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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:c25d:dd:dd:dd:f00/120
First address
2c19:dd:c25:c25d:dd:dd:dd:f00
Last address
2c19:dd:c25:c25d:dd:dd:dd:fff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:0c25:c25d:00dd:00dd:00dd:0f00
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
f.0.d.d.0.0.d.d.0.0.d.d.0.0.d.5.2.c.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:c25d:dd:dd:dd:f00/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:c25:c25d:dd:dd:dd:f00/1282c19:dd:c25:c25d:dd:dd:dd:f00
22c19:dd:c25:c25d:dd:dd:dd:f01/1282c19:dd:c25:c25d:dd:dd:dd:f01
32c19:dd:c25:c25d:dd:dd:dd:f02/1282c19:dd:c25:c25d:dd:dd:dd:f02
42c19:dd:c25:c25d:dd:dd:dd:f03/1282c19:dd:c25:c25d:dd:dd:dd:f03
52c19:dd:c25:c25d:dd:dd:dd:f04/1282c19:dd:c25:c25d:dd:dd:dd:f04
62c19:dd:c25:c25d:dd:dd:dd:f05/1282c19:dd:c25:c25d:dd:dd:dd:f05
72c19:dd:c25:c25d:dd:dd:dd:f06/1282c19:dd:c25:c25d:dd:dd:dd:f06
82c19:dd:c25:c25d:dd:dd:dd:f07/1282c19:dd:c25:c25d:dd:dd:dd:f07
92c19:dd:c25:c25d:dd:dd:dd:f08/1282c19:dd:c25:c25d:dd:dd:dd:f08
102c19:dd:c25:c25d:dd:dd:dd:f09/1282c19:dd:c25:c25d:dd:dd:dd:f09
112c19:dd:c25:c25d:dd:dd:dd:f0a/1282c19:dd:c25:c25d:dd:dd:dd:f0a
122c19:dd:c25:c25d:dd:dd:dd:f0b/1282c19:dd:c25:c25d:dd:dd:dd:f0b
132c19:dd:c25:c25d:dd:dd:dd:f0c/1282c19:dd:c25:c25d:dd:dd:dd:f0c
142c19:dd:c25:c25d:dd:dd:dd:f0d/1282c19:dd:c25:c25d:dd:dd:dd:f0d
152c19:dd:c25:c25d:dd:dd:dd:f0e/1282c19:dd:c25:c25d:dd:dd:dd:f0e
162c19:dd:c25:c25d:dd:dd:dd:f0f/1282c19:dd:c25:c25d:dd:dd:dd:f0f
172c19:dd:c25:c25d:dd:dd:dd:f10/1282c19:dd:c25:c25d:dd:dd:dd:f10
182c19:dd:c25:c25d:dd:dd:dd:f11/1282c19:dd:c25:c25d:dd:dd:dd:f11
192c19:dd:c25:c25d:dd:dd:dd:f12/1282c19:dd:c25:c25d:dd:dd:dd:f12
202c19:dd:c25:c25d:dd:dd:dd:f13/1282c19:dd:c25:c25d:dd:dd:dd:f13
212c19:dd:c25:c25d:dd:dd:dd:f14/1282c19:dd:c25:c25d:dd:dd:dd:f14
222c19:dd:c25:c25d:dd:dd:dd:f15/1282c19:dd:c25:c25d:dd:dd:dd:f15
232c19:dd:c25:c25d:dd:dd:dd:f16/1282c19:dd:c25:c25d:dd:dd:dd:f16
242c19:dd:c25:c25d:dd:dd:dd:f17/1282c19:dd:c25:c25d:dd:dd:dd:f17
252c19:dd:c25:c25d:dd:dd:dd:f18/1282c19:dd:c25:c25d:dd:dd:dd:f18
262c19:dd:c25:c25d:dd:dd:dd:f19/1282c19:dd:c25:c25d:dd:dd:dd:f19
