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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:400/120
First address
2c19:dd:c25:c25d:dd:dd:dd:400
Last address
2c19:dd:c25:c25d:dd:dd:dd:4ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:0c25:c25d:00dd:00dd:00dd:0400
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
4.0.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:400/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:c25:c25d:dd:dd:dd:400/1282c19:dd:c25:c25d:dd:dd:dd:400
22c19:dd:c25:c25d:dd:dd:dd:401/1282c19:dd:c25:c25d:dd:dd:dd:401
32c19:dd:c25:c25d:dd:dd:dd:402/1282c19:dd:c25:c25d:dd:dd:dd:402
42c19:dd:c25:c25d:dd:dd:dd:403/1282c19:dd:c25:c25d:dd:dd:dd:403
52c19:dd:c25:c25d:dd:dd:dd:404/1282c19:dd:c25:c25d:dd:dd:dd:404
62c19:dd:c25:c25d:dd:dd:dd:405/1282c19:dd:c25:c25d:dd:dd:dd:405
72c19:dd:c25:c25d:dd:dd:dd:406/1282c19:dd:c25:c25d:dd:dd:dd:406
82c19:dd:c25:c25d:dd:dd:dd:407/1282c19:dd:c25:c25d:dd:dd:dd:407
92c19:dd:c25:c25d:dd:dd:dd:408/1282c19:dd:c25:c25d:dd:dd:dd:408
102c19:dd:c25:c25d:dd:dd:dd:409/1282c19:dd:c25:c25d:dd:dd:dd:409
112c19:dd:c25:c25d:dd:dd:dd:40a/1282c19:dd:c25:c25d:dd:dd:dd:40a
122c19:dd:c25:c25d:dd:dd:dd:40b/1282c19:dd:c25:c25d:dd:dd:dd:40b
132c19:dd:c25:c25d:dd:dd:dd:40c/1282c19:dd:c25:c25d:dd:dd:dd:40c
142c19:dd:c25:c25d:dd:dd:dd:40d/1282c19:dd:c25:c25d:dd:dd:dd:40d
152c19:dd:c25:c25d:dd:dd:dd:40e/1282c19:dd:c25:c25d:dd:dd:dd:40e
162c19:dd:c25:c25d:dd:dd:dd:40f/1282c19:dd:c25:c25d:dd:dd:dd:40f
172c19:dd:c25:c25d:dd:dd:dd:410/1282c19:dd:c25:c25d:dd:dd:dd:410
182c19:dd:c25:c25d:dd:dd:dd:411/1282c19:dd:c25:c25d:dd:dd:dd:411
192c19:dd:c25:c25d:dd:dd:dd:412/1282c19:dd:c25:c25d:dd:dd:dd:412
202c19:dd:c25:c25d:dd:dd:dd:413/1282c19:dd:c25:c25d:dd:dd:dd:413
212c19:dd:c25:c25d:dd:dd:dd:414/1282c19:dd:c25:c25d:dd:dd:dd:414
222c19:dd:c25:c25d:dd:dd:dd:415/1282c19:dd:c25:c25d:dd:dd:dd:415
232c19:dd:c25:c25d:dd:dd:dd:416/1282c19:dd:c25:c25d:dd:dd:dd:416
242c19:dd:c25:c25d:dd:dd:dd:417/1282c19:dd:c25:c25d:dd:dd:dd:417
252c19:dd:c25:c25d:dd:dd:dd:418/1282c19:dd:c25:c25d:dd:dd:dd:418
262c19:dd:c25:c25d:dd:dd:dd:419/1282c19:dd:c25:c25d:dd:dd:dd:419
272c19:dd:c25:c25d:dd:dd:dd:41a/1282c19:dd:c25:c25d:dd:dd:dd:41a
