:dd:c25:c25:94de:6101
32c19:dd:d9:dd:c25:c25:94de:6102/1282c19:dd:d9:dd:c25:c25:94de:6102
42c19:dd:d9:dd:c25:c25:94de:6103/1282c19:dd:d9:dd:c25:c25:94de:6103
52c19:dd:d9:dd:c25:c25:94de:6104/1282c19:dd:d9:dd:c25:c25:94de:6104
62c19:dd:d9:dd:c25:c25:94de:6105/1282c19:dd:d9:dd:c25:c25:94de:6105
72c19:dd:d9:dd:c25:c25:94de:6106/1282c19:dd:d9:dd:c25:c25:94de:6106
82c19:dd:d9:dd:c25:c25:94de:6107/1282c19:dd:d9:dd:c25:c25:94de:6107
92c19:dd:d9:dd:c25:c25:94de:6108/1282c19:dd:d9:dd:c25:c25:94de:6108
102c19:dd:d9:dd:c25:c25:94de:6109/1282c19:dd:d9:dd:c25:c25:94de:6109
112c19:dd:d9:dd:c25:c25:94de:610a/1282c19:dd:d9:dd:c25:c25:94de:610a
122c19:dd:d9:dd:c25:c25:94de:610b/1282c19:dd:d9:dd:c25:c25:94de:610b
132c19:dd:d9:dd:c25:c25:94de:610c/1282c19:dd:d9:dd:c25:c25:94de:610c
142c19:dd:d9:dd:c25:c25:94de:610d/1282c19:dd:d9:dd:c25:c25:94de:610d
152c19:dd:d9:dd:c25:c25:94de:610e/1282c19:dd:d9:dd:c25:c25:94de:610e
162c19:dd:d9:dd:c25:c25:94de:610f/1282c19:dd:d9:dd:c25:c25:94de:610f
172c19:dd:d9:dd:c25:c25:94de:6110/1282c19:dd:d9:dd:c25:c25:94de:6110
182c19:dd:d9:dd:c25:c25:94de:6111/1282c19:dd:d9:dd:c25:c25:94de:6111
192c19:dd:d9:dd:c25:c25:94de:6112/1282c19:dd:d9:dd:c25:c25:94de:6112
202c19:dd:d9:dd:c25:c25:94de:6113/1282c19:dd:d9:dd:c25:c25:94de:6113
212c19:dd:d9:dd:c25:c25:94de:6114/1282c19:dd:d9:dd:c25:c25:94de:6114
222c19:dd:d9:dd:c25:c25:94de:6115/1282c19:dd:d9:dd:c25:c25:94de:6115
232c19:dd:d9:dd:c25:c25:94de:6116/1282c19:dd:d9:dd:c25:c25:94de:6116
242c19:dd:d9:dd:c25:c25:94de:6117/1282c19:dd:d9:dd:c25:c25:94de:6117
252c19:dd:d9:dd:c25:c25:94de:6118/1282c19:dd:d9:dd:c25:c25:94de:6118
262c19:dd:d9:dd:c25:c25:94de:6119/1282c19:dd:d9:dd:c25:c25:94de:6119
272c19:dd:d9:dd:c25:c25:94de:611a/1282c19:dd:d9:dd:c25:c25:94de:611a
282c19:dd:d9:dd:c25:c25:94de:611b/1282c19:dd:d9:dd:c25:c25:94de:611b
292c19:dd:d9:dd:c25:c25:94de:611c/1282c19:dd:d9:dd:c25:c25:94de:611c
302c19:dd:d9:dd:c25:c25:94de:611d/1282c19:dd:d9:dd:c25:c25:94de:611d
312c19:dd:d9:dd:c25:c25:94de:611e/1282c19:dd:d9:dd:c25:c25:94de:611e
322c19:dd:d9:dd:c25:c25:94de:611f/1282c19:dd:d9:dd:c25:c25:94de:611f
332c19:dd:d9:dd:c25:c25:94de:6120/1282c19:dd:d9:dd:c25:c25:94de:6120
342c19:dd:d9:dd:c25:c25:94de:6121/1282c19:dd:d9:dd:c25:c25:94de:6121
