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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:300/120
First address
2c19:dd:c25:c25d:dd:dd:dd:300
Last address
2c19:dd:c25:c25d:dd:dd:dd:3ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:0c25:c25d:00dd:00dd:00dd:0300
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
3.0.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:300/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:c25:c25d:dd:dd:dd:300/1282c19:dd:c25:c25d:dd:dd:dd:300
22c19:dd:c25:c25d:dd:dd:dd:301/1282c19:dd:c25:c25d:dd:dd:dd:301
32c19:dd:c25:c25d:dd:dd:dd:302/1282c19:dd:c25:c25d:dd:dd:dd:302
42c19:dd:c25:c25d:dd:dd:dd:303/1282c19:dd:c25:c25d:dd:dd:dd:303
52c19:dd:c25:c25d:dd:dd:dd:304/1282c19:dd:c25:c25d:dd:dd:dd:304
62c19:dd:c25:c25d:dd:dd:dd:305/1282c19:dd:c25:c25d:dd:dd:dd:305
72c19:dd:c25:c25d:dd:dd:dd:306/1282c19:dd:c25:c25d:dd:dd:dd:306
82c19:dd:c25:c25d:dd:dd:dd:307/1282c19:dd:c25:c25d:dd:dd:dd:307
92c19:dd:c25:c25d:dd:dd:dd:308/1282c19:dd:c25:c25d:dd:dd:dd:308
102c19:dd:c25:c25d:dd:dd:dd:309/1282c19:dd:c25:c25d:dd:dd:dd:309
112c19:dd:c25:c25d:dd:dd:dd:30a/1282c19:dd:c25:c25d:dd:dd:dd:30a
122c19:dd:c25:c25d:dd:dd:dd:30b/1282c19:dd:c25:c25d:dd:dd:dd:30b
132c19:dd:c25:c25d:dd:dd:dd:30c/1282c19:dd:c25:c25d:dd:dd:dd:30c
142c19:dd:c25:c25d:dd:dd:dd:30d/1282c19:dd:c25:c25d:dd:dd:dd:30d
152c19:dd:c25:c25d:dd:dd:dd:30e/1282c19:dd:c25:c25d:dd:dd:dd:30e
162c19:dd:c25:c25d:dd:dd:dd:30f/1282c19:dd:c25:c25d:dd:dd:dd:30f
172c19:dd:c25:c25d:dd:dd:dd:310/1282c19:dd:c25:c25d:dd:dd:dd:310
182c19:dd:c25:c25d:dd:dd:dd:311/1282c19:dd:c25:c25d:dd:dd:dd:311
192c19:dd:c25:c25d:dd:dd:dd:312/1282c19:dd:c25:c25d:dd:dd:dd:312
202c19:dd:c25:c25d:dd:dd:dd:313/1282c19:dd:c25:c25d:dd:dd:dd:313
212c19:dd:c25:c25d:dd:dd:dd:314/1282c19:dd:c25:c25d:dd:dd:dd:314
222c19:dd:c25:c25d:dd:dd:dd:315/1282c19:dd:c25:c25d:dd:dd:dd:315
232c19:dd:c25:c25d:dd:dd:dd:316/1282c19:dd:c25:c25d:dd:dd:dd:316
242c19:dd:c25:c25d:dd:dd:dd:317/1282c19:dd:c25:c25d:dd:dd:dd:317
252c19:dd:c25:c25d:dd:dd:dd:318/1282c19:dd:c25:c25d:dd:dd:dd:318
262c19:dd:c25:c25d:dd:dd:dd:319/1282c19:dd:c25:c25d:dd:dd:dd:319
272c19:dd:c25:c25d:dd:dd:dd:31a/1282c19:dd:c25:c25d:dd:dd:dd:31a
