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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:c25c:400a:100/120
First address
2c19:dd:d9:dd:c25:c25c:400a:100
Last address
2c19:dd:d9:dd:c25:c25c:400a:1ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:c25c:400a:0100
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
1.0.a.0.0.4.c.5.2.c.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:c25c:400a:100/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25c:400a:100/1282c19:dd:d9:dd:c25:c25c:400a:100
22c19:dd:d9:dd:c25:c25c:400a:101/1282c19:dd:d9:dd:c25:c25c:400a:101
32c19:dd:d9:dd:c25:c25c:400a:102/1282c19:dd:d9:dd:c25:c25c:400a:102
42c19:dd:d9:dd:c25:c25c:400a:103/1282c19:dd:d9:dd:c25:c25c:400a:103
52c19:dd:d9:dd:c25:c25c:400a:104/1282c19:dd:d9:dd:c25:c25c:400a:104
62c19:dd:d9:dd:c25:c25c:400a:105/1282c19:dd:d9:dd:c25:c25c:400a:105
72c19:dd:d9:dd:c25:c25c:400a:106/1282c19:dd:d9:dd:c25:c25c:400a:106
82c19:dd:d9:dd:c25:c25c:400a:107/1282c19:dd:d9:dd:c25:c25c:400a:107
92c19:dd:d9:dd:c25:c25c:400a:108/1282c19:dd:d9:dd:c25:c25c:400a:108
102c19:dd:d9:dd:c25:c25c:400a:109/1282c19:dd:d9:dd:c25:c25c:400a:109
112c19:dd:d9:dd:c25:c25c:400a:10a/1282c19:dd:d9:dd:c25:c25c:400a:10a
122c19:dd:d9:dd:c25:c25c:400a:10b/1282c19:dd:d9:dd:c25:c25c:400a:10b
132c19:dd:d9:dd:c25:c25c:400a:10c/1282c19:dd:d9:dd:c25:c25c:400a:10c
142c19:dd:d9:dd:c25:c25c:400a:10d/1282c19:dd:d9:dd:c25:c25c:400a:10d
152c19:dd:d9:dd:c25:c25c:400a:10e/1282c19:dd:d9:dd:c25:c25c:400a:10e
162c19:dd:d9:dd:c25:c25c:400a:10f/1282c19:dd:d9:dd:c25:c25c:400a:10f
172c19:dd:d9:dd:c25:c25c:400a:110/1282c19:dd:d9:dd:c25:c25c:400a:110
182c19:dd:d9:dd:c25:c25c:400a:111/1282c19:dd:d9:dd:c25:c25c:400a:111
192c19:dd:d9:dd:c25:c25c:400a:112/1282c19:dd:d9:dd:c25:c25c:400a:112
202c19:dd:d9:dd:c25:c25c:400a:113/1282c19:dd:d9:dd:c25:c25c:400a:113
212c19:dd:d9:dd:c25:c25c:400a:114/1282c19:dd:d9:dd:c25:c25c:400a:114
222c19:dd:d9:dd:c25:c25c:400a:115/1282c19:dd:d9:dd:c25:c25c:400a:115
232c19:dd:d9:dd:c25:c25c:400a:116/1282c19:dd:d9:dd:c25:c25c:400a:116
242c19:dd:d9:dd:c25:c25c:400a:117/1282c19:dd:d9:dd:c25:c25c:400a:117
252c19:dd:d9:dd:c25:c25c:400a:118/1282c19:dd:d9:dd:c25:c25c:400a:118
262c19:dd:d9:dd:c25:c25c:400a:119/1282c19:dd:d9:dd:c25:c25c:400a:119
272c19:dd:d9:dd:c25:c25c:400a:11a/1282c19:dd:d9:dd:c25:c25c:400a:11a
