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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:a00/120
First address
2c19:dd:c25:c25d:dd:dd:dd:a00
Last address
2c19:dd:c25:c25d:dd:dd:dd:aff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:0c25:c25d:00dd:00dd:00dd:0a00
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
a.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:a00/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:c25:c25d:dd:dd:dd:a00/1282c19:dd:c25:c25d:dd:dd:dd:a00
22c19:dd:c25:c25d:dd:dd:dd:a01/1282c19:dd:c25:c25d:dd:dd:dd:a01
32c19:dd:c25:c25d:dd:dd:dd:a02/1282c19:dd:c25:c25d:dd:dd:dd:a02
42c19:dd:c25:c25d:dd:dd:dd:a03/1282c19:dd:c25:c25d:dd:dd:dd:a03
52c19:dd:c25:c25d:dd:dd:dd:a04/1282c19:dd:c25:c25d:dd:dd:dd:a04
62c19:dd:c25:c25d:dd:dd:dd:a05/1282c19:dd:c25:c25d:dd:dd:dd:a05
72c19:dd:c25:c25d:dd:dd:dd:a06/1282c19:dd:c25:c25d:dd:dd:dd:a06
82c19:dd:c25:c25d:dd:dd:dd:a07/1282c19:dd:c25:c25d:dd:dd:dd:a07
92c19:dd:c25:c25d:dd:dd:dd:a08/1282c19:dd:c25:c25d:dd:dd:dd:a08
102c19:dd:c25:c25d:dd:dd:dd:a09/1282c19:dd:c25:c25d:dd:dd:dd:a09
112c19:dd:c25:c25d:dd:dd:dd:a0a/1282c19:dd:c25:c25d:dd:dd:dd:a0a
122c19:dd:c25:c25d:dd:dd:dd:a0b/1282c19:dd:c25:c25d:dd:dd:dd:a0b
132c19:dd:c25:c25d:dd:dd:dd:a0c/1282c19:dd:c25:c25d:dd:dd:dd:a0c
142c19:dd:c25:c25d:dd:dd:dd:a0d/1282c19:dd:c25:c25d:dd:dd:dd:a0d
152c19:dd:c25:c25d:dd:dd:dd:a0e/1282c19:dd:c25:c25d:dd:dd:dd:a0e
162c19:dd:c25:c25d:dd:dd:dd:a0f/1282c19:dd:c25:c25d:dd:dd:dd:a0f
172c19:dd:c25:c25d:dd:dd:dd:a10/1282c19:dd:c25:c25d:dd:dd:dd:a10
182c19:dd:c25:c25d:dd:dd:dd:a11/1282c19:dd:c25:c25d:dd:dd:dd:a11
192c19:dd:c25:c25d:dd:dd:dd:a12/1282c19:dd:c25:c25d:dd:dd:dd:a12
202c19:dd:c25:c25d:dd:dd:dd:a13/1282c19:dd:c25:c25d:dd:dd:dd:a13
212c19:dd:c25:c25d:dd:dd:dd:a14/1282c19:dd:c25:c25d:dd:dd:dd:a14
222c19:dd:c25:c25d:dd:dd:dd:a15/1282c19:dd:c25:c25d:dd:dd:dd:a15
232c19:dd:c25:c25d:dd:dd:dd:a16/1282c19:dd:c25:c25d:dd:dd:dd:a16
242c19:dd:c25:c25d:dd:dd:dd:a17/1282c19:dd:c25:c25d:dd:dd:dd:a17
252c19:dd:c25:c25d:dd:dd:dd:a18/1282c19:dd:c25:c25d:dd:dd:dd:a18
262c19:dd:c25:c25d:dd:dd:dd:a19/1282c19:dd:c25:c25d:dd:dd:dd:a19
272c19:dd:c25:c25d:dd:dd:dd:a1a/1282c19:dd:c25:c25d:dd:dd:dd:a1a
