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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:4300/120
First address
2c19:dd:d9:dd:c25:c25:94de:4300
Last address
2c19:dd:d9:dd:c25:c25:94de:43ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:94de:4300
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
3.4.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:4300/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:94de:4300/1282c19:dd:d9:dd:c25:c25:94de:4300
22c19:dd:d9:dd:c25:c25:94de:4301/1282c19:dd:d9:dd:c25:c25:94de:4301
32c19:dd:d9:dd:c25:c25:94de:4302/1282c19:dd:d9:dd:c25:c25:94de:4302
42c19:dd:d9:dd:c25:c25:94de:4303/1282c19:dd:d9:dd:c25:c25:94de:4303
52c19:dd:d9:dd:c25:c25:94de:4304/1282c19:dd:d9:dd:c25:c25:94de:4304
62c19:dd:d9:dd:c25:c25:94de:4305/1282c19:dd:d9:dd:c25:c25:94de:4305
72c19:dd:d9:dd:c25:c25:94de:4306/1282c19:dd:d9:dd:c25:c25:94de:4306
82c19:dd:d9:dd:c25:c25:94de:4307/1282c19:dd:d9:dd:c25:c25:94de:4307
92c19:dd:d9:dd:c25:c25:94de:4308/1282c19:dd:d9:dd:c25:c25:94de:4308
102c19:dd:d9:dd:c25:c25:94de:4309/1282c19:dd:d9:dd:c25:c25:94de:4309
112c19:dd:d9:dd:c25:c25:94de:430a/1282c19:dd:d9:dd:c25:c25:94de:430a
122c19:dd:d9:dd:c25:c25:94de:430b/1282c19:dd:d9:dd:c25:c25:94de:430b
132c19:dd:d9:dd:c25:c25:94de:430c/1282c19:dd:d9:dd:c25:c25:94de:430c
142c19:dd:d9:dd:c25:c25:94de:430d/1282c19:dd:d9:dd:c25:c25:94de:430d
152c19:dd:d9:dd:c25:c25:94de:430e/1282c19:dd:d9:dd:c25:c25:94de:430e
162c19:dd:d9:dd:c25:c25:94de:430f/1282c19:dd:d9:dd:c25:c25:94de:430f
172c19:dd:d9:dd:c25:c25:94de:4310/1282c19:dd:d9:dd:c25:c25:94de:4310
182c19:dd:d9:dd:c25:c25:94de:4311/1282c19:dd:d9:dd:c25:c25:94de:4311
192c19:dd:d9:dd:c25:c25:94de:4312/1282c19:dd:d9:dd:c25:c25:94de:4312
202c19:dd:d9:dd:c25:c25:94de:4313/1282c19:dd:d9:dd:c25:c25:94de:4313
212c19:dd:d9:dd:c25:c25:94de:4314/1282c19:dd:d9:dd:c25:c25:94de:4314
222c19:dd:d9:dd:c25:c25:94de:4315/1282c19:dd:d9:dd:c25:c25:94de:4315
232c19:dd:d9:dd:c25:c25:94de:4316/1282c19:dd:d9:dd:c25:c25:94de:4316
242c19:dd:d9:dd:c25:c25:94de:4317/1282c19:dd:d9:dd:c25:c25:94de:4317
252c19:dd:d9:dd:c25:c25:94de:4318/1282c19:dd:d9:dd:c25:c25:94de:4318
262c19:dd:d9:dd:c25:c25:94de:4319/1282c19:dd:d9:dd:c25:c25:94de:4319
272c19:dd:d9:dd:c25:c25:94de:431a/1282c19:dd:d9:dd:c25:c25:94de:431a