272c19:dd:c25:c25d:dd:dd:dd:f1a/1282c19:dd:c25:c25d:dd:dd:dd:f1a
282c19:dd:c25:c25d:dd:dd:dd:f1b/1282c19:dd:c25:c25d:dd:dd:dd:f1b
292c19:dd:c25:c25d:dd:dd:dd:f1c/1282c19:dd:c25:c25d:dd:dd:dd:f1c
302c19:dd:c25:c25d:dd:dd:dd:f1d/1282c19:dd:c25:c25d:dd:dd:dd:f1d
312c19:dd:c25:c25d:dd:dd:dd:f1e/1282c19:dd:c25:c25d:dd:dd:dd:f1e
322c19:dd:c25:c25d:dd:dd:dd:f1f/1282c19:dd:c25:c25d:dd:dd:dd:f1f
332c19:dd:c25:c25d:dd:dd:dd:f20/1282c19:dd:c25:c25d:dd:dd:dd:f20
342c19:dd:c25:c25d:dd:dd:dd:f21/1282c19:dd:c25:c25d:dd:dd:dd:f21
352c19:dd:c25:c25d:dd:dd:dd:f22/1282c19:dd:c25:c25d:dd:dd:dd:f22
362c19:dd:c25:c25d:dd:dd:dd:f23/1282c19:dd:c25:c25d:dd:dd:dd:f23
372c19:dd:c25:c25d:dd:dd:dd:f24/1282c19:dd:c25:c25d:dd:dd:dd:f24
382c19:dd:c25:c25d:dd:dd:dd:f25/1282c19:dd:c25:c25d:dd:dd:dd:f25
392c19:dd:c25:c25d:dd:dd:dd:f26/1282c19:dd:c25:c25d:dd:dd:dd:f26
402c19:dd:c25:c25d:dd:dd:dd:f27/1282c19:dd:c25:c25d:dd:dd:dd:f27
412c19:dd:c25:c25d:dd:dd:dd:f28/1282c19:dd:c25:c25d:dd:dd:dd:f28
422c19:dd:c25:c25d:dd:dd:dd:f29/1282c19:dd:c25:c25d:dd:dd:dd:f29
432c19:dd:c25:c25d:dd:dd:dd:f2a/1282c19:dd:c25:c25d:dd:dd:dd:f2a
442c19:dd:c25:c25d:dd:dd:dd:f2b/1282c19:dd:c25:c25d:dd:dd:dd:f2b
452c19:dd:c25:c25d:dd:dd:dd:f2c/1282c19:dd:c25:c25d:dd:dd:dd:f2c
462c19:dd:c25:c25d:dd:dd:dd:f2d/1282c19:dd:c25:c25d:dd:dd:dd:f2d
472c19:dd:c25:c25d:dd:dd:dd:f2e/1282c19:dd:c25:c25d:dd:dd:dd:f2e
482c19:dd:c25:c25d:dd:dd:dd:f2f/1282c19:dd:c25:c25d:dd:dd:dd:f2f
492c19:dd:c25:c25d:dd:dd:dd:f30/1282c19:dd:c25:c25d:dd:dd:dd:f30
502c19:dd:c25:c25d:dd:dd:dd:f31/1282c19:dd:c25:c25d:dd:dd:dd:f31
512c19:dd:c25:c25d:dd:dd:dd:f32/1282c19:dd:c25:c25d:dd:dd:dd:f32
522c19:dd:c25:c25d:dd:dd:dd:f33/1282c19:dd:c25:c25d:dd:dd:dd:f33
532c19:dd:c25:c25d:dd:dd:dd:f34/1282c19:dd:c25:c25d:dd:dd:dd:f34
542c19:dd:c25:c25d:dd:dd:dd:f35/1282c19:dd:c25:c25d:dd:dd:dd:f35
552c19:dd:c25:c25d:dd:dd:dd:f36/1282c19:dd:c25:c25d:dd:dd:dd:f36
562c19:dd:c25:c25d:dd:dd:dd:f37/1282c19:dd:c25:c25d:dd:dd:dd:f37
572c19:dd:c25:c25d:dd:dd:dd:f38/1282c19:dd:c25:c25d:dd:dd:dd:f38
582c19:dd:c25:c25d:dd:dd:dd:f39/1282c19:dd:c25:c25d:dd:dd:dd:f39
592c19:dd:c25:c25d:dd:dd:dd:f3a/1282c19:dd:c25:c25d:dd:dd:dd:f3a