282c19:dd:d9:dd:c25:c25c:400a:11b/1282c19:dd:d9:dd:c25:c25c:400a:11b
292c19:dd:d9:dd:c25:c25c:400a:11c/1282c19:dd:d9:dd:c25:c25c:400a:11c
302c19:dd:d9:dd:c25:c25c:400a:11d/1282c19:dd:d9:dd:c25:c25c:400a:11d
312c19:dd:d9:dd:c25:c25c:400a:11e/1282c19:dd:d9:dd:c25:c25c:400a:11e
322c19:dd:d9:dd:c25:c25c:400a:11f/1282c19:dd:d9:dd:c25:c25c:400a:11f
332c19:dd:d9:dd:c25:c25c:400a:120/1282c19:dd:d9:dd:c25:c25c:400a:120
342c19:dd:d9:dd:c25:c25c:400a:121/1282c19:dd:d9:dd:c25:c25c:400a:121
352c19:dd:d9:dd:c25:c25c:400a:122/1282c19:dd:d9:dd:c25:c25c:400a:122
362c19:dd:d9:dd:c25:c25c:400a:123/1282c19:dd:d9:dd:c25:c25c:400a:123
372c19:dd:d9:dd:c25:c25c:400a:124/1282c19:dd:d9:dd:c25:c25c:400a:124
382c19:dd:d9:dd:c25:c25c:400a:125/1282c19:dd:d9:dd:c25:c25c:400a:125
392c19:dd:d9:dd:c25:c25c:400a:126/1282c19:dd:d9:dd:c25:c25c:400a:126
402c19:dd:d9:dd:c25:c25c:400a:127/1282c19:dd:d9:dd:c25:c25c:400a:127
412c19:dd:d9:dd:c25:c25c:400a:128/1282c19:dd:d9:dd:c25:c25c:400a:128
422c19:dd:d9:dd:c25:c25c:400a:129/1282c19:dd:d9:dd:c25:c25c:400a:129
432c19:dd:d9:dd:c25:c25c:400a:12a/1282c19:dd:d9:dd:c25:c25c:400a:12a
442c19:dd:d9:dd:c25:c25c:400a:12b/1282c19:dd:d9:dd:c25:c25c:400a:12b
452c19:dd:d9:dd:c25:c25c:400a:12c/1282c19:dd:d9:dd:c25:c25c:400a:12c
462c19:dd:d9:dd:c25:c25c:400a:12d/1282c19:dd:d9:dd:c25:c25c:400a:12d
472c19:dd:d9:dd:c25:c25c:400a:12e/1282c19:dd:d9:dd:c25:c25c:400a:12e
482c19:dd:d9:dd:c25:c25c:400a:12f/1282c19:dd:d9:dd:c25:c25c:400a:12f
492c19:dd:d9:dd:c25:c25c:400a:130/1282c19:dd:d9:dd:c25:c25c:400a:130
502c19:dd:d9:dd:c25:c25c:400a:131/1282c19:dd:d9:dd:c25:c25c:400a:131
512c19:dd:d9:dd:c25:c25c:400a:132/1282c19:dd:d9:dd:c25:c25c:400a:132
522c19:dd:d9:dd:c25:c25c:400a:133/1282c19:dd:d9:dd:c25:c25c:400a:133
532c19:dd:d9:dd:c25:c25c:400a:134/1282c19:dd:d9:dd:c25:c25c:400a:134
542c19:dd:d9:dd:c25:c25c:400a:135/1282c19:dd:d9:dd:c25:c25c:400a:135
552c19:dd:d9:dd:c25:c25c:400a:136/1282c19:dd:d9:dd:c25:c25c:400a:136
562c19:dd:d9:dd:c25:c25c:400a:137/1282c19:dd:d9:dd:c25:c25c:400a:137
572c19:dd:d9:dd:c25:c25c:400a:138/1282c19:dd:d9:dd:c25:c25c:400a:138
582c19:dd:d9:dd:c25:c25c:400a:139/1282c19:dd:d9:dd:c25:c25c:400a:139
592c19:dd:d9:dd:c25:c25c:400a:13a/1282c19:dd:d9:dd:c25:c25c:400a:13a
602c19:dd:d9:dd:c25:c25c:400a:13b/1282c19:dd:d9:dd:c25:c25c:400a:13b