282c19:dd:d9:dd:c25:c25:94de:431b/1282c19:dd:d9:dd:c25:c25:94de:431b
292c19:dd:d9:dd:c25:c25:94de:431c/1282c19:dd:d9:dd:c25:c25:94de:431c
302c19:dd:d9:dd:c25:c25:94de:431d/1282c19:dd:d9:dd:c25:c25:94de:431d
312c19:dd:d9:dd:c25:c25:94de:431e/1282c19:dd:d9:dd:c25:c25:94de:431e
322c19:dd:d9:dd:c25:c25:94de:431f/1282c19:dd:d9:dd:c25:c25:94de:431f
332c19:dd:d9:dd:c25:c25:94de:4320/1282c19:dd:d9:dd:c25:c25:94de:4320
342c19:dd:d9:dd:c25:c25:94de:4321/1282c19:dd:d9:dd:c25:c25:94de:4321
352c19:dd:d9:dd:c25:c25:94de:4322/1282c19:dd:d9:dd:c25:c25:94de:4322
362c19:dd:d9:dd:c25:c25:94de:4323/1282c19:dd:d9:dd:c25:c25:94de:4323
372c19:dd:d9:dd:c25:c25:94de:4324/1282c19:dd:d9:dd:c25:c25:94de:4324
382c19:dd:d9:dd:c25:c25:94de:4325/1282c19:dd:d9:dd:c25:c25:94de:4325
392c19:dd:d9:dd:c25:c25:94de:4326/1282c19:dd:d9:dd:c25:c25:94de:4326
402c19:dd:d9:dd:c25:c25:94de:4327/1282c19:dd:d9:dd:c25:c25:94de:4327
412c19:dd:d9:dd:c25:c25:94de:4328/1282c19:dd:d9:dd:c25:c25:94de:4328
422c19:dd:d9:dd:c25:c25:94de:4329/1282c19:dd:d9:dd:c25:c25:94de:4329
432c19:dd:d9:dd:c25:c25:94de:432a/1282c19:dd:d9:dd:c25:c25:94de:432a
442c19:dd:d9:dd:c25:c25:94de:432b/1282c19:dd:d9:dd:c25:c25:94de:432b
452c19:dd:d9:dd:c25:c25:94de:432c/1282c19:dd:d9:dd:c25:c25:94de:432c
462c19:dd:d9:dd:c25:c25:94de:432d/1282c19:dd:d9:dd:c25:c25:94de:432d
472c19:dd:d9:dd:c25:c25:94de:432e/1282c19:dd:d9:dd:c25:c25:94de:432e
482c19:dd:d9:dd:c25:c25:94de:432f/1282c19:dd:d9:dd:c25:c25:94de:432f
492c19:dd:d9:dd:c25:c25:94de:4330/1282c19:dd:d9:dd:c25:c25:94de:4330
502c19:dd:d9:dd:c25:c25:94de:4331/1282c19:dd:d9:dd:c25:c25:94de:4331
512c19:dd:d9:dd:c25:c25:94de:4332/1282c19:dd:d9:dd:c25:c25:94de:4332
522c19:dd:d9:dd:c25:c25:94de:4333/1282c19:dd:d9:dd:c25:c25:94de:4333
532c19:dd:d9:dd:c25:c25:94de:4334/1282c19:dd:d9:dd:c25:c25:94de:4334
542c19:dd:d9:dd:c25:c25:94de:4335/1282c19:dd:d9:dd:c25:c25:94de:4335
552c19:dd:d9:dd:c25:c25:94de:4336/1282c19:dd:d9:dd:c25:c25:94de:4336
562c19:dd:d9:dd:c25:c25:94de:4337/1282c19:dd:d9:dd:c25:c25:94de:4337
572c19:dd:d9:dd:c25:c25:94de:4338/1282c19:dd:d9:dd:c25:c25:94de:4338
582c19:dd:d9:dd:c25:c25:94de:4339/1282c19:dd:d9:dd:c25:c25:94de:4339
592c19:dd:d9:dd:c25:c25:94de:433a/1282c19:dd:d9:dd:c25:c25:94de:433a
602c19:dd:d9:dd:c25:c25:94de:433b/1282c19:dd:d9:dd:c25:c25:94de:433b