602c19:dd:c25:c25d:dd:dd:dd:f3b/1282c19:dd:c25:c25d:dd:dd:dd:f3b
612c19:dd:c25:c25d:dd:dd:dd:f3c/1282c19:dd:c25:c25d:dd:dd:dd:f3c
622c19:dd:c25:c25d:dd:dd:dd:f3d/1282c19:dd:c25:c25d:dd:dd:dd:f3d
632c19:dd:c25:c25d:dd:dd:dd:f3e/1282c19:dd:c25:c25d:dd:dd:dd:f3e
642c19:dd:c25:c25d:dd:dd:dd:f3f/1282c19:dd:c25:c25d:dd:dd:dd:f3f
652c19:dd:c25:c25d:dd:dd:dd:f40/1282c19:dd:c25:c25d:dd:dd:dd:f40
662c19:dd:c25:c25d:dd:dd:dd:f41/1282c19:dd:c25:c25d:dd:dd:dd:f41
672c19:dd:c25:c25d:dd:dd:dd:f42/1282c19:dd:c25:c25d:dd:dd:dd:f42
682c19:dd:c25:c25d:dd:dd:dd:f43/1282c19:dd:c25:c25d:dd:dd:dd:f43
692c19:dd:c25:c25d:dd:dd:dd:f44/1282c19:dd:c25:c25d:dd:dd:dd:f44
702c19:dd:c25:c25d:dd:dd:dd:f45/1282c19:dd:c25:c25d:dd:dd:dd:f45
712c19:dd:c25:c25d:dd:dd:dd:f46/1282c19:dd:c25:c25d:dd:dd:dd:f46
722c19:dd:c25:c25d:dd:dd:dd:f47/1282c19:dd:c25:c25d:dd:dd:dd:f47
732c19:dd:c25:c25d:dd:dd:dd:f48/1282c19:dd:c25:c25d:dd:dd:dd:f48
742c19:dd:c25:c25d:dd:dd:dd:f49/1282c19:dd:c25:c25d:dd:dd:dd:f49
752c19:dd:c25:c25d:dd:dd:dd:f4a/1282c19:dd:c25:c25d:dd:dd:dd:f4a
762c19:dd:c25:c25d:dd:dd:dd:f4b/1282c19:dd:c25:c25d:dd:dd:dd:f4b
772c19:dd:c25:c25d:dd:dd:dd:f4c/1282c19:dd:c25:c25d:dd:dd:dd:f4c
782c19:dd:c25:c25d:dd:dd:dd:f4d/1282c19:dd:c25:c25d:dd:dd:dd:f4d
792c19:dd:c25:c25d:dd:dd:dd:f4e/1282c19:dd:c25:c25d:dd:dd:dd:f4e
802c19:dd:c25:c25d:dd:dd:dd:f4f/1282c19:dd:c25:c25d:dd:dd:dd:f4f
812c19:dd:c25:c25d:dd:dd:dd:f50/1282c19:dd:c25:c25d:dd:dd:dd:f50
822c19:dd:c25:c25d:dd:dd:dd:f51/1282c19:dd:c25:c25d:dd:dd:dd:f51
832c19:dd:c25:c25d:dd:dd:dd:f52/1282c19:dd:c25:c25d:dd:dd:dd:f52
842c19:dd:c25:c25d:dd:dd:dd:f53/1282c19:dd:c25:c25d:dd:dd:dd:f53
852c19:dd:c25:c25d:dd:dd:dd:f54/1282c19:dd:c25:c25d:dd:dd:dd:f54
862c19:dd:c25:c25d:dd:dd:dd:f55/1282c19:dd:c25:c25d:dd:dd:dd:f55
872c19:dd:c25:c25d:dd:dd:dd:f56/1282c19:dd:c25:c25d:dd:dd:dd:f56
882c19:dd:c25:c25d:dd:dd:dd:f57/1282c19:dd:c25:c25d:dd:dd:dd:f57
892c19:dd:c25:c25d:dd:dd:dd:f58/1282c19:dd:c25:c25d:dd:dd:dd:f58
902c19:dd:c25:c25d:dd:dd:dd:f59/1282c19:dd:c25:c25d:dd:dd:dd:f59
912c19:dd:c25:c25d:dd:dd:dd:f5a/1282c19:dd:c25:c25d:dd:dd:dd:f5a
922c19:dd:c25:c25d:dd:dd:dd:f5b/1282c19:dd:c25:c25d:dd:dd:dd:f5b