612c19:dd:d9:dd:c25:c25c:400a:13c/1282c19:dd:d9:dd:c25:c25c:400a:13c
622c19:dd:d9:dd:c25:c25c:400a:13d/1282c19:dd:d9:dd:c25:c25c:400a:13d
632c19:dd:d9:dd:c25:c25c:400a:13e/1282c19:dd:d9:dd:c25:c25c:400a:13e
642c19:dd:d9:dd:c25:c25c:400a:13f/1282c19:dd:d9:dd:c25:c25c:400a:13f
652c19:dd:d9:dd:c25:c25c:400a:140/1282c19:dd:d9:dd:c25:c25c:400a:140
662c19:dd:d9:dd:c25:c25c:400a:141/1282c19:dd:d9:dd:c25:c25c:400a:141
672c19:dd:d9:dd:c25:c25c:400a:142/1282c19:dd:d9:dd:c25:c25c:400a:142
682c19:dd:d9:dd:c25:c25c:400a:143/1282c19:dd:d9:dd:c25:c25c:400a:143
692c19:dd:d9:dd:c25:c25c:400a:144/1282c19:dd:d9:dd:c25:c25c:400a:144
702c19:dd:d9:dd:c25:c25c:400a:145/1282c19:dd:d9:dd:c25:c25c:400a:145
712c19:dd:d9:dd:c25:c25c:400a:146/1282c19:dd:d9:dd:c25:c25c:400a:146
722c19:dd:d9:dd:c25:c25c:400a:147/1282c19:dd:d9:dd:c25:c25c:400a:147
732c19:dd:d9:dd:c25:c25c:400a:148/1282c19:dd:d9:dd:c25:c25c:400a:148
742c19:dd:d9:dd:c25:c25c:400a:149/1282c19:dd:d9:dd:c25:c25c:400a:149
752c19:dd:d9:dd:c25:c25c:400a:14a/1282c19:dd:d9:dd:c25:c25c:400a:14a
762c19:dd:d9:dd:c25:c25c:400a:14b/1282c19:dd:d9:dd:c25:c25c:400a:14b
772c19:dd:d9:dd:c25:c25c:400a:14c/1282c19:dd:d9:dd:c25:c25c:400a:14c
782c19:dd:d9:dd:c25:c25c:400a:14d/1282c19:dd:d9:dd:c25:c25c:400a:14d
792c19:dd:d9:dd:c25:c25c:400a:14e/1282c19:dd:d9:dd:c25:c25c:400a:14e
802c19:dd:d9:dd:c25:c25c:400a:14f/1282c19:dd:d9:dd:c25:c25c:400a:14f
812c19:dd:d9:dd:c25:c25c:400a:150/1282c19:dd:d9:dd:c25:c25c:400a:150
822c19:dd:d9:dd:c25:c25c:400a:151/1282c19:dd:d9:dd:c25:c25c:400a:151
832c19:dd:d9:dd:c25:c25c:400a:152/1282c19:dd:d9:dd:c25:c25c:400a:152
842c19:dd:d9:dd:c25:c25c:400a:153/1282c19:dd:d9:dd:c25:c25c:400a:153
852c19:dd:d9:dd:c25:c25c:400a:154/1282c19:dd:d9:dd:c25:c25c:400a:154
862c19:dd:d9:dd:c25:c25c:400a:155/1282c19:dd:d9:dd:c25:c25c:400a:155
872c19:dd:d9:dd:c25:c25c:400a:156/1282c19:dd:d9:dd:c25:c25c:400a:156
882c19:dd:d9:dd:c25:c25c:400a:157/1282c19:dd:d9:dd:c25:c25c:400a:157
892c19:dd:d9:dd:c25:c25c:400a:158/1282c19:dd:d9:dd:c25:c25c:400a:158
902c19:dd:d9:dd:c25:c25c:400a:159/1282c19:dd:d9:dd:c25:c25c:400a:159
912c19:dd:d9:dd:c25:c25c:400a:15a/1282c19:dd:d9:dd:c25:c25c:400a:15a
922c19:dd:d9:dd:c25:c25c:400a:15b/1282c19:dd:d9:dd:c25:c25c:400a:15b
932c19:dd:d9:dd:c25:c25c:400a:15c/1282c19:dd:d9:dd:c25:c25c:400a:15c