612c19:dd:d9:dd:c25:c25:94de:433c/1282c19:dd:d9:dd:c25:c25:94de:433c
622c19:dd:d9:dd:c25:c25:94de:433d/1282c19:dd:d9:dd:c25:c25:94de:433d
632c19:dd:d9:dd:c25:c25:94de:433e/1282c19:dd:d9:dd:c25:c25:94de:433e
642c19:dd:d9:dd:c25:c25:94de:433f/1282c19:dd:d9:dd:c25:c25:94de:433f
652c19:dd:d9:dd:c25:c25:94de:4340/1282c19:dd:d9:dd:c25:c25:94de:4340
662c19:dd:d9:dd:c25:c25:94de:4341/1282c19:dd:d9:dd:c25:c25:94de:4341
672c19:dd:d9:dd:c25:c25:94de:4342/1282c19:dd:d9:dd:c25:c25:94de:4342
682c19:dd:d9:dd:c25:c25:94de:4343/1282c19:dd:d9:dd:c25:c25:94de:4343
692c19:dd:d9:dd:c25:c25:94de:4344/1282c19:dd:d9:dd:c25:c25:94de:4344
702c19:dd:d9:dd:c25:c25:94de:4345/1282c19:dd:d9:dd:c25:c25:94de:4345
712c19:dd:d9:dd:c25:c25:94de:4346/1282c19:dd:d9:dd:c25:c25:94de:4346
722c19:dd:d9:dd:c25:c25:94de:4347/1282c19:dd:d9:dd:c25:c25:94de:4347
732c19:dd:d9:dd:c25:c25:94de:4348/1282c19:dd:d9:dd:c25:c25:94de:4348
742c19:dd:d9:dd:c25:c25:94de:4349/1282c19:dd:d9:dd:c25:c25:94de:4349
752c19:dd:d9:dd:c25:c25:94de:434a/1282c19:dd:d9:dd:c25:c25:94de:434a
762c19:dd:d9:dd:c25:c25:94de:434b/1282c19:dd:d9:dd:c25:c25:94de:434b
772c19:dd:d9:dd:c25:c25:94de:434c/1282c19:dd:d9:dd:c25:c25:94de:434c
782c19:dd:d9:dd:c25:c25:94de:434d/1282c19:dd:d9:dd:c25:c25:94de:434d
792c19:dd:d9:dd:c25:c25:94de:434e/1282c19:dd:d9:dd:c25:c25:94de:434e
802c19:dd:d9:dd:c25:c25:94de:434f/1282c19:dd:d9:dd:c25:c25:94de:434f
812c19:dd:d9:dd:c25:c25:94de:4350/1282c19:dd:d9:dd:c25:c25:94de:4350
822c19:dd:d9:dd:c25:c25:94de:4351/1282c19:dd:d9:dd:c25:c25:94de:4351
832c19:dd:d9:dd:c25:c25:94de:4352/1282c19:dd:d9:dd:c25:c25:94de:4352
842c19:dd:d9:dd:c25:c25:94de:4353/1282c19:dd:d9:dd:c25:c25:94de:4353
852c19:dd:d9:dd:c25:c25:94de:4354/1282c19:dd:d9:dd:c25:c25:94de:4354
862c19:dd:d9:dd:c25:c25:94de:4355/1282c19:dd:d9:dd:c25:c25:94de:4355
872c19:dd:d9:dd:c25:c25:94de:4356/1282c19:dd:d9:dd:c25:c25:94de:4356
882c19:dd:d9:dd:c25:c25:94de:4357/1282c19:dd:d9:dd:c25:c25:94de:4357
892c19:dd:d9:dd:c25:c25:94de:4358/1282c19:dd:d9:dd:c25:c25:94de:4358
902c19:dd:d9:dd:c25:c25:94de:4359/1282c19:dd:d9:dd:c25:c25:94de:4359
912c19:dd:d9:dd:c25:c25:94de:435a/1282c19:dd:d9:dd:c25:c25:94de:435a
922c19:dd:d9:dd:c25:c25:94de:435b/1282c19:dd:d9:dd:c25:c25:94de:435b
932c19:dd:d9:dd:c25:c25:94de:435c/1282c19:dd:d9:dd:c25:c25:94de:435c
