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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:c25:c25:dd:dd:dd:3d00/120
First address
2c19:dd:c25:c25:dd:dd:dd:3d00
Last address
2c19:dd:c25:c25:dd:dd:dd:3dff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:0c25:0c25:00dd:00dd:00dd:3d00
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
d.3.d.d.0.0.d.d.0.0.d.d.0.0.5.2.c.0.5.2.c.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:c25:c25:dd:dd:dd:3d00/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:c25:c25:dd:dd:dd:3d00/1282c19:dd:c25:c25:dd:dd:dd:3d00
22c19:dd:c25:c25:dd:dd:dd:3d01/1282c19:dd:c25:c25:dd:dd:dd:3d01
32c19:dd:c25:c25:dd:dd:dd:3d02/1282c19:dd:c25:c25:dd:dd:dd:3d02
42c19:dd:c25:c25:dd:dd:dd:3d03/1282c19:dd:c25:c25:dd:dd:dd:3d03
52c19:dd:c25:c25:dd:dd:dd:3d04/1282c19:dd:c25:c25:dd:dd:dd:3d04
62c19:dd:c25:c25:dd:dd:dd:3d05/1282c19:dd:c25:c25:dd:dd:dd:3d05
72c19:dd:c25:c25:dd:dd:dd:3d06/1282c19:dd:c25:c25:dd:dd:dd:3d06
82c19:dd:c25:c25:dd:dd:dd:3d07/1282c19:dd:c25:c25:dd:dd:dd:3d07
92c19:dd:c25:c25:dd:dd:dd:3d08/1282c19:dd:c25:c25:dd:dd:dd:3d08
102c19:dd:c25:c25:dd:dd:dd:3d09/1282c19:dd:c25:c25:dd:dd:dd:3d09
112c19:dd:c25:c25:dd:dd:dd:3d0a/1282c19:dd:c25:c25:dd:dd:dd:3d0a
122c19:dd:c25:c25:dd:dd:dd:3d0b/1282c19:dd:c25:c25:dd:dd:dd:3d0b
132c19:dd:c25:c25:dd:dd:dd:3d0c/1282c19:dd:c25:c25:dd:dd:dd:3d0c
142c19:dd:c25:c25:dd:dd:dd:3d0d/1282c19:dd:c25:c25:dd:dd:dd:3d0d
152c19:dd:c25:c25:dd:dd:dd:3d0e/1282c19:dd:c25:c25:dd:dd:dd:3d0e
162c19:dd:c25:c25:dd:dd:dd:3d0f/1282c19:dd:c25:c25:dd:dd:dd:3d0f
172c19:dd:c25:c25:dd:dd:dd:3d10/1282c19:dd:c25:c25:dd:dd:dd:3d10
182c19:dd:c25:c25:dd:dd:dd:3d11/1282c19:dd:c25:c25:dd:dd:dd:3d11
192c19:dd:c25:c25:dd:dd:dd:3d12/1282c19:dd:c25:c25:dd:dd:dd:3d12
202c19:dd:c25:c25:dd:dd:dd:3d13/1282c19:dd:c25:c25:dd:dd:dd:3d13
212c19:dd:c25:c25:dd:dd:dd:3d14/1282c19:dd:c25:c25:dd:dd:dd:3d14
222c19:dd:c25:c25:dd:dd:dd:3d15/1282c19:dd:c25:c25:dd:dd:dd:3d15
232c19:dd:c25:c25:dd:dd:dd:3d16/1282c19:dd:c25:c25:dd:dd:dd:3d16
242c19:dd:c25:c25:dd:dd:dd:3d17/1282c19:dd:c25:c25:dd:dd:dd:3d17
252c19:dd:c25:c25:dd:dd:dd:3d18/1282c19:dd:c25:c25:dd:dd:dd:3d18
262c19:dd:c25:c25:dd:dd:dd:3d19/1282c19:dd:c25:c25:dd:dd:dd:3d19