932c19:dd:c25:c25d:dd:dd:dd:f5c/1282c19:dd:c25:c25d:dd:dd:dd:f5c
942c19:dd:c25:c25d:dd:dd:dd:f5d/1282c19:dd:c25:c25d:dd:dd:dd:f5d
952c19:dd:c25:c25d:dd:dd:dd:f5e/1282c19:dd:c25:c25d:dd:dd:dd:f5e
962c19:dd:c25:c25d:dd:dd:dd:f5f/1282c19:dd:c25:c25d:dd:dd:dd:f5f
972c19:dd:c25:c25d:dd:dd:dd:f60/1282c19:dd:c25:c25d:dd:dd:dd:f60
982c19:dd:c25:c25d:dd:dd:dd:f61/1282c19:dd:c25:c25d:dd:dd:dd:f61
992c19:dd:c25:c25d:dd:dd:dd:f62/1282c19:dd:c25:c25d:dd:dd:dd:f62
1002c19:dd:c25:c25d:dd:dd:dd:f63/1282c19:dd:c25:c25d:dd:dd:dd:f63
1012c19:dd:c25:c25d:dd:dd:dd:f64/1282c19:dd:c25:c25d:dd:dd:dd:f64
1022c19:dd:c25:c25d:dd:dd:dd:f65/1282c19:dd:c25:c25d:dd:dd:dd:f65
1032c19:dd:c25:c25d:dd:dd:dd:f66/1282c19:dd:c25:c25d:dd:dd:dd:f66
1042c19:dd:c25:c25d:dd:dd:dd:f67/1282c19:dd:c25:c25d:dd:dd:dd:f67
1052c19:dd:c25:c25d:dd:dd:dd:f68/1282c19:dd:c25:c25d:dd:dd:dd:f68
1062c19:dd:c25:c25d:dd:dd:dd:f69/1282c19:dd:c25:c25d:dd:dd:dd:f69
1072c19:dd:c25:c25d:dd:dd:dd:f6a/1282c19:dd:c25:c25d:dd:dd:dd:f6a
1082c19:dd:c25:c25d:dd:dd:dd:f6b/1282c19:dd:c25:c25d:dd:dd:dd:f6b
1092c19:dd:c25:c25d:dd:dd:dd:f6c/1282c19:dd:c25:c25d:dd:dd:dd:f6c
1102c19:dd:c25:c25d:dd:dd:dd:f6d/1282c19:dd:c25:c25d:dd:dd:dd:f6d
1112c19:dd:c25:c25d:dd:dd:dd:f6e/1282c19:dd:c25:c25d:dd:dd:dd:f6e
1122c19:dd:c25:c25d:dd:dd:dd:f6f/1282c19:dd:c25:c25d:dd:dd:dd:f6f
1132c19:dd:c25:c25d:dd:dd:dd:f70/1282c19:dd:c25:c25d:dd:dd:dd:f70
1142c19:dd:c25:c25d:dd:dd:dd:f71/1282c19:dd:c25:c25d:dd:dd:dd:f71
1152c19:dd:c25:c25d:dd:dd:dd:f72/1282c19:dd:c25:c25d:dd:dd:dd:f72
1162c19:dd:c25:c25d:dd:dd:dd:f73/1282c19:dd:c25:c25d:dd:dd:dd:f73
1172c19:dd:c25:c25d:dd:dd:dd:f74/1282c19:dd:c25:c25d:dd:dd:dd:f74
1182c19:dd:c25:c25d:dd:dd:dd:f75/1282c19:dd:c25:c25d:dd:dd:dd:f75
1192c19:dd:c25:c25d:dd:dd:dd:f76/1282c19:dd:c25:c25d:dd:dd:dd:f76
1202c19:dd:c25:c25d:dd:dd:dd:f77/1282c19:dd:c25:c25d:dd:dd:dd:f77
1212c19:dd:c25:c25d:dd:dd:dd:f78/1282c19:dd:c25:c25d:dd:dd:dd:f78
1222c19:dd:c25:c25d:dd:dd:dd:f79/1282c19:dd:c25:c25d:dd:dd:dd:f79
1232c19:dd:c25:c25d:dd:dd:dd:f7a/1282c19:dd:c25:c25d:dd:dd:dd:f7a
1242c19:dd:c25:c25d:dd:dd:dd:f7b/1282c19:dd:c25:c25d:dd:dd:dd:f7b
1252c19:dd:c25:c25d:dd:dd:dd:f7c/1282c19:dd:c25:c25d:dd:dd:dd:f7c