942c19:dd:d9:dd:c25:c25c:400a:15d/1282c19:dd:d9:dd:c25:c25c:400a:15d
952c19:dd:d9:dd:c25:c25c:400a:15e/1282c19:dd:d9:dd:c25:c25c:400a:15e
962c19:dd:d9:dd:c25:c25c:400a:15f/1282c19:dd:d9:dd:c25:c25c:400a:15f
972c19:dd:d9:dd:c25:c25c:400a:160/1282c19:dd:d9:dd:c25:c25c:400a:160
982c19:dd:d9:dd:c25:c25c:400a:161/1282c19:dd:d9:dd:c25:c25c:400a:161
992c19:dd:d9:dd:c25:c25c:400a:162/1282c19:dd:d9:dd:c25:c25c:400a:162
1002c19:dd:d9:dd:c25:c25c:400a:163/1282c19:dd:d9:dd:c25:c25c:400a:163
1012c19:dd:d9:dd:c25:c25c:400a:164/1282c19:dd:d9:dd:c25:c25c:400a:164
1022c19:dd:d9:dd:c25:c25c:400a:165/1282c19:dd:d9:dd:c25:c25c:400a:165
1032c19:dd:d9:dd:c25:c25c:400a:166/1282c19:dd:d9:dd:c25:c25c:400a:166
1042c19:dd:d9:dd:c25:c25c:400a:167/1282c19:dd:d9:dd:c25:c25c:400a:167
1052c19:dd:d9:dd:c25:c25c:400a:168/1282c19:dd:d9:dd:c25:c25c:400a:168
1062c19:dd:d9:dd:c25:c25c:400a:169/1282c19:dd:d9:dd:c25:c25c:400a:169
1072c19:dd:d9:dd:c25:c25c:400a:16a/1282c19:dd:d9:dd:c25:c25c:400a:16a
1082c19:dd:d9:dd:c25:c25c:400a:16b/1282c19:dd:d9:dd:c25:c25c:400a:16b
1092c19:dd:d9:dd:c25:c25c:400a:16c/1282c19:dd:d9:dd:c25:c25c:400a:16c
1102c19:dd:d9:dd:c25:c25c:400a:16d/1282c19:dd:d9:dd:c25:c25c:400a:16d
1112c19:dd:d9:dd:c25:c25c:400a:16e/1282c19:dd:d9:dd:c25:c25c:400a:16e
1122c19:dd:d9:dd:c25:c25c:400a:16f/1282c19:dd:d9:dd:c25:c25c:400a:16f
1132c19:dd:d9:dd:c25:c25c:400a:170/1282c19:dd:d9:dd:c25:c25c:400a:170
1142c19:dd:d9:dd:c25:c25c:400a:171/1282c19:dd:d9:dd:c25:c25c:400a:171
1152c19:dd:d9:dd:c25:c25c:400a:172/1282c19:dd:d9:dd:c25:c25c:400a:172
1162c19:dd:d9:dd:c25:c25c:400a:173/1282c19:dd:d9:dd:c25:c25c:400a:173
1172c19:dd:d9:dd:c25:c25c:400a:174/1282c19:dd:d9:dd:c25:c25c:400a:174
1182c19:dd:d9:dd:c25:c25c:400a:175/1282c19:dd:d9:dd:c25:c25c:400a:175
1192c19:dd:d9:dd:c25:c25c:400a:176/1282c19:dd:d9:dd:c25:c25c:400a:176
1202c19:dd:d9:dd:c25:c25c:400a:177/1282c19:dd:d9:dd:c25:c25c:400a:177
1212c19:dd:d9:dd:c25:c25c:400a:178/1282c19:dd:d9:dd:c25:c25c:400a:178
1222c19:dd:d9:dd:c25:c25c:400a:179/1282c19:dd:d9:dd:c25:c25c:400a:179
1232c19:dd:d9:dd:c25:c25c:400a:17a/1282c19:dd:d9:dd:c25:c25c:400a:17a
1242c19:dd:d9:dd:c25:c25c:400a:17b/1282c19:dd:d9:dd:c25:c25c:400a:17b
1252c19:dd:d9:dd:c25:c25c:400a:17c/1282c19:dd:d9:dd:c25:c25c:400a:17c
1262c19:dd:d9:dd:c25:c25c:400a:17d/1282c19:dd:d9:dd:c25:c25c:400a:17d