282c19:dd:c25:c25d:dd:dd:dd:a1b/1282c19:dd:c25:c25d:dd:dd:dd:a1b
292c19:dd:c25:c25d:dd:dd:dd:a1c/1282c19:dd:c25:c25d:dd:dd:dd:a1c
302c19:dd:c25:c25d:dd:dd:dd:a1d/1282c19:dd:c25:c25d:dd:dd:dd:a1d
312c19:dd:c25:c25d:dd:dd:dd:a1e/1282c19:dd:c25:c25d:dd:dd:dd:a1e
322c19:dd:c25:c25d:dd:dd:dd:a1f/1282c19:dd:c25:c25d:dd:dd:dd:a1f
332c19:dd:c25:c25d:dd:dd:dd:a20/1282c19:dd:c25:c25d:dd:dd:dd:a20
342c19:dd:c25:c25d:dd:dd:dd:a21/1282c19:dd:c25:c25d:dd:dd:dd:a21
352c19:dd:c25:c25d:dd:dd:dd:a22/1282c19:dd:c25:c25d:dd:dd:dd:a22
362c19:dd:c25:c25d:dd:dd:dd:a23/1282c19:dd:c25:c25d:dd:dd:dd:a23
372c19:dd:c25:c25d:dd:dd:dd:a24/1282c19:dd:c25:c25d:dd:dd:dd:a24
382c19:dd:c25:c25d:dd:dd:dd:a25/1282c19:dd:c25:c25d:dd:dd:dd:a25
392c19:dd:c25:c25d:dd:dd:dd:a26/1282c19:dd:c25:c25d:dd:dd:dd:a26
402c19:dd:c25:c25d:dd:dd:dd:a27/1282c19:dd:c25:c25d:dd:dd:dd:a27
412c19:dd:c25:c25d:dd:dd:dd:a28/1282c19:dd:c25:c25d:dd:dd:dd:a28
422c19:dd:c25:c25d:dd:dd:dd:a29/1282c19:dd:c25:c25d:dd:dd:dd:a29
432c19:dd:c25:c25d:dd:dd:dd:a2a/1282c19:dd:c25:c25d:dd:dd:dd:a2a
442c19:dd:c25:c25d:dd:dd:dd:a2b/1282c19:dd:c25:c25d:dd:dd:dd:a2b
452c19:dd:c25:c25d:dd:dd:dd:a2c/1282c19:dd:c25:c25d:dd:dd:dd:a2c
462c19:dd:c25:c25d:dd:dd:dd:a2d/1282c19:dd:c25:c25d:dd:dd:dd:a2d
472c19:dd:c25:c25d:dd:dd:dd:a2e/1282c19:dd:c25:c25d:dd:dd:dd:a2e
482c19:dd:c25:c25d:dd:dd:dd:a2f/1282c19:dd:c25:c25d:dd:dd:dd:a2f
492c19:dd:c25:c25d:dd:dd:dd:a30/1282c19:dd:c25:c25d:dd:dd:dd:a30
502c19:dd:c25:c25d:dd:dd:dd:a31/1282c19:dd:c25:c25d:dd:dd:dd:a31
512c19:dd:c25:c25d:dd:dd:dd:a32/1282c19:dd:c25:c25d:dd:dd:dd:a32
522c19:dd:c25:c25d:dd:dd:dd:a33/1282c19:dd:c25:c25d:dd:dd:dd:a33
532c19:dd:c25:c25d:dd:dd:dd:a34/1282c19:dd:c25:c25d:dd:dd:dd:a34
542c19:dd:c25:c25d:dd:dd:dd:a35/1282c19:dd:c25:c25d:dd:dd:dd:a35
552c19:dd:c25:c25d:dd:dd:dd:a36/1282c19:dd:c25:c25d:dd:dd:dd:a36
562c19:dd:c25:c25d:dd:dd:dd:a37/1282c19:dd:c25:c25d:dd:dd:dd:a37
572c19:dd:c25:c25d:dd:dd:dd:a38/1282c19:dd:c25:c25d:dd:dd:dd:a38
582c19:dd:c25:c25d:dd:dd:dd:a39/1282c19:dd:c25:c25d:dd:dd:dd:a39
592c19:dd:c25:c25d:dd:dd:dd:a3a/1282c19:dd:c25:c25d:dd:dd:dd:a3a
602c19:dd:c25:c25d:dd:dd:dd:a3b/1282c19:dd:c25:c25d:dd:dd:dd:a3b