272c19:dd:c25:c25:dd:dd:dd:3d1a/1282c19:dd:c25:c25:dd:dd:dd:3d1a
282c19:dd:c25:c25:dd:dd:dd:3d1b/1282c19:dd:c25:c25:dd:dd:dd:3d1b
292c19:dd:c25:c25:dd:dd:dd:3d1c/1282c19:dd:c25:c25:dd:dd:dd:3d1c
302c19:dd:c25:c25:dd:dd:dd:3d1d/1282c19:dd:c25:c25:dd:dd:dd:3d1d
312c19:dd:c25:c25:dd:dd:dd:3d1e/1282c19:dd:c25:c25:dd:dd:dd:3d1e
322c19:dd:c25:c25:dd:dd:dd:3d1f/1282c19:dd:c25:c25:dd:dd:dd:3d1f
332c19:dd:c25:c25:dd:dd:dd:3d20/1282c19:dd:c25:c25:dd:dd:dd:3d20
342c19:dd:c25:c25:dd:dd:dd:3d21/1282c19:dd:c25:c25:dd:dd:dd:3d21
352c19:dd:c25:c25:dd:dd:dd:3d22/1282c19:dd:c25:c25:dd:dd:dd:3d22
362c19:dd:c25:c25:dd:dd:dd:3d23/1282c19:dd:c25:c25:dd:dd:dd:3d23
372c19:dd:c25:c25:dd:dd:dd:3d24/1282c19:dd:c25:c25:dd:dd:dd:3d24
382c19:dd:c25:c25:dd:dd:dd:3d25/1282c19:dd:c25:c25:dd:dd:dd:3d25
392c19:dd:c25:c25:dd:dd:dd:3d26/1282c19:dd:c25:c25:dd:dd:dd:3d26
402c19:dd:c25:c25:dd:dd:dd:3d27/1282c19:dd:c25:c25:dd:dd:dd:3d27
412c19:dd:c25:c25:dd:dd:dd:3d28/1282c19:dd:c25:c25:dd:dd:dd:3d28
422c19:dd:c25:c25:dd:dd:dd:3d29/1282c19:dd:c25:c25:dd:dd:dd:3d29
432c19:dd:c25:c25:dd:dd:dd:3d2a/1282c19:dd:c25:c25:dd:dd:dd:3d2a
442c19:dd:c25:c25:dd:dd:dd:3d2b/1282c19:dd:c25:c25:dd:dd:dd:3d2b
452c19:dd:c25:c25:dd:dd:dd:3d2c/1282c19:dd:c25:c25:dd:dd:dd:3d2c
462c19:dd:c25:c25:dd:dd:dd:3d2d/1282c19:dd:c25:c25:dd:dd:dd:3d2d
472c19:dd:c25:c25:dd:dd:dd:3d2e/1282c19:dd:c25:c25:dd:dd:dd:3d2e
482c19:dd:c25:c25:dd:dd:dd:3d2f/1282c19:dd:c25:c25:dd:dd:dd:3d2f
492c19:dd:c25:c25:dd:dd:dd:3d30/1282c19:dd:c25:c25:dd:dd:dd:3d30
502c19:dd:c25:c25:dd:dd:dd:3d31/1282c19:dd:c25:c25:dd:dd:dd:3d31
512c19:dd:c25:c25:dd:dd:dd:3d32/1282c19:dd:c25:c25:dd:dd:dd:3d32
522c19:dd:c25:c25:dd:dd:dd:3d33/1282c19:dd:c25:c25:dd:dd:dd:3d33
532c19:dd:c25:c25:dd:dd:dd:3d34/1282c19:dd:c25:c25:dd:dd:dd:3d34
542c19:dd:c25:c25:dd:dd:dd:3d35/1282c19:dd:c25:c25:dd:dd:dd:3d35
552c19:dd:c25:c25:dd:dd:dd:3d36/1282c19:dd:c25:c25:dd:dd:dd:3d36
562c19:dd:c25:c25:dd:dd:dd:3d37/1282c19:dd:c25:c25:dd:dd:dd:3d37
572c19:dd:c25:c25:dd:dd:dd:3d38/1282c19:dd:c25:c25:dd:dd:dd:3d38
582c19:dd:c25:c25:dd:dd:dd:3d39/1282c19:dd:c25:c25:dd:dd:dd:3d39
592c19:dd:c25:c25:dd:dd:dd:3d3a/1282c19:dd:c25:c25:dd:dd:dd:3d3a
