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IP subnet calculator

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

Prefix/120
Addresses256
/64 networksPart of one
Network
2c19:dd:d9:dd:c25:c25:94de:cf00/120
First address
2c19:dd:d9:dd:c25:c25:94de:cf00
Last address
2c19:dd:d9:dd:c25:c25:94de:cfff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:94de:cf00
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
f.c.e.d.4.9.5.2.c.0.5.2.c.0.d.d.0.0.9.d.0.0.d.d.0.0.9.1.c.2.ip6.arpa
Split into smaller subnets/128
/121 (2)/122 (4)/123 (8)/124 (16)/127 (128)/128 (256)

2c19:dd:d9:dd:c25:c25:94de:cf00/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:94de:cf00/1282c19:dd:d9:dd:c25:c25:94de:cf00
22c19:dd:d9:dd:c25:c25:94de:cf01/1282c19:dd:d9:dd:c25:c25:94de:cf01
32c19:dd:d9:dd:c25:c25:94de:cf02/1282c19:dd:d9:dd:c25:c25:94de:cf02
42c19:dd:d9:dd:c25:c25:94de:cf03/1282c19:dd:d9:dd:c25:c25:94de:cf03
52c19:dd:d9:dd:c25:c25:94de:cf04/1282c19:dd:d9:dd:c25:c25:94de:cf04
62c19:dd:d9:dd:c25:c25:94de:cf05/1282c19:dd:d9:dd:c25:c25:94de:cf05
72c19:dd:d9:dd:c25:c25:94de:cf06/1282c19:dd:d9:dd:c25:c25:94de:cf06
82c19:dd:d9:dd:c25:c25:94de:cf07/1282c19:dd:d9:dd:c25:c25:94de:cf07
92c19:dd:d9:dd:c25:c25:94de:cf08/1282c19:dd:d9:dd:c25:c25:94de:cf08
102c19:dd:d9:dd:c25:c25:94de:cf09/1282c19:dd:d9:dd:c25:c25:94de:cf09
112c19:dd:d9:dd:c25:c25:94de:cf0a/1282c19:dd:d9:dd:c25:c25:94de:cf0a
122c19:dd:d9:dd:c25:c25:94de:cf0b/1282c19:dd:d9:dd:c25:c25:94de:cf0b
132c19:dd:d9:dd:c25:c25:94de:cf0c/1282c19:dd:d9:dd:c25:c25:94de:cf0c
142c19:dd:d9:dd:c25:c25:94de:cf0d/1282c19:dd:d9:dd:c25:c25:94de:cf0d
152c19:dd:d9:dd:c25:c25:94de:cf0e/1282c19:dd:d9:dd:c25:c25:94de:cf0e
162c19:dd:d9:dd:c25:c25:94de:cf0f/1282c19:dd:d9:dd:c25:c25:94de:cf0f
172c19:dd:d9:dd:c25:c25:94de:cf10/1282c19:dd:d9:dd:c25:c25:94de:cf10
182c19:dd:d9:dd:c25:c25:94de:cf11/1282c19:dd:d9:dd:c25:c25:94de:cf11
192c19:dd:d9:dd:c25:c25:94de:cf12/1282c19:dd:d9:dd:c25:c25:94de:cf12
202c19:dd:d9:dd:c25:c25:94de:cf13/1282c19:dd:d9:dd:c25:c25:94de:cf13
212c19:dd:d9:dd:c25:c25:94de:cf14/1282c19:dd:d9:dd:c25:c25:94de:cf14
222c19:dd:d9:dd:c25:c25:94de:cf15/1282c19:dd:d9:dd:c25:c25:94de:cf15
232c19:dd:d9:dd:c25:c25:94de:cf16/1282c19:dd:d9:dd:c25:c25:94de:cf16
242c19:dd:d9:dd:c25:c25:94de:cf17/1282c19:dd:d9:dd:c25:c25:94de:cf17