612c19:dd:c25:c25d:dd:dd:dd:a3c/1282c19:dd:c25:c25d:dd:dd:dd:a3c
622c19:dd:c25:c25d:dd:dd:dd:a3d/1282c19:dd:c25:c25d:dd:dd:dd:a3d
632c19:dd:c25:c25d:dd:dd:dd:a3e/1282c19:dd:c25:c25d:dd:dd:dd:a3e
642c19:dd:c25:c25d:dd:dd:dd:a3f/1282c19:dd:c25:c25d:dd:dd:dd:a3f
652c19:dd:c25:c25d:dd:dd:dd:a40/1282c19:dd:c25:c25d:dd:dd:dd:a40
662c19:dd:c25:c25d:dd:dd:dd:a41/1282c19:dd:c25:c25d:dd:dd:dd:a41
672c19:dd:c25:c25d:dd:dd:dd:a42/1282c19:dd:c25:c25d:dd:dd:dd:a42
682c19:dd:c25:c25d:dd:dd:dd:a43/1282c19:dd:c25:c25d:dd:dd:dd:a43
692c19:dd:c25:c25d:dd:dd:dd:a44/1282c19:dd:c25:c25d:dd:dd:dd:a44
702c19:dd:c25:c25d:dd:dd:dd:a45/1282c19:dd:c25:c25d:dd:dd:dd:a45
712c19:dd:c25:c25d:dd:dd:dd:a46/1282c19:dd:c25:c25d:dd:dd:dd:a46
722c19:dd:c25:c25d:dd:dd:dd:a47/1282c19:dd:c25:c25d:dd:dd:dd:a47
732c19:dd:c25:c25d:dd:dd:dd:a48/1282c19:dd:c25:c25d:dd:dd:dd:a48
742c19:dd:c25:c25d:dd:dd:dd:a49/1282c19:dd:c25:c25d:dd:dd:dd:a49
752c19:dd:c25:c25d:dd:dd:dd:a4a/1282c19:dd:c25:c25d:dd:dd:dd:a4a
762c19:dd:c25:c25d:dd:dd:dd:a4b/1282c19:dd:c25:c25d:dd:dd:dd:a4b
772c19:dd:c25:c25d:dd:dd:dd:a4c/1282c19:dd:c25:c25d:dd:dd:dd:a4c
782c19:dd:c25:c25d:dd:dd:dd:a4d/1282c19:dd:c25:c25d:dd:dd:dd:a4d
792c19:dd:c25:c25d:dd:dd:dd:a4e/1282c19:dd:c25:c25d:dd:dd:dd:a4e
802c19:dd:c25:c25d:dd:dd:dd:a4f/1282c19:dd:c25:c25d:dd:dd:dd:a4f
812c19:dd:c25:c25d:dd:dd:dd:a50/1282c19:dd:c25:c25d:dd:dd:dd:a50
822c19:dd:c25:c25d:dd:dd:dd:a51/1282c19:dd:c25:c25d:dd:dd:dd:a51
832c19:dd:c25:c25d:dd:dd:dd:a52/1282c19:dd:c25:c25d:dd:dd:dd:a52
842c19:dd:c25:c25d:dd:dd:dd:a53/1282c19:dd:c25:c25d:dd:dd:dd:a53
852c19:dd:c25:c25d:dd:dd:dd:a54/1282c19:dd:c25:c25d:dd:dd:dd:a54
862c19:dd:c25:c25d:dd:dd:dd:a55/1282c19:dd:c25:c25d:dd:dd:dd:a55
872c19:dd:c25:c25d:dd:dd:dd:a56/1282c19:dd:c25:c25d:dd:dd:dd:a56
882c19:dd:c25:c25d:dd:dd:dd:a57/1282c19:dd:c25:c25d:dd:dd:dd:a57
892c19:dd:c25:c25d:dd:dd:dd:a58/1282c19:dd:c25:c25d:dd:dd:dd:a58
902c19:dd:c25:c25d:dd:dd:dd:a59/1282c19:dd:c25:c25d:dd:dd:dd:a59
912c19:dd:c25:c25d:dd:dd:dd:a5a/1282c19:dd:c25:c25d:dd:dd:dd:a5a
922c19:dd:c25:c25d:dd:dd:dd:a5b/1282c19:dd:c25:c25d:dd:dd:dd:a5b
932c19:dd:c25:c25d:dd:dd:dd:a5c/1282c19:dd:c25:c25d:dd:dd:dd:a5c