942c19:dd:d9:dd:c25:c25:94de:435d/1282c19:dd:d9:dd:c25:c25:94de:435d
952c19:dd:d9:dd:c25:c25:94de:435e/1282c19:dd:d9:dd:c25:c25:94de:435e
962c19:dd:d9:dd:c25:c25:94de:435f/1282c19:dd:d9:dd:c25:c25:94de:435f
972c19:dd:d9:dd:c25:c25:94de:4360/1282c19:dd:d9:dd:c25:c25:94de:4360
982c19:dd:d9:dd:c25:c25:94de:4361/1282c19:dd:d9:dd:c25:c25:94de:4361
992c19:dd:d9:dd:c25:c25:94de:4362/1282c19:dd:d9:dd:c25:c25:94de:4362
1002c19:dd:d9:dd:c25:c25:94de:4363/1282c19:dd:d9:dd:c25:c25:94de:4363
1012c19:dd:d9:dd:c25:c25:94de:4364/1282c19:dd:d9:dd:c25:c25:94de:4364
1022c19:dd:d9:dd:c25:c25:94de:4365/1282c19:dd:d9:dd:c25:c25:94de:4365
1032c19:dd:d9:dd:c25:c25:94de:4366/1282c19:dd:d9:dd:c25:c25:94de:4366
1042c19:dd:d9:dd:c25:c25:94de:4367/1282c19:dd:d9:dd:c25:c25:94de:4367
1052c19:dd:d9:dd:c25:c25:94de:4368/1282c19:dd:d9:dd:c25:c25:94de:4368
1062c19:dd:d9:dd:c25:c25:94de:4369/1282c19:dd:d9:dd:c25:c25:94de:4369
1072c19:dd:d9:dd:c25:c25:94de:436a/1282c19:dd:d9:dd:c25:c25:94de:436a
1082c19:dd:d9:dd:c25:c25:94de:436b/1282c19:dd:d9:dd:c25:c25:94de:436b
1092c19:dd:d9:dd:c25:c25:94de:436c/1282c19:dd:d9:dd:c25:c25:94de:436c
1102c19:dd:d9:dd:c25:c25:94de:436d/1282c19:dd:d9:dd:c25:c25:94de:436d
1112c19:dd:d9:dd:c25:c25:94de:436e/1282c19:dd:d9:dd:c25:c25:94de:436e
1122c19:dd:d9:dd:c25:c25:94de:436f/1282c19:dd:d9:dd:c25:c25:94de:436f
1132c19:dd:d9:dd:c25:c25:94de:4370/1282c19:dd:d9:dd:c25:c25:94de:4370
1142c19:dd:d9:dd:c25:c25:94de:4371/1282c19:dd:d9:dd:c25:c25:94de:4371
1152c19:dd:d9:dd:c25:c25:94de:4372/1282c19:dd:d9:dd:c25:c25:94de:4372
1162c19:dd:d9:dd:c25:c25:94de:4373/1282c19:dd:d9:dd:c25:c25:94de:4373
1172c19:dd:d9:dd:c25:c25:94de:4374/1282c19:dd:d9:dd:c25:c25:94de:4374
1182c19:dd:d9:dd:c25:c25:94de:4375/1282c19:dd:d9:dd:c25:c25:94de:4375
1192c19:dd:d9:dd:c25:c25:94de:4376/1282c19:dd:d9:dd:c25:c25:94de:4376
1202c19:dd:d9:dd:c25:c25:94de:4377/1282c19:dd:d9:dd:c25:c25:94de:4377
1212c19:dd:d9:dd:c25:c25:94de:4378/1282c19:dd:d9:dd:c25:c25:94de:4378
1222c19:dd:d9:dd:c25:c25:94de:4379/1282c19:dd:d9:dd:c25:c25:94de:4379
1232c19:dd:d9:dd:c25:c25:94de:437a/1282c19:dd:d9:dd:c25:c25:94de:437a
1242c19:dd:d9:dd:c25:c25:94de:437b/1282c19:dd:d9:dd:c25:c25:94de:437b
1252c19:dd:d9:dd:c25:c25:94de:437c/1282c19:dd:d9:dd:c25:c25:94de:437c
1262c19:dd:d9:dd:c25:c25:94de:437d/1282c19:dd:d9:dd:c25:c25:94de:437d
