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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:dd0:ec00:c25:c25:dd0:c100/120
First address
2c19:dd:dd0:ec00:c25:c25:dd0:c100
Last address
2c19:dd:dd0:ec00:c25:c25:dd0:c1ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:0dd0:ec00:0c25:0c25:0dd0:c100
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
1.c.0.d.d.0.5.2.c.0.5.2.c.0.0.0.c.e.0.d.d.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:dd0:ec00:c25:c25:dd0:c100/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:dd0:ec00:c25:c25:dd0:c100/1282c19:dd:dd0:ec00:c25:c25:dd0:c100
22c19:dd:dd0:ec00:c25:c25:dd0:c101/1282c19:dd:dd0:ec00:c25:c25:dd0:c101
32c19:dd:dd0:ec00:c25:c25:dd0:c102/1282c19:dd:dd0:ec00:c25:c25:dd0:c102
42c19:dd:dd0:ec00:c25:c25:dd0:c103/1282c19:dd:dd0:ec00:c25:c25:dd0:c103
52c19:dd:dd0:ec00:c25:c25:dd0:c104/1282c19:dd:dd0:ec00:c25:c25:dd0:c104
62c19:dd:dd0:ec00:c25:c25:dd0:c105/1282c19:dd:dd0:ec00:c25:c25:dd0:c105
72c19:dd:dd0:ec00:c25:c25:dd0:c106/1282c19:dd:dd0:ec00:c25:c25:dd0:c106
82c19:dd:dd0:ec00:c25:c25:dd0:c107/1282c19:dd:dd0:ec00:c25:c25:dd0:c107
92c19:dd:dd0:ec00:c25:c25:dd0:c108/1282c19:dd:dd0:ec00:c25:c25:dd0:c108
102c19:dd:dd0:ec00:c25:c25:dd0:c109/1282c19:dd:dd0:ec00:c25:c25:dd0:c109
112c19:dd:dd0:ec00:c25:c25:dd0:c10a/1282c19:dd:dd0:ec00:c25:c25:dd0:c10a
122c19:dd:dd0:ec00:c25:c25:dd0:c10b/1282c19:dd:dd0:ec00:c25:c25:dd0:c10b
132c19:dd:dd0:ec00:c25:c25:dd0:c10c/1282c19:dd:dd0:ec00:c25:c25:dd0:c10c
142c19:dd:dd0:ec00:c25:c25:dd0:c10d/1282c19:dd:dd0:ec00:c25:c25:dd0:c10d
152c19:dd:dd0:ec00:c25:c25:dd0:c10e/1282c19:dd:dd0:ec00:c25:c25:dd0:c10e
162c19:dd:dd0:ec00:c25:c25:dd0:c10f/1282c19:dd:dd0:ec00:c25:c25:dd0:c10f
172c19:dd:dd0:ec00:c25:c25:dd0:c110/1282c19:dd:dd0:ec00:c25:c25:dd0:c110
182c19:dd:dd0:ec00:c25:c25:dd0:c111/1282c19:dd:dd0:ec00:c25:c25:dd0:c111
192c19:dd:dd0:ec00:c25:c25:dd0:c112/1282c19:dd:dd0:ec00:c25:c25:dd0:c112
202c19:dd:dd0:ec00:c25:c25:dd0:c113/1282c19:dd:dd0:ec00:c25:c25:dd0:c113
212c19:dd:dd0:ec00:c25:c25:dd0:c114/1282c19:dd:dd0:ec00:c25:c25:dd0:c114
222c19:dd:dd0:ec00:c25:c25:dd0:c115/1282c19:dd:dd0:ec00:c25:c25:dd0:c115
232c19:dd:dd0:ec00:c25:c25:dd0:c116/1282c19:dd:dd0:ec00:c25:c25:dd0:c116
242c19:dd:dd0:ec00:c25:c25:dd0:c117/1282c19:dd:dd0:ec00:c25:c25:dd0:c117
252c19:dd:dd0:ec00:c25:c25:dd0:c118/1282c19:dd:dd0:ec00:c25:c25:dd0:c118
262c19:dd:dd0:ec00:c25:c25:dd0:c119/1282c19:dd:dd0:ec00:c25:c25:dd0:c119