942c19:dd:c25:c25d:dd:dd:dd:a5d/1282c19:dd:c25:c25d:dd:dd:dd:a5d
952c19:dd:c25:c25d:dd:dd:dd:a5e/1282c19:dd:c25:c25d:dd:dd:dd:a5e
962c19:dd:c25:c25d:dd:dd:dd:a5f/1282c19:dd:c25:c25d:dd:dd:dd:a5f
972c19:dd:c25:c25d:dd:dd:dd:a60/1282c19:dd:c25:c25d:dd:dd:dd:a60
982c19:dd:c25:c25d:dd:dd:dd:a61/1282c19:dd:c25:c25d:dd:dd:dd:a61
992c19:dd:c25:c25d:dd:dd:dd:a62/1282c19:dd:c25:c25d:dd:dd:dd:a62
1002c19:dd:c25:c25d:dd:dd:dd:a63/1282c19:dd:c25:c25d:dd:dd:dd:a63
1012c19:dd:c25:c25d:dd:dd:dd:a64/1282c19:dd:c25:c25d:dd:dd:dd:a64
1022c19:dd:c25:c25d:dd:dd:dd:a65/1282c19:dd:c25:c25d:dd:dd:dd:a65
1032c19:dd:c25:c25d:dd:dd:dd:a66/1282c19:dd:c25:c25d:dd:dd:dd:a66
1042c19:dd:c25:c25d:dd:dd:dd:a67/1282c19:dd:c25:c25d:dd:dd:dd:a67
1052c19:dd:c25:c25d:dd:dd:dd:a68/1282c19:dd:c25:c25d:dd:dd:dd:a68
1062c19:dd:c25:c25d:dd:dd:dd:a69/1282c19:dd:c25:c25d:dd:dd:dd:a69
1072c19:dd:c25:c25d:dd:dd:dd:a6a/1282c19:dd:c25:c25d:dd:dd:dd:a6a
1082c19:dd:c25:c25d:dd:dd:dd:a6b/1282c19:dd:c25:c25d:dd:dd:dd:a6b
1092c19:dd:c25:c25d:dd:dd:dd:a6c/1282c19:dd:c25:c25d:dd:dd:dd:a6c
1102c19:dd:c25:c25d:dd:dd:dd:a6d/1282c19:dd:c25:c25d:dd:dd:dd:a6d
1112c19:dd:c25:c25d:dd:dd:dd:a6e/1282c19:dd:c25:c25d:dd:dd:dd:a6e
1122c19:dd:c25:c25d:dd:dd:dd:a6f/1282c19:dd:c25:c25d:dd:dd:dd:a6f
1132c19:dd:c25:c25d:dd:dd:dd:a70/1282c19:dd:c25:c25d:dd:dd:dd:a70
1142c19:dd:c25:c25d:dd:dd:dd:a71/1282c19:dd:c25:c25d:dd:dd:dd:a71
1152c19:dd:c25:c25d:dd:dd:dd:a72/1282c19:dd:c25:c25d:dd:dd:dd:a72
1162c19:dd:c25:c25d:dd:dd:dd:a73/1282c19:dd:c25:c25d:dd:dd:dd:a73
1172c19:dd:c25:c25d:dd:dd:dd:a74/1282c19:dd:c25:c25d:dd:dd:dd:a74
1182c19:dd:c25:c25d:dd:dd:dd:a75/1282c19:dd:c25:c25d:dd:dd:dd:a75
1192c19:dd:c25:c25d:dd:dd:dd:a76/1282c19:dd:c25:c25d:dd:dd:dd:a76
1202c19:dd:c25:c25d:dd:dd:dd:a77/1282c19:dd:c25:c25d:dd:dd:dd:a77
1212c19:dd:c25:c25d:dd:dd:dd:a78/1282c19:dd:c25:c25d:dd:dd:dd:a78
1222c19:dd:c25:c25d:dd:dd:dd:a79/1282c19:dd:c25:c25d:dd:dd:dd:a79
1232c19:dd:c25:c25d:dd:dd:dd:a7a/1282c19:dd:c25:c25d:dd:dd:dd:a7a
1242c19:dd:c25:c25d:dd:dd:dd:a7b/1282c19:dd:c25:c25d:dd:dd:dd:a7b
1252c19:dd:c25:c25d:dd:dd:dd:a7c/1282c19:dd:c25:c25d:dd:dd:dd:a7c
1262c19:dd:c25:c25d:dd:dd:dd:a7d/1282c19:dd:c25:c25d:dd:dd:dd:a7d