602c19:dd:c25:c25:dd:dd:dd:3d3b/1282c19:dd:c25:c25:dd:dd:dd:3d3b
612c19:dd:c25:c25:dd:dd:dd:3d3c/1282c19:dd:c25:c25:dd:dd:dd:3d3c
622c19:dd:c25:c25:dd:dd:dd:3d3d/1282c19:dd:c25:c25:dd:dd:dd:3d3d
632c19:dd:c25:c25:dd:dd:dd:3d3e/1282c19:dd:c25:c25:dd:dd:dd:3d3e
642c19:dd:c25:c25:dd:dd:dd:3d3f/1282c19:dd:c25:c25:dd:dd:dd:3d3f
652c19:dd:c25:c25:dd:dd:dd:3d40/1282c19:dd:c25:c25:dd:dd:dd:3d40
662c19:dd:c25:c25:dd:dd:dd:3d41/1282c19:dd:c25:c25:dd:dd:dd:3d41
672c19:dd:c25:c25:dd:dd:dd:3d42/1282c19:dd:c25:c25:dd:dd:dd:3d42
682c19:dd:c25:c25:dd:dd:dd:3d43/1282c19:dd:c25:c25:dd:dd:dd:3d43
692c19:dd:c25:c25:dd:dd:dd:3d44/1282c19:dd:c25:c25:dd:dd:dd:3d44
702c19:dd:c25:c25:dd:dd:dd:3d45/1282c19:dd:c25:c25:dd:dd:dd:3d45
712c19:dd:c25:c25:dd:dd:dd:3d46/1282c19:dd:c25:c25:dd:dd:dd:3d46
722c19:dd:c25:c25:dd:dd:dd:3d47/1282c19:dd:c25:c25:dd:dd:dd:3d47
732c19:dd:c25:c25:dd:dd:dd:3d48/1282c19:dd:c25:c25:dd:dd:dd:3d48
742c19:dd:c25:c25:dd:dd:dd:3d49/1282c19:dd:c25:c25:dd:dd:dd:3d49
752c19:dd:c25:c25:dd:dd:dd:3d4a/1282c19:dd:c25:c25:dd:dd:dd:3d4a
762c19:dd:c25:c25:dd:dd:dd:3d4b/1282c19:dd:c25:c25:dd:dd:dd:3d4b
772c19:dd:c25:c25:dd:dd:dd:3d4c/1282c19:dd:c25:c25:dd:dd:dd:3d4c
782c19:dd:c25:c25:dd:dd:dd:3d4d/1282c19:dd:c25:c25:dd:dd:dd:3d4d
792c19:dd:c25:c25:dd:dd:dd:3d4e/1282c19:dd:c25:c25:dd:dd:dd:3d4e
802c19:dd:c25:c25:dd:dd:dd:3d4f/1282c19:dd:c25:c25:dd:dd:dd:3d4f
812c19:dd:c25:c25:dd:dd:dd:3d50/1282c19:dd:c25:c25:dd:dd:dd:3d50
822c19:dd:c25:c25:dd:dd:dd:3d51/1282c19:dd:c25:c25:dd:dd:dd:3d51
832c19:dd:c25:c25:dd:dd:dd:3d52/1282c19:dd:c25:c25:dd:dd:dd:3d52
842c19:dd:c25:c25:dd:dd:dd:3d53/1282c19:dd:c25:c25:dd:dd:dd:3d53
852c19:dd:c25:c25:dd:dd:dd:3d54/1282c19:dd:c25:c25:dd:dd:dd:3d54
862c19:dd:c25:c25:dd:dd:dd:3d55/1282c19:dd:c25:c25:dd:dd:dd:3d55
872c19:dd:c25:c25:dd:dd:dd:3d56/1282c19:dd:c25:c25:dd:dd:dd:3d56
882c19:dd:c25:c25:dd:dd:dd:3d57/1282c19:dd:c25:c25:dd:dd:dd:3d57
892c19:dd:c25:c25:dd:dd:dd:3d58/1282c19:dd:c25:c25:dd:dd:dd:3d58
902c19:dd:c25:c25:dd:dd:dd:3d59/1282c19:dd:c25:c25:dd:dd:dd:3d59
912c19:dd:c25:c25:dd:dd:dd:3d5a/1282c19:dd:c25:c25:dd:dd:dd:3d5a
922c19:dd:c25:c25:dd:dd:dd:3d5b/1282c19:dd:c25:c25:dd:dd:dd:3d5b