252c19:dd:d9:dd:c25:c25:94de:cf18/1282c19:dd:d9:dd:c25:c25:94de:cf18
262c19:dd:d9:dd:c25:c25:94de:cf19/1282c19:dd:d9:dd:c25:c25:94de:cf19
272c19:dd:d9:dd:c25:c25:94de:cf1a/1282c19:dd:d9:dd:c25:c25:94de:cf1a
282c19:dd:d9:dd:c25:c25:94de:cf1b/1282c19:dd:d9:dd:c25:c25:94de:cf1b
292c19:dd:d9:dd:c25:c25:94de:cf1c/1282c19:dd:d9:dd:c25:c25:94de:cf1c
302c19:dd:d9:dd:c25:c25:94de:cf1d/1282c19:dd:d9:dd:c25:c25:94de:cf1d
312c19:dd:d9:dd:c25:c25:94de:cf1e/1282c19:dd:d9:dd:c25:c25:94de:cf1e
322c19:dd:d9:dd:c25:c25:94de:cf1f/1282c19:dd:d9:dd:c25:c25:94de:cf1f
332c19:dd:d9:dd:c25:c25:94de:cf20/1282c19:dd:d9:dd:c25:c25:94de:cf20
342c19:dd:d9:dd:c25:c25:94de:cf21/1282c19:dd:d9:dd:c25:c25:94de:cf21
352c19:dd:d9:dd:c25:c25:94de:cf22/1282c19:dd:d9:dd:c25:c25:94de:cf22
362c19:dd:d9:dd:c25:c25:94de:cf23/1282c19:dd:d9:dd:c25:c25:94de:cf23
372c19:dd:d9:dd:c25:c25:94de:cf24/1282c19:dd:d9:dd:c25:c25:94de:cf24
382c19:dd:d9:dd:c25:c25:94de:cf25/1282c19:dd:d9:dd:c25:c25:94de:cf25
392c19:dd:d9:dd:c25:c25:94de:cf26/1282c19:dd:d9:dd:c25:c25:94de:cf26
402c19:dd:d9:dd:c25:c25:94de:cf27/1282c19:dd:d9:dd:c25:c25:94de:cf27
412c19:dd:d9:dd:c25:c25:94de:cf28/1282c19:dd:d9:dd:c25:c25:94de:cf28
422c19:dd:d9:dd:c25:c25:94de:cf29/1282c19:dd:d9:dd:c25:c25:94de:cf29
432c19:dd:d9:dd:c25:c25:94de:cf2a/1282c19:dd:d9:dd:c25:c25:94de:cf2a
442c19:dd:d9:dd:c25:c25:94de:cf2b/1282c19:dd:d9:dd:c25:c25:94de:cf2b
452c19:dd:d9:dd:c25:c25:94de:cf2c/1282c19:dd:d9:dd:c25:c25:94de:cf2c
462c19:dd:d9:dd:c25:c25:94de:cf2d/1282c19:dd:d9:dd:c25:c25:94de:cf2d
472c19:dd:d9:dd:c25:c25:94de:cf2e/1282c19:dd:d9:dd:c25:c25:94de:cf2e
482c19:dd:d9:dd:c25:c25:94de:cf2f/1282c19:dd:d9:dd:c25:c25:94de:cf2f
492c19:dd:d9:dd:c25:c25:94de:cf30/1282c19:dd:d9:dd:c25:c25:94de:cf30
502c19:dd:d9:dd:c25:c25:94de:cf31/1282c19:dd:d9:dd:c25:c25:94de:cf31
512c19:dd:d9:dd:c25:c25:94de:cf32/1282c19:dd:d9:dd:c25:c25:94de:cf32
522c19:dd:d9:dd:c25:c25:94de:cf33/1282c19:dd:d9:dd:c25:c25:94de:cf33
532c19:dd:d9:dd:c25:c25:94de:cf34/1282c19:dd:d9:dd:c25:c25:94de:cf34
542c19:dd:d9:dd:c25:c25:94de:cf35/1282c19:dd:d9:dd:c25:c25:94de:cf35
552c19:dd:d9:dd:c25:c25:94de:cf36/1282c19:dd:d9:dd:c25:c25:94de:cf36
562c19:dd:d9:dd:c25:c25:94de:cf37/1282c19:dd:d9:dd:c25:c25:94de:cf37
572c19:dd:d9:dd:c25:c25:94de:cf38/1282c19:dd:d9:dd:c25:c25:94de:cf38
582c19:dd:d9:dd:c25:c25:94de:cf39/1282c19:dd:d9:dd:c25:c25:94de:cf39