1262c19:dd:c25:c25d:dd:dd:dd:f7d/1282c19:dd:c25:c25d:dd:dd:dd:f7d
1272c19:dd:c25:c25d:dd:dd:dd:f7e/1282c19:dd:c25:c25d:dd:dd:dd:f7e
1282c19:dd:c25:c25d:dd:dd:dd:f7f/1282c19:dd:c25:c25d:dd:dd:dd:f7f
1292c19:dd:c25:c25d:dd:dd:dd:f80/1282c19:dd:c25:c25d:dd:dd:dd:f80
1302c19:dd:c25:c25d:dd:dd:dd:f81/1282c19:dd:c25:c25d:dd:dd:dd:f81
1312c19:dd:c25:c25d:dd:dd:dd:f82/1282c19:dd:c25:c25d:dd:dd:dd:f82
1322c19:dd:c25:c25d:dd:dd:dd:f83/1282c19:dd:c25:c25d:dd:dd:dd:f83
1332c19:dd:c25:c25d:dd:dd:dd:f84/1282c19:dd:c25:c25d:dd:dd:dd:f84
1342c19:dd:c25:c25d:dd:dd:dd:f85/1282c19:dd:c25:c25d:dd:dd:dd:f85
1352c19:dd:c25:c25d:dd:dd:dd:f86/1282c19:dd:c25:c25d:dd:dd:dd:f86
1362c19:dd:c25:c25d:dd:dd:dd:f87/1282c19:dd:c25:c25d:dd:dd:dd:f87
1372c19:dd:c25:c25d:dd:dd:dd:f88/1282c19:dd:c25:c25d:dd:dd:dd:f88
1382c19:dd:c25:c25d:dd:dd:dd:f89/1282c19:dd:c25:c25d:dd:dd:dd:f89
1392c19:dd:c25:c25d:dd:dd:dd:f8a/1282c19:dd:c25:c25d:dd:dd:dd:f8a
1402c19:dd:c25:c25d:dd:dd:dd:f8b/1282c19:dd:c25:c25d:dd:dd:dd:f8b
1412c19:dd:c25:c25d:dd:dd:dd:f8c/1282c19:dd:c25:c25d:dd:dd:dd:f8c
1422c19:dd:c25:c25d:dd:dd:dd:f8d/1282c19:dd:c25:c25d:dd:dd:dd:f8d
1432c19:dd:c25:c25d:dd:dd:dd:f8e/1282c19:dd:c25:c25d:dd:dd:dd:f8e
1442c19:dd:c25:c25d:dd:dd:dd:f8f/1282c19:dd:c25:c25d:dd:dd:dd:f8f
1452c19:dd:c25:c25d:dd:dd:dd:f90/1282c19:dd:c25:c25d:dd:dd:dd:f90
1462c19:dd:c25:c25d:dd:dd:dd:f91/1282c19:dd:c25:c25d:dd:dd:dd:f91
1472c19:dd:c25:c25d:dd:dd:dd:f92/1282c19:dd:c25:c25d:dd:dd:dd:f92
1482c19:dd:c25:c25d:dd:dd:dd:f93/1282c19:dd:c25:c25d:dd:dd:dd:f93
1492c19:dd:c25:c25d:dd:dd:dd:f94/1282c19:dd:c25:c25d:dd:dd:dd:f94
1502c19:dd:c25:c25d:dd:dd:dd:f95/1282c19:dd:c25:c25d:dd:dd:dd:f95
1512c19:dd:c25:c25d:dd:dd:dd:f96/1282c19:dd:c25:c25d:dd:dd:dd:f96
1522c19:dd:c25:c25d:dd:dd:dd:f97/1282c19:dd:c25:c25d:dd:dd:dd:f97
1532c19:dd:c25:c25d:dd:dd:dd:f98/1282c19:dd:c25:c25d:dd:dd:dd:f98
1542c19:dd:c25:c25d:dd:dd:dd:f99/1282c19:dd:c25:c25d:dd:dd:dd:f99
1552c19:dd:c25:c25d:dd:dd:dd:f9a/1282c19:dd:c25:c25d:dd:dd:dd:f9a
1562c19:dd:c25:c25d:dd:dd:dd:f9b/1282c19:dd:c25:c25d:dd:dd:dd:f9b
1572c19:dd:c25:c25d:dd:dd:dd:f9c/1282c19:dd:c25:c25d:dd:dd:dd:f9c
1582c19:dd:c25:c25d:dd:dd:dd:f9d/1282c19:dd:c25:c25d:dd:dd:dd:f9d