1272c19:dd:d9:dd:c25:c25:94de:437e/1282c19:dd:d9:dd:c25:c25:94de:437e
1282c19:dd:d9:dd:c25:c25:94de:437f/1282c19:dd:d9:dd:c25:c25:94de:437f
1292c19:dd:d9:dd:c25:c25:94de:4380/1282c19:dd:d9:dd:c25:c25:94de:4380
1302c19:dd:d9:dd:c25:c25:94de:4381/1282c19:dd:d9:dd:c25:c25:94de:4381
1312c19:dd:d9:dd:c25:c25:94de:4382/1282c19:dd:d9:dd:c25:c25:94de:4382
1322c19:dd:d9:dd:c25:c25:94de:4383/1282c19:dd:d9:dd:c25:c25:94de:4383
1332c19:dd:d9:dd:c25:c25:94de:4384/1282c19:dd:d9:dd:c25:c25:94de:4384
1342c19:dd:d9:dd:c25:c25:94de:4385/1282c19:dd:d9:dd:c25:c25:94de:4385
1352c19:dd:d9:dd:c25:c25:94de:4386/1282c19:dd:d9:dd:c25:c25:94de:4386
1362c19:dd:d9:dd:c25:c25:94de:4387/1282c19:dd:d9:dd:c25:c25:94de:4387
1372c19:dd:d9:dd:c25:c25:94de:4388/1282c19:dd:d9:dd:c25:c25:94de:4388
1382c19:dd:d9:dd:c25:c25:94de:4389/1282c19:dd:d9:dd:c25:c25:94de:4389
1392c19:dd:d9:dd:c25:c25:94de:438a/1282c19:dd:d9:dd:c25:c25:94de:438a
1402c19:dd:d9:dd:c25:c25:94de:438b/1282c19:dd:d9:dd:c25:c25:94de:438b
1412c19:dd:d9:dd:c25:c25:94de:438c/1282c19:dd:d9:dd:c25:c25:94de:438c
1422c19:dd:d9:dd:c25:c25:94de:438d/1282c19:dd:d9:dd:c25:c25:94de:438d
1432c19:dd:d9:dd:c25:c25:94de:438e/1282c19:dd:d9:dd:c25:c25:94de:438e
1442c19:dd:d9:dd:c25:c25:94de:438f/1282c19:dd:d9:dd:c25:c25:94de:438f
1452c19:dd:d9:dd:c25:c25:94de:4390/1282c19:dd:d9:dd:c25:c25:94de:4390
1462c19:dd:d9:dd:c25:c25:94de:4391/1282c19:dd:d9:dd:c25:c25:94de:4391
1472c19:dd:d9:dd:c25:c25:94de:4392/1282c19:dd:d9:dd:c25:c25:94de:4392
1482c19:dd:d9:dd:c25:c25:94de:4393/1282c19:dd:d9:dd:c25:c25:94de:4393
1492c19:dd:d9:dd:c25:c25:94de:4394/1282c19:dd:d9:dd:c25:c25:94de:4394
1502c19:dd:d9:dd:c25:c25:94de:4395/1282c19:dd:d9:dd:c25:c25:94de:4395
1512c19:dd:d9:dd:c25:c25:94de:4396/1282c19:dd:d9:dd:c25:c25:94de:4396
1522c19:dd:d9:dd:c25:c25:94de:4397/1282c19:dd:d9:dd:c25:c25:94de:4397
1532c19:dd:d9:dd:c25:c25:94de:4398/1282c19:dd:d9:dd:c25:c25:94de:4398
1542c19:dd:d9:dd:c25:c25:94de:4399/1282c19:dd:d9:dd:c25:c25:94de:4399
1552c19:dd:d9:dd:c25:c25:94de:439a/1282c19:dd:d9:dd:c25:c25:94de:439a
1562c19:dd:d9:dd:c25:c25:94de:439b/1282c19:dd:d9:dd:c25:c25:94de:439b
1572c19:dd:d9:dd:c25:c25:94de:439c/1282c19:dd:d9:dd:c25:c25:94de:439c
1582c19:dd:d9:dd:c25:c25:94de:439d/1282c19:dd:d9:dd:c25:c25:94de:439d
1592c19:dd:d9:dd:c25:c25:94de:439e/1282c19:dd:d9:dd:c25:c25:94de:439e