1272c19:dd:c25:c25d:dd:dd:dd:a7e/1282c19:dd:c25:c25d:dd:dd:dd:a7e
1282c19:dd:c25:c25d:dd:dd:dd:a7f/1282c19:dd:c25:c25d:dd:dd:dd:a7f
1292c19:dd:c25:c25d:dd:dd:dd:a80/1282c19:dd:c25:c25d:dd:dd:dd:a80
1302c19:dd:c25:c25d:dd:dd:dd:a81/1282c19:dd:c25:c25d:dd:dd:dd:a81
1312c19:dd:c25:c25d:dd:dd:dd:a82/1282c19:dd:c25:c25d:dd:dd:dd:a82
1322c19:dd:c25:c25d:dd:dd:dd:a83/1282c19:dd:c25:c25d:dd:dd:dd:a83
1332c19:dd:c25:c25d:dd:dd:dd:a84/1282c19:dd:c25:c25d:dd:dd:dd:a84
1342c19:dd:c25:c25d:dd:dd:dd:a85/1282c19:dd:c25:c25d:dd:dd:dd:a85
1352c19:dd:c25:c25d:dd:dd:dd:a86/1282c19:dd:c25:c25d:dd:dd:dd:a86
1362c19:dd:c25:c25d:dd:dd:dd:a87/1282c19:dd:c25:c25d:dd:dd:dd:a87
1372c19:dd:c25:c25d:dd:dd:dd:a88/1282c19:dd:c25:c25d:dd:dd:dd:a88
1382c19:dd:c25:c25d:dd:dd:dd:a89/1282c19:dd:c25:c25d:dd:dd:dd:a89
1392c19:dd:c25:c25d:dd:dd:dd:a8a/1282c19:dd:c25:c25d:dd:dd:dd:a8a
1402c19:dd:c25:c25d:dd:dd:dd:a8b/1282c19:dd:c25:c25d:dd:dd:dd:a8b
1412c19:dd:c25:c25d:dd:dd:dd:a8c/1282c19:dd:c25:c25d:dd:dd:dd:a8c
1422c19:dd:c25:c25d:dd:dd:dd:a8d/1282c19:dd:c25:c25d:dd:dd:dd:a8d
1432c19:dd:c25:c25d:dd:dd:dd:a8e/1282c19:dd:c25:c25d:dd:dd:dd:a8e
1442c19:dd:c25:c25d:dd:dd:dd:a8f/1282c19:dd:c25:c25d:dd:dd:dd:a8f
1452c19:dd:c25:c25d:dd:dd:dd:a90/1282c19:dd:c25:c25d:dd:dd:dd:a90
1462c19:dd:c25:c25d:dd:dd:dd:a91/1282c19:dd:c25:c25d:dd:dd:dd:a91
1472c19:dd:c25:c25d:dd:dd:dd:a92/1282c19:dd:c25:c25d:dd:dd:dd:a92
1482c19:dd:c25:c25d:dd:dd:dd:a93/1282c19:dd:c25:c25d:dd:dd:dd:a93
1492c19:dd:c25:c25d:dd:dd:dd:a94/1282c19:dd:c25:c25d:dd:dd:dd:a94
1502c19:dd:c25:c25d:dd:dd:dd:a95/1282c19:dd:c25:c25d:dd:dd:dd:a95
1512c19:dd:c25:c25d:dd:dd:dd:a96/1282c19:dd:c25:c25d:dd:dd:dd:a96
1522c19:dd:c25:c25d:dd:dd:dd:a97/1282c19:dd:c25:c25d:dd:dd:dd:a97
1532c19:dd:c25:c25d:dd:dd:dd:a98/1282c19:dd:c25:c25d:dd:dd:dd:a98
1542c19:dd:c25:c25d:dd:dd:dd:a99/1282c19:dd:c25:c25d:dd:dd:dd:a99
1552c19:dd:c25:c25d:dd:dd:dd:a9a/1282c19:dd:c25:c25d:dd:dd:dd:a9a
1562c19:dd:c25:c25d:dd:dd:dd:a9b/1282c19:dd:c25:c25d:dd:dd:dd:a9b
1572c19:dd:c25:c25d:dd:dd:dd:a9c/1282c19:dd:c25:c25d:dd:dd:dd:a9c
1582c19:dd:c25:c25d:dd:dd:dd:a9d/1282c19:dd:c25:c25d:dd:dd:dd:a9d
1592c19:dd:c25:c25d:dd:dd:dd:a9e/1282c19:dd:c25:c25d:dd:dd:dd:a9e