1592c19:dd:c25:c25d:dd:dd:dd:f9e/1282c19:dd:c25:c25d:dd:dd:dd:f9e
1602c19:dd:c25:c25d:dd:dd:dd:f9f/1282c19:dd:c25:c25d:dd:dd:dd:f9f
1612c19:dd:c25:c25d:dd:dd:dd:fa0/1282c19:dd:c25:c25d:dd:dd:dd:fa0
1622c19:dd:c25:c25d:dd:dd:dd:fa1/1282c19:dd:c25:c25d:dd:dd:dd:fa1
1632c19:dd:c25:c25d:dd:dd:dd:fa2/1282c19:dd:c25:c25d:dd:dd:dd:fa2
1642c19:dd:c25:c25d:dd:dd:dd:fa3/1282c19:dd:c25:c25d:dd:dd:dd:fa3
1652c19:dd:c25:c25d:dd:dd:dd:fa4/1282c19:dd:c25:c25d:dd:dd:dd:fa4
1662c19:dd:c25:c25d:dd:dd:dd:fa5/1282c19:dd:c25:c25d:dd:dd:dd:fa5
1672c19:dd:c25:c25d:dd:dd:dd:fa6/1282c19:dd:c25:c25d:dd:dd:dd:fa6
1682c19:dd:c25:c25d:dd:dd:dd:fa7/1282c19:dd:c25:c25d:dd:dd:dd:fa7
1692c19:dd:c25:c25d:dd:dd:dd:fa8/1282c19:dd:c25:c25d:dd:dd:dd:fa8
1702c19:dd:c25:c25d:dd:dd:dd:fa9/1282c19:dd:c25:c25d:dd:dd:dd:fa9
1712c19:dd:c25:c25d:dd:dd:dd:faa/1282c19:dd:c25:c25d:dd:dd:dd:faa
1722c19:dd:c25:c25d:dd:dd:dd:fab/1282c19:dd:c25:c25d:dd:dd:dd:fab
1732c19:dd:c25:c25d:dd:dd:dd:fac/1282c19:dd:c25:c25d:dd:dd:dd:fac
1742c19:dd:c25:c25d:dd:dd:dd:fad/1282c19:dd:c25:c25d:dd:dd:dd:fad
1752c19:dd:c25:c25d:dd:dd:dd:fae/1282c19:dd:c25:c25d:dd:dd:dd:fae
1762c19:dd:c25:c25d:dd:dd:dd:faf/1282c19:dd:c25:c25d:dd:dd:dd:faf
1772c19:dd:c25:c25d:dd:dd:dd:fb0/1282c19:dd:c25:c25d:dd:dd:dd:fb0
1782c19:dd:c25:c25d:dd:dd:dd:fb1/1282c19:dd:c25:c25d:dd:dd:dd:fb1
1792c19:dd:c25:c25d:dd:dd:dd:fb2/1282c19:dd:c25:c25d:dd:dd:dd:fb2
1802c19:dd:c25:c25d:dd:dd:dd:fb3/1282c19:dd:c25:c25d:dd:dd:dd:fb3
1812c19:dd:c25:c25d:dd:dd:dd:fb4/1282c19:dd:c25:c25d:dd:dd:dd:fb4
1822c19:dd:c25:c25d:dd:dd:dd:fb5/1282c19:dd:c25:c25d:dd:dd:dd:fb5
1832c19:dd:c25:c25d:dd:dd:dd:fb6/1282c19:dd:c25:c25d:dd:dd:dd:fb6
1842c19:dd:c25:c25d:dd:dd:dd:fb7/1282c19:dd:c25:c25d:dd:dd:dd:fb7
1852c19:dd:c25:c25d:dd:dd:dd:fb8/1282c19:dd:c25:c25d:dd:dd:dd:fb8
1862c19:dd:c25:c25d:dd:dd:dd:fb9/1282c19:dd:c25:c25d:dd:dd:dd:fb9
1872c19:dd:c25:c25d:dd:dd:dd:fba/1282c19:dd:c25:c25d:dd:dd:dd:fba
1882c19:dd:c25:c25d:dd:dd:dd:fbb/1282c19:dd:c25:c25d:dd:dd:dd:fbb
1892c19:dd:c25:c25d:dd:dd:dd:fbc/1282c19:dd:c25:c25d:dd:dd:dd:fbc
1902c19:dd:c25:c25d:dd:dd:dd:fbd/1282c19:dd:c25:c25d:dd:dd:dd:fbd
1912c19:dd:c25:c25d:dd:dd:dd:fbe/1282c19:dd:c25:c25d:dd:dd:dd:fbe