592c19:dd:d9:dd:c25:c25:94de:cf3a/1282c19:dd:d9:dd:c25:c25:94de:cf3a
602c19:dd:d9:dd:c25:c25:94de:cf3b/1282c19:dd:d9:dd:c25:c25:94de:cf3b
612c19:dd:d9:dd:c25:c25:94de:cf3c/1282c19:dd:d9:dd:c25:c25:94de:cf3c
622c19:dd:d9:dd:c25:c25:94de:cf3d/1282c19:dd:d9:dd:c25:c25:94de:cf3d
632c19:dd:d9:dd:c25:c25:94de:cf3e/1282c19:dd:d9:dd:c25:c25:94de:cf3e
642c19:dd:d9:dd:c25:c25:94de:cf3f/1282c19:dd:d9:dd:c25:c25:94de:cf3f
652c19:dd:d9:dd:c25:c25:94de:cf40/1282c19:dd:d9:dd:c25:c25:94de:cf40
662c19:dd:d9:dd:c25:c25:94de:cf41/1282c19:dd:d9:dd:c25:c25:94de:cf41
672c19:dd:d9:dd:c25:c25:94de:cf42/1282c19:dd:d9:dd:c25:c25:94de:cf42
682c19:dd:d9:dd:c25:c25:94de:cf43/1282c19:dd:d9:dd:c25:c25:94de:cf43
692c19:dd:d9:dd:c25:c25:94de:cf44/1282c19:dd:d9:dd:c25:c25:94de:cf44
702c19:dd:d9:dd:c25:c25:94de:cf45/1282c19:dd:d9:dd:c25:c25:94de:cf45
712c19:dd:d9:dd:c25:c25:94de:cf46/1282c19:dd:d9:dd:c25:c25:94de:cf46
722c19:dd:d9:dd:c25:c25:94de:cf47/1282c19:dd:d9:dd:c25:c25:94de:cf47
732c19:dd:d9:dd:c25:c25:94de:cf48/1282c19:dd:d9:dd:c25:c25:94de:cf48
742c19:dd:d9:dd:c25:c25:94de:cf49/1282c19:dd:d9:dd:c25:c25:94de:cf49
752c19:dd:d9:dd:c25:c25:94de:cf4a/1282c19:dd:d9:dd:c25:c25:94de:cf4a
762c19:dd:d9:dd:c25:c25:94de:cf4b/1282c19:dd:d9:dd:c25:c25:94de:cf4b
772c19:dd:d9:dd:c25:c25:94de:cf4c/1282c19:dd:d9:dd:c25:c25:94de:cf4c
782c19:dd:d9:dd:c25:c25:94de:cf4d/1282c19:dd:d9:dd:c25:c25:94de:cf4d
792c19:dd:d9:dd:c25:c25:94de:cf4e/1282c19:dd:d9:dd:c25:c25:94de:cf4e
802c19:dd:d9:dd:c25:c25:94de:cf4f/1282c19:dd:d9:dd:c25:c25:94de:cf4f
812c19:dd:d9:dd:c25:c25:94de:cf50/1282c19:dd:d9:dd:c25:c25:94de:cf50
822c19:dd:d9:dd:c25:c25:94de:cf51/1282c19:dd:d9:dd:c25:c25:94de:cf51
832c19:dd:d9:dd:c25:c25:94de:cf52/1282c19:dd:d9:dd:c25:c25:94de:cf52
842c19:dd:d9:dd:c25:c25:94de:cf53/1282c19:dd:d9:dd:c25:c25:94de:cf53
852c19:dd:d9:dd:c25:c25:94de:cf54/1282c19:dd:d9:dd:c25:c25:94de:cf54
862c19:dd:d9:dd:c25:c25:94de:cf55/1282c19:dd:d9:dd:c25:c25:94de:cf55
872c19:dd:d9:dd:c25:c25:94de:cf56/1282c19:dd:d9:dd:c25:c25:94de:cf56
882c19:dd:d9:dd:c25:c25:94de:cf57/1282c19:dd:d9:dd:c25:c25:94de:cf57
892c19:dd:d9:dd:c25:c25:94de:cf58/1282c19:dd:d9:dd:c25:c25:94de:cf58
902c19:dd:d9:dd:c25:c25:94de:cf59/1282c19:dd:d9:dd:c25:c25:94de:cf59
912c19:dd:d9:dd:c25:c25:94de:cf5a/1282c19:dd:d9:dd:c25:c25:94de:cf5a