1602c19:dd:c25:c25d:dd:dd:dd:a9f/1282c19:dd:c25:c25d:dd:dd:dd:a9f
1612c19:dd:c25:c25d:dd:dd:dd:aa0/1282c19:dd:c25:c25d:dd:dd:dd:aa0
1622c19:dd:c25:c25d:dd:dd:dd:aa1/1282c19:dd:c25:c25d:dd:dd:dd:aa1
1632c19:dd:c25:c25d:dd:dd:dd:aa2/1282c19:dd:c25:c25d:dd:dd:dd:aa2
1642c19:dd:c25:c25d:dd:dd:dd:aa3/1282c19:dd:c25:c25d:dd:dd:dd:aa3
1652c19:dd:c25:c25d:dd:dd:dd:aa4/1282c19:dd:c25:c25d:dd:dd:dd:aa4
1662c19:dd:c25:c25d:dd:dd:dd:aa5/1282c19:dd:c25:c25d:dd:dd:dd:aa5
1672c19:dd:c25:c25d:dd:dd:dd:aa6/1282c19:dd:c25:c25d:dd:dd:dd:aa6
1682c19:dd:c25:c25d:dd:dd:dd:aa7/1282c19:dd:c25:c25d:dd:dd:dd:aa7
1692c19:dd:c25:c25d:dd:dd:dd:aa8/1282c19:dd:c25:c25d:dd:dd:dd:aa8
1702c19:dd:c25:c25d:dd:dd:dd:aa9/1282c19:dd:c25:c25d:dd:dd:dd:aa9
1712c19:dd:c25:c25d:dd:dd:dd:aaa/1282c19:dd:c25:c25d:dd:dd:dd:aaa
1722c19:dd:c25:c25d:dd:dd:dd:aab/1282c19:dd:c25:c25d:dd:dd:dd:aab
1732c19:dd:c25:c25d:dd:dd:dd:aac/1282c19:dd:c25:c25d:dd:dd:dd:aac
1742c19:dd:c25:c25d:dd:dd:dd:aad/1282c19:dd:c25:c25d:dd:dd:dd:aad
1752c19:dd:c25:c25d:dd:dd:dd:aae/1282c19:dd:c25:c25d:dd:dd:dd:aae
1762c19:dd:c25:c25d:dd:dd:dd:aaf/1282c19:dd:c25:c25d:dd:dd:dd:aaf
1772c19:dd:c25:c25d:dd:dd:dd:ab0/1282c19:dd:c25:c25d:dd:dd:dd:ab0
1782c19:dd:c25:c25d:dd:dd:dd:ab1/1282c19:dd:c25:c25d:dd:dd:dd:ab1
1792c19:dd:c25:c25d:dd:dd:dd:ab2/1282c19:dd:c25:c25d:dd:dd:dd:ab2
1802c19:dd:c25:c25d:dd:dd:dd:ab3/1282c19:dd:c25:c25d:dd:dd:dd:ab3
1812c19:dd:c25:c25d:dd:dd:dd:ab4/1282c19:dd:c25:c25d:dd:dd:dd:ab4
1822c19:dd:c25:c25d:dd:dd:dd:ab5/1282c19:dd:c25:c25d:dd:dd:dd:ab5
1832c19:dd:c25:c25d:dd:dd:dd:ab6/1282c19:dd:c25:c25d:dd:dd:dd:ab6
1842c19:dd:c25:c25d:dd:dd:dd:ab7/1282c19:dd:c25:c25d:dd:dd:dd:ab7
1852c19:dd:c25:c25d:dd:dd:dd:ab8/1282c19:dd:c25:c25d:dd:dd:dd:ab8
1862c19:dd:c25:c25d:dd:dd:dd:ab9/1282c19:dd:c25:c25d:dd:dd:dd:ab9
1872c19:dd:c25:c25d:dd:dd:dd:aba/1282c19:dd:c25:c25d:dd:dd:dd:aba
1882c19:dd:c25:c25d:dd:dd:dd:abb/1282c19:dd:c25:c25d:dd:dd:dd:abb
1892c19:dd:c25:c25d:dd:dd:dd:abc/1282c19:dd:c25:c25d:dd:dd:dd:abc
1902c19:dd:c25:c25d:dd:dd:dd:abd/1282c19:dd:c25:c25d:dd:dd:dd:abd
1912c19:dd:c25:c25d:dd:dd:dd:abe/1282c19:dd:c25:c25d:dd:dd:dd:abe