352c19:dd:d9:dd:c25:c25:94de:6122/1282c19:dd:d9:dd:c25:c25:94de:6122
362c19:dd:d9:dd:c25:c25:94de:6123/1282c19:dd:d9:dd:c25:c25:94de:6123
372c19:dd:d9:dd:c25:c25:94de:6124/1282c19:dd:d9:dd:c25:c25:94de:6124
382c19:dd:d9:dd:c25:c25:94de:6125/1282c19:dd:d9:dd:c25:c25:94de:6125
392c19:dd:d9:dd:c25:c25:94de:6126/1282c19:dd:d9:dd:c25:c25:94de:6126
402c19:dd:d9:dd:c25:c25:94de:6127/1282c19:dd:d9:dd:c25:c25:94de:6127
412c19:dd:d9:dd:c25:c25:94de:6128/1282c19:dd:d9:dd:c25:c25:94de:6128
422c19:dd:d9:dd:c25:c25:94de:6129/1282c19:dd:d9:dd:c25:c25:94de:6129
432c19:dd:d9:dd:c25:c25:94de:612a/1282c19:dd:d9:dd:c25:c25:94de:612a
442c19:dd:d9:dd:c25:c25:94de:612b/1282c19:dd:d9:dd:c25:c25:94de:612b
452c19:dd:d9:dd:c25:c25:94de:612c/1282c19:dd:d9:dd:c25:c25:94de:612c
462c19:dd:d9:dd:c25:c25:94de:612d/1282c19:dd:d9:dd:c25:c25:94de:612d
472c19:dd:d9:dd:c25:c25:94de:612e/1282c19:dd:d9:dd:c25:c25:94de:612e
482c19:dd:d9:dd:c25:c25:94de:612f/1282c19:dd:d9:dd:c25:c25:94de:612f
492c19:dd:d9:dd:c25:c25:94de:6130/1282c19:dd:d9:dd:c25:c25:94de:6130
502c19:dd:d9:dd:c25:c25:94de:6131/1282c19:dd:d9:dd:c25:c25:94de:6131
512c19:dd:d9:dd:c25:c25:94de:6132/1282c19:dd:d9:dd:c25:c25:94de:6132
522c19:dd:d9:dd:c25:c25:94de:6133/1282c19:dd:d9:dd:c25:c25:94de:6133
532c19:dd:d9:dd:c25:c25:94de:6134/1282c19:dd:d9:dd:c25:c25:94de:6134
542c19:dd:d9:dd:c25:c25:94de:6135/1282c19:dd:d9:dd:c25:c25:94de:6135
552c19:dd:d9:dd:c25:c25:94de:6136/1282c19:dd:d9:dd:c25:c25:94de:6136
562c19:dd:d9:dd:c25:c25:94de:6137/1282c19:dd:d9:dd:c25:c25:94de:6137
572c19:dd:d9:dd:c25:c25:94de:6138/1282c19:dd:d9:dd:c25:c25:94de:6138
582c19:dd:d9:dd:c25:c25:94de:6139/1282c19:dd:d9:dd:c25:c25:94de:6139
592c19:dd:d9:dd:c25:c25:94de:613a/1282c19:dd:d9:dd:c25:c25:94de:613a
602c19:dd:d9:dd:c25:c25:94de:613b/1282c19:dd:d9:dd:c25:c25:94de:613b
612c19:dd:d9:dd:c25:c25:94de:613c/1282c19:dd:d9:dd:c25:c25:94de:613c
622c19:dd:d9:dd:c25:c25:94de:613d/1282c19:dd:d9:dd:c25:c25:94de:613d
632c19:dd:d9:dd:c25:c25:94de:613e/1282c19:dd:d9:dd:c25:c25:94de:613e
642c19:dd:d9:dd:c25:c25:94de:613f/1282c19:dd:d9:dd:c25:c25:94de:613f
652c19:dd:d9:dd:c25:c25:94de:6140/1282c19:dd:d9:dd:c25:c25:94de:6140
662c19:dd:d9:dd:c25:c25:94de:6141/1282c19:dd:d9:dd:c25:c25:94de:6141