282c19:dd:c25:c25d:dd:dd:dd:41b/1282c19:dd:c25:c25d:dd:dd:dd:41b
292c19:dd:c25:c25d:dd:dd:dd:41c/1282c19:dd:c25:c25d:dd:dd:dd:41c
302c19:dd:c25:c25d:dd:dd:dd:41d/1282c19:dd:c25:c25d:dd:dd:dd:41d
312c19:dd:c25:c25d:dd:dd:dd:41e/1282c19:dd:c25:c25d:dd:dd:dd:41e
322c19:dd:c25:c25d:dd:dd:dd:41f/1282c19:dd:c25:c25d:dd:dd:dd:41f
332c19:dd:c25:c25d:dd:dd:dd:420/1282c19:dd:c25:c25d:dd:dd:dd:420
342c19:dd:c25:c25d:dd:dd:dd:421/1282c19:dd:c25:c25d:dd:dd:dd:421
352c19:dd:c25:c25d:dd:dd:dd:422/1282c19:dd:c25:c25d:dd:dd:dd:422
362c19:dd:c25:c25d:dd:dd:dd:423/1282c19:dd:c25:c25d:dd:dd:dd:423
372c19:dd:c25:c25d:dd:dd:dd:424/1282c19:dd:c25:c25d:dd:dd:dd:424
382c19:dd:c25:c25d:dd:dd:dd:425/1282c19:dd:c25:c25d:dd:dd:dd:425
392c19:dd:c25:c25d:dd:dd:dd:426/1282c19:dd:c25:c25d:dd:dd:dd:426
402c19:dd:c25:c25d:dd:dd:dd:427/1282c19:dd:c25:c25d:dd:dd:dd:427
412c19:dd:c25:c25d:dd:dd:dd:428/1282c19:dd:c25:c25d:dd:dd:dd:428
422c19:dd:c25:c25d:dd:dd:dd:429/1282c19:dd:c25:c25d:dd:dd:dd:429
432c19:dd:c25:c25d:dd:dd:dd:42a/1282c19:dd:c25:c25d:dd:dd:dd:42a
442c19:dd:c25:c25d:dd:dd:dd:42b/1282c19:dd:c25:c25d:dd:dd:dd:42b
452c19:dd:c25:c25d:dd:dd:dd:42c/1282c19:dd:c25:c25d:dd:dd:dd:42c
462c19:dd:c25:c25d:dd:dd:dd:42d/1282c19:dd:c25:c25d:dd:dd:dd:42d
472c19:dd:c25:c25d:dd:dd:dd:42e/1282c19:dd:c25:c25d:dd:dd:dd:42e
482c19:dd:c25:c25d:dd:dd:dd:42f/1282c19:dd:c25:c25d:dd:dd:dd:42f
492c19:dd:c25:c25d:dd:dd:dd:430/1282c19:dd:c25:c25d:dd:dd:dd:430
502c19:dd:c25:c25d:dd:dd:dd:431/1282c19:dd:c25:c25d:dd:dd:dd:431
512c19:dd:c25:c25d:dd:dd:dd:432/1282c19:dd:c25:c25d:dd:dd:dd:432
522c19:dd:c25:c25d:dd:dd:dd:433/1282c19:dd:c25:c25d:dd:dd:dd:433
532c19:dd:c25:c25d:dd:dd:dd:434/1282c19:dd:c25:c25d:dd:dd:dd:434
542c19:dd:c25:c25d:dd:dd:dd:435/1282c19:dd:c25:c25d:dd:dd:dd:435
552c19:dd:c25:c25d:dd:dd:dd:436/1282c19:dd:c25:c25d:dd:dd:dd:436
562c19:dd:c25:c25d:dd:dd:dd:437/1282c19:dd:c25:c25d:dd:dd:dd:437
572c19:dd:c25:c25d:dd:dd:dd:438/1282c19:dd:c25:c25d:dd:dd:dd:438
582c19:dd:c25:c25d:dd:dd:dd:439/1282c19:dd:c25:c25d:dd:dd:dd:439
592c19:dd:c25:c25d:dd:dd:dd:43a/1282c19:dd:c25:c25d:dd:dd:dd:43a
602c19:dd:c25:c25d:dd:dd:dd:43b/1282c19:dd:c25:c25d:dd:dd:dd:43b