1272c19:dd:d9:dd:c25:c25c:400a:17e/1282c19:dd:d9:dd:c25:c25c:400a:17e
1282c19:dd:d9:dd:c25:c25c:400a:17f/1282c19:dd:d9:dd:c25:c25c:400a:17f
1292c19:dd:d9:dd:c25:c25c:400a:180/1282c19:dd:d9:dd:c25:c25c:400a:180
1302c19:dd:d9:dd:c25:c25c:400a:181/1282c19:dd:d9:dd:c25:c25c:400a:181
1312c19:dd:d9:dd:c25:c25c:400a:182/1282c19:dd:d9:dd:c25:c25c:400a:182
1322c19:dd:d9:dd:c25:c25c:400a:183/1282c19:dd:d9:dd:c25:c25c:400a:183
1332c19:dd:d9:dd:c25:c25c:400a:184/1282c19:dd:d9:dd:c25:c25c:400a:184
1342c19:dd:d9:dd:c25:c25c:400a:185/1282c19:dd:d9:dd:c25:c25c:400a:185
1352c19:dd:d9:dd:c25:c25c:400a:186/1282c19:dd:d9:dd:c25:c25c:400a:186
1362c19:dd:d9:dd:c25:c25c:400a:187/1282c19:dd:d9:dd:c25:c25c:400a:187
1372c19:dd:d9:dd:c25:c25c:400a:188/1282c19:dd:d9:dd:c25:c25c:400a:188
1382c19:dd:d9:dd:c25:c25c:400a:189/1282c19:dd:d9:dd:c25:c25c:400a:189
1392c19:dd:d9:dd:c25:c25c:400a:18a/1282c19:dd:d9:dd:c25:c25c:400a:18a
1402c19:dd:d9:dd:c25:c25c:400a:18b/1282c19:dd:d9:dd:c25:c25c:400a:18b
1412c19:dd:d9:dd:c25:c25c:400a:18c/1282c19:dd:d9:dd:c25:c25c:400a:18c
1422c19:dd:d9:dd:c25:c25c:400a:18d/1282c19:dd:d9:dd:c25:c25c:400a:18d
1432c19:dd:d9:dd:c25:c25c:400a:18e/1282c19:dd:d9:dd:c25:c25c:400a:18e
1442c19:dd:d9:dd:c25:c25c:400a:18f/1282c19:dd:d9:dd:c25:c25c:400a:18f
1452c19:dd:d9:dd:c25:c25c:400a:190/1282c19:dd:d9:dd:c25:c25c:400a:190
1462c19:dd:d9:dd:c25:c25c:400a:191/1282c19:dd:d9:dd:c25:c25c:400a:191
1472c19:dd:d9:dd:c25:c25c:400a:192/1282c19:dd:d9:dd:c25:c25c:400a:192
1482c19:dd:d9:dd:c25:c25c:400a:193/1282c19:dd:d9:dd:c25:c25c:400a:193
1492c19:dd:d9:dd:c25:c25c:400a:194/1282c19:dd:d9:dd:c25:c25c:400a:194
1502c19:dd:d9:dd:c25:c25c:400a:195/1282c19:dd:d9:dd:c25:c25c:400a:195
1512c19:dd:d9:dd:c25:c25c:400a:196/1282c19:dd:d9:dd:c25:c25c:400a:196
1522c19:dd:d9:dd:c25:c25c:400a:197/1282c19:dd:d9:dd:c25:c25c:400a:197
1532c19:dd:d9:dd:c25:c25c:400a:198/1282c19:dd:d9:dd:c25:c25c:400a:198
1542c19:dd:d9:dd:c25:c25c:400a:199/1282c19:dd:d9:dd:c25:c25c:400a:199
1552c19:dd:d9:dd:c25:c25c:400a:19a/1282c19:dd:d9:dd:c25:c25c:400a:19a
1562c19:dd:d9:dd:c25:c25c:400a:19b/1282c19:dd:d9:dd:c25:c25c:400a:19b
1572c19:dd:d9:dd:c25:c25c:400a:19c/1282c19:dd:d9:dd:c25:c25c:400a:19c
1582c19:dd:d9:dd:c25:c25c:400a:19d/1282c19:dd:d9:dd:c25:c25c:400a:19d
1592c19:dd:d9:dd:c25:c25c:400a:19e/1282c19:dd:d9:dd:c25:c25c:400a:19e