672c19:dd:d9:dd:c25:c25:94de:6142/1282c19:dd:d9:dd:c25:c25:94de:6142
682c19:dd:d9:dd:c25:c25:94de:6143/1282c19:dd:d9:dd:c25:c25:94de:6143
692c19:dd:d9:dd:c25:c25:94de:6144/1282c19:dd:d9:dd:c25:c25:94de:6144
702c19:dd:d9:dd:c25:c25:94de:6145/1282c19:dd:d9:dd:c25:c25:94de:6145
712c19:dd:d9:dd:c25:c25:94de:6146/1282c19:dd:d9:dd:c25:c25:94de:6146
722c19:dd:d9:dd:c25:c25:94de:6147/1282c19:dd:d9:dd:c25:c25:94de:6147
732c19:dd:d9:dd:c25:c25:94de:6148/1282c19:dd:d9:dd:c25:c25:94de:6148
742c19:dd:d9:dd:c25:c25:94de:6149/1282c19:dd:d9:dd:c25:c25:94de:6149
752c19:dd:d9:dd:c25:c25:94de:614a/1282c19:dd:d9:dd:c25:c25:94de:614a
762c19:dd:d9:dd:c25:c25:94de:614b/1282c19:dd:d9:dd:c25:c25:94de:614b
772c19:dd:d9:dd:c25:c25:94de:614c/1282c19:dd:d9:dd:c25:c25:94de:614c
782c19:dd:d9:dd:c25:c25:94de:614d/1282c19:dd:d9:dd:c25:c25:94de:614d
792c19:dd:d9:dd:c25:c25:94de:614e/1282c19:dd:d9:dd:c25:c25:94de:614e
802c19:dd:d9:dd:c25:c25:94de:614f/1282c19:dd:d9:dd:c25:c25:94de:614f
812c19:dd:d9:dd:c25:c25:94de:6150/1282c19:dd:d9:dd:c25:c25:94de:6150
822c19:dd:d9:dd:c25:c25:94de:6151/1282c19:dd:d9:dd:c25:c25:94de:6151
832c19:dd:d9:dd:c25:c25:94de:6152/1282c19:dd:d9:dd:c25:c25:94de:6152
842c19:dd:d9:dd:c25:c25:94de:6153/1282c19:dd:d9:dd:c25:c25:94de:6153
852c19:dd:d9:dd:c25:c25:94de:6154/1282c19:dd:d9:dd:c25:c25:94de:6154
862c19:dd:d9:dd:c25:c25:94de:6155/1282c19:dd:d9:dd:c25:c25:94de:6155
872c19:dd:d9:dd:c25:c25:94de:6156/1282c19:dd:d9:dd:c25:c25:94de:6156
882c19:dd:d9:dd:c25:c25:94de:6157/1282c19:dd:d9:dd:c25:c25:94de:6157
892c19:dd:d9:dd:c25:c25:94de:6158/1282c19:dd:d9:dd:c25:c25:94de:6158
902c19:dd:d9:dd:c25:c25:94de:6159/1282c19:dd:d9:dd:c25:c25:94de:6159
912c19:dd:d9:dd:c25:c25:94de:615a/1282c19:dd:d9:dd:c25:c25:94de:615a
922c19:dd:d9:dd:c25:c25:94de:615b/1282c19:dd:d9:dd:c25:c25:94de:615b
932c19:dd:d9:dd:c25:c25:94de:615c/1282c19:dd:d9:dd:c25:c25:94de:615c
942c19:dd:d9:dd:c25:c25:94de:615d/1282c19:dd:d9:dd:c25:c25:94de:615d
952c19:dd:d9:dd:c25:c25:94de:615e/1282c19:dd:d9:dd:c25:c25:94de:615e
962c19:dd:d9:dd:c25:c25:94de:615f/1282c19:dd:d9:dd:c25:c25:94de:615f
972c19:dd:d9:dd:c25:c25:94de:6160/1282c19:dd:d9:dd:c25:c25:94de:6160
982c19:dd:d9:dd:c25:c25:94de:6161/1282c19:dd:d9:dd:c25:c25:94de:6161