612c19:dd:c25:c25d:dd:dd:dd:43c/1282c19:dd:c25:c25d:dd:dd:dd:43c
622c19:dd:c25:c25d:dd:dd:dd:43d/1282c19:dd:c25:c25d:dd:dd:dd:43d
632c19:dd:c25:c25d:dd:dd:dd:43e/1282c19:dd:c25:c25d:dd:dd:dd:43e
642c19:dd:c25:c25d:dd:dd:dd:43f/1282c19:dd:c25:c25d:dd:dd:dd:43f
652c19:dd:c25:c25d:dd:dd:dd:440/1282c19:dd:c25:c25d:dd:dd:dd:440
662c19:dd:c25:c25d:dd:dd:dd:441/1282c19:dd:c25:c25d:dd:dd:dd:441
672c19:dd:c25:c25d:dd:dd:dd:442/1282c19:dd:c25:c25d:dd:dd:dd:442
682c19:dd:c25:c25d:dd:dd:dd:443/1282c19:dd:c25:c25d:dd:dd:dd:443
692c19:dd:c25:c25d:dd:dd:dd:444/1282c19:dd:c25:c25d:dd:dd:dd:444
702c19:dd:c25:c25d:dd:dd:dd:445/1282c19:dd:c25:c25d:dd:dd:dd:445
712c19:dd:c25:c25d:dd:dd:dd:446/1282c19:dd:c25:c25d:dd:dd:dd:446
722c19:dd:c25:c25d:dd:dd:dd:447/1282c19:dd:c25:c25d:dd:dd:dd:447
732c19:dd:c25:c25d:dd:dd:dd:448/1282c19:dd:c25:c25d:dd:dd:dd:448
742c19:dd:c25:c25d:dd:dd:dd:449/1282c19:dd:c25:c25d:dd:dd:dd:449
752c19:dd:c25:c25d:dd:dd:dd:44a/1282c19:dd:c25:c25d:dd:dd:dd:44a
762c19:dd:c25:c25d:dd:dd:dd:44b/1282c19:dd:c25:c25d:dd:dd:dd:44b
772c19:dd:c25:c25d:dd:dd:dd:44c/1282c19:dd:c25:c25d:dd:dd:dd:44c
782c19:dd:c25:c25d:dd:dd:dd:44d/1282c19:dd:c25:c25d:dd:dd:dd:44d
792c19:dd:c25:c25d:dd:dd:dd:44e/1282c19:dd:c25:c25d:dd:dd:dd:44e
802c19:dd:c25:c25d:dd:dd:dd:44f/1282c19:dd:c25:c25d:dd:dd:dd:44f
812c19:dd:c25:c25d:dd:dd:dd:450/1282c19:dd:c25:c25d:dd:dd:dd:450
822c19:dd:c25:c25d:dd:dd:dd:451/1282c19:dd:c25:c25d:dd:dd:dd:451
832c19:dd:c25:c25d:dd:dd:dd:452/1282c19:dd:c25:c25d:dd:dd:dd:452
842c19:dd:c25:c25d:dd:dd:dd:453/1282c19:dd:c25:c25d:dd:dd:dd:453
852c19:dd:c25:c25d:dd:dd:dd:454/1282c19:dd:c25:c25d:dd:dd:dd:454
862c19:dd:c25:c25d:dd:dd:dd:455/1282c19:dd:c25:c25d:dd:dd:dd:455
872c19:dd:c25:c25d:dd:dd:dd:456/1282c19:dd:c25:c25d:dd:dd:dd:456
882c19:dd:c25:c25d:dd:dd:dd:457/1282c19:dd:c25:c25d:dd:dd:dd:457
892c19:dd:c25:c25d:dd:dd:dd:458/1282c19:dd:c25:c25d:dd:dd:dd:458
902c19:dd:c25:c25d:dd:dd:dd:459/1282c19:dd:c25:c25d:dd:dd:dd:459
912c19:dd:c25:c25d:dd:dd:dd:45a/1282c19:dd:c25:c25d:dd:dd:dd:45a
922c19:dd:c25:c25d:dd:dd:dd:45b/1282c19:dd:c25:c25d:dd:dd:dd:45b
932c19:dd:c25:c25d:dd:dd:dd:45c/1282c19:dd:c25:c25d:dd:dd:dd:45c