272c19:dd:dd0:ec00:c25:c25:dd0:c11a/1282c19:dd:dd0:ec00:c25:c25:dd0:c11a
282c19:dd:dd0:ec00:c25:c25:dd0:c11b/1282c19:dd:dd0:ec00:c25:c25:dd0:c11b
292c19:dd:dd0:ec00:c25:c25:dd0:c11c/1282c19:dd:dd0:ec00:c25:c25:dd0:c11c
302c19:dd:dd0:ec00:c25:c25:dd0:c11d/1282c19:dd:dd0:ec00:c25:c25:dd0:c11d
312c19:dd:dd0:ec00:c25:c25:dd0:c11e/1282c19:dd:dd0:ec00:c25:c25:dd0:c11e
322c19:dd:dd0:ec00:c25:c25:dd0:c11f/1282c19:dd:dd0:ec00:c25:c25:dd0:c11f
332c19:dd:dd0:ec00:c25:c25:dd0:c120/1282c19:dd:dd0:ec00:c25:c25:dd0:c120
342c19:dd:dd0:ec00:c25:c25:dd0:c121/1282c19:dd:dd0:ec00:c25:c25:dd0:c121
352c19:dd:dd0:ec00:c25:c25:dd0:c122/1282c19:dd:dd0:ec00:c25:c25:dd0:c122
362c19:dd:dd0:ec00:c25:c25:dd0:c123/1282c19:dd:dd0:ec00:c25:c25:dd0:c123
372c19:dd:dd0:ec00:c25:c25:dd0:c124/1282c19:dd:dd0:ec00:c25:c25:dd0:c124
382c19:dd:dd0:ec00:c25:c25:dd0:c125/1282c19:dd:dd0:ec00:c25:c25:dd0:c125
392c19:dd:dd0:ec00:c25:c25:dd0:c126/1282c19:dd:dd0:ec00:c25:c25:dd0:c126
402c19:dd:dd0:ec00:c25:c25:dd0:c127/1282c19:dd:dd0:ec00:c25:c25:dd0:c127
412c19:dd:dd0:ec00:c25:c25:dd0:c128/1282c19:dd:dd0:ec00:c25:c25:dd0:c128
422c19:dd:dd0:ec00:c25:c25:dd0:c129/1282c19:dd:dd0:ec00:c25:c25:dd0:c129
432c19:dd:dd0:ec00:c25:c25:dd0:c12a/1282c19:dd:dd0:ec00:c25:c25:dd0:c12a
442c19:dd:dd0:ec00:c25:c25:dd0:c12b/1282c19:dd:dd0:ec00:c25:c25:dd0:c12b
452c19:dd:dd0:ec00:c25:c25:dd0:c12c/1282c19:dd:dd0:ec00:c25:c25:dd0:c12c
462c19:dd:dd0:ec00:c25:c25:dd0:c12d/1282c19:dd:dd0:ec00:c25:c25:dd0:c12d
472c19:dd:dd0:ec00:c25:c25:dd0:c12e/1282c19:dd:dd0:ec00:c25:c25:dd0:c12e
482c19:dd:dd0:ec00:c25:c25:dd0:c12f/1282c19:dd:dd0:ec00:c25:c25:dd0:c12f
492c19:dd:dd0:ec00:c25:c25:dd0:c130/1282c19:dd:dd0:ec00:c25:c25:dd0:c130
502c19:dd:dd0:ec00:c25:c25:dd0:c131/1282c19:dd:dd0:ec00:c25:c25:dd0:c131
512c19:dd:dd0:ec00:c25:c25:dd0:c132/1282c19:dd:dd0:ec00:c25:c25:dd0:c132
522c19:dd:dd0:ec00:c25:c25:dd0:c133/1282c19:dd:dd0:ec00:c25:c25:dd0:c133
532c19:dd:dd0:ec00:c25:c25:dd0:c134/1282c19:dd:dd0:ec00:c25:c25:dd0:c134
542c19:dd:dd0:ec00:c25:c25:dd0:c135/1282c19:dd:dd0:ec00:c25:c25:dd0:c135
552c19:dd:dd0:ec00:c25:c25:dd0:c136/1282c19:dd:dd0:ec00:c25:c25:dd0:c136
562c19:dd:dd0:ec00:c25:c25:dd0:c137/1282c19:dd:dd0:ec00:c25:c25:dd0:c137
572c19:dd:dd0:ec00:c25:c25:dd0:c138/1282c19:dd:dd0:ec00:c25:c25:dd0:c138
582c19:dd:dd0:ec00:c25:c25:dd0:c139/1282c19:dd:dd0:ec00:c25:c25:dd0:c139
592c19:dd:dd0:ec00:c25:c25:dd0:c13a/1282c19:dd:dd0:ec00:c25:c25:dd0:c13a
602c19:dd:dd0:ec00:c25:c25:dd0:c13b/1282c19:dd:dd0:ec00:c25:c25:dd0:c13b