992c19:dd:d9:dd:c25:c25:94de:6162/1282c19:dd:d9:dd:c25:c25:94de:6162
1002c19:dd:d9:dd:c25:c25:94de:6163/1282c19:dd:d9:dd:c25:c25:94de:6163
1012c19:dd:d9:dd:c25:c25:94de:6164/1282c19:dd:d9:dd:c25:c25:94de:6164
1022c19:dd:d9:dd:c25:c25:94de:6165/1282c19:dd:d9:dd:c25:c25:94de:6165
1032c19:dd:d9:dd:c25:c25:94de:6166/1282c19:dd:d9:dd:c25:c25:94de:6166
1042c19:dd:d9:dd:c25:c25:94de:6167/1282c19:dd:d9:dd:c25:c25:94de:6167
1052c19:dd:d9:dd:c25:c25:94de:6168/1282c19:dd:d9:dd:c25:c25:94de:6168
1062c19:dd:d9:dd:c25:c25:94de:6169/1282c19:dd:d9:dd:c25:c25:94de:6169
1072c19:dd:d9:dd:c25:c25:94de:616a/1282c19:dd:d9:dd:c25:c25:94de:616a
1082c19:dd:d9:dd:c25:c25:94de:616b/1282c19:dd:d9:dd:c25:c25:94de:616b
1092c19:dd:d9:dd:c25:c25:94de:616c/1282c19:dd:d9:dd:c25:c25:94de:616c
1102c19:dd:d9:dd:c25:c25:94de:616d/1282c19:dd:d9:dd:c25:c25:94de:616d
1112c19:dd:d9:dd:c25:c25:94de:616e/1282c19:dd:d9:dd:c25:c25:94de:616e
1122c19:dd:d9:dd:c25:c25:94de:616f/1282c19:dd:d9:dd:c25:c25:94de:616f
1132c19:dd:d9:dd:c25:c25:94de:6170/1282c19:dd:d9:dd:c25:c25:94de:6170
1142c19:dd:d9:dd:c25:c25:94de:6171/1282c19:dd:d9:dd:c25:c25:94de:6171
1152c19:dd:d9:dd:c25:c25:94de:6172/1282c19:dd:d9:dd:c25:c25:94de:6172
1162c19:dd:d9:dd:c25:c25:94de:6173/1282c19:dd:d9:dd:c25:c25:94de:6173
1172c19:dd:d9:dd:c25:c25:94de:6174/1282c19:dd:d9:dd:c25:c25:94de:6174
1182c19:dd:d9:dd:c25:c25:94de:6175/1282c19:dd:d9:dd:c25:c25:94de:6175
1192c19:dd:d9:dd:c25:c25:94de:6176/1282c19:dd:d9:dd:c25:c25:94de:6176
1202c19:dd:d9:dd:c25:c25:94de:6177/1282c19:dd:d9:dd:c25:c25:94de:6177
1212c19:dd:d9:dd:c25:c25:94de:6178/1282c19:dd:d9:dd:c25:c25:94de:6178
1222c19:dd:d9:dd:c25:c25:94de:6179/1282c19:dd:d9:dd:c25:c25:94de:6179
1232c19:dd:d9:dd:c25:c25:94de:617a/1282c19:dd:d9:dd:c25:c25:94de:617a
1242c19:dd:d9:dd:c25:c25:94de:617b/1282c19:dd:d9:dd:c25:c25:94de:617b
1252c19:dd:d9:dd:c25:c25:94de:617c/1282c19:dd:d9:dd:c25:c25:94de:617c
1262c19:dd:d9:dd:c25:c25:94de:617d/1282c19:dd:d9:dd:c25:c25:94de:617d
1272c19:dd:d9:dd:c25:c25:94de:617e/1282c19:dd:d9:dd:c25:c25:94de:617e
1282c19:dd:d9:dd:c25:c25:94de:617f/1282c19:dd:d9:dd:c25:c25:94de:617f
1292c19:dd:d9:dd:c25:c25:94de:6180/1282c19:dd:d9:dd:c25:c25:94de:6180
1302c19:dd:d9:dd:c25:c25:94de:6181/1282c19:dd:d9:dd:c25:c25:94de:6181