1602c19:dd:d9:dd:c25:c25:94de:439f/1282c19:dd:d9:dd:c25:c25:94de:439f
1612c19:dd:d9:dd:c25:c25:94de:43a0/1282c19:dd:d9:dd:c25:c25:94de:43a0
1622c19:dd:d9:dd:c25:c25:94de:43a1/1282c19:dd:d9:dd:c25:c25:94de:43a1
1632c19:dd:d9:dd:c25:c25:94de:43a2/1282c19:dd:d9:dd:c25:c25:94de:43a2
1642c19:dd:d9:dd:c25:c25:94de:43a3/1282c19:dd:d9:dd:c25:c25:94de:43a3
1652c19:dd:d9:dd:c25:c25:94de:43a4/1282c19:dd:d9:dd:c25:c25:94de:43a4
1662c19:dd:d9:dd:c25:c25:94de:43a5/1282c19:dd:d9:dd:c25:c25:94de:43a5
1672c19:dd:d9:dd:c25:c25:94de:43a6/1282c19:dd:d9:dd:c25:c25:94de:43a6
1682c19:dd:d9:dd:c25:c25:94de:43a7/1282c19:dd:d9:dd:c25:c25:94de:43a7
1692c19:dd:d9:dd:c25:c25:94de:43a8/1282c19:dd:d9:dd:c25:c25:94de:43a8
1702c19:dd:d9:dd:c25:c25:94de:43a9/1282c19:dd:d9:dd:c25:c25:94de:43a9
1712c19:dd:d9:dd:c25:c25:94de:43aa/1282c19:dd:d9:dd:c25:c25:94de:43aa
1722c19:dd:d9:dd:c25:c25:94de:43ab/1282c19:dd:d9:dd:c25:c25:94de:43ab
1732c19:dd:d9:dd:c25:c25:94de:43ac/1282c19:dd:d9:dd:c25:c25:94de:43ac
1742c19:dd:d9:dd:c25:c25:94de:43ad/1282c19:dd:d9:dd:c25:c25:94de:43ad
1752c19:dd:d9:dd:c25:c25:94de:43ae/1282c19:dd:d9:dd:c25:c25:94de:43ae
1762c19:dd:d9:dd:c25:c25:94de:43af/1282c19:dd:d9:dd:c25:c25:94de:43af
1772c19:dd:d9:dd:c25:c25:94de:43b0/1282c19:dd:d9:dd:c25:c25:94de:43b0
1782c19:dd:d9:dd:c25:c25:94de:43b1/1282c19:dd:d9:dd:c25:c25:94de:43b1
1792c19:dd:d9:dd:c25:c25:94de:43b2/1282c19:dd:d9:dd:c25:c25:94de:43b2
1802c19:dd:d9:dd:c25:c25:94de:43b3/1282c19:dd:d9:dd:c25:c25:94de:43b3
1812c19:dd:d9:dd:c25:c25:94de:43b4/1282c19:dd:d9:dd:c25:c25:94de:43b4
1822c19:dd:d9:dd:c25:c25:94de:43b5/1282c19:dd:d9:dd:c25:c25:94de:43b5
1832c19:dd:d9:dd:c25:c25:94de:43b6/1282c19:dd:d9:dd:c25:c25:94de:43b6
1842c19:dd:d9:dd:c25:c25:94de:43b7/1282c19:dd:d9:dd:c25:c25:94de:43b7
1852c19:dd:d9:dd:c25:c25:94de:43b8/1282c19:dd:d9:dd:c25:c25:94de:43b8
1862c19:dd:d9:dd:c25:c25:94de:43b9/1282c19:dd:d9:dd:c25:c25:94de:43b9
1872c19:dd:d9:dd:c25:c25:94de:43ba/1282c19:dd:d9:dd:c25:c25:94de:43ba
1882c19:dd:d9:dd:c25:c25:94de:43bb/1282c19:dd:d9:dd:c25:c25:94de:43bb
1892c19:dd:d9:dd:c25:c25:94de:43bc/1282c19:dd:d9:dd:c25:c25:94de:43bc
1902c19:dd:d9:dd:c25:c25:94de:43bd/1282c19:dd:d9:dd:c25:c25:94de:43bd
1912c19:dd:d9:dd:c25:c25:94de:43be/1282c19:dd:d9:dd:c25:c25:94de:43be