922c19:dd:d9:dd:c25:c25:94de:cf5b/1282c19:dd:d9:dd:c25:c25:94de:cf5b
932c19:dd:d9:dd:c25:c25:94de:cf5c/1282c19:dd:d9:dd:c25:c25:94de:cf5c
942c19:dd:d9:dd:c25:c25:94de:cf5d/1282c19:dd:d9:dd:c25:c25:94de:cf5d
952c19:dd:d9:dd:c25:c25:94de:cf5e/1282c19:dd:d9:dd:c25:c25:94de:cf5e
962c19:dd:d9:dd:c25:c25:94de:cf5f/1282c19:dd:d9:dd:c25:c25:94de:cf5f
972c19:dd:d9:dd:c25:c25:94de:cf60/1282c19:dd:d9:dd:c25:c25:94de:cf60
982c19:dd:d9:dd:c25:c25:94de:cf61/1282c19:dd:d9:dd:c25:c25:94de:cf61
992c19:dd:d9:dd:c25:c25:94de:cf62/1282c19:dd:d9:dd:c25:c25:94de:cf62
1002c19:dd:d9:dd:c25:c25:94de:cf63/1282c19:dd:d9:dd:c25:c25:94de:cf63
1012c19:dd:d9:dd:c25:c25:94de:cf64/1282c19:dd:d9:dd:c25:c25:94de:cf64
1022c19:dd:d9:dd:c25:c25:94de:cf65/1282c19:dd:d9:dd:c25:c25:94de:cf65
1032c19:dd:d9:dd:c25:c25:94de:cf66/1282c19:dd:d9:dd:c25:c25:94de:cf66
1042c19:dd:d9:dd:c25:c25:94de:cf67/1282c19:dd:d9:dd:c25:c25:94de:cf67
1052c19:dd:d9:dd:c25:c25:94de:cf68/1282c19:dd:d9:dd:c25:c25:94de:cf68
1062c19:dd:d9:dd:c25:c25:94de:cf69/1282c19:dd:d9:dd:c25:c25:94de:cf69
1072c19:dd:d9:dd:c25:c25:94de:cf6a/1282c19:dd:d9:dd:c25:c25:94de:cf6a
1082c19:dd:d9:dd:c25:c25:94de:cf6b/1282c19:dd:d9:dd:c25:c25:94de:cf6b
1092c19:dd:d9:dd:c25:c25:94de:cf6c/1282c19:dd:d9:dd:c25:c25:94de:cf6c
1102c19:dd:d9:dd:c25:c25:94de:cf6d/1282c19:dd:d9:dd:c25:c25:94de:cf6d
1112c19:dd:d9:dd:c25:c25:94de:cf6e/1282c19:dd:d9:dd:c25:c25:94de:cf6e
1122c19:dd:d9:dd:c25:c25:94de:cf6f/1282c19:dd:d9:dd:c25:c25:94de:cf6f
1132c19:dd:d9:dd:c25:c25:94de:cf70/1282c19:dd:d9:dd:c25:c25:94de:cf70
1142c19:dd:d9:dd:c25:c25:94de:cf71/1282c19:dd:d9:dd:c25:c25:94de:cf71
1152c19:dd:d9:dd:c25:c25:94de:cf72/1282c19:dd:d9:dd:c25:c25:94de:cf72
1162c19:dd:d9:dd:c25:c25:94de:cf73/1282c19:dd:d9:dd:c25:c25:94de:cf73
1172c19:dd:d9:dd:c25:c25:94de:cf74/1282c19:dd:d9:dd:c25:c25:94de:cf74
1182c19:dd:d9:dd:c25:c25:94de:cf75/1282c19:dd:d9:dd:c25:c25:94de:cf75
1192c19:dd:d9:dd:c25:c25:94de:cf76/1282c19:dd:d9:dd:c25:c25:94de:cf76
1202c19:dd:d9:dd:c25:c25:94de:cf77/1282c19:dd:d9:dd:c25:c25:94de:cf77
1212c19:dd:d9:dd:c25:c25:94de:cf78/1282c19:dd:d9:dd:c25:c25:94de:cf78
1222c19:dd:d9:dd:c25:c25:94de:cf79/1282c19:dd:d9:dd:c25:c25:94de:cf79
1232c19:dd:d9:dd:c25:c25:94de:cf7a/1282c19:dd:d9:dd:c25:c25:94de:cf7a
1242c19:dd:d9:dd:c25:c25:94de:cf7b/1282c19:dd:d9:dd:c25:c25:94de:cf7b
1252c19:dd:d9:dd:c25:c25:94de:cf7c/1282c19:dd:d9:dd:c25:c25:94de:cf7c