1922c19:dd:c25:c25d:dd:dd:dd:abf/1282c19:dd:c25:c25d:dd:dd:dd:abf
1932c19:dd:c25:c25d:dd:dd:dd:ac0/1282c19:dd:c25:c25d:dd:dd:dd:ac0
1942c19:dd:c25:c25d:dd:dd:dd:ac1/1282c19:dd:c25:c25d:dd:dd:dd:ac1
1952c19:dd:c25:c25d:dd:dd:dd:ac2/1282c19:dd:c25:c25d:dd:dd:dd:ac2
1962c19:dd:c25:c25d:dd:dd:dd:ac3/1282c19:dd:c25:c25d:dd:dd:dd:ac3
1972c19:dd:c25:c25d:dd:dd:dd:ac4/1282c19:dd:c25:c25d:dd:dd:dd:ac4
1982c19:dd:c25:c25d:dd:dd:dd:ac5/1282c19:dd:c25:c25d:dd:dd:dd:ac5
1992c19:dd:c25:c25d:dd:dd:dd:ac6/1282c19:dd:c25:c25d:dd:dd:dd:ac6
2002c19:dd:c25:c25d:dd:dd:dd:ac7/1282c19:dd:c25:c25d:dd:dd:dd:ac7
2012c19:dd:c25:c25d:dd:dd:dd:ac8/1282c19:dd:c25:c25d:dd:dd:dd:ac8
2022c19:dd:c25:c25d:dd:dd:dd:ac9/1282c19:dd:c25:c25d:dd:dd:dd:ac9
2032c19:dd:c25:c25d:dd:dd:dd:aca/1282c19:dd:c25:c25d:dd:dd:dd:aca
2042c19:dd:c25:c25d:dd:dd:dd:acb/1282c19:dd:c25:c25d:dd:dd:dd:acb
2052c19:dd:c25:c25d:dd:dd:dd:acc/1282c19:dd:c25:c25d:dd:dd:dd:acc
2062c19:dd:c25:c25d:dd:dd:dd:acd/1282c19:dd:c25:c25d:dd:dd:dd:acd
2072c19:dd:c25:c25d:dd:dd:dd:ace/1282c19:dd:c25:c25d:dd:dd:dd:ace
2082c19:dd:c25:c25d:dd:dd:dd:acf/1282c19:dd:c25:c25d:dd:dd:dd:acf
2092c19:dd:c25:c25d:dd:dd:dd:ad0/1282c19:dd:c25:c25d:dd:dd:dd:ad0
2102c19:dd:c25:c25d:dd:dd:dd:ad1/1282c19:dd:c25:c25d:dd:dd:dd:ad1
2112c19:dd:c25:c25d:dd:dd:dd:ad2/1282c19:dd:c25:c25d:dd:dd:dd:ad2
2122c19:dd:c25:c25d:dd:dd:dd:ad3/1282c19:dd:c25:c25d:dd:dd:dd:ad3
2132c19:dd:c25:c25d:dd:dd:dd:ad4/1282c19:dd:c25:c25d:dd:dd:dd:ad4
2142c19:dd:c25:c25d:dd:dd:dd:ad5/1282c19:dd:c25:c25d:dd:dd:dd:ad5
2152c19:dd:c25:c25d:dd:dd:dd:ad6/1282c19:dd:c25:c25d:dd:dd:dd:ad6
2162c19:dd:c25:c25d:dd:dd:dd:ad7/1282c19:dd:c25:c25d:dd:dd:dd:ad7
2172c19:dd:c25:c25d:dd:dd:dd:ad8/1282c19:dd:c25:c25d:dd:dd:dd:ad8
2182c19:dd:c25:c25d:dd:dd:dd:ad9/1282c19:dd:c25:c25d:dd:dd:dd:ad9
2192c19:dd:c25:c25d:dd:dd:dd:ada/1282c19:dd:c25:c25d:dd:dd:dd:ada
2202c19:dd:c25:c25d:dd:dd:dd:adb/1282c19:dd:c25:c25d:dd:dd:dd:adb
2212c19:dd:c25:c25d:dd:dd:dd:adc/1282c19:dd:c25:c25d:dd:dd:dd:adc
2222c19:dd:c25:c25d:dd:dd:dd:add/1282c19:dd:c25:c25d:dd:dd:dd:add
2232c19:dd:c25:c25d:dd:dd:dd:ade/1282c19:dd:c25:c25d:dd:dd:dd:ade
2242c19:dd:c25:c25d:dd:dd:dd:adf/1282c19:dd:c25:c25d:dd:dd:dd:adf