612c19:dd:dd0:ec00:c25:c25:dd0:c13c/1282c19:dd:dd0:ec00:c25:c25:dd0:c13c
622c19:dd:dd0:ec00:c25:c25:dd0:c13d/1282c19:dd:dd0:ec00:c25:c25:dd0:c13d
632c19:dd:dd0:ec00:c25:c25:dd0:c13e/1282c19:dd:dd0:ec00:c25:c25:dd0:c13e
642c19:dd:dd0:ec00:c25:c25:dd0:c13f/1282c19:dd:dd0:ec00:c25:c25:dd0:c13f
652c19:dd:dd0:ec00:c25:c25:dd0:c140/1282c19:dd:dd0:ec00:c25:c25:dd0:c140
662c19:dd:dd0:ec00:c25:c25:dd0:c141/1282c19:dd:dd0:ec00:c25:c25:dd0:c141
672c19:dd:dd0:ec00:c25:c25:dd0:c142/1282c19:dd:dd0:ec00:c25:c25:dd0:c142
682c19:dd:dd0:ec00:c25:c25:dd0:c143/1282c19:dd:dd0:ec00:c25:c25:dd0:c143
692c19:dd:dd0:ec00:c25:c25:dd0:c144/1282c19:dd:dd0:ec00:c25:c25:dd0:c144
702c19:dd:dd0:ec00:c25:c25:dd0:c145/1282c19:dd:dd0:ec00:c25:c25:dd0:c145
712c19:dd:dd0:ec00:c25:c25:dd0:c146/1282c19:dd:dd0:ec00:c25:c25:dd0:c146
722c19:dd:dd0:ec00:c25:c25:dd0:c147/1282c19:dd:dd0:ec00:c25:c25:dd0:c147
732c19:dd:dd0:ec00:c25:c25:dd0:c148/1282c19:dd:dd0:ec00:c25:c25:dd0:c148
742c19:dd:dd0:ec00:c25:c25:dd0:c149/1282c19:dd:dd0:ec00:c25:c25:dd0:c149
752c19:dd:dd0:ec00:c25:c25:dd0:c14a/1282c19:dd:dd0:ec00:c25:c25:dd0:c14a
762c19:dd:dd0:ec00:c25:c25:dd0:c14b/1282c19:dd:dd0:ec00:c25:c25:dd0:c14b
772c19:dd:dd0:ec00:c25:c25:dd0:c14c/1282c19:dd:dd0:ec00:c25:c25:dd0:c14c
782c19:dd:dd0:ec00:c25:c25:dd0:c14d/1282c19:dd:dd0:ec00:c25:c25:dd0:c14d
792c19:dd:dd0:ec00:c25:c25:dd0:c14e/1282c19:dd:dd0:ec00:c25:c25:dd0:c14e
802c19:dd:dd0:ec00:c25:c25:dd0:c14f/1282c19:dd:dd0:ec00:c25:c25:dd0:c14f
812c19:dd:dd0:ec00:c25:c25:dd0:c150/1282c19:dd:dd0:ec00:c25:c25:dd0:c150
822c19:dd:dd0:ec00:c25:c25:dd0:c151/1282c19:dd:dd0:ec00:c25:c25:dd0:c151
832c19:dd:dd0:ec00:c25:c25:dd0:c152/1282c19:dd:dd0:ec00:c25:c25:dd0:c152
842c19:dd:dd0:ec00:c25:c25:dd0:c153/1282c19:dd:dd0:ec00:c25:c25:dd0:c153
852c19:dd:dd0:ec00:c25:c25:dd0:c154/1282c19:dd:dd0:ec00:c25:c25:dd0:c154
862c19:dd:dd0:ec00:c25:c25:dd0:c155/1282c19:dd:dd0:ec00:c25:c25:dd0:c155
872c19:dd:dd0:ec00:c25:c25:dd0:c156/1282c19:dd:dd0:ec00:c25:c25:dd0:c156
882c19:dd:dd0:ec00:c25:c25:dd0:c157/1282c19:dd:dd0:ec00:c25:c25:dd0:c157
892c19:dd:dd0:ec00:c25:c25:dd0:c158/1282c19:dd:dd0:ec00:c25:c25:dd0:c158
902c19:dd:dd0:ec00:c25:c25:dd0:c159/1282c19:dd:dd0:ec00:c25:c25:dd0:c159
912c19:dd:dd0:ec00:c25:c25:dd0:c15a/1282c19:dd:dd0:ec00:c25:c25:dd0:c15a
922c19:dd:dd0:ec00:c25:c25:dd0:c15b/1282c19:dd:dd0:ec00:c25:c25:dd0:c15b
932c19:dd:dd0:ec00:c25:c25:dd0:c15c/1282c19:dd:dd0:ec00:c25:c25:dd0:c15c
942c19:dd:dd0:ec00:c25:c25:dd0:c15d/1282c19:dd:dd0:ec00:c25:c25:dd0:c15d