932c19:dd:c25:c25:dd:dd:dd:3d5c/1282c19:dd:c25:c25:dd:dd:dd:3d5c
942c19:dd:c25:c25:dd:dd:dd:3d5d/1282c19:dd:c25:c25:dd:dd:dd:3d5d
952c19:dd:c25:c25:dd:dd:dd:3d5e/1282c19:dd:c25:c25:dd:dd:dd:3d5e
962c19:dd:c25:c25:dd:dd:dd:3d5f/1282c19:dd:c25:c25:dd:dd:dd:3d5f
972c19:dd:c25:c25:dd:dd:dd:3d60/1282c19:dd:c25:c25:dd:dd:dd:3d60
982c19:dd:c25:c25:dd:dd:dd:3d61/1282c19:dd:c25:c25:dd:dd:dd:3d61
992c19:dd:c25:c25:dd:dd:dd:3d62/1282c19:dd:c25:c25:dd:dd:dd:3d62
1002c19:dd:c25:c25:dd:dd:dd:3d63/1282c19:dd:c25:c25:dd:dd:dd:3d63
1012c19:dd:c25:c25:dd:dd:dd:3d64/1282c19:dd:c25:c25:dd:dd:dd:3d64
1022c19:dd:c25:c25:dd:dd:dd:3d65/1282c19:dd:c25:c25:dd:dd:dd:3d65
1032c19:dd:c25:c25:dd:dd:dd:3d66/1282c19:dd:c25:c25:dd:dd:dd:3d66
1042c19:dd:c25:c25:dd:dd:dd:3d67/1282c19:dd:c25:c25:dd:dd:dd:3d67
1052c19:dd:c25:c25:dd:dd:dd:3d68/1282c19:dd:c25:c25:dd:dd:dd:3d68
1062c19:dd:c25:c25:dd:dd:dd:3d69/1282c19:dd:c25:c25:dd:dd:dd:3d69
1072c19:dd:c25:c25:dd:dd:dd:3d6a/1282c19:dd:c25:c25:dd:dd:dd:3d6a
1082c19:dd:c25:c25:dd:dd:dd:3d6b/1282c19:dd:c25:c25:dd:dd:dd:3d6b
1092c19:dd:c25:c25:dd:dd:dd:3d6c/1282c19:dd:c25:c25:dd:dd:dd:3d6c
1102c19:dd:c25:c25:dd:dd:dd:3d6d/1282c19:dd:c25:c25:dd:dd:dd:3d6d
1112c19:dd:c25:c25:dd:dd:dd:3d6e/1282c19:dd:c25:c25:dd:dd:dd:3d6e
1122c19:dd:c25:c25:dd:dd:dd:3d6f/1282c19:dd:c25:c25:dd:dd:dd:3d6f
1132c19:dd:c25:c25:dd:dd:dd:3d70/1282c19:dd:c25:c25:dd:dd:dd:3d70
1142c19:dd:c25:c25:dd:dd:dd:3d71/1282c19:dd:c25:c25:dd:dd:dd:3d71
1152c19:dd:c25:c25:dd:dd:dd:3d72/1282c19:dd:c25:c25:dd:dd:dd:3d72
1162c19:dd:c25:c25:dd:dd:dd:3d73/1282c19:dd:c25:c25:dd:dd:dd:3d73
1172c19:dd:c25:c25:dd:dd:dd:3d74/1282c19:dd:c25:c25:dd:dd:dd:3d74
1182c19:dd:c25:c25:dd:dd:dd:3d75/1282c19:dd:c25:c25:dd:dd:dd:3d75
1192c19:dd:c25:c25:dd:dd:dd:3d76/1282c19:dd:c25:c25:dd:dd:dd:3d76
1202c19:dd:c25:c25:dd:dd:dd:3d77/1282c19:dd:c25:c25:dd:dd:dd:3d77
1212c19:dd:c25:c25:dd:dd:dd:3d78/1282c19:dd:c25:c25:dd:dd:dd:3d78
1222c19:dd:c25:c25:dd:dd:dd:3d79/1282c19:dd:c25:c25:dd:dd:dd:3d79
1232c19:dd:c25:c25:dd:dd:dd:3d7a/1282c19:dd:c25:c25:dd:dd:dd:3d7a
1242c19:dd:c25:c25:dd:dd:dd:3d7b/1282c19:dd:c25:c25:dd:dd:dd:3d7b
1252c19:dd:c25:c25:dd:dd:dd:3d7c/1282c19:dd:c25:c25:dd:dd:dd:3d7c