282c19:dd:c25:c25d:dd:dd:dd:31b/1282c19:dd:c25:c25d:dd:dd:dd:31b
292c19:dd:c25:c25d:dd:dd:dd:31c/1282c19:dd:c25:c25d:dd:dd:dd:31c
302c19:dd:c25:c25d:dd:dd:dd:31d/1282c19:dd:c25:c25d:dd:dd:dd:31d
312c19:dd:c25:c25d:dd:dd:dd:31e/1282c19:dd:c25:c25d:dd:dd:dd:31e
322c19:dd:c25:c25d:dd:dd:dd:31f/1282c19:dd:c25:c25d:dd:dd:dd:31f
332c19:dd:c25:c25d:dd:dd:dd:320/1282c19:dd:c25:c25d:dd:dd:dd:320
342c19:dd:c25:c25d:dd:dd:dd:321/1282c19:dd:c25:c25d:dd:dd:dd:321
352c19:dd:c25:c25d:dd:dd:dd:322/1282c19:dd:c25:c25d:dd:dd:dd:322
362c19:dd:c25:c25d:dd:dd:dd:323/1282c19:dd:c25:c25d:dd:dd:dd:323
372c19:dd:c25:c25d:dd:dd:dd:324/1282c19:dd:c25:c25d:dd:dd:dd:324
382c19:dd:c25:c25d:dd:dd:dd:325/1282c19:dd:c25:c25d:dd:dd:dd:325
392c19:dd:c25:c25d:dd:dd:dd:326/1282c19:dd:c25:c25d:dd:dd:dd:326
402c19:dd:c25:c25d:dd:dd:dd:327/1282c19:dd:c25:c25d:dd:dd:dd:327
412c19:dd:c25:c25d:dd:dd:dd:328/1282c19:dd:c25:c25d:dd:dd:dd:328
422c19:dd:c25:c25d:dd:dd:dd:329/1282c19:dd:c25:c25d:dd:dd:dd:329
432c19:dd:c25:c25d:dd:dd:dd:32a/1282c19:dd:c25:c25d:dd:dd:dd:32a
442c19:dd:c25:c25d:dd:dd:dd:32b/1282c19:dd:c25:c25d:dd:dd:dd:32b
452c19:dd:c25:c25d:dd:dd:dd:32c/1282c19:dd:c25:c25d:dd:dd:dd:32c
462c19:dd:c25:c25d:dd:dd:dd:32d/1282c19:dd:c25:c25d:dd:dd:dd:32d
472c19:dd:c25:c25d:dd:dd:dd:32e/1282c19:dd:c25:c25d:dd:dd:dd:32e
482c19:dd:c25:c25d:dd:dd:dd:32f/1282c19:dd:c25:c25d:dd:dd:dd:32f
492c19:dd:c25:c25d:dd:dd:dd:330/1282c19:dd:c25:c25d:dd:dd:dd:330
502c19:dd:c25:c25d:dd:dd:dd:331/1282c19:dd:c25:c25d:dd:dd:dd:331
512c19:dd:c25:c25d:dd:dd:dd:332/1282c19:dd:c25:c25d:dd:dd:dd:332
522c19:dd:c25:c25d:dd:dd:dd:333/1282c19:dd:c25:c25d:dd:dd:dd:333
532c19:dd:c25:c25d:dd:dd:dd:334/1282c19:dd:c25:c25d:dd:dd:dd:334
542c19:dd:c25:c25d:dd:dd:dd:335/1282c19:dd:c25:c25d:dd:dd:dd:335
552c19:dd:c25:c25d:dd:dd:dd:336/1282c19:dd:c25:c25d:dd:dd:dd:336
562c19:dd:c25:c25d:dd:dd:dd:337/1282c19:dd:c25:c25d:dd:dd:dd:337
572c19:dd:c25:c25d:dd:dd:dd:338/1282c19:dd:c25:c25d:dd:dd:dd:338
582c19:dd:c25:c25d:dd:dd:dd:339/1282c19:dd:c25:c25d:dd:dd:dd:339
592c19:dd:c25:c25d:dd:dd:dd:33a/1282c19:dd:c25:c25d:dd:dd:dd:33a
602c19:dd:c25:c25d:dd:dd:dd:33b/1282c19:dd:c25:c25d:dd:dd:dd:33b
612c19:dd:c25:c25d:dd:dd:dd:33c/1282c19:dd:c25:c25d:dd:dd:dd:33c
622c19:dd:c25:c25d:dd:dd:dd:33d/1282c19:dd:c25:c25d:dd:dd:dd:33d