942c19:dd:c25:c25d:dd:dd:dd:45d/1282c19:dd:c25:c25d:dd:dd:dd:45d
952c19:dd:c25:c25d:dd:dd:dd:45e/1282c19:dd:c25:c25d:dd:dd:dd:45e
962c19:dd:c25:c25d:dd:dd:dd:45f/1282c19:dd:c25:c25d:dd:dd:dd:45f
972c19:dd:c25:c25d:dd:dd:dd:460/1282c19:dd:c25:c25d:dd:dd:dd:460
982c19:dd:c25:c25d:dd:dd:dd:461/1282c19:dd:c25:c25d:dd:dd:dd:461
992c19:dd:c25:c25d:dd:dd:dd:462/1282c19:dd:c25:c25d:dd:dd:dd:462
1002c19:dd:c25:c25d:dd:dd:dd:463/1282c19:dd:c25:c25d:dd:dd:dd:463
1012c19:dd:c25:c25d:dd:dd:dd:464/1282c19:dd:c25:c25d:dd:dd:dd:464
1022c19:dd:c25:c25d:dd:dd:dd:465/1282c19:dd:c25:c25d:dd:dd:dd:465
1032c19:dd:c25:c25d:dd:dd:dd:466/1282c19:dd:c25:c25d:dd:dd:dd:466
1042c19:dd:c25:c25d:dd:dd:dd:467/1282c19:dd:c25:c25d:dd:dd:dd:467
1052c19:dd:c25:c25d:dd:dd:dd:468/1282c19:dd:c25:c25d:dd:dd:dd:468
1062c19:dd:c25:c25d:dd:dd:dd:469/1282c19:dd:c25:c25d:dd:dd:dd:469
1072c19:dd:c25:c25d:dd:dd:dd:46a/1282c19:dd:c25:c25d:dd:dd:dd:46a
1082c19:dd:c25:c25d:dd:dd:dd:46b/1282c19:dd:c25:c25d:dd:dd:dd:46b
1092c19:dd:c25:c25d:dd:dd:dd:46c/1282c19:dd:c25:c25d:dd:dd:dd:46c
1102c19:dd:c25:c25d:dd:dd:dd:46d/1282c19:dd:c25:c25d:dd:dd:dd:46d
1112c19:dd:c25:c25d:dd:dd:dd:46e/1282c19:dd:c25:c25d:dd:dd:dd:46e
1122c19:dd:c25:c25d:dd:dd:dd:46f/1282c19:dd:c25:c25d:dd:dd:dd:46f
1132c19:dd:c25:c25d:dd:dd:dd:470/1282c19:dd:c25:c25d:dd:dd:dd:470
1142c19:dd:c25:c25d:dd:dd:dd:471/1282c19:dd:c25:c25d:dd:dd:dd:471
1152c19:dd:c25:c25d:dd:dd:dd:472/1282c19:dd:c25:c25d:dd:dd:dd:472
1162c19:dd:c25:c25d:dd:dd:dd:473/1282c19:dd:c25:c25d:dd:dd:dd:473
1172c19:dd:c25:c25d:dd:dd:dd:474/1282c19:dd:c25:c25d:dd:dd:dd:474
1182c19:dd:c25:c25d:dd:dd:dd:475/1282c19:dd:c25:c25d:dd:dd:dd:475
1192c19:dd:c25:c25d:dd:dd:dd:476/1282c19:dd:c25:c25d:dd:dd:dd:476
1202c19:dd:c25:c25d:dd:dd:dd:477/1282c19:dd:c25:c25d:dd:dd:dd:477
1212c19:dd:c25:c25d:dd:dd:dd:478/1282c19:dd:c25:c25d:dd:dd:dd:478
1222c19:dd:c25:c25d:dd:dd:dd:479/1282c19:dd:c25:c25d:dd:dd:dd:479
1232c19:dd:c25:c25d:dd:dd:dd:47a/1282c19:dd:c25:c25d:dd:dd:dd:47a
1242c19:dd:c25:c25d:dd:dd:dd:47b/1282c19:dd:c25:c25d:dd:dd:dd:47b
1252c19:dd:c25:c25d:dd:dd:dd:47c/1282c19:dd:c25:c25d:dd:dd:dd:47c
1262c19:dd:c25:c25d:dd:dd:dd:47d/1282c19:dd:c25:c25d:dd:dd:dd:47d