1262c19:dd:c25:c25:dd:dd:dd:3d7d/1282c19:dd:c25:c25:dd:dd:dd:3d7d
1272c19:dd:c25:c25:dd:dd:dd:3d7e/1282c19:dd:c25:c25:dd:dd:dd:3d7e
1282c19:dd:c25:c25:dd:dd:dd:3d7f/1282c19:dd:c25:c25:dd:dd:dd:3d7f
1292c19:dd:c25:c25:dd:dd:dd:3d80/1282c19:dd:c25:c25:dd:dd:dd:3d80
1302c19:dd:c25:c25:dd:dd:dd:3d81/1282c19:dd:c25:c25:dd:dd:dd:3d81
1312c19:dd:c25:c25:dd:dd:dd:3d82/1282c19:dd:c25:c25:dd:dd:dd:3d82
1322c19:dd:c25:c25:dd:dd:dd:3d83/1282c19:dd:c25:c25:dd:dd:dd:3d83
1332c19:dd:c25:c25:dd:dd:dd:3d84/1282c19:dd:c25:c25:dd:dd:dd:3d84
1342c19:dd:c25:c25:dd:dd:dd:3d85/1282c19:dd:c25:c25:dd:dd:dd:3d85
1352c19:dd:c25:c25:dd:dd:dd:3d86/1282c19:dd:c25:c25:dd:dd:dd:3d86
1362c19:dd:c25:c25:dd:dd:dd:3d87/1282c19:dd:c25:c25:dd:dd:dd:3d87
1372c19:dd:c25:c25:dd:dd:dd:3d88/1282c19:dd:c25:c25:dd:dd:dd:3d88
1382c19:dd:c25:c25:dd:dd:dd:3d89/1282c19:dd:c25:c25:dd:dd:dd:3d89
1392c19:dd:c25:c25:dd:dd:dd:3d8a/1282c19:dd:c25:c25:dd:dd:dd:3d8a
1402c19:dd:c25:c25:dd:dd:dd:3d8b/1282c19:dd:c25:c25:dd:dd:dd:3d8b
1412c19:dd:c25:c25:dd:dd:dd:3d8c/1282c19:dd:c25:c25:dd:dd:dd:3d8c
1422c19:dd:c25:c25:dd:dd:dd:3d8d/1282c19:dd:c25:c25:dd:dd:dd:3d8d
1432c19:dd:c25:c25:dd:dd:dd:3d8e/1282c19:dd:c25:c25:dd:dd:dd:3d8e
1442c19:dd:c25:c25:dd:dd:dd:3d8f/1282c19:dd:c25:c25:dd:dd:dd:3d8f
1452c19:dd:c25:c25:dd:dd:dd:3d90/1282c19:dd:c25:c25:dd:dd:dd:3d90
1462c19:dd:c25:c25:dd:dd:dd:3d91/1282c19:dd:c25:c25:dd:dd:dd:3d91
1472c19:dd:c25:c25:dd:dd:dd:3d92/1282c19:dd:c25:c25:dd:dd:dd:3d92
1482c19:dd:c25:c25:dd:dd:dd:3d93/1282c19:dd:c25:c25:dd:dd:dd:3d93
1492c19:dd:c25:c25:dd:dd:dd:3d94/1282c19:dd:c25:c25:dd:dd:dd:3d94
1502c19:dd:c25:c25:dd:dd:dd:3d95/1282c19:dd:c25:c25:dd:dd:dd:3d95
1512c19:dd:c25:c25:dd:dd:dd:3d96/1282c19:dd:c25:c25:dd:dd:dd:3d96
1522c19:dd:c25:c25:dd:dd:dd:3d97/1282c19:dd:c25:c25:dd:dd:dd:3d97
1532c19:dd:c25:c25:dd:dd:dd:3d98/1282c19:dd:c25:c25:dd:dd:dd:3d98
1542c19:dd:c25:c25:dd:dd:dd:3d99/1282c19:dd:c25:c25:dd:dd:dd:3d99
1552c19:dd:c25:c25:dd:dd:dd:3d9a/1282c19:dd:c25:c25:dd:dd:dd:3d9a
1562c19:dd:c25:c25:dd:dd:dd:3d9b/1282c19:dd:c25:c25:dd:dd:dd:3d9b
1572c19:dd:c25:c25:dd:dd:dd:3d9c/1282c19:dd:c25:c25:dd:dd:dd:3d9c
1582c19:dd:c25:c25:dd:dd:dd:3d9d/1282c19:dd:c25:c25:dd:dd:dd:3d9d