1312c19:dd:d9:dd:c25:c25:94de:6182/1282c19:dd:d9:dd:c25:c25:94de:6182
1322c19:dd:d9:dd:c25:c25:94de:6183/1282c19:dd:d9:dd:c25:c25:94de:6183
1332c19:dd:d9:dd:c25:c25:94de:6184/1282c19:dd:d9:dd:c25:c25:94de:6184
1342c19:dd:d9:dd:c25:c25:94de:6185/1282c19:dd:d9:dd:c25:c25:94de:6185
1352c19:dd:d9:dd:c25:c25:94de:6186/1282c19:dd:d9:dd:c25:c25:94de:6186
1362c19:dd:d9:dd:c25:c25:94de:6187/1282c19:dd:d9:dd:c25:c25:94de:6187
1372c19:dd:d9:dd:c25:c25:94de:6188/1282c19:dd:d9:dd:c25:c25:94de:6188
1382c19:dd:d9:dd:c25:c25:94de:6189/1282c19:dd:d9:dd:c25:c25:94de:6189
1392c19:dd:d9:dd:c25:c25:94de:618a/1282c19:dd:d9:dd:c25:c25:94de:618a
1402c19:dd:d9:dd:c25:c25:94de:618b/1282c19:dd:d9:dd:c25:c25:94de:618b
1412c19:dd:d9:dd:c25:c25:94de:618c/1282c19:dd:d9:dd:c25:c25:94de:618c
1422c19:dd:d9:dd:c25:c25:94de:618d/1282c19:dd:d9:dd:c25:c25:94de:618d
1432c19:dd:d9:dd:c25:c25:94de:618e/1282c19:dd:d9:dd:c25:c25:94de:618e
1442c19:dd:d9:dd:c25:c25:94de:618f/1282c19:dd:d9:dd:c25:c25:94de:618f
1452c19:dd:d9:dd:c25:c25:94de:6190/1282c19:dd:d9:dd:c25:c25:94de:6190
1462c19:dd:d9:dd:c25:c25:94de:6191/1282c19:dd:d9:dd:c25:c25:94de:6191
1472c19:dd:d9:dd:c25:c25:94de:6192/1282c19:dd:d9:dd:c25:c25:94de:6192
1482c19:dd:d9:dd:c25:c25:94de:6193/1282c19:dd:d9:dd:c25:c25:94de:6193
1492c19:dd:d9:dd:c25:c25:94de:6194/1282c19:dd:d9:dd:c25:c25:94de:6194
1502c19:dd:d9:dd:c25:c25:94de:6195/1282c19:dd:d9:dd:c25:c25:94de:6195
1512c19:dd:d9:dd:c25:c25:94de:6196/1282c19:dd:d9:dd:c25:c25:94de:6196
1522c19:dd:d9:dd:c25:c25:94de:6197/1282c19:dd:d9:dd:c25:c25:94de:6197
1532c19:dd:d9:dd:c25:c25:94de:6198/1282c19:dd:d9:dd:c25:c25:94de:6198
1542c19:dd:d9:dd:c25:c25:94de:6199/1282c19:dd:d9:dd:c25:c25:94de:6199
1552c19:dd:d9:dd:c25:c25:94de:619a/1282c19:dd:d9:dd:c25:c25:94de:619a
1562c19:dd:d9:dd:c25:c25:94de:619b/1282c19:dd:d9:dd:c25:c25:94de:619b
1572c19:dd:d9:dd:c25:c25:94de:619c/1282c19:dd:d9:dd:c25:c25:94de:619c
1582c19:dd:d9:dd:c25:c25:94de:619d/1282c19:dd:d9:dd:c25:c25:94de:619d
1592c19:dd:d9:dd:c25:c25:94de:619e/1282c19:dd:d9:dd:c25:c25:94de:619e
1602c19:dd:d9:dd:c25:c25:94de:619f/1282c19:dd:d9:dd:c25:c25:94de:619f
1612c19:dd:d9:dd:c25:c25:94de:61a0/1282c19:dd:d9:dd:c25:c25:94de:61a0
1622c19:dd:d9:dd:c25:c25:94de:61a1/1282c19:dd:d9:dd:c25:c25:94de:61a1