1922c19:dd:d9:dd:c25:c25:94de:43bf/1282c19:dd:d9:dd:c25:c25:94de:43bf
1932c19:dd:d9:dd:c25:c25:94de:43c0/1282c19:dd:d9:dd:c25:c25:94de:43c0
1942c19:dd:d9:dd:c25:c25:94de:43c1/1282c19:dd:d9:dd:c25:c25:94de:43c1
1952c19:dd:d9:dd:c25:c25:94de:43c2/1282c19:dd:d9:dd:c25:c25:94de:43c2
1962c19:dd:d9:dd:c25:c25:94de:43c3/1282c19:dd:d9:dd:c25:c25:94de:43c3
1972c19:dd:d9:dd:c25:c25:94de:43c4/1282c19:dd:d9:dd:c25:c25:94de:43c4
1982c19:dd:d9:dd:c25:c25:94de:43c5/1282c19:dd:d9:dd:c25:c25:94de:43c5
1992c19:dd:d9:dd:c25:c25:94de:43c6/1282c19:dd:d9:dd:c25:c25:94de:43c6
2002c19:dd:d9:dd:c25:c25:94de:43c7/1282c19:dd:d9:dd:c25:c25:94de:43c7
2012c19:dd:d9:dd:c25:c25:94de:43c8/1282c19:dd:d9:dd:c25:c25:94de:43c8
2022c19:dd:d9:dd:c25:c25:94de:43c9/1282c19:dd:d9:dd:c25:c25:94de:43c9
2032c19:dd:d9:dd:c25:c25:94de:43ca/1282c19:dd:d9:dd:c25:c25:94de:43ca
2042c19:dd:d9:dd:c25:c25:94de:43cb/1282c19:dd:d9:dd:c25:c25:94de:43cb
2052c19:dd:d9:dd:c25:c25:94de:43cc/1282c19:dd:d9:dd:c25:c25:94de:43cc
2062c19:dd:d9:dd:c25:c25:94de:43cd/1282c19:dd:d9:dd:c25:c25:94de:43cd
2072c19:dd:d9:dd:c25:c25:94de:43ce/1282c19:dd:d9:dd:c25:c25:94de:43ce
2082c19:dd:d9:dd:c25:c25:94de:43cf/1282c19:dd:d9:dd:c25:c25:94de:43cf
2092c19:dd:d9:dd:c25:c25:94de:43d0/1282c19:dd:d9:dd:c25:c25:94de:43d0
2102c19:dd:d9:dd:c25:c25:94de:43d1/1282c19:dd:d9:dd:c25:c25:94de:43d1
2112c19:dd:d9:dd:c25:c25:94de:43d2/1282c19:dd:d9:dd:c25:c25:94de:43d2
2122c19:dd:d9:dd:c25:c25:94de:43d3/1282c19:dd:d9:dd:c25:c25:94de:43d3
2132c19:dd:d9:dd:c25:c25:94de:43d4/1282c19:dd:d9:dd:c25:c25:94de:43d4
2142c19:dd:d9:dd:c25:c25:94de:43d5/1282c19:dd:d9:dd:c25:c25:94de:43d5
2152c19:dd:d9:dd:c25:c25:94de:43d6/1282c19:dd:d9:dd:c25:c25:94de:43d6
2162c19:dd:d9:dd:c25:c25:94de:43d7/1282c19:dd:d9:dd:c25:c25:94de:43d7
2172c19:dd:d9:dd:c25:c25:94de:43d8/1282c19:dd:d9:dd:c25:c25:94de:43d8
2182c19:dd:d9:dd:c25:c25:94de:43d9/1282c19:dd:d9:dd:c25:c25:94de:43d9
2192c19:dd:d9:dd:c25:c25:94de:43da/1282c19:dd:d9:dd:c25:c25:94de:43da
2202c19:dd:d9:dd:c25:c25:94de:43db/1282c19:dd:d9:dd:c25:c25:94de:43db
2212c19:dd:d9:dd:c25:c25:94de:43dc/1282c19:dd:d9:dd:c25:c25:94de:43dc
2222c19:dd:d9:dd:c25:c25:94de:43dd/1282c19:dd:d9:dd:c25:c25:94de:43dd
2232c19:dd:d9:dd:c25:c25:94de:43de/1282c19:dd:d9:dd:c25:c25:94de:43de
2242c19:dd:d9:dd:c25:c25:94de:43df/1282c19:dd:d9:dd:c25:c25:94de:43df