1262c19:dd:d9:dd:c25:c25:94de:cf7d/1282c19:dd:d9:dd:c25:c25:94de:cf7d
1272c19:dd:d9:dd:c25:c25:94de:cf7e/1282c19:dd:d9:dd:c25:c25:94de:cf7e
1282c19:dd:d9:dd:c25:c25:94de:cf7f/1282c19:dd:d9:dd:c25:c25:94de:cf7f
1292c19:dd:d9:dd:c25:c25:94de:cf80/1282c19:dd:d9:dd:c25:c25:94de:cf80
1302c19:dd:d9:dd:c25:c25:94de:cf81/1282c19:dd:d9:dd:c25:c25:94de:cf81
1312c19:dd:d9:dd:c25:c25:94de:cf82/1282c19:dd:d9:dd:c25:c25:94de:cf82
1322c19:dd:d9:dd:c25:c25:94de:cf83/1282c19:dd:d9:dd:c25:c25:94de:cf83
1332c19:dd:d9:dd:c25:c25:94de:cf84/1282c19:dd:d9:dd:c25:c25:94de:cf84
1342c19:dd:d9:dd:c25:c25:94de:cf85/1282c19:dd:d9:dd:c25:c25:94de:cf85
1352c19:dd:d9:dd:c25:c25:94de:cf86/1282c19:dd:d9:dd:c25:c25:94de:cf86
1362c19:dd:d9:dd:c25:c25:94de:cf87/1282c19:dd:d9:dd:c25:c25:94de:cf87
1372c19:dd:d9:dd:c25:c25:94de:cf88/1282c19:dd:d9:dd:c25:c25:94de:cf88
1382c19:dd:d9:dd:c25:c25:94de:cf89/1282c19:dd:d9:dd:c25:c25:94de:cf89
1392c19:dd:d9:dd:c25:c25:94de:cf8a/1282c19:dd:d9:dd:c25:c25:94de:cf8a
1402c19:dd:d9:dd:c25:c25:94de:cf8b/1282c19:dd:d9:dd:c25:c25:94de:cf8b
1412c19:dd:d9:dd:c25:c25:94de:cf8c/1282c19:dd:d9:dd:c25:c25:94de:cf8c
1422c19:dd:d9:dd:c25:c25:94de:cf8d/1282c19:dd:d9:dd:c25:c25:94de:cf8d
1432c19:dd:d9:dd:c25:c25:94de:cf8e/1282c19:dd:d9:dd:c25:c25:94de:cf8e
1442c19:dd:d9:dd:c25:c25:94de:cf8f/1282c19:dd:d9:dd:c25:c25:94de:cf8f
1452c19:dd:d9:dd:c25:c25:94de:cf90/1282c19:dd:d9:dd:c25:c25:94de:cf90
1462c19:dd:d9:dd:c25:c25:94de:cf91/1282c19:dd:d9:dd:c25:c25:94de:cf91
1472c19:dd:d9:dd:c25:c25:94de:cf92/1282c19:dd:d9:dd:c25:c25:94de:cf92
1482c19:dd:d9:dd:c25:c25:94de:cf93/1282c19:dd:d9:dd:c25:c25:94de:cf93
1492c19:dd:d9:dd:c25:c25:94de:cf94/1282c19:dd:d9:dd:c25:c25:94de:cf94
1502c19:dd:d9:dd:c25:c25:94de:cf95/1282c19:dd:d9:dd:c25:c25:94de:cf95
1512c19:dd:d9:dd:c25:c25:94de:cf96/1282c19:dd:d9:dd:c25:c25:94de:cf96
1522c19:dd:d9:dd:c25:c25:94de:cf97/1282c19:dd:d9:dd:c25:c25:94de:cf97
1532c19:dd:d9:dd:c25:c25:94de:cf98/1282c19:dd:d9:dd:c25:c25:94de:cf98
1542c19:dd:d9:dd:c25:c25:94de:cf99/1282c19:dd:d9:dd:c25:c25:94de:cf99
1552c19:dd:d9:dd:c25:c25:94de:cf9a/1282c19:dd:d9:dd:c25:c25:94de:cf9a
1562c19:dd:d9:dd:c25:c25:94de:cf9b/1282c19:dd:d9:dd:c25:c25:94de:cf9b
1572c19:dd:d9:dd:c25:c25:94de:cf9c/1282c19:dd:d9:dd:c25:c25:94de:cf9c
1582c19:dd:d9:dd:c25:c25:94de:cf9d/1282c19:dd:d9:dd:c25:c25:94de:cf9d