1632c19:dd:d9:dd:c25:c25:94de:61a2/1282c19:dd:d9:dd:c25:c25:94de:61a2
1642c19:dd:d9:dd:c25:c25:94de:61a3/1282c19:dd:d9:dd:c25:c25:94de:61a3
1652c19:dd:d9:dd:c25:c25:94de:61a4/1282c19:dd:d9:dd:c25:c25:94de:61a4
1662c19:dd:d9:dd:c25:c25:94de:61a5/1282c19:dd:d9:dd:c25:c25:94de:61a5
1672c19:dd:d9:dd:c25:c25:94de:61a6/1282c19:dd:d9:dd:c25:c25:94de:61a6
1682c19:dd:d9:dd:c25:c25:94de:61a7/1282c19:dd:d9:dd:c25:c25:94de:61a7
1692c19:dd:d9:dd:c25:c25:94de:61a8/1282c19:dd:d9:dd:c25:c25:94de:61a8
1702c19:dd:d9:dd:c25:c25:94de:61a9/1282c19:dd:d9:dd:c25:c25:94de:61a9
1712c19:dd:d9:dd:c25:c25:94de:61aa/1282c19:dd:d9:dd:c25:c25:94de:61aa
1722c19:dd:d9:dd:c25:c25:94de:61ab/1282c19:dd:d9:dd:c25:c25:94de:61ab
1732c19:dd:d9:dd:c25:c25:94de:61ac/1282c19:dd:d9:dd:c25:c25:94de:61ac
1742c19:dd:d9:dd:c25:c25:94de:61ad/1282c19:dd:d9:dd:c25:c25:94de:61ad
1752c19:dd:d9:dd:c25:c25:94de:61ae/1282c19:dd:d9:dd:c25:c25:94de:61ae
1762c19:dd:d9:dd:c25:c25:94de:61af/1282c19:dd:d9:dd:c25:c25:94de:61af
1772c19:dd:d9:dd:c25:c25:94de:61b0/1282c19:dd:d9:dd:c25:c25:94de:61b0
1782c19:dd:d9:dd:c25:c25:94de:61b1/1282c19:dd:d9:dd:c25:c25:94de:61b1
1792c19:dd:d9:dd:c25:c25:94de:61b2/1282c19:dd:d9:dd:c25:c25:94de:61b2
1802c19:dd:d9:dd:c25:c25:94de:61b3/1282c19:dd:d9:dd:c25:c25:94de:61b3
1812c19:dd:d9:dd:c25:c25:94de:61b4/1282c19:dd:d9:dd:c25:c25:94de:61b4
1822c19:dd:d9:dd:c25:c25:94de:61b5/1282c19:dd:d9:dd:c25:c25:94de:61b5
1832c19:dd:d9:dd:c25:c25:94de:61b6/1282c19:dd:d9:dd:c25:c25:94de:61b6
1842c19:dd:d9:dd:c25:c25:94de:61b7/1282c19:dd:d9:dd:c25:c25:94de:61b7
1852c19:dd:d9:dd:c25:c25:94de:61b8/1282c19:dd:d9:dd:c25:c25:94de:61b8
1862c19:dd:d9:dd:c25:c25:94de:61b9/1282c19:dd:d9:dd:c25:c25:94de:61b9
1872c19:dd:d9:dd:c25:c25:94de:61ba/1282c19:dd:d9:dd:c25:c25:94de:61ba
1882c19:dd:d9:dd:c25:c25:94de:61bb/1282c19:dd:d9:dd:c25:c25:94de:61bb
1892c19:dd:d9:dd:c25:c25:94de:61bc/1282c19:dd:d9:dd:c25:c25:94de:61bc
1902c19:dd:d9:dd:c25:c25:94de:61bd/1282c19:dd:d9:dd:c25:c25:94de:61bd
1912c19:dd:d9:dd:c25:c25:94de:61be/1282c19:dd:d9:dd:c25:c25:94de:61be
1922c19:dd:d9:dd:c25:c25:94de:61bf/1282c19:dd:d9:dd:c25:c25:94de:61bf
1932c19:dd:d9:dd:c25:c25:94de:61c0/1282c19:dd:d9:dd:c25:c25:94de:61c0