2252c19:dd:d9:dd:c25:c25:94de:43e0/1282c19:dd:d9:dd:c25:c25:94de:43e0
2262c19:dd:d9:dd:c25:c25:94de:43e1/1282c19:dd:d9:dd:c25:c25:94de:43e1
2272c19:dd:d9:dd:c25:c25:94de:43e2/1282c19:dd:d9:dd:c25:c25:94de:43e2
2282c19:dd:d9:dd:c25:c25:94de:43e3/1282c19:dd:d9:dd:c25:c25:94de:43e3
2292c19:dd:d9:dd:c25:c25:94de:43e4/1282c19:dd:d9:dd:c25:c25:94de:43e4
2302c19:dd:d9:dd:c25:c25:94de:43e5/1282c19:dd:d9:dd:c25:c25:94de:43e5
2312c19:dd:d9:dd:c25:c25:94de:43e6/1282c19:dd:d9:dd:c25:c25:94de:43e6
2322c19:dd:d9:dd:c25:c25:94de:43e7/1282c19:dd:d9:dd:c25:c25:94de:43e7
2332c19:dd:d9:dd:c25:c25:94de:43e8/1282c19:dd:d9:dd:c25:c25:94de:43e8
2342c19:dd:d9:dd:c25:c25:94de:43e9/1282c19:dd:d9:dd:c25:c25:94de:43e9
2352c19:dd:d9:dd:c25:c25:94de:43ea/1282c19:dd:d9:dd:c25:c25:94de:43ea
2362c19:dd:d9:dd:c25:c25:94de:43eb/1282c19:dd:d9:dd:c25:c25:94de:43eb
2372c19:dd:d9:dd:c25:c25:94de:43ec/1282c19:dd:d9:dd:c25:c25:94de:43ec
2382c19:dd:d9:dd:c25:c25:94de:43ed/1282c19:dd:d9:dd:c25:c25:94de:43ed
2392c19:dd:d9:dd:c25:c25:94de:43ee/1282c19:dd:d9:dd:c25:c25:94de:43ee
2402c19:dd:d9:dd:c25:c25:94de:43ef/1282c19:dd:d9:dd:c25:c25:94de:43ef
2412c19:dd:d9:dd:c25:c25:94de:43f0/1282c19:dd:d9:dd:c25:c25:94de:43f0
2422c19:dd:d9:dd:c25:c25:94de:43f1/1282c19:dd:d9:dd:c25:c25:94de:43f1
2432c19:dd:d9:dd:c25:c25:94de:43f2/1282c19:dd:d9:dd:c25:c25:94de:43f2
2442c19:dd:d9:dd:c25:c25:94de:43f3/1282c19:dd:d9:dd:c25:c25:94de:43f3
2452c19:dd:d9:dd:c25:c25:94de:43f4/1282c19:dd:d9:dd:c25:c25:94de:43f4
2462c19:dd:d9:dd:c25:c25:94de:43f5/1282c19:dd:d9:dd:c25:c25:94de:43f5
2472c19:dd:d9:dd:c25:c25:94de:43f6/1282c19:dd:d9:dd:c25:c25:94de:43f6
2482c19:dd:d9:dd:c25:c25:94de:43f7/1282c19:dd:d9:dd:c25:c25:94de:43f7
2492c19:dd:d9:dd:c25:c25:94de:43f8/1282c19:dd:d9:dd:c25:c25:94de:43f8
2502c19:dd:d9:dd:c25:c25:94de:43f9/1282c19:dd:d9:dd:c25:c25:94de:43f9
2512c19:dd:d9:dd:c25:c25:94de:43fa/1282c19:dd:d9:dd:c25:c25:94de:43fa
2522c19:dd:d9:dd:c25:c25:94de:43fb/1282c19:dd:d9:dd:c25:c25:94de:43fb
2532c19:dd:d9:dd:c25:c25:94de:43fc/1282c19:dd:d9:dd:c25:c25:94de:43fc
2542c19:dd:d9:dd:c25:c25:94de:43fd/1282c19:dd:d9:dd:c25:c25:94de:43fd
2552c19:dd:d9:dd:c25:c25:94de:43fe/1282c19:dd:d9:dd:c25:c25:94de:43fe
2562c19:dd:d9:dd:c25:c25:94de:43ff/1282c19:dd:d9:dd:c25:c25:94de:43ff

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.