1592c19:dd:d9:dd:c25:c25:94de:cf9e/1282c19:dd:d9:dd:c25:c25:94de:cf9e
1602c19:dd:d9:dd:c25:c25:94de:cf9f/1282c19:dd:d9:dd:c25:c25:94de:cf9f
1612c19:dd:d9:dd:c25:c25:94de:cfa0/1282c19:dd:d9:dd:c25:c25:94de:cfa0
1622c19:dd:d9:dd:c25:c25:94de:cfa1/1282c19:dd:d9:dd:c25:c25:94de:cfa1
1632c19:dd:d9:dd:c25:c25:94de:cfa2/1282c19:dd:d9:dd:c25:c25:94de:cfa2
1642c19:dd:d9:dd:c25:c25:94de:cfa3/1282c19:dd:d9:dd:c25:c25:94de:cfa3
1652c19:dd:d9:dd:c25:c25:94de:cfa4/1282c19:dd:d9:dd:c25:c25:94de:cfa4
1662c19:dd:d9:dd:c25:c25:94de:cfa5/1282c19:dd:d9:dd:c25:c25:94de:cfa5
1672c19:dd:d9:dd:c25:c25:94de:cfa6/1282c19:dd:d9:dd:c25:c25:94de:cfa6
1682c19:dd:d9:dd:c25:c25:94de:cfa7/1282c19:dd:d9:dd:c25:c25:94de:cfa7
1692c19:dd:d9:dd:c25:c25:94de:cfa8/1282c19:dd:d9:dd:c25:c25:94de:cfa8
1702c19:dd:d9:dd:c25:c25:94de:cfa9/1282c19:dd:d9:dd:c25:c25:94de:cfa9
1712c19:dd:d9:dd:c25:c25:94de:cfaa/1282c19:dd:d9:dd:c25:c25:94de:cfaa
1722c19:dd:d9:dd:c25:c25:94de:cfab/1282c19:dd:d9:dd:c25:c25:94de:cfab
1732c19:dd:d9:dd:c25:c25:94de:cfac/1282c19:dd:d9:dd:c25:c25:94de:cfac
1742c19:dd:d9:dd:c25:c25:94de:cfad/1282c19:dd:d9:dd:c25:c25:94de:cfad
1752c19:dd:d9:dd:c25:c25:94de:cfae/1282c19:dd:d9:dd:c25:c25:94de:cfae
1762c19:dd:d9:dd:c25:c25:94de:cfaf/1282c19:dd:d9:dd:c25:c25:94de:cfaf
1772c19:dd:d9:dd:c25:c25:94de:cfb0/1282c19:dd:d9:dd:c25:c25:94de:cfb0
1782c19:dd:d9:dd:c25:c25:94de:cfb1/1282c19:dd:d9:dd:c25:c25:94de:cfb1
1792c19:dd:d9:dd:c25:c25:94de:cfb2/1282c19:dd:d9:dd:c25:c25:94de:cfb2
1802c19:dd:d9:dd:c25:c25:94de:cfb3/1282c19:dd:d9:dd:c25:c25:94de:cfb3
1812c19:dd:d9:dd:c25:c25:94de:cfb4/1282c19:dd:d9:dd:c25:c25:94de:cfb4
1822c19:dd:d9:dd:c25:c25:94de:cfb5/1282c19:dd:d9:dd:c25:c25:94de:cfb5
1832c19:dd:d9:dd:c25:c25:94de:cfb6/1282c19:dd:d9:dd:c25:c25:94de:cfb6
1842c19:dd:d9:dd:c25:c25:94de:cfb7/1282c19:dd:d9:dd:c25:c25:94de:cfb7
1852c19:dd:d9:dd:c25:c25:94de:cfb8/1282c19:dd:d9:dd:c25:c25:94de:cfb8
1862c19:dd:d9:dd:c25:c25:94de:cfb9/1282c19:dd:d9:dd:c25:c25:94de:cfb9
1872c19:dd:d9:dd:c25:c25:94de:cfba/1282c19:dd:d9:dd:c25:c25:94de:cfba
1882c19:dd:d9:dd:c25:c25:94de:cfbb/1282c19:dd:d9:dd:c25:c25:94de:cfbb
1892c19:dd:d9:dd:c25:c25:94de:cfbc/1282c19:dd:d9:dd:c25:c25:94de:cfbc
1902c19:dd:d9:dd:c25:c25:94de:cfbd/1282c19:dd:d9:dd:c25:c25:94de:cfbd
1912c19:dd:d9:dd:c25:c25:94de:cfbe/1282c19:dd:d9:dd:c25:c25:94de:cfbe