1942c19:dd:d9:dd:c25:c25:94de:61c1/1282c19:dd:d9:dd:c25:c25:94de:61c1
1952c19:dd:d9:dd:c25:c25:94de:61c2/1282c19:dd:d9:dd:c25:c25:94de:61c2
1962c19:dd:d9:dd:c25:c25:94de:61c3/1282c19:dd:d9:dd:c25:c25:94de:61c3
1972c19:dd:d9:dd:c25:c25:94de:61c4/1282c19:dd:d9:dd:c25:c25:94de:61c4
1982c19:dd:d9:dd:c25:c25:94de:61c5/1282c19:dd:d9:dd:c25:c25:94de:61c5
1992c19:dd:d9:dd:c25:c25:94de:61c6/1282c19:dd:d9:dd:c25:c25:94de:61c6
2002c19:dd:d9:dd:c25:c25:94de:61c7/1282c19:dd:d9:dd:c25:c25:94de:61c7
2012c19:dd:d9:dd:c25:c25:94de:61c8/1282c19:dd:d9:dd:c25:c25:94de:61c8
2022c19:dd:d9:dd:c25:c25:94de:61c9/1282c19:dd:d9:dd:c25:c25:94de:61c9
2032c19:dd:d9:dd:c25:c25:94de:61ca/1282c19:dd:d9:dd:c25:c25:94de:61ca
2042c19:dd:d9:dd:c25:c25:94de:61cb/1282c19:dd:d9:dd:c25:c25:94de:61cb
2052c19:dd:d9:dd:c25:c25:94de:61cc/1282c19:dd:d9:dd:c25:c25:94de:61cc
2062c19:dd:d9:dd:c25:c25:94de:61cd/1282c19:dd:d9:dd:c25:c25:94de:61cd
2072c19:dd:d9:dd:c25:c25:94de:61ce/1282c19:dd:d9:dd:c25:c25:94de:61ce
2082c19:dd:d9:dd:c25:c25:94de:61cf/1282c19:dd:d9:dd:c25:c25:94de:61cf
2092c19:dd:d9:dd:c25:c25:94de:61d0/1282c19:dd:d9:dd:c25:c25:94de:61d0
2102c19:dd:d9:dd:c25:c25:94de:61d1/1282c19:dd:d9:dd:c25:c25:94de:61d1
2112c19:dd:d9:dd:c25:c25:94de:61d2/1282c19:dd:d9:dd:c25:c25:94de:61d2
2122c19:dd:d9:dd:c25:c25:94de:61d3/1282c19:dd:d9:dd:c25:c25:94de:61d3
2132c19:dd:d9:dd:c25:c25:94de:61d4/1282c19:dd:d9:dd:c25:c25:94de:61d4
2142c19:dd:d9:dd:c25:c25:94de:61d5/1282c19:dd:d9:dd:c25:c25:94de:61d5
2152c19:dd:d9:dd:c25:c25:94de:61d6/1282c19:dd:d9:dd:c25:c25:94de:61d6
2162c19:dd:d9:dd:c25:c25:94de:61d7/1282c19:dd:d9:dd:c25:c25:94de:61d7
2172c19:dd:d9:dd:c25:c25:94de:61d8/1282c19:dd:d9:dd:c25:c25:94de:61d8
2182c19:dd:d9:dd:c25:c25:94de:61d9/1282c19:dd:d9:dd:c25:c25:94de:61d9
2192c19:dd:d9:dd:c25:c25:94de:61da/1282c19:dd:d9:dd:c25:c25:94de:61da
2202c19:dd:d9:dd:c25:c25:94de:61db/1282c19:dd:d9:dd:c25:c25:94de:61db
2212c19:dd:d9:dd:c25:c25:94de:61dc/1282c19:dd:d9:dd:c25:c25:94de:61dc
2222c19:dd:d9:dd:c25:c25:94de:61dd/1282c19:dd:d9:dd:c25:c25:94de:61dd
2232c19:dd:d9:dd:c25:c25:94de:61de/1282c19:dd:d9:dd:c25:c25:94de:61de
2242c19:dd:d9:dd:c25:c25:94de:61df/1282c19:dd:d9:dd:c25:c25:94de:61df
2252c19:dd:d9:dd:c25:c25:94de:61e0/1282c19:dd:d9:dd:c25:c25:94de:61e0