952c19:dd:dd0:ec00:c25:c25:dd0:c15e/1282c19:dd:dd0:ec00:c25:c25:dd0:c15e
962c19:dd:dd0:ec00:c25:c25:dd0:c15f/1282c19:dd:dd0:ec00:c25:c25:dd0:c15f
972c19:dd:dd0:ec00:c25:c25:dd0:c160/1282c19:dd:dd0:ec00:c25:c25:dd0:c160
982c19:dd:dd0:ec00:c25:c25:dd0:c161/1282c19:dd:dd0:ec00:c25:c25:dd0:c161
992c19:dd:dd0:ec00:c25:c25:dd0:c162/1282c19:dd:dd0:ec00:c25:c25:dd0:c162
1002c19:dd:dd0:ec00:c25:c25:dd0:c163/1282c19:dd:dd0:ec00:c25:c25:dd0:c163
1012c19:dd:dd0:ec00:c25:c25:dd0:c164/1282c19:dd:dd0:ec00:c25:c25:dd0:c164
1022c19:dd:dd0:ec00:c25:c25:dd0:c165/1282c19:dd:dd0:ec00:c25:c25:dd0:c165
1032c19:dd:dd0:ec00:c25:c25:dd0:c166/1282c19:dd:dd0:ec00:c25:c25:dd0:c166
1042c19:dd:dd0:ec00:c25:c25:dd0:c167/1282c19:dd:dd0:ec00:c25:c25:dd0:c167
1052c19:dd:dd0:ec00:c25:c25:dd0:c168/1282c19:dd:dd0:ec00:c25:c25:dd0:c168
1062c19:dd:dd0:ec00:c25:c25:dd0:c169/1282c19:dd:dd0:ec00:c25:c25:dd0:c169
1072c19:dd:dd0:ec00:c25:c25:dd0:c16a/1282c19:dd:dd0:ec00:c25:c25:dd0:c16a
1082c19:dd:dd0:ec00:c25:c25:dd0:c16b/1282c19:dd:dd0:ec00:c25:c25:dd0:c16b
1092c19:dd:dd0:ec00:c25:c25:dd0:c16c/1282c19:dd:dd0:ec00:c25:c25:dd0:c16c
1102c19:dd:dd0:ec00:c25:c25:dd0:c16d/1282c19:dd:dd0:ec00:c25:c25:dd0:c16d
1112c19:dd:dd0:ec00:c25:c25:dd0:c16e/1282c19:dd:dd0:ec00:c25:c25:dd0:c16e
1122c19:dd:dd0:ec00:c25:c25:dd0:c16f/1282c19:dd:dd0:ec00:c25:c25:dd0:c16f
1132c19:dd:dd0:ec00:c25:c25:dd0:c170/1282c19:dd:dd0:ec00:c25:c25:dd0:c170
1142c19:dd:dd0:ec00:c25:c25:dd0:c171/1282c19:dd:dd0:ec00:c25:c25:dd0:c171
1152c19:dd:dd0:ec00:c25:c25:dd0:c172/1282c19:dd:dd0:ec00:c25:c25:dd0:c172
1162c19:dd:dd0:ec00:c25:c25:dd0:c173/1282c19:dd:dd0:ec00:c25:c25:dd0:c173
1172c19:dd:dd0:ec00:c25:c25:dd0:c174/1282c19:dd:dd0:ec00:c25:c25:dd0:c174
1182c19:dd:dd0:ec00:c25:c25:dd0:c175/1282c19:dd:dd0:ec00:c25:c25:dd0:c175
1192c19:dd:dd0:ec00:c25:c25:dd0:c176/1282c19:dd:dd0:ec00:c25:c25:dd0:c176
1202c19:dd:dd0:ec00:c25:c25:dd0:c177/1282c19:dd:dd0:ec00:c25:c25:dd0:c177
1212c19:dd:dd0:ec00:c25:c25:dd0:c178/1282c19:dd:dd0:ec00:c25:c25:dd0:c178
1222c19:dd:dd0:ec00:c25:c25:dd0:c179/1282c19:dd:dd0:ec00:c25:c25:dd0:c179
1232c19:dd:dd0:ec00:c25:c25:dd0:c17a/1282c19:dd:dd0:ec00:c25:c25:dd0:c17a
1242c19:dd:dd0:ec00:c25:c25:dd0:c17b/1282c19:dd:dd0:ec00:c25:c25:dd0:c17b
1252c19:dd:dd0:ec00:c25:c25:dd0:c17c/1282c19:dd:dd0:ec00:c25:c25:dd0:c17c
1262c19:dd:dd0:ec00:c25:c25:dd0:c17d/1282c19:dd:dd0:ec00:c25:c25:dd0:c17d
1272c19:dd:dd0:ec00:c25:c25:dd0:c17e/1282c19:dd:dd0:ec00:c25:c25:dd0:c17e