1592c19:dd:c25:c25:dd:dd:dd:3d9e/1282c19:dd:c25:c25:dd:dd:dd:3d9e
1602c19:dd:c25:c25:dd:dd:dd:3d9f/1282c19:dd:c25:c25:dd:dd:dd:3d9f
1612c19:dd:c25:c25:dd:dd:dd:3da0/1282c19:dd:c25:c25:dd:dd:dd:3da0
1622c19:dd:c25:c25:dd:dd:dd:3da1/1282c19:dd:c25:c25:dd:dd:dd:3da1
1632c19:dd:c25:c25:dd:dd:dd:3da2/1282c19:dd:c25:c25:dd:dd:dd:3da2
1642c19:dd:c25:c25:dd:dd:dd:3da3/1282c19:dd:c25:c25:dd:dd:dd:3da3
1652c19:dd:c25:c25:dd:dd:dd:3da4/1282c19:dd:c25:c25:dd:dd:dd:3da4
1662c19:dd:c25:c25:dd:dd:dd:3da5/1282c19:dd:c25:c25:dd:dd:dd:3da5
1672c19:dd:c25:c25:dd:dd:dd:3da6/1282c19:dd:c25:c25:dd:dd:dd:3da6
1682c19:dd:c25:c25:dd:dd:dd:3da7/1282c19:dd:c25:c25:dd:dd:dd:3da7
1692c19:dd:c25:c25:dd:dd:dd:3da8/1282c19:dd:c25:c25:dd:dd:dd:3da8
1702c19:dd:c25:c25:dd:dd:dd:3da9/1282c19:dd:c25:c25:dd:dd:dd:3da9
1712c19:dd:c25:c25:dd:dd:dd:3daa/1282c19:dd:c25:c25:dd:dd:dd:3daa
1722c19:dd:c25:c25:dd:dd:dd:3dab/1282c19:dd:c25:c25:dd:dd:dd:3dab
1732c19:dd:c25:c25:dd:dd:dd:3dac/1282c19:dd:c25:c25:dd:dd:dd:3dac
1742c19:dd:c25:c25:dd:dd:dd:3dad/1282c19:dd:c25:c25:dd:dd:dd:3dad
1752c19:dd:c25:c25:dd:dd:dd:3dae/1282c19:dd:c25:c25:dd:dd:dd:3dae
1762c19:dd:c25:c25:dd:dd:dd:3daf/1282c19:dd:c25:c25:dd:dd:dd:3daf
1772c19:dd:c25:c25:dd:dd:dd:3db0/1282c19:dd:c25:c25:dd:dd:dd:3db0
1782c19:dd:c25:c25:dd:dd:dd:3db1/1282c19:dd:c25:c25:dd:dd:dd:3db1
1792c19:dd:c25:c25:dd:dd:dd:3db2/1282c19:dd:c25:c25:dd:dd:dd:3db2
1802c19:dd:c25:c25:dd:dd:dd:3db3/1282c19:dd:c25:c25:dd:dd:dd:3db3
1812c19:dd:c25:c25:dd:dd:dd:3db4/1282c19:dd:c25:c25:dd:dd:dd:3db4
1822c19:dd:c25:c25:dd:dd:dd:3db5/1282c19:dd:c25:c25:dd:dd:dd:3db5
1832c19:dd:c25:c25:dd:dd:dd:3db6/1282c19:dd:c25:c25:dd:dd:dd:3db6
1842c19:dd:c25:c25:dd:dd:dd:3db7/1282c19:dd:c25:c25:dd:dd:dd:3db7
1852c19:dd:c25:c25:dd:dd:dd:3db8/1282c19:dd:c25:c25:dd:dd:dd:3db8
1862c19:dd:c25:c25:dd:dd:dd:3db9/1282c19:dd:c25:c25:dd:dd:dd:3db9
1872c19:dd:c25:c25:dd:dd:dd:3dba/1282c19:dd:c25:c25:dd:dd:dd:3dba
1882c19:dd:c25:c25:dd:dd:dd:3dbb/1282c19:dd:c25:c25:dd:dd:dd:3dbb
1892c19:dd:c25:c25:dd:dd:dd:3dbc/1282c19:dd:c25:c25:dd:dd:dd:3dbc
1902c19:dd:c25:c25:dd:dd:dd:3dbd/1282c19:dd:c25:c25:dd:dd:dd:3dbd
1912c19:dd:c25:c25:dd:dd:dd:3dbe/1282c19:dd:c25:c25:dd:dd:dd:3dbe