1922c19:dd:d9:dd:c25:c25:94de:cfbf/1282c19:dd:d9:dd:c25:c25:94de:cfbf
1932c19:dd:d9:dd:c25:c25:94de:cfc0/1282c19:dd:d9:dd:c25:c25:94de:cfc0
1942c19:dd:d9:dd:c25:c25:94de:cfc1/1282c19:dd:d9:dd:c25:c25:94de:cfc1
1952c19:dd:d9:dd:c25:c25:94de:cfc2/1282c19:dd:d9:dd:c25:c25:94de:cfc2
1962c19:dd:d9:dd:c25:c25:94de:cfc3/1282c19:dd:d9:dd:c25:c25:94de:cfc3
1972c19:dd:d9:dd:c25:c25:94de:cfc4/1282c19:dd:d9:dd:c25:c25:94de:cfc4
1982c19:dd:d9:dd:c25:c25:94de:cfc5/1282c19:dd:d9:dd:c25:c25:94de:cfc5
1992c19:dd:d9:dd:c25:c25:94de:cfc6/1282c19:dd:d9:dd:c25:c25:94de:cfc6
2002c19:dd:d9:dd:c25:c25:94de:cfc7/1282c19:dd:d9:dd:c25:c25:94de:cfc7
2012c19:dd:d9:dd:c25:c25:94de:cfc8/1282c19:dd:d9:dd:c25:c25:94de:cfc8
2022c19:dd:d9:dd:c25:c25:94de:cfc9/1282c19:dd:d9:dd:c25:c25:94de:cfc9
2032c19:dd:d9:dd:c25:c25:94de:cfca/1282c19:dd:d9:dd:c25:c25:94de:cfca
2042c19:dd:d9:dd:c25:c25:94de:cfcb/1282c19:dd:d9:dd:c25:c25:94de:cfcb
2052c19:dd:d9:dd:c25:c25:94de:cfcc/1282c19:dd:d9:dd:c25:c25:94de:cfcc
2062c19:dd:d9:dd:c25:c25:94de:cfcd/1282c19:dd:d9:dd:c25:c25:94de:cfcd
2072c19:dd:d9:dd:c25:c25:94de:cfce/1282c19:dd:d9:dd:c25:c25:94de:cfce
2082c19:dd:d9:dd:c25:c25:94de:cfcf/1282c19:dd:d9:dd:c25:c25:94de:cfcf
2092c19:dd:d9:dd:c25:c25:94de:cfd0/1282c19:dd:d9:dd:c25:c25:94de:cfd0
2102c19:dd:d9:dd:c25:c25:94de:cfd1/1282c19:dd:d9:dd:c25:c25:94de:cfd1
2112c19:dd:d9:dd:c25:c25:94de:cfd2/1282c19:dd:d9:dd:c25:c25:94de:cfd2
2122c19:dd:d9:dd:c25:c25:94de:cfd3/1282c19:dd:d9:dd:c25:c25:94de:cfd3
2132c19:dd:d9:dd:c25:c25:94de:cfd4/1282c19:dd:d9:dd:c25:c25:94de:cfd4
2142c19:dd:d9:dd:c25:c25:94de:cfd5/1282c19:dd:d9:dd:c25:c25:94de:cfd5
2152c19:dd:d9:dd:c25:c25:94de:cfd6/1282c19:dd:d9:dd:c25:c25:94de:cfd6
2162c19:dd:d9:dd:c25:c25:94de:cfd7/1282c19:dd:d9:dd:c25:c25:94de:cfd7
2172c19:dd:d9:dd:c25:c25:94de:cfd8/1282c19:dd:d9:dd:c25:c25:94de:cfd8
2182c19:dd:d9:dd:c25:c25:94de:cfd9/1282c19:dd:d9:dd:c25:c25:94de:cfd9
2192c19:dd:d9:dd:c25:c25:94de:cfda/1282c19:dd:d9:dd:c25:c25:94de:cfda
2202c19:dd:d9:dd:c25:c25:94de:cfdb/1282c19:dd:d9:dd:c25:c25:94de:cfdb
2212c19:dd:d9:dd:c25:c25:94de:cfdc/1282c19:dd:d9:dd:c25:c25:94de:cfdc
2222c19:dd:d9:dd:c25:c25:94de:cfdd/1282c19:dd:d9:dd:c25:c25:94de:cfdd
2232c19:dd:d9:dd:c25:c25:94de:cfde/1282c19:dd:d9:dd:c25:c25:94de:cfde
2242c19:dd:d9:dd:c25:c25:94de:cfdf/1282c19:dd:d9:dd:c25:c25:94de:cfdf