1282c19:dd:dd0:ec00:c25:c25:dd0:c17f/1282c19:dd:dd0:ec00:c25:c25:dd0:c17f
1292c19:dd:dd0:ec00:c25:c25:dd0:c180/1282c19:dd:dd0:ec00:c25:c25:dd0:c180
1302c19:dd:dd0:ec00:c25:c25:dd0:c181/1282c19:dd:dd0:ec00:c25:c25:dd0:c181
1312c19:dd:dd0:ec00:c25:c25:dd0:c182/1282c19:dd:dd0:ec00:c25:c25:dd0:c182
1322c19:dd:dd0:ec00:c25:c25:dd0:c183/1282c19:dd:dd0:ec00:c25:c25:dd0:c183
1332c19:dd:dd0:ec00:c25:c25:dd0:c184/1282c19:dd:dd0:ec00:c25:c25:dd0:c184
1342c19:dd:dd0:ec00:c25:c25:dd0:c185/1282c19:dd:dd0:ec00:c25:c25:dd0:c185
1352c19:dd:dd0:ec00:c25:c25:dd0:c186/1282c19:dd:dd0:ec00:c25:c25:dd0:c186
1362c19:dd:dd0:ec00:c25:c25:dd0:c187/1282c19:dd:dd0:ec00:c25:c25:dd0:c187
1372c19:dd:dd0:ec00:c25:c25:dd0:c188/1282c19:dd:dd0:ec00:c25:c25:dd0:c188
1382c19:dd:dd0:ec00:c25:c25:dd0:c189/1282c19:dd:dd0:ec00:c25:c25:dd0:c189
1392c19:dd:dd0:ec00:c25:c25:dd0:c18a/1282c19:dd:dd0:ec00:c25:c25:dd0:c18a
1402c19:dd:dd0:ec00:c25:c25:dd0:c18b/1282c19:dd:dd0:ec00:c25:c25:dd0:c18b
1412c19:dd:dd0:ec00:c25:c25:dd0:c18c/1282c19:dd:dd0:ec00:c25:c25:dd0:c18c
1422c19:dd:dd0:ec00:c25:c25:dd0:c18d/1282c19:dd:dd0:ec00:c25:c25:dd0:c18d
1432c19:dd:dd0:ec00:c25:c25:dd0:c18e/1282c19:dd:dd0:ec00:c25:c25:dd0:c18e
1442c19:dd:dd0:ec00:c25:c25:dd0:c18f/1282c19:dd:dd0:ec00:c25:c25:dd0:c18f
1452c19:dd:dd0:ec00:c25:c25:dd0:c190/1282c19:dd:dd0:ec00:c25:c25:dd0:c190
1462c19:dd:dd0:ec00:c25:c25:dd0:c191/1282c19:dd:dd0:ec00:c25:c25:dd0:c191
1472c19:dd:dd0:ec00:c25:c25:dd0:c192/1282c19:dd:dd0:ec00:c25:c25:dd0:c192
1482c19:dd:dd0:ec00:c25:c25:dd0:c193/1282c19:dd:dd0:ec00:c25:c25:dd0:c193
1492c19:dd:dd0:ec00:c25:c25:dd0:c194/1282c19:dd:dd0:ec00:c25:c25:dd0:c194
1502c19:dd:dd0:ec00:c25:c25:dd0:c195/1282c19:dd:dd0:ec00:c25:c25:dd0:c195
1512c19:dd:dd0:ec00:c25:c25:dd0:c196/1282c19:dd:dd0:ec00:c25:c25:dd0:c196
1522c19:dd:dd0:ec00:c25:c25:dd0:c197/1282c19:dd:dd0:ec00:c25:c25:dd0:c197
1532c19:dd:dd0:ec00:c25:c25:dd0:c198/1282c19:dd:dd0:ec00:c25:c25:dd0:c198
1542c19:dd:dd0:ec00:c25:c25:dd0:c199/1282c19:dd:dd0:ec00:c25:c25:dd0:c199
1552c19:dd:dd0:ec00:c25:c25:dd0:c19a/1282c19:dd:dd0:ec00:c25:c25:dd0:c19a
1562c19:dd:dd0:ec00:c25:c25:dd0:c19b/1282c19:dd:dd0:ec00:c25:c25:dd0:c19b
1572c19:dd:dd0:ec00:c25:c25:dd0:c19c/1282c19:dd:dd0:ec00:c25:c25:dd0:c19c
1582c19:dd:dd0:ec00:c25:c25:dd0:c19d/1282c19:dd:dd0:ec00:c25:c25:dd0:c19d
1592c19:dd:dd0:ec00:c25:c25:dd0:c19e/1282c19:dd:dd0:ec00:c25:c25:dd0:c19e
1602c19:dd:dd0:ec00:c25:c25:dd0:c19f/1282c19:dd:dd0:ec00:c25:c25:dd0:c19f