2252c19:dd:c25:c25d:dd:dd:dd:ae0/1282c19:dd:c25:c25d:dd:dd:dd:ae0
2262c19:dd:c25:c25d:dd:dd:dd:ae1/1282c19:dd:c25:c25d:dd:dd:dd:ae1
2272c19:dd:c25:c25d:dd:dd:dd:ae2/1282c19:dd:c25:c25d:dd:dd:dd:ae2
2282c19:dd:c25:c25d:dd:dd:dd:ae3/1282c19:dd:c25:c25d:dd:dd:dd:ae3
2292c19:dd:c25:c25d:dd:dd:dd:ae4/1282c19:dd:c25:c25d:dd:dd:dd:ae4
2302c19:dd:c25:c25d:dd:dd:dd:ae5/1282c19:dd:c25:c25d:dd:dd:dd:ae5
2312c19:dd:c25:c25d:dd:dd:dd:ae6/1282c19:dd:c25:c25d:dd:dd:dd:ae6
2322c19:dd:c25:c25d:dd:dd:dd:ae7/1282c19:dd:c25:c25d:dd:dd:dd:ae7
2332c19:dd:c25:c25d:dd:dd:dd:ae8/1282c19:dd:c25:c25d:dd:dd:dd:ae8
2342c19:dd:c25:c25d:dd:dd:dd:ae9/1282c19:dd:c25:c25d:dd:dd:dd:ae9
2352c19:dd:c25:c25d:dd:dd:dd:aea/1282c19:dd:c25:c25d:dd:dd:dd:aea
2362c19:dd:c25:c25d:dd:dd:dd:aeb/1282c19:dd:c25:c25d:dd:dd:dd:aeb
2372c19:dd:c25:c25d:dd:dd:dd:aec/1282c19:dd:c25:c25d:dd:dd:dd:aec
2382c19:dd:c25:c25d:dd:dd:dd:aed/1282c19:dd:c25:c25d:dd:dd:dd:aed
2392c19:dd:c25:c25d:dd:dd:dd:aee/1282c19:dd:c25:c25d:dd:dd:dd:aee
2402c19:dd:c25:c25d:dd:dd:dd:aef/1282c19:dd:c25:c25d:dd:dd:dd:aef
2412c19:dd:c25:c25d:dd:dd:dd:af0/1282c19:dd:c25:c25d:dd:dd:dd:af0
2422c19:dd:c25:c25d:dd:dd:dd:af1/1282c19:dd:c25:c25d:dd:dd:dd:af1
2432c19:dd:c25:c25d:dd:dd:dd:af2/1282c19:dd:c25:c25d:dd:dd:dd:af2
2442c19:dd:c25:c25d:dd:dd:dd:af3/1282c19:dd:c25:c25d:dd:dd:dd:af3
2452c19:dd:c25:c25d:dd:dd:dd:af4/1282c19:dd:c25:c25d:dd:dd:dd:af4
2462c19:dd:c25:c25d:dd:dd:dd:af5/1282c19:dd:c25:c25d:dd:dd:dd:af5
2472c19:dd:c25:c25d:dd:dd:dd:af6/1282c19:dd:c25:c25d:dd:dd:dd:af6
2482c19:dd:c25:c25d:dd:dd:dd:af7/1282c19:dd:c25:c25d:dd:dd:dd:af7
2492c19:dd:c25:c25d:dd:dd:dd:af8/1282c19:dd:c25:c25d:dd:dd:dd:af8
2502c19:dd:c25:c25d:dd:dd:dd:af9/1282c19:dd:c25:c25d:dd:dd:dd:af9
2512c19:dd:c25:c25d:dd:dd:dd:afa/1282c19:dd:c25:c25d:dd:dd:dd:afa
2522c19:dd:c25:c25d:dd:dd:dd:afb/1282c19:dd:c25:c25d:dd:dd:dd:afb
2532c19:dd:c25:c25d:dd:dd:dd:afc/1282c19:dd:c25:c25d:dd:dd:dd:afc
2542c19:dd:c25:c25d:dd:dd:dd:afd/1282c19:dd:c25:c25d:dd:dd:dd:afd
2552c19:dd:c25:c25d:dd:dd:dd:afe/1282c19:dd:c25:c25d:dd:dd:dd:afe
2562c19:dd:c25:c25d:dd:dd:dd:aff/1282c19:dd:c25:c25d:dd:dd:dd:aff

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.