1922c19:dd:c25:c25:dd:dd:dd:3dbf/1282c19:dd:c25:c25:dd:dd:dd:3dbf
1932c19:dd:c25:c25:dd:dd:dd:3dc0/1282c19:dd:c25:c25:dd:dd:dd:3dc0
1942c19:dd:c25:c25:dd:dd:dd:3dc1/1282c19:dd:c25:c25:dd:dd:dd:3dc1
1952c19:dd:c25:c25:dd:dd:dd:3dc2/1282c19:dd:c25:c25:dd:dd:dd:3dc2
1962c19:dd:c25:c25:dd:dd:dd:3dc3/1282c19:dd:c25:c25:dd:dd:dd:3dc3
1972c19:dd:c25:c25:dd:dd:dd:3dc4/1282c19:dd:c25:c25:dd:dd:dd:3dc4
1982c19:dd:c25:c25:dd:dd:dd:3dc5/1282c19:dd:c25:c25:dd:dd:dd:3dc5
1992c19:dd:c25:c25:dd:dd:dd:3dc6/1282c19:dd:c25:c25:dd:dd:dd:3dc6
2002c19:dd:c25:c25:dd:dd:dd:3dc7/1282c19:dd:c25:c25:dd:dd:dd:3dc7
2012c19:dd:c25:c25:dd:dd:dd:3dc8/1282c19:dd:c25:c25:dd:dd:dd:3dc8
2022c19:dd:c25:c25:dd:dd:dd:3dc9/1282c19:dd:c25:c25:dd:dd:dd:3dc9
2032c19:dd:c25:c25:dd:dd:dd:3dca/1282c19:dd:c25:c25:dd:dd:dd:3dca
2042c19:dd:c25:c25:dd:dd:dd:3dcb/1282c19:dd:c25:c25:dd:dd:dd:3dcb
2052c19:dd:c25:c25:dd:dd:dd:3dcc/1282c19:dd:c25:c25:dd:dd:dd:3dcc
2062c19:dd:c25:c25:dd:dd:dd:3dcd/1282c19:dd:c25:c25:dd:dd:dd:3dcd
2072c19:dd:c25:c25:dd:dd:dd:3dce/1282c19:dd:c25:c25:dd:dd:dd:3dce
2082c19:dd:c25:c25:dd:dd:dd:3dcf/1282c19:dd:c25:c25:dd:dd:dd:3dcf
2092c19:dd:c25:c25:dd:dd:dd:3dd0/1282c19:dd:c25:c25:dd:dd:dd:3dd0
2102c19:dd:c25:c25:dd:dd:dd:3dd1/1282c19:dd:c25:c25:dd:dd:dd:3dd1
2112c19:dd:c25:c25:dd:dd:dd:3dd2/1282c19:dd:c25:c25:dd:dd:dd:3dd2
2122c19:dd:c25:c25:dd:dd:dd:3dd3/1282c19:dd:c25:c25:dd:dd:dd:3dd3
2132c19:dd:c25:c25:dd:dd:dd:3dd4/1282c19:dd:c25:c25:dd:dd:dd:3dd4
2142c19:dd:c25:c25:dd:dd:dd:3dd5/1282c19:dd:c25:c25:dd:dd:dd:3dd5
2152c19:dd:c25:c25:dd:dd:dd:3dd6/1282c19:dd:c25:c25:dd:dd:dd:3dd6
2162c19:dd:c25:c25:dd:dd:dd:3dd7/1282c19:dd:c25:c25:dd:dd:dd:3dd7
2172c19:dd:c25:c25:dd:dd:dd:3dd8/1282c19:dd:c25:c25:dd:dd:dd:3dd8
2182c19:dd:c25:c25:dd:dd:dd:3dd9/1282c19:dd:c25:c25:dd:dd:dd:3dd9
2192c19:dd:c25:c25:dd:dd:dd:3dda/1282c19:dd:c25:c25:dd:dd:dd:3dda
2202c19:dd:c25:c25:dd:dd:dd:3ddb/1282c19:dd:c25:c25:dd:dd:dd:3ddb
2212c19:dd:c25:c25:dd:dd:dd:3ddc/1282c19:dd:c25:c25:dd:dd:dd:3ddc
2222c19:dd:c25:c25:dd:dd:dd:3ddd/1282c19:dd:c25:c25:dd:dd:dd:3ddd
2232c19:dd:c25:c25:dd:dd:dd:3dde/1282c19:dd:c25:c25:dd:dd:dd:3dde
2242c19:dd:c25:c25:dd:dd:dd:3ddf/1282c19:dd:c25:c25:dd:dd:dd:3ddf