1612c19:dd:dd0:ec00:c25:c25:dd0:c1a0/1282c19:dd:dd0:ec00:c25:c25:dd0:c1a0
1622c19:dd:dd0:ec00:c25:c25:dd0:c1a1/1282c19:dd:dd0:ec00:c25:c25:dd0:c1a1
1632c19:dd:dd0:ec00:c25:c25:dd0:c1a2/1282c19:dd:dd0:ec00:c25:c25:dd0:c1a2
1642c19:dd:dd0:ec00:c25:c25:dd0:c1a3/1282c19:dd:dd0:ec00:c25:c25:dd0:c1a3
1652c19:dd:dd0:ec00:c25:c25:dd0:c1a4/1282c19:dd:dd0:ec00:c25:c25:dd0:c1a4
1662c19:dd:dd0:ec00:c25:c25:dd0:c1a5/1282c19:dd:dd0:ec00:c25:c25:dd0:c1a5
1672c19:dd:dd0:ec00:c25:c25:dd0:c1a6/1282c19:dd:dd0:ec00:c25:c25:dd0:c1a6
1682c19:dd:dd0:ec00:c25:c25:dd0:c1a7/1282c19:dd:dd0:ec00:c25:c25:dd0:c1a7
1692c19:dd:dd0:ec00:c25:c25:dd0:c1a8/1282c19:dd:dd0:ec00:c25:c25:dd0:c1a8
1702c19:dd:dd0:ec00:c25:c25:dd0:c1a9/1282c19:dd:dd0:ec00:c25:c25:dd0:c1a9
1712c19:dd:dd0:ec00:c25:c25:dd0:c1aa/1282c19:dd:dd0:ec00:c25:c25:dd0:c1aa
1722c19:dd:dd0:ec00:c25:c25:dd0:c1ab/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ab
1732c19:dd:dd0:ec00:c25:c25:dd0:c1ac/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ac
1742c19:dd:dd0:ec00:c25:c25:dd0:c1ad/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ad
1752c19:dd:dd0:ec00:c25:c25:dd0:c1ae/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ae
1762c19:dd:dd0:ec00:c25:c25:dd0:c1af/1282c19:dd:dd0:ec00:c25:c25:dd0:c1af
1772c19:dd:dd0:ec00:c25:c25:dd0:c1b0/1282c19:dd:dd0:ec00:c25:c25:dd0:c1b0
1782c19:dd:dd0:ec00:c25:c25:dd0:c1b1/1282c19:dd:dd0:ec00:c25:c25:dd0:c1b1
1792c19:dd:dd0:ec00:c25:c25:dd0:c1b2/1282c19:dd:dd0:ec00:c25:c25:dd0:c1b2
1802c19:dd:dd0:ec00:c25:c25:dd0:c1b3/1282c19:dd:dd0:ec00:c25:c25:dd0:c1b3
1812c19:dd:dd0:ec00:c25:c25:dd0:c1b4/1282c19:dd:dd0:ec00:c25:c25:dd0:c1b4
1822c19:dd:dd0:ec00:c25:c25:dd0:c1b5/1282c19:dd:dd0:ec00:c25:c25:dd0:c1b5
1832c19:dd:dd0:ec00:c25:c25:dd0:c1b6/1282c19:dd:dd0:ec00:c25:c25:dd0:c1b6
1842c19:dd:dd0:ec00:c25:c25:dd0:c1b7/1282c19:dd:dd0:ec00:c25:c25:dd0:c1b7
1852c19:dd:dd0:ec00:c25:c25:dd0:c1b8/1282c19:dd:dd0:ec00:c25:c25:dd0:c1b8
1862c19:dd:dd0:ec00:c25:c25:dd0:c1b9/1282c19:dd:dd0:ec00:c25:c25:dd0:c1b9
1872c19:dd:dd0:ec00:c25:c25:dd0:c1ba/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ba
1882c19:dd:dd0:ec00:c25:c25:dd0:c1bb/1282c19:dd:dd0:ec00:c25:c25:dd0:c1bb
1892c19:dd:dd0:ec00:c25:c25:dd0:c1bc/1282c19:dd:dd0:ec00:c25:c25:dd0:c1bc
1902c19:dd:dd0:ec00:c25:c25:dd0:c1bd/1282c19:dd:dd0:ec00:c25:c25:dd0:c1bd
1912c19:dd:dd0:ec00:c25:c25:dd0:c1be/1282c19:dd:dd0:ec00:c25:c25:dd0:c1be
1922c19:dd:dd0:ec00:c25:c25:dd0:c1bf/1282c19:dd:dd0:ec00:c25:c25:dd0:c1bf