1922c19:dd:c25:c25d:dd:dd:dd:fbf/1282c19:dd:c25:c25d:dd:dd:dd:fbf
1932c19:dd:c25:c25d:dd:dd:dd:fc0/1282c19:dd:c25:c25d:dd:dd:dd:fc0
1942c19:dd:c25:c25d:dd:dd:dd:fc1/1282c19:dd:c25:c25d:dd:dd:dd:fc1
1952c19:dd:c25:c25d:dd:dd:dd:fc2/1282c19:dd:c25:c25d:dd:dd:dd:fc2
1962c19:dd:c25:c25d:dd:dd:dd:fc3/1282c19:dd:c25:c25d:dd:dd:dd:fc3
1972c19:dd:c25:c25d:dd:dd:dd:fc4/1282c19:dd:c25:c25d:dd:dd:dd:fc4
1982c19:dd:c25:c25d:dd:dd:dd:fc5/1282c19:dd:c25:c25d:dd:dd:dd:fc5
1992c19:dd:c25:c25d:dd:dd:dd:fc6/1282c19:dd:c25:c25d:dd:dd:dd:fc6
2002c19:dd:c25:c25d:dd:dd:dd:fc7/1282c19:dd:c25:c25d:dd:dd:dd:fc7
2012c19:dd:c25:c25d:dd:dd:dd:fc8/1282c19:dd:c25:c25d:dd:dd:dd:fc8
2022c19:dd:c25:c25d:dd:dd:dd:fc9/1282c19:dd:c25:c25d:dd:dd:dd:fc9
2032c19:dd:c25:c25d:dd:dd:dd:fca/1282c19:dd:c25:c25d:dd:dd:dd:fca
2042c19:dd:c25:c25d:dd:dd:dd:fcb/1282c19:dd:c25:c25d:dd:dd:dd:fcb
2052c19:dd:c25:c25d:dd:dd:dd:fcc/1282c19:dd:c25:c25d:dd:dd:dd:fcc
2062c19:dd:c25:c25d:dd:dd:dd:fcd/1282c19:dd:c25:c25d:dd:dd:dd:fcd
2072c19:dd:c25:c25d:dd:dd:dd:fce/1282c19:dd:c25:c25d:dd:dd:dd:fce
2082c19:dd:c25:c25d:dd:dd:dd:fcf/1282c19:dd:c25:c25d:dd:dd:dd:fcf
2092c19:dd:c25:c25d:dd:dd:dd:fd0/1282c19:dd:c25:c25d:dd:dd:dd:fd0
2102c19:dd:c25:c25d:dd:dd:dd:fd1/1282c19:dd:c25:c25d:dd:dd:dd:fd1
2112c19:dd:c25:c25d:dd:dd:dd:fd2/1282c19:dd:c25:c25d:dd:dd:dd:fd2
2122c19:dd:c25:c25d:dd:dd:dd:fd3/1282c19:dd:c25:c25d:dd:dd:dd:fd3
2132c19:dd:c25:c25d:dd:dd:dd:fd4/1282c19:dd:c25:c25d:dd:dd:dd:fd4
2142c19:dd:c25:c25d:dd:dd:dd:fd5/1282c19:dd:c25:c25d:dd:dd:dd:fd5
2152c19:dd:c25:c25d:dd:dd:dd:fd6/1282c19:dd:c25:c25d:dd:dd:dd:fd6
2162c19:dd:c25:c25d:dd:dd:dd:fd7/1282c19:dd:c25:c25d:dd:dd:dd:fd7
2172c19:dd:c25:c25d:dd:dd:dd:fd8/1282c19:dd:c25:c25d:dd:dd:dd:fd8
2182c19:dd:c25:c25d:dd:dd:dd:fd9/1282c19:dd:c25:c25d:dd:dd:dd:fd9
2192c19:dd:c25:c25d:dd:dd:dd:fda/1282c19:dd:c25:c25d:dd:dd:dd:fda
2202c19:dd:c25:c25d:dd:dd:dd:fdb/1282c19:dd:c25:c25d:dd:dd:dd:fdb
2212c19:dd:c25:c25d:dd:dd:dd:fdc/1282c19:dd:c25:c25d:dd:dd:dd:fdc
2222c19:dd:c25:c25d:dd:dd:dd:fdd/1282c19:dd:c25:c25d:dd:dd:dd:fdd
2232c19:dd:c25:c25d:dd:dd:dd:fde/1282c19:dd:c25:c25d:dd:dd:dd:fde
2242c19:dd:c25:c25d:dd:dd:dd:fdf/1282c19:dd:c25:c25d:dd:dd:dd:fdf