1272c19:dd:c25:c25d:dd:dd:dd:47e/1282c19:dd:c25:c25d:dd:dd:dd:47e
1282c19:dd:c25:c25d:dd:dd:dd:47f/1282c19:dd:c25:c25d:dd:dd:dd:47f
1292c19:dd:c25:c25d:dd:dd:dd:480/1282c19:dd:c25:c25d:dd:dd:dd:480
1302c19:dd:c25:c25d:dd:dd:dd:481/1282c19:dd:c25:c25d:dd:dd:dd:481
1312c19:dd:c25:c25d:dd:dd:dd:482/1282c19:dd:c25:c25d:dd:dd:dd:482
1322c19:dd:c25:c25d:dd:dd:dd:483/1282c19:dd:c25:c25d:dd:dd:dd:483
1332c19:dd:c25:c25d:dd:dd:dd:484/1282c19:dd:c25:c25d:dd:dd:dd:484
1342c19:dd:c25:c25d:dd:dd:dd:485/1282c19:dd:c25:c25d:dd:dd:dd:485
1352c19:dd:c25:c25d:dd:dd:dd:486/1282c19:dd:c25:c25d:dd:dd:dd:486
1362c19:dd:c25:c25d:dd:dd:dd:487/1282c19:dd:c25:c25d:dd:dd:dd:487
1372c19:dd:c25:c25d:dd:dd:dd:488/1282c19:dd:c25:c25d:dd:dd:dd:488
1382c19:dd:c25:c25d:dd:dd:dd:489/1282c19:dd:c25:c25d:dd:dd:dd:489
1392c19:dd:c25:c25d:dd:dd:dd:48a/1282c19:dd:c25:c25d:dd:dd:dd:48a
1402c19:dd:c25:c25d:dd:dd:dd:48b/1282c19:dd:c25:c25d:dd:dd:dd:48b
1412c19:dd:c25:c25d:dd:dd:dd:48c/1282c19:dd:c25:c25d:dd:dd:dd:48c
1422c19:dd:c25:c25d:dd:dd:dd:48d/1282c19:dd:c25:c25d:dd:dd:dd:48d
1432c19:dd:c25:c25d:dd:dd:dd:48e/1282c19:dd:c25:c25d:dd:dd:dd:48e
1442c19:dd:c25:c25d:dd:dd:dd:48f/1282c19:dd:c25:c25d:dd:dd:dd:48f
1452c19:dd:c25:c25d:dd:dd:dd:490/1282c19:dd:c25:c25d:dd:dd:dd:490
1462c19:dd:c25:c25d:dd:dd:dd:491/1282c19:dd:c25:c25d:dd:dd:dd:491
1472c19:dd:c25:c25d:dd:dd:dd:492/1282c19:dd:c25:c25d:dd:dd:dd:492
1482c19:dd:c25:c25d:dd:dd:dd:493/1282c19:dd:c25:c25d:dd:dd:dd:493
1492c19:dd:c25:c25d:dd:dd:dd:494/1282c19:dd:c25:c25d:dd:dd:dd:494
1502c19:dd:c25:c25d:dd:dd:dd:495/1282c19:dd:c25:c25d:dd:dd:dd:495
1512c19:dd:c25:c25d:dd:dd:dd:496/1282c19:dd:c25:c25d:dd:dd:dd:496
1522c19:dd:c25:c25d:dd:dd:dd:497/1282c19:dd:c25:c25d:dd:dd:dd:497
1532c19:dd:c25:c25d:dd:dd:dd:498/1282c19:dd:c25:c25d:dd:dd:dd:498
1542c19:dd:c25:c25d:dd:dd:dd:499/1282c19:dd:c25:c25d:dd:dd:dd:499
1552c19:dd:c25:c25d:dd:dd:dd:49a/1282c19:dd:c25:c25d:dd:dd:dd:49a
1562c19:dd:c25:c25d:dd:dd:dd:49b/1282c19:dd:c25:c25d:dd:dd:dd:49b
1572c19:dd:c25:c25d:dd:dd:dd:49c/1282c19:dd:c25:c25d:dd:dd:dd:49c
1582c19:dd:c25:c25d:dd:dd:dd:49d/1282c19:dd:c25:c25d:dd:dd:dd:49d
1592c19:dd:c25:c25d:dd:dd:dd:49e/1282c19:dd:c25:c25d:dd:dd:dd:49e