2252c19:dd:c25:c25:dd:dd:dd:3de0/1282c19:dd:c25:c25:dd:dd:dd:3de0
2262c19:dd:c25:c25:dd:dd:dd:3de1/1282c19:dd:c25:c25:dd:dd:dd:3de1
2272c19:dd:c25:c25:dd:dd:dd:3de2/1282c19:dd:c25:c25:dd:dd:dd:3de2
2282c19:dd:c25:c25:dd:dd:dd:3de3/1282c19:dd:c25:c25:dd:dd:dd:3de3
2292c19:dd:c25:c25:dd:dd:dd:3de4/1282c19:dd:c25:c25:dd:dd:dd:3de4
2302c19:dd:c25:c25:dd:dd:dd:3de5/1282c19:dd:c25:c25:dd:dd:dd:3de5
2312c19:dd:c25:c25:dd:dd:dd:3de6/1282c19:dd:c25:c25:dd:dd:dd:3de6
2322c19:dd:c25:c25:dd:dd:dd:3de7/1282c19:dd:c25:c25:dd:dd:dd:3de7
2332c19:dd:c25:c25:dd:dd:dd:3de8/1282c19:dd:c25:c25:dd:dd:dd:3de8
2342c19:dd:c25:c25:dd:dd:dd:3de9/1282c19:dd:c25:c25:dd:dd:dd:3de9
2352c19:dd:c25:c25:dd:dd:dd:3dea/1282c19:dd:c25:c25:dd:dd:dd:3dea
2362c19:dd:c25:c25:dd:dd:dd:3deb/1282c19:dd:c25:c25:dd:dd:dd:3deb
2372c19:dd:c25:c25:dd:dd:dd:3dec/1282c19:dd:c25:c25:dd:dd:dd:3dec
2382c19:dd:c25:c25:dd:dd:dd:3ded/1282c19:dd:c25:c25:dd:dd:dd:3ded
2392c19:dd:c25:c25:dd:dd:dd:3dee/1282c19:dd:c25:c25:dd:dd:dd:3dee
2402c19:dd:c25:c25:dd:dd:dd:3def/1282c19:dd:c25:c25:dd:dd:dd:3def
2412c19:dd:c25:c25:dd:dd:dd:3df0/1282c19:dd:c25:c25:dd:dd:dd:3df0
2422c19:dd:c25:c25:dd:dd:dd:3df1/1282c19:dd:c25:c25:dd:dd:dd:3df1
2432c19:dd:c25:c25:dd:dd:dd:3df2/1282c19:dd:c25:c25:dd:dd:dd:3df2
2442c19:dd:c25:c25:dd:dd:dd:3df3/1282c19:dd:c25:c25:dd:dd:dd:3df3
2452c19:dd:c25:c25:dd:dd:dd:3df4/1282c19:dd:c25:c25:dd:dd:dd:3df4
2462c19:dd:c25:c25:dd:dd:dd:3df5/1282c19:dd:c25:c25:dd:dd:dd:3df5
2472c19:dd:c25:c25:dd:dd:dd:3df6/1282c19:dd:c25:c25:dd:dd:dd:3df6
2482c19:dd:c25:c25:dd:dd:dd:3df7/1282c19:dd:c25:c25:dd:dd:dd:3df7
2492c19:dd:c25:c25:dd:dd:dd:3df8/1282c19:dd:c25:c25:dd:dd:dd:3df8
2502c19:dd:c25:c25:dd:dd:dd:3df9/1282c19:dd:c25:c25:dd:dd:dd:3df9
2512c19:dd:c25:c25:dd:dd:dd:3dfa/1282c19:dd:c25:c25:dd:dd:dd:3dfa
2522c19:dd:c25:c25:dd:dd:dd:3dfb/1282c19:dd:c25:c25:dd:dd:dd:3dfb
2532c19:dd:c25:c25:dd:dd:dd:3dfc/1282c19:dd:c25:c25:dd:dd:dd:3dfc
2542c19:dd:c25:c25:dd:dd:dd:3dfd/1282c19:dd:c25:c25:dd:dd:dd:3dfd
2552c19:dd:c25:c25:dd:dd:dd:3dfe/1282c19:dd:c25:c25:dd:dd:dd:3dfe
2562c19:dd:c25:c25:dd:dd:dd:3dff/1282c19:dd:c25:c25:dd:dd:dd:3dff

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.