1602c19:dd:d9:dd:c25:c25c:400a:19f/1282c19:dd:d9:dd:c25:c25c:400a:19f
1612c19:dd:d9:dd:c25:c25c:400a:1a0/1282c19:dd:d9:dd:c25:c25c:400a:1a0
1622c19:dd:d9:dd:c25:c25c:400a:1a1/1282c19:dd:d9:dd:c25:c25c:400a:1a1
1632c19:dd:d9:dd:c25:c25c:400a:1a2/1282c19:dd:d9:dd:c25:c25c:400a:1a2
1642c19:dd:d9:dd:c25:c25c:400a:1a3/1282c19:dd:d9:dd:c25:c25c:400a:1a3
1652c19:dd:d9:dd:c25:c25c:400a:1a4/1282c19:dd:d9:dd:c25:c25c:400a:1a4
1662c19:dd:d9:dd:c25:c25c:400a:1a5/1282c19:dd:d9:dd:c25:c25c:400a:1a5
1672c19:dd:d9:dd:c25:c25c:400a:1a6/1282c19:dd:d9:dd:c25:c25c:400a:1a6
1682c19:dd:d9:dd:c25:c25c:400a:1a7/1282c19:dd:d9:dd:c25:c25c:400a:1a7
1692c19:dd:d9:dd:c25:c25c:400a:1a8/1282c19:dd:d9:dd:c25:c25c:400a:1a8
1702c19:dd:d9:dd:c25:c25c:400a:1a9/1282c19:dd:d9:dd:c25:c25c:400a:1a9
1712c19:dd:d9:dd:c25:c25c:400a:1aa/1282c19:dd:d9:dd:c25:c25c:400a:1aa
1722c19:dd:d9:dd:c25:c25c:400a:1ab/1282c19:dd:d9:dd:c25:c25c:400a:1ab
1732c19:dd:d9:dd:c25:c25c:400a:1ac/1282c19:dd:d9:dd:c25:c25c:400a:1ac
1742c19:dd:d9:dd:c25:c25c:400a:1ad/1282c19:dd:d9:dd:c25:c25c:400a:1ad
1752c19:dd:d9:dd:c25:c25c:400a:1ae/1282c19:dd:d9:dd:c25:c25c:400a:1ae
1762c19:dd:d9:dd:c25:c25c:400a:1af/1282c19:dd:d9:dd:c25:c25c:400a:1af
1772c19:dd:d9:dd:c25:c25c:400a:1b0/1282c19:dd:d9:dd:c25:c25c:400a:1b0
1782c19:dd:d9:dd:c25:c25c:400a:1b1/1282c19:dd:d9:dd:c25:c25c:400a:1b1
1792c19:dd:d9:dd:c25:c25c:400a:1b2/1282c19:dd:d9:dd:c25:c25c:400a:1b2
1802c19:dd:d9:dd:c25:c25c:400a:1b3/1282c19:dd:d9:dd:c25:c25c:400a:1b3
1812c19:dd:d9:dd:c25:c25c:400a:1b4/1282c19:dd:d9:dd:c25:c25c:400a:1b4
1822c19:dd:d9:dd:c25:c25c:400a:1b5/1282c19:dd:d9:dd:c25:c25c:400a:1b5
1832c19:dd:d9:dd:c25:c25c:400a:1b6/1282c19:dd:d9:dd:c25:c25c:400a:1b6
1842c19:dd:d9:dd:c25:c25c:400a:1b7/1282c19:dd:d9:dd:c25:c25c:400a:1b7
1852c19:dd:d9:dd:c25:c25c:400a:1b8/1282c19:dd:d9:dd:c25:c25c:400a:1b8
1862c19:dd:d9:dd:c25:c25c:400a:1b9/1282c19:dd:d9:dd:c25:c25c:400a:1b9
1872c19:dd:d9:dd:c25:c25c:400a:1ba/1282c19:dd:d9:dd:c25:c25c:400a:1ba
1882c19:dd:d9:dd:c25:c25c:400a:1bb/1282c19:dd:d9:dd:c25:c25c:400a:1bb
1892c19:dd:d9:dd:c25:c25c:400a:1bc/1282c19:dd:d9:dd:c25:c25c:400a:1bc
1902c19:dd:d9:dd:c25:c25c:400a:1bd/1282c19:dd:d9:dd:c25:c25c:400a:1bd
1912c19:dd:d9:dd:c25:c25c:400a:1be/1282c19:dd:d9:dd:c25:c25c:400a:1be