1602c19:dd:c25:c25d:dd:dd:dd:49f/1282c19:dd:c25:c25d:dd:dd:dd:49f
1612c19:dd:c25:c25d:dd:dd:dd:4a0/1282c19:dd:c25:c25d:dd:dd:dd:4a0
1622c19:dd:c25:c25d:dd:dd:dd:4a1/1282c19:dd:c25:c25d:dd:dd:dd:4a1
1632c19:dd:c25:c25d:dd:dd:dd:4a2/1282c19:dd:c25:c25d:dd:dd:dd:4a2
1642c19:dd:c25:c25d:dd:dd:dd:4a3/1282c19:dd:c25:c25d:dd:dd:dd:4a3
1652c19:dd:c25:c25d:dd:dd:dd:4a4/1282c19:dd:c25:c25d:dd:dd:dd:4a4
1662c19:dd:c25:c25d:dd:dd:dd:4a5/1282c19:dd:c25:c25d:dd:dd:dd:4a5
1672c19:dd:c25:c25d:dd:dd:dd:4a6/1282c19:dd:c25:c25d:dd:dd:dd:4a6
1682c19:dd:c25:c25d:dd:dd:dd:4a7/1282c19:dd:c25:c25d:dd:dd:dd:4a7
1692c19:dd:c25:c25d:dd:dd:dd:4a8/1282c19:dd:c25:c25d:dd:dd:dd:4a8
1702c19:dd:c25:c25d:dd:dd:dd:4a9/1282c19:dd:c25:c25d:dd:dd:dd:4a9
1712c19:dd:c25:c25d:dd:dd:dd:4aa/1282c19:dd:c25:c25d:dd:dd:dd:4aa
1722c19:dd:c25:c25d:dd:dd:dd:4ab/1282c19:dd:c25:c25d:dd:dd:dd:4ab
1732c19:dd:c25:c25d:dd:dd:dd:4ac/1282c19:dd:c25:c25d:dd:dd:dd:4ac
1742c19:dd:c25:c25d:dd:dd:dd:4ad/1282c19:dd:c25:c25d:dd:dd:dd:4ad
1752c19:dd:c25:c25d:dd:dd:dd:4ae/1282c19:dd:c25:c25d:dd:dd:dd:4ae
1762c19:dd:c25:c25d:dd:dd:dd:4af/1282c19:dd:c25:c25d:dd:dd:dd:4af
1772c19:dd:c25:c25d:dd:dd:dd:4b0/1282c19:dd:c25:c25d:dd:dd:dd:4b0
1782c19:dd:c25:c25d:dd:dd:dd:4b1/1282c19:dd:c25:c25d:dd:dd:dd:4b1
1792c19:dd:c25:c25d:dd:dd:dd:4b2/1282c19:dd:c25:c25d:dd:dd:dd:4b2
1802c19:dd:c25:c25d:dd:dd:dd:4b3/1282c19:dd:c25:c25d:dd:dd:dd:4b3
1812c19:dd:c25:c25d:dd:dd:dd:4b4/1282c19:dd:c25:c25d:dd:dd:dd:4b4
1822c19:dd:c25:c25d:dd:dd:dd:4b5/1282c19:dd:c25:c25d:dd:dd:dd:4b5
1832c19:dd:c25:c25d:dd:dd:dd:4b6/1282c19:dd:c25:c25d:dd:dd:dd:4b6
1842c19:dd:c25:c25d:dd:dd:dd:4b7/1282c19:dd:c25:c25d:dd:dd:dd:4b7
1852c19:dd:c25:c25d:dd:dd:dd:4b8/1282c19:dd:c25:c25d:dd:dd:dd:4b8
1862c19:dd:c25:c25d:dd:dd:dd:4b9/1282c19:dd:c25:c25d:dd:dd:dd:4b9
1872c19:dd:c25:c25d:dd:dd:dd:4ba/1282c19:dd:c25:c25d:dd:dd:dd:4ba
1882c19:dd:c25:c25d:dd:dd:dd:4bb/1282c19:dd:c25:c25d:dd:dd:dd:4bb
1892c19:dd:c25:c25d:dd:dd:dd:4bc/1282c19:dd:c25:c25d:dd:dd:dd:4bc
1902c19:dd:c25:c25d:dd:dd:dd:4bd/1282c19:dd:c25:c25d:dd:dd:dd:4bd
1912c19:dd:c25:c25d:dd:dd:dd:4be/1282c19:dd:c25:c25d:dd:dd:dd:4be