1932c19:dd:dd0:ec00:c25:c25:dd0:c1c0/1282c19:dd:dd0:ec00:c25:c25:dd0:c1c0
1942c19:dd:dd0:ec00:c25:c25:dd0:c1c1/1282c19:dd:dd0:ec00:c25:c25:dd0:c1c1
1952c19:dd:dd0:ec00:c25:c25:dd0:c1c2/1282c19:dd:dd0:ec00:c25:c25:dd0:c1c2
1962c19:dd:dd0:ec00:c25:c25:dd0:c1c3/1282c19:dd:dd0:ec00:c25:c25:dd0:c1c3
1972c19:dd:dd0:ec00:c25:c25:dd0:c1c4/1282c19:dd:dd0:ec00:c25:c25:dd0:c1c4
1982c19:dd:dd0:ec00:c25:c25:dd0:c1c5/1282c19:dd:dd0:ec00:c25:c25:dd0:c1c5
1992c19:dd:dd0:ec00:c25:c25:dd0:c1c6/1282c19:dd:dd0:ec00:c25:c25:dd0:c1c6
2002c19:dd:dd0:ec00:c25:c25:dd0:c1c7/1282c19:dd:dd0:ec00:c25:c25:dd0:c1c7
2012c19:dd:dd0:ec00:c25:c25:dd0:c1c8/1282c19:dd:dd0:ec00:c25:c25:dd0:c1c8
2022c19:dd:dd0:ec00:c25:c25:dd0:c1c9/1282c19:dd:dd0:ec00:c25:c25:dd0:c1c9
2032c19:dd:dd0:ec00:c25:c25:dd0:c1ca/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ca
2042c19:dd:dd0:ec00:c25:c25:dd0:c1cb/1282c19:dd:dd0:ec00:c25:c25:dd0:c1cb
2052c19:dd:dd0:ec00:c25:c25:dd0:c1cc/1282c19:dd:dd0:ec00:c25:c25:dd0:c1cc
2062c19:dd:dd0:ec00:c25:c25:dd0:c1cd/1282c19:dd:dd0:ec00:c25:c25:dd0:c1cd
2072c19:dd:dd0:ec00:c25:c25:dd0:c1ce/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ce
2082c19:dd:dd0:ec00:c25:c25:dd0:c1cf/1282c19:dd:dd0:ec00:c25:c25:dd0:c1cf
2092c19:dd:dd0:ec00:c25:c25:dd0:c1d0/1282c19:dd:dd0:ec00:c25:c25:dd0:c1d0
2102c19:dd:dd0:ec00:c25:c25:dd0:c1d1/1282c19:dd:dd0:ec00:c25:c25:dd0:c1d1
2112c19:dd:dd0:ec00:c25:c25:dd0:c1d2/1282c19:dd:dd0:ec00:c25:c25:dd0:c1d2
2122c19:dd:dd0:ec00:c25:c25:dd0:c1d3/1282c19:dd:dd0:ec00:c25:c25:dd0:c1d3
2132c19:dd:dd0:ec00:c25:c25:dd0:c1d4/1282c19:dd:dd0:ec00:c25:c25:dd0:c1d4
2142c19:dd:dd0:ec00:c25:c25:dd0:c1d5/1282c19:dd:dd0:ec00:c25:c25:dd0:c1d5
2152c19:dd:dd0:ec00:c25:c25:dd0:c1d6/1282c19:dd:dd0:ec00:c25:c25:dd0:c1d6
2162c19:dd:dd0:ec00:c25:c25:dd0:c1d7/1282c19:dd:dd0:ec00:c25:c25:dd0:c1d7
2172c19:dd:dd0:ec00:c25:c25:dd0:c1d8/1282c19:dd:dd0:ec00:c25:c25:dd0:c1d8
2182c19:dd:dd0:ec00:c25:c25:dd0:c1d9/1282c19:dd:dd0:ec00:c25:c25:dd0:c1d9
2192c19:dd:dd0:ec00:c25:c25:dd0:c1da/1282c19:dd:dd0:ec00:c25:c25:dd0:c1da
2202c19:dd:dd0:ec00:c25:c25:dd0:c1db/1282c19:dd:dd0:ec00:c25:c25:dd0:c1db
2212c19:dd:dd0:ec00:c25:c25:dd0:c1dc/1282c19:dd:dd0:ec00:c25:c25:dd0:c1dc
2222c19:dd:dd0:ec00:c25:c25:dd0:c1dd/1282c19:dd:dd0:ec00:c25:c25:dd0:c1dd
2232c19:dd:dd0:ec00:c25:c25:dd0:c1de/1282c19:dd:dd0:ec00:c25:c25:dd0:c1de
2242c19:dd:dd0:ec00:c25:c25:dd0:c1df/1282c19:dd:dd0:ec00:c25:c25:dd0:c1df
2252c19:dd:dd0:ec00:c25:c25:dd0:c1e0/1282c19:dd:dd0:ec00:c25:c25:dd0:c1e0