1922c19:dd:d9:dd:c25:c25c:400a:1bf/1282c19:dd:d9:dd:c25:c25c:400a:1bf
1932c19:dd:d9:dd:c25:c25c:400a:1c0/1282c19:dd:d9:dd:c25:c25c:400a:1c0
1942c19:dd:d9:dd:c25:c25c:400a:1c1/1282c19:dd:d9:dd:c25:c25c:400a:1c1
1952c19:dd:d9:dd:c25:c25c:400a:1c2/1282c19:dd:d9:dd:c25:c25c:400a:1c2
1962c19:dd:d9:dd:c25:c25c:400a:1c3/1282c19:dd:d9:dd:c25:c25c:400a:1c3
1972c19:dd:d9:dd:c25:c25c:400a:1c4/1282c19:dd:d9:dd:c25:c25c:400a:1c4
1982c19:dd:d9:dd:c25:c25c:400a:1c5/1282c19:dd:d9:dd:c25:c25c:400a:1c5
1992c19:dd:d9:dd:c25:c25c:400a:1c6/1282c19:dd:d9:dd:c25:c25c:400a:1c6
2002c19:dd:d9:dd:c25:c25c:400a:1c7/1282c19:dd:d9:dd:c25:c25c:400a:1c7
2012c19:dd:d9:dd:c25:c25c:400a:1c8/1282c19:dd:d9:dd:c25:c25c:400a:1c8
2022c19:dd:d9:dd:c25:c25c:400a:1c9/1282c19:dd:d9:dd:c25:c25c:400a:1c9
2032c19:dd:d9:dd:c25:c25c:400a:1ca/1282c19:dd:d9:dd:c25:c25c:400a:1ca
2042c19:dd:d9:dd:c25:c25c:400a:1cb/1282c19:dd:d9:dd:c25:c25c:400a:1cb
2052c19:dd:d9:dd:c25:c25c:400a:1cc/1282c19:dd:d9:dd:c25:c25c:400a:1cc
2062c19:dd:d9:dd:c25:c25c:400a:1cd/1282c19:dd:d9:dd:c25:c25c:400a:1cd
2072c19:dd:d9:dd:c25:c25c:400a:1ce/1282c19:dd:d9:dd:c25:c25c:400a:1ce
2082c19:dd:d9:dd:c25:c25c:400a:1cf/1282c19:dd:d9:dd:c25:c25c:400a:1cf
2092c19:dd:d9:dd:c25:c25c:400a:1d0/1282c19:dd:d9:dd:c25:c25c:400a:1d0
2102c19:dd:d9:dd:c25:c25c:400a:1d1/1282c19:dd:d9:dd:c25:c25c:400a:1d1
2112c19:dd:d9:dd:c25:c25c:400a:1d2/1282c19:dd:d9:dd:c25:c25c:400a:1d2
2122c19:dd:d9:dd:c25:c25c:400a:1d3/1282c19:dd:d9:dd:c25:c25c:400a:1d3
2132c19:dd:d9:dd:c25:c25c:400a:1d4/1282c19:dd:d9:dd:c25:c25c:400a:1d4
2142c19:dd:d9:dd:c25:c25c:400a:1d5/1282c19:dd:d9:dd:c25:c25c:400a:1d5
2152c19:dd:d9:dd:c25:c25c:400a:1d6/1282c19:dd:d9:dd:c25:c25c:400a:1d6
2162c19:dd:d9:dd:c25:c25c:400a:1d7/1282c19:dd:d9:dd:c25:c25c:400a:1d7
2172c19:dd:d9:dd:c25:c25c:400a:1d8/1282c19:dd:d9:dd:c25:c25c:400a:1d8
2182c19:dd:d9:dd:c25:c25c:400a:1d9/1282c19:dd:d9:dd:c25:c25c:400a:1d9
2192c19:dd:d9:dd:c25:c25c:400a:1da/1282c19:dd:d9:dd:c25:c25c:400a:1da
2202c19:dd:d9:dd:c25:c25c:400a:1db/1282c19:dd:d9:dd:c25:c25c:400a:1db
2212c19:dd:d9:dd:c25:c25c:400a:1dc/1282c19:dd:d9:dd:c25:c25c:400a:1dc
2222c19:dd:d9:dd:c25:c25c:400a:1dd/1282c19:dd:d9:dd:c25:c25c:400a:1dd
2232c19:dd:d9:dd:c25:c25c:400a:1de/1282c19:dd:d9:dd:c25:c25c:400a:1de
2242c19:dd:d9:dd:c25:c25c:400a:1df/1282c19:dd:d9:dd:c25:c25c:400a:1df