1922c19:dd:c25:c25d:dd:dd:dd:4bf/1282c19:dd:c25:c25d:dd:dd:dd:4bf
1932c19:dd:c25:c25d:dd:dd:dd:4c0/1282c19:dd:c25:c25d:dd:dd:dd:4c0
1942c19:dd:c25:c25d:dd:dd:dd:4c1/1282c19:dd:c25:c25d:dd:dd:dd:4c1
1952c19:dd:c25:c25d:dd:dd:dd:4c2/1282c19:dd:c25:c25d:dd:dd:dd:4c2
1962c19:dd:c25:c25d:dd:dd:dd:4c3/1282c19:dd:c25:c25d:dd:dd:dd:4c3
1972c19:dd:c25:c25d:dd:dd:dd:4c4/1282c19:dd:c25:c25d:dd:dd:dd:4c4
1982c19:dd:c25:c25d:dd:dd:dd:4c5/1282c19:dd:c25:c25d:dd:dd:dd:4c5
1992c19:dd:c25:c25d:dd:dd:dd:4c6/1282c19:dd:c25:c25d:dd:dd:dd:4c6
2002c19:dd:c25:c25d:dd:dd:dd:4c7/1282c19:dd:c25:c25d:dd:dd:dd:4c7
2012c19:dd:c25:c25d:dd:dd:dd:4c8/1282c19:dd:c25:c25d:dd:dd:dd:4c8
2022c19:dd:c25:c25d:dd:dd:dd:4c9/1282c19:dd:c25:c25d:dd:dd:dd:4c9
2032c19:dd:c25:c25d:dd:dd:dd:4ca/1282c19:dd:c25:c25d:dd:dd:dd:4ca
2042c19:dd:c25:c25d:dd:dd:dd:4cb/1282c19:dd:c25:c25d:dd:dd:dd:4cb
2052c19:dd:c25:c25d:dd:dd:dd:4cc/1282c19:dd:c25:c25d:dd:dd:dd:4cc
2062c19:dd:c25:c25d:dd:dd:dd:4cd/1282c19:dd:c25:c25d:dd:dd:dd:4cd
2072c19:dd:c25:c25d:dd:dd:dd:4ce/1282c19:dd:c25:c25d:dd:dd:dd:4ce
2082c19:dd:c25:c25d:dd:dd:dd:4cf/1282c19:dd:c25:c25d:dd:dd:dd:4cf
2092c19:dd:c25:c25d:dd:dd:dd:4d0/1282c19:dd:c25:c25d:dd:dd:dd:4d0
2102c19:dd:c25:c25d:dd:dd:dd:4d1/1282c19:dd:c25:c25d:dd:dd:dd:4d1
2112c19:dd:c25:c25d:dd:dd:dd:4d2/1282c19:dd:c25:c25d:dd:dd:dd:4d2
2122c19:dd:c25:c25d:dd:dd:dd:4d3/1282c19:dd:c25:c25d:dd:dd:dd:4d3
2132c19:dd:c25:c25d:dd:dd:dd:4d4/1282c19:dd:c25:c25d:dd:dd:dd:4d4
2142c19:dd:c25:c25d:dd:dd:dd:4d5/1282c19:dd:c25:c25d:dd:dd:dd:4d5
2152c19:dd:c25:c25d:dd:dd:dd:4d6/1282c19:dd:c25:c25d:dd:dd:dd:4d6
2162c19:dd:c25:c25d:dd:dd:dd:4d7/1282c19:dd:c25:c25d:dd:dd:dd:4d7
2172c19:dd:c25:c25d:dd:dd:dd:4d8/1282c19:dd:c25:c25d:dd:dd:dd:4d8
2182c19:dd:c25:c25d:dd:dd:dd:4d9/1282c19:dd:c25:c25d:dd:dd:dd:4d9
2192c19:dd:c25:c25d:dd:dd:dd:4da/1282c19:dd:c25:c25d:dd:dd:dd:4da
2202c19:dd:c25:c25d:dd:dd:dd:4db/1282c19:dd:c25:c25d:dd:dd:dd:4db
2212c19:dd:c25:c25d:dd:dd:dd:4dc/1282c19:dd:c25:c25d:dd:dd:dd:4dc
2222c19:dd:c25:c25d:dd:dd:dd:4dd/1282c19:dd:c25:c25d:dd:dd:dd:4dd
2232c19:dd:c25:c25d:dd:dd:dd:4de/1282c19:dd:c25:c25d:dd:dd:dd:4de
2242c19:dd:c25:c25d:dd:dd:dd:4df/1282c19:dd:c25:c25d:dd:dd:dd:4df