2252c19:dd:c25:c25d:dd:dd:dd:fe0/1282c19:dd:c25:c25d:dd:dd:dd:fe0
2262c19:dd:c25:c25d:dd:dd:dd:fe1/1282c19:dd:c25:c25d:dd:dd:dd:fe1
2272c19:dd:c25:c25d:dd:dd:dd:fe2/1282c19:dd:c25:c25d:dd:dd:dd:fe2
2282c19:dd:c25:c25d:dd:dd:dd:fe3/1282c19:dd:c25:c25d:dd:dd:dd:fe3
2292c19:dd:c25:c25d:dd:dd:dd:fe4/1282c19:dd:c25:c25d:dd:dd:dd:fe4
2302c19:dd:c25:c25d:dd:dd:dd:fe5/1282c19:dd:c25:c25d:dd:dd:dd:fe5
2312c19:dd:c25:c25d:dd:dd:dd:fe6/1282c19:dd:c25:c25d:dd:dd:dd:fe6
2322c19:dd:c25:c25d:dd:dd:dd:fe7/1282c19:dd:c25:c25d:dd:dd:dd:fe7
2332c19:dd:c25:c25d:dd:dd:dd:fe8/1282c19:dd:c25:c25d:dd:dd:dd:fe8
2342c19:dd:c25:c25d:dd:dd:dd:fe9/1282c19:dd:c25:c25d:dd:dd:dd:fe9
2352c19:dd:c25:c25d:dd:dd:dd:fea/1282c19:dd:c25:c25d:dd:dd:dd:fea
2362c19:dd:c25:c25d:dd:dd:dd:feb/1282c19:dd:c25:c25d:dd:dd:dd:feb
2372c19:dd:c25:c25d:dd:dd:dd:fec/1282c19:dd:c25:c25d:dd:dd:dd:fec
2382c19:dd:c25:c25d:dd:dd:dd:fed/1282c19:dd:c25:c25d:dd:dd:dd:fed
2392c19:dd:c25:c25d:dd:dd:dd:fee/1282c19:dd:c25:c25d:dd:dd:dd:fee
2402c19:dd:c25:c25d:dd:dd:dd:fef/1282c19:dd:c25:c25d:dd:dd:dd:fef
2412c19:dd:c25:c25d:dd:dd:dd:ff0/1282c19:dd:c25:c25d:dd:dd:dd:ff0
2422c19:dd:c25:c25d:dd:dd:dd:ff1/1282c19:dd:c25:c25d:dd:dd:dd:ff1
2432c19:dd:c25:c25d:dd:dd:dd:ff2/1282c19:dd:c25:c25d:dd:dd:dd:ff2
2442c19:dd:c25:c25d:dd:dd:dd:ff3/1282c19:dd:c25:c25d:dd:dd:dd:ff3
2452c19:dd:c25:c25d:dd:dd:dd:ff4/1282c19:dd:c25:c25d:dd:dd:dd:ff4
2462c19:dd:c25:c25d:dd:dd:dd:ff5/1282c19:dd:c25:c25d:dd:dd:dd:ff5
2472c19:dd:c25:c25d:dd:dd:dd:ff6/1282c19:dd:c25:c25d:dd:dd:dd:ff6
2482c19:dd:c25:c25d:dd:dd:dd:ff7/1282c19:dd:c25:c25d:dd:dd:dd:ff7
2492c19:dd:c25:c25d:dd:dd:dd:ff8/1282c19:dd:c25:c25d:dd:dd:dd:ff8
2502c19:dd:c25:c25d:dd:dd:dd:ff9/1282c19:dd:c25:c25d:dd:dd:dd:ff9
2512c19:dd:c25:c25d:dd:dd:dd:ffa/1282c19:dd:c25:c25d:dd:dd:dd:ffa
2522c19:dd:c25:c25d:dd:dd:dd:ffb/1282c19:dd:c25:c25d:dd:dd:dd:ffb
2532c19:dd:c25:c25d:dd:dd:dd:ffc/1282c19:dd:c25:c25d:dd:dd:dd:ffc
2542c19:dd:c25:c25d:dd:dd:dd:ffd/1282c19:dd:c25:c25d:dd:dd:dd:ffd
2552c19:dd:c25:c25d:dd:dd:dd:ffe/1282c19:dd:c25:c25d:dd:dd:dd:ffe
2562c19:dd:c25:c25d:dd:dd:dd:fff/1282c19:dd:c25:c25d:dd:dd:dd:fff

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.