2252c19:dd:d9:dd:c25:c25:94de:cfe0/1282c19:dd:d9:dd:c25:c25:94de:cfe0
2262c19:dd:d9:dd:c25:c25:94de:cfe1/1282c19:dd:d9:dd:c25:c25:94de:cfe1
2272c19:dd:d9:dd:c25:c25:94de:cfe2/1282c19:dd:d9:dd:c25:c25:94de:cfe2
2282c19:dd:d9:dd:c25:c25:94de:cfe3/1282c19:dd:d9:dd:c25:c25:94de:cfe3
2292c19:dd:d9:dd:c25:c25:94de:cfe4/1282c19:dd:d9:dd:c25:c25:94de:cfe4
2302c19:dd:d9:dd:c25:c25:94de:cfe5/1282c19:dd:d9:dd:c25:c25:94de:cfe5
2312c19:dd:d9:dd:c25:c25:94de:cfe6/1282c19:dd:d9:dd:c25:c25:94de:cfe6
2322c19:dd:d9:dd:c25:c25:94de:cfe7/1282c19:dd:d9:dd:c25:c25:94de:cfe7
2332c19:dd:d9:dd:c25:c25:94de:cfe8/1282c19:dd:d9:dd:c25:c25:94de:cfe8
2342c19:dd:d9:dd:c25:c25:94de:cfe9/1282c19:dd:d9:dd:c25:c25:94de:cfe9
2352c19:dd:d9:dd:c25:c25:94de:cfea/1282c19:dd:d9:dd:c25:c25:94de:cfea
2362c19:dd:d9:dd:c25:c25:94de:cfeb/1282c19:dd:d9:dd:c25:c25:94de:cfeb
2372c19:dd:d9:dd:c25:c25:94de:cfec/1282c19:dd:d9:dd:c25:c25:94de:cfec
2382c19:dd:d9:dd:c25:c25:94de:cfed/1282c19:dd:d9:dd:c25:c25:94de:cfed
2392c19:dd:d9:dd:c25:c25:94de:cfee/1282c19:dd:d9:dd:c25:c25:94de:cfee
2402c19:dd:d9:dd:c25:c25:94de:cfef/1282c19:dd:d9:dd:c25:c25:94de:cfef
2412c19:dd:d9:dd:c25:c25:94de:cff0/1282c19:dd:d9:dd:c25:c25:94de:cff0
2422c19:dd:d9:dd:c25:c25:94de:cff1/1282c19:dd:d9:dd:c25:c25:94de:cff1
2432c19:dd:d9:dd:c25:c25:94de:cff2/1282c19:dd:d9:dd:c25:c25:94de:cff2
2442c19:dd:d9:dd:c25:c25:94de:cff3/1282c19:dd:d9:dd:c25:c25:94de:cff3
2452c19:dd:d9:dd:c25:c25:94de:cff4/1282c19:dd:d9:dd:c25:c25:94de:cff4
2462c19:dd:d9:dd:c25:c25:94de:cff5/1282c19:dd:d9:dd:c25:c25:94de:cff5
2472c19:dd:d9:dd:c25:c25:94de:cff6/1282c19:dd:d9:dd:c25:c25:94de:cff6
2482c19:dd:d9:dd:c25:c25:94de:cff7/1282c19:dd:d9:dd:c25:c25:94de:cff7
2492c19:dd:d9:dd:c25:c25:94de:cff8/1282c19:dd:d9:dd:c25:c25:94de:cff8
2502c19:dd:d9:dd:c25:c25:94de:cff9/1282c19:dd:d9:dd:c25:c25:94de:cff9
2512c19:dd:d9:dd:c25:c25:94de:cffa/1282c19:dd:d9:dd:c25:c25:94de:cffa
2522c19:dd:d9:dd:c25:c25:94de:cffb/1282c19:dd:d9:dd:c25:c25:94de:cffb
2532c19:dd:d9:dd:c25:c25:94de:cffc/1282c19:dd:d9:dd:c25:c25:94de:cffc
2542c19:dd:d9:dd:c25:c25:94de:cffd/1282c19:dd:d9:dd:c25:c25:94de:cffd
2552c19:dd:d9:dd:c25:c25:94de:cffe/1282c19:dd:d9:dd:c25:c25:94de:cffe
2562c19:dd:d9:dd:c25:c25:94de:cfff/1282c19:dd:d9:dd:c25:c25:94de:cfff

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.