2262c19:dd:d9:dd:c25:c25:94de:61e1/1282c19:dd:d9:dd:c25:c25:94de:61e1
2272c19:dd:d9:dd:c25:c25:94de:61e2/1282c19:dd:d9:dd:c25:c25:94de:61e2
2282c19:dd:d9:dd:c25:c25:94de:61e3/1282c19:dd:d9:dd:c25:c25:94de:61e3
2292c19:dd:d9:dd:c25:c25:94de:61e4/1282c19:dd:d9:dd:c25:c25:94de:61e4
2302c19:dd:d9:dd:c25:c25:94de:61e5/1282c19:dd:d9:dd:c25:c25:94de:61e5
2312c19:dd:d9:dd:c25:c25:94de:61e6/1282c19:dd:d9:dd:c25:c25:94de:61e6
2322c19:dd:d9:dd:c25:c25:94de:61e7/1282c19:dd:d9:dd:c25:c25:94de:61e7
2332c19:dd:d9:dd:c25:c25:94de:61e8/1282c19:dd:d9:dd:c25:c25:94de:61e8
2342c19:dd:d9:dd:c25:c25:94de:61e9/1282c19:dd:d9:dd:c25:c25:94de:61e9
2352c19:dd:d9:dd:c25:c25:94de:61ea/1282c19:dd:d9:dd:c25:c25:94de:61ea
2362c19:dd:d9:dd:c25:c25:94de:61eb/1282c19:dd:d9:dd:c25:c25:94de:61eb
2372c19:dd:d9:dd:c25:c25:94de:61ec/1282c19:dd:d9:dd:c25:c25:94de:61ec
2382c19:dd:d9:dd:c25:c25:94de:61ed/1282c19:dd:d9:dd:c25:c25:94de:61ed
2392c19:dd:d9:dd:c25:c25:94de:61ee/1282c19:dd:d9:dd:c25:c25:94de:61ee
2402c19:dd:d9:dd:c25:c25:94de:61ef/1282c19:dd:d9:dd:c25:c25:94de:61ef
2412c19:dd:d9:dd:c25:c25:94de:61f0/1282c19:dd:d9:dd:c25:c25:94de:61f0
2422c19:dd:d9:dd:c25:c25:94de:61f1/1282c19:dd:d9:dd:c25:c25:94de:61f1
2432c19:dd:d9:dd:c25:c25:94de:61f2/1282c19:dd:d9:dd:c25:c25:94de:61f2
2442c19:dd:d9:dd:c25:c25:94de:61f3/1282c19:dd:d9:dd:c25:c25:94de:61f3
2452c19:dd:d9:dd:c25:c25:94de:61f4/1282c19:dd:d9:dd:c25:c25:94de:61f4
2462c19:dd:d9:dd:c25:c25:94de:61f5/1282c19:dd:d9:dd:c25:c25:94de:61f5
2472c19:dd:d9:dd:c25:c25:94de:61f6/1282c19:dd:d9:dd:c25:c25:94de:61f6
2482c19:dd:d9:dd:c25:c25:94de:61f7/1282c19:dd:d9:dd:c25:c25:94de:61f7
2492c19:dd:d9:dd:c25:c25:94de:61f8/1282c19:dd:d9:dd:c25:c25:94de:61f8
2502c19:dd:d9:dd:c25:c25:94de:61f9/1282c19:dd:d9:dd:c25:c25:94de:61f9
2512c19:dd:d9:dd:c25:c25:94de:61fa/1282c19:dd:d9:dd:c25:c25:94de:61fa
2522c19:dd:d9:dd:c25:c25:94de:61fb/1282c19:dd:d9:dd:c25:c25:94de:61fb
2532c19:dd:d9:dd:c25:c25:94de:61fc/1282c19:dd:d9:dd:c25:c25:94de:61fc
2542c19:dd:d9:dd:c25:c25:94de:61fd/1282c19:dd:d9:dd:c25:c25:94de:61fd
2552c19:dd:d9:dd:c25:c25:94de:61fe/1282c19:dd:d9:dd:c25:c25:94de:61fe
2562c19:dd:d9:dd:c25:c25:94de:61ff/1282c19:dd:d9:dd:c25:c25:94de:61ff

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.