2252c19:dd:c25:c25d:dd:dd:dd:4e0/1282c19:dd:c25:c25d:dd:dd:dd:4e0
2262c19:dd:c25:c25d:dd:dd:dd:4e1/1282c19:dd:c25:c25d:dd:dd:dd:4e1
2272c19:dd:c25:c25d:dd:dd:dd:4e2/1282c19:dd:c25:c25d:dd:dd:dd:4e2
2282c19:dd:c25:c25d:dd:dd:dd:4e3/1282c19:dd:c25:c25d:dd:dd:dd:4e3
2292c19:dd:c25:c25d:dd:dd:dd:4e4/1282c19:dd:c25:c25d:dd:dd:dd:4e4
2302c19:dd:c25:c25d:dd:dd:dd:4e5/1282c19:dd:c25:c25d:dd:dd:dd:4e5
2312c19:dd:c25:c25d:dd:dd:dd:4e6/1282c19:dd:c25:c25d:dd:dd:dd:4e6
2322c19:dd:c25:c25d:dd:dd:dd:4e7/1282c19:dd:c25:c25d:dd:dd:dd:4e7
2332c19:dd:c25:c25d:dd:dd:dd:4e8/1282c19:dd:c25:c25d:dd:dd:dd:4e8
2342c19:dd:c25:c25d:dd:dd:dd:4e9/1282c19:dd:c25:c25d:dd:dd:dd:4e9
2352c19:dd:c25:c25d:dd:dd:dd:4ea/1282c19:dd:c25:c25d:dd:dd:dd:4ea
2362c19:dd:c25:c25d:dd:dd:dd:4eb/1282c19:dd:c25:c25d:dd:dd:dd:4eb
2372c19:dd:c25:c25d:dd:dd:dd:4ec/1282c19:dd:c25:c25d:dd:dd:dd:4ec
2382c19:dd:c25:c25d:dd:dd:dd:4ed/1282c19:dd:c25:c25d:dd:dd:dd:4ed
2392c19:dd:c25:c25d:dd:dd:dd:4ee/1282c19:dd:c25:c25d:dd:dd:dd:4ee
2402c19:dd:c25:c25d:dd:dd:dd:4ef/1282c19:dd:c25:c25d:dd:dd:dd:4ef
2412c19:dd:c25:c25d:dd:dd:dd:4f0/1282c19:dd:c25:c25d:dd:dd:dd:4f0
2422c19:dd:c25:c25d:dd:dd:dd:4f1/1282c19:dd:c25:c25d:dd:dd:dd:4f1
2432c19:dd:c25:c25d:dd:dd:dd:4f2/1282c19:dd:c25:c25d:dd:dd:dd:4f2
2442c19:dd:c25:c25d:dd:dd:dd:4f3/1282c19:dd:c25:c25d:dd:dd:dd:4f3
2452c19:dd:c25:c25d:dd:dd:dd:4f4/1282c19:dd:c25:c25d:dd:dd:dd:4f4
2462c19:dd:c25:c25d:dd:dd:dd:4f5/1282c19:dd:c25:c25d:dd:dd:dd:4f5
2472c19:dd:c25:c25d:dd:dd:dd:4f6/1282c19:dd:c25:c25d:dd:dd:dd:4f6
2482c19:dd:c25:c25d:dd:dd:dd:4f7/1282c19:dd:c25:c25d:dd:dd:dd:4f7
2492c19:dd:c25:c25d:dd:dd:dd:4f8/1282c19:dd:c25:c25d:dd:dd:dd:4f8
2502c19:dd:c25:c25d:dd:dd:dd:4f9/1282c19:dd:c25:c25d:dd:dd:dd:4f9
2512c19:dd:c25:c25d:dd:dd:dd:4fa/1282c19:dd:c25:c25d:dd:dd:dd:4fa
2522c19:dd:c25:c25d:dd:dd:dd:4fb/1282c19:dd:c25:c25d:dd:dd:dd:4fb
2532c19:dd:c25:c25d:dd:dd:dd:4fc/1282c19:dd:c25:c25d:dd:dd:dd:4fc
2542c19:dd:c25:c25d:dd:dd:dd:4fd/1282c19:dd:c25:c25d:dd:dd:dd:4fd
2552c19:dd:c25:c25d:dd:dd:dd:4fe/1282c19:dd:c25:c25d:dd:dd:dd:4fe
2562c19:dd:c25:c25d:dd:dd:dd:4ff/1282c19:dd:c25:c25d:dd:dd:dd:4ff

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.