2252c19:dd:d9:dd:c25:c25c:400a:1e0/1282c19:dd:d9:dd:c25:c25c:400a:1e0
2262c19:dd:d9:dd:c25:c25c:400a:1e1/1282c19:dd:d9:dd:c25:c25c:400a:1e1
2272c19:dd:d9:dd:c25:c25c:400a:1e2/1282c19:dd:d9:dd:c25:c25c:400a:1e2
2282c19:dd:d9:dd:c25:c25c:400a:1e3/1282c19:dd:d9:dd:c25:c25c:400a:1e3
2292c19:dd:d9:dd:c25:c25c:400a:1e4/1282c19:dd:d9:dd:c25:c25c:400a:1e4
2302c19:dd:d9:dd:c25:c25c:400a:1e5/1282c19:dd:d9:dd:c25:c25c:400a:1e5
2312c19:dd:d9:dd:c25:c25c:400a:1e6/1282c19:dd:d9:dd:c25:c25c:400a:1e6
2322c19:dd:d9:dd:c25:c25c:400a:1e7/1282c19:dd:d9:dd:c25:c25c:400a:1e7
2332c19:dd:d9:dd:c25:c25c:400a:1e8/1282c19:dd:d9:dd:c25:c25c:400a:1e8
2342c19:dd:d9:dd:c25:c25c:400a:1e9/1282c19:dd:d9:dd:c25:c25c:400a:1e9
2352c19:dd:d9:dd:c25:c25c:400a:1ea/1282c19:dd:d9:dd:c25:c25c:400a:1ea
2362c19:dd:d9:dd:c25:c25c:400a:1eb/1282c19:dd:d9:dd:c25:c25c:400a:1eb
2372c19:dd:d9:dd:c25:c25c:400a:1ec/1282c19:dd:d9:dd:c25:c25c:400a:1ec
2382c19:dd:d9:dd:c25:c25c:400a:1ed/1282c19:dd:d9:dd:c25:c25c:400a:1ed
2392c19:dd:d9:dd:c25:c25c:400a:1ee/1282c19:dd:d9:dd:c25:c25c:400a:1ee
2402c19:dd:d9:dd:c25:c25c:400a:1ef/1282c19:dd:d9:dd:c25:c25c:400a:1ef
2412c19:dd:d9:dd:c25:c25c:400a:1f0/1282c19:dd:d9:dd:c25:c25c:400a:1f0
2422c19:dd:d9:dd:c25:c25c:400a:1f1/1282c19:dd:d9:dd:c25:c25c:400a:1f1
2432c19:dd:d9:dd:c25:c25c:400a:1f2/1282c19:dd:d9:dd:c25:c25c:400a:1f2
2442c19:dd:d9:dd:c25:c25c:400a:1f3/1282c19:dd:d9:dd:c25:c25c:400a:1f3
2452c19:dd:d9:dd:c25:c25c:400a:1f4/1282c19:dd:d9:dd:c25:c25c:400a:1f4
2462c19:dd:d9:dd:c25:c25c:400a:1f5/1282c19:dd:d9:dd:c25:c25c:400a:1f5
2472c19:dd:d9:dd:c25:c25c:400a:1f6/1282c19:dd:d9:dd:c25:c25c:400a:1f6
2482c19:dd:d9:dd:c25:c25c:400a:1f7/1282c19:dd:d9:dd:c25:c25c:400a:1f7
2492c19:dd:d9:dd:c25:c25c:400a:1f8/1282c19:dd:d9:dd:c25:c25c:400a:1f8
2502c19:dd:d9:dd:c25:c25c:400a:1f9/1282c19:dd:d9:dd:c25:c25c:400a:1f9
2512c19:dd:d9:dd:c25:c25c:400a:1fa/1282c19:dd:d9:dd:c25:c25c:400a:1fa
2522c19:dd:d9:dd:c25:c25c:400a:1fb/1282c19:dd:d9:dd:c25:c25c:400a:1fb
2532c19:dd:d9:dd:c25:c25c:400a:1fc/1282c19:dd:d9:dd:c25:c25c:400a:1fc
2542c19:dd:d9:dd:c25:c25c:400a:1fd/1282c19:dd:d9:dd:c25:c25c:400a:1fd
2552c19:dd:d9:dd:c25:c25c:400a:1fe/1282c19:dd:d9:dd:c25:c25c:400a:1fe
2562c19:dd:d9:dd:c25:c25c:400a:1ff/1282c19:dd:d9:dd:c25:c25c:400a:1ff

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.