2262c19:dd:dd0:ec00:c25:c25:dd0:c1e1/1282c19:dd:dd0:ec00:c25:c25:dd0:c1e1
2272c19:dd:dd0:ec00:c25:c25:dd0:c1e2/1282c19:dd:dd0:ec00:c25:c25:dd0:c1e2
2282c19:dd:dd0:ec00:c25:c25:dd0:c1e3/1282c19:dd:dd0:ec00:c25:c25:dd0:c1e3
2292c19:dd:dd0:ec00:c25:c25:dd0:c1e4/1282c19:dd:dd0:ec00:c25:c25:dd0:c1e4
2302c19:dd:dd0:ec00:c25:c25:dd0:c1e5/1282c19:dd:dd0:ec00:c25:c25:dd0:c1e5
2312c19:dd:dd0:ec00:c25:c25:dd0:c1e6/1282c19:dd:dd0:ec00:c25:c25:dd0:c1e6
2322c19:dd:dd0:ec00:c25:c25:dd0:c1e7/1282c19:dd:dd0:ec00:c25:c25:dd0:c1e7
2332c19:dd:dd0:ec00:c25:c25:dd0:c1e8/1282c19:dd:dd0:ec00:c25:c25:dd0:c1e8
2342c19:dd:dd0:ec00:c25:c25:dd0:c1e9/1282c19:dd:dd0:ec00:c25:c25:dd0:c1e9
2352c19:dd:dd0:ec00:c25:c25:dd0:c1ea/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ea
2362c19:dd:dd0:ec00:c25:c25:dd0:c1eb/1282c19:dd:dd0:ec00:c25:c25:dd0:c1eb
2372c19:dd:dd0:ec00:c25:c25:dd0:c1ec/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ec
2382c19:dd:dd0:ec00:c25:c25:dd0:c1ed/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ed
2392c19:dd:dd0:ec00:c25:c25:dd0:c1ee/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ee
2402c19:dd:dd0:ec00:c25:c25:dd0:c1ef/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ef
2412c19:dd:dd0:ec00:c25:c25:dd0:c1f0/1282c19:dd:dd0:ec00:c25:c25:dd0:c1f0
2422c19:dd:dd0:ec00:c25:c25:dd0:c1f1/1282c19:dd:dd0:ec00:c25:c25:dd0:c1f1
2432c19:dd:dd0:ec00:c25:c25:dd0:c1f2/1282c19:dd:dd0:ec00:c25:c25:dd0:c1f2
2442c19:dd:dd0:ec00:c25:c25:dd0:c1f3/1282c19:dd:dd0:ec00:c25:c25:dd0:c1f3
2452c19:dd:dd0:ec00:c25:c25:dd0:c1f4/1282c19:dd:dd0:ec00:c25:c25:dd0:c1f4
2462c19:dd:dd0:ec00:c25:c25:dd0:c1f5/1282c19:dd:dd0:ec00:c25:c25:dd0:c1f5
2472c19:dd:dd0:ec00:c25:c25:dd0:c1f6/1282c19:dd:dd0:ec00:c25:c25:dd0:c1f6
2482c19:dd:dd0:ec00:c25:c25:dd0:c1f7/1282c19:dd:dd0:ec00:c25:c25:dd0:c1f7
2492c19:dd:dd0:ec00:c25:c25:dd0:c1f8/1282c19:dd:dd0:ec00:c25:c25:dd0:c1f8
2502c19:dd:dd0:ec00:c25:c25:dd0:c1f9/1282c19:dd:dd0:ec00:c25:c25:dd0:c1f9
2512c19:dd:dd0:ec00:c25:c25:dd0:c1fa/1282c19:dd:dd0:ec00:c25:c25:dd0:c1fa
2522c19:dd:dd0:ec00:c25:c25:dd0:c1fb/1282c19:dd:dd0:ec00:c25:c25:dd0:c1fb
2532c19:dd:dd0:ec00:c25:c25:dd0:c1fc/1282c19:dd:dd0:ec00:c25:c25:dd0:c1fc
2542c19:dd:dd0:ec00:c25:c25:dd0:c1fd/1282c19:dd:dd0:ec00:c25:c25:dd0:c1fd
2552c19:dd:dd0:ec00:c25:c25:dd0:c1fe/1282c19:dd:dd0:ec00:c25:c25:dd0:c1fe
2562c19:dd:dd0:ec00:c25:c25:dd0:c1ff/1282c19:dd:dd0:ec00:c25:c25:dd0:c1ff

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.