632c19:dd:c25:c25d:dd:dd:dd:33e/1282c19:dd:c25:c25d:dd:dd:dd:33e
642c19:dd:c25:c25d:dd:dd:dd:33f/1282c19:dd:c25:c25d:dd:dd:dd:33f
652c19:dd:c25:c25d:dd:dd:dd:340/1282c19:dd:c25:c25d:dd:dd:dd:340
662c19:dd:c25:c25d:dd:dd:dd:341/1282c19:dd:c25:c25d:dd:dd:dd:341
672c19:dd:c25:c25d:dd:dd:dd:342/1282c19:dd:c25:c25d:dd:dd:dd:342
682c19:dd:c25:c25d:dd:dd:dd:343/1282c19:dd:c25:c25d:dd:dd:dd:343
692c19:dd:c25:c25d:dd:dd:dd:344/1282c19:dd:c25:c25d:dd:dd:dd:344
702c19:dd:c25:c25d:dd:dd:dd:345/1282c19:dd:c25:c25d:dd:dd:dd:345
712c19:dd:c25:c25d:dd:dd:dd:346/1282c19:dd:c25:c25d:dd:dd:dd:346
722c19:dd:c25:c25d:dd:dd:dd:347/1282c19:dd:c25:c25d:dd:dd:dd:347
732c19:dd:c25:c25d:dd:dd:dd:348/1282c19:dd:c25:c25d:dd:dd:dd:348
742c19:dd:c25:c25d:dd:dd:dd:349/1282c19:dd:c25:c25d:dd:dd:dd:349
752c19:dd:c25:c25d:dd:dd:dd:34a/1282c19:dd:c25:c25d:dd:dd:dd:34a
762c19:dd:c25:c25d:dd:dd:dd:34b/1282c19:dd:c25:c25d:dd:dd:dd:34b
772c19:dd:c25:c25d:dd:dd:dd:34c/1282c19:dd:c25:c25d:dd:dd:dd:34c
782c19:dd:c25:c25d:dd:dd:dd:34d/1282c19:dd:c25:c25d:dd:dd:dd:34d
792c19:dd:c25:c25d:dd:dd:dd:34e/1282c19:dd:c25:c25d:dd:dd:dd:34e
802c19:dd:c25:c25d:dd:dd:dd:34f/1282c19:dd:c25:c25d:dd:dd:dd:34f
812c19:dd:c25:c25d:dd:dd:dd:350/1282c19:dd:c25:c25d:dd:dd:dd:350
822c19:dd:c25:c25d:dd:dd:dd:351/1282c19:dd:c25:c25d:dd:dd:dd:351
832c19:dd:c25:c25d:dd:dd:dd:352/1282c19:dd:c25:c25d:dd:dd:dd:352
842c19:dd:c25:c25d:dd:dd:dd:353/1282c19:dd:c25:c25d:dd:dd:dd:353
852c19:dd:c25:c25d:dd:dd:dd:354/1282c19:dd:c25:c25d:dd:dd:dd:354
862c19:dd:c25:c25d:dd:dd:dd:355/1282c19:dd:c25:c25d:dd:dd:dd:355
872c19:dd:c25:c25d:dd:dd:dd:356/1282c19:dd:c25:c25d:dd:dd:dd:356
882c19:dd:c25:c25d:dd:dd:dd:357/1282c19:dd:c25:c25d:dd:dd:dd:357
892c19:dd:c25:c25d:dd:dd:dd:358/1282c19:dd:c25:c25d:dd:dd:dd:358
902c19:dd:c25:c25d:dd:dd:dd:359/1282c19:dd:c25:c25d:dd:dd:dd:359
912c19:dd:c25:c25d:dd:dd:dd:35a/1282c19:dd:c25:c25d:dd:dd:dd:35a
922c19:dd:c25:c25d:dd:dd:dd:35b/1282c19:dd:c25:c25d:dd:dd:dd:35b
932c19:dd:c25:c25d:dd:dd:dd:35c/1282c19:dd:c25:c25d:dd:dd:dd:35c
942c19:dd:c25:c25d:dd:dd:dd:35d/1282c19:dd:c25:c25d:dd:dd:dd:35d
952c19:dd:c25:c25d:dd:dd:dd:35e/1282c19:dd:c25:c25d:dd:dd:dd:35e
962c19:dd:c25:c25d:dd:dd:dd:35f/1282c19:dd:c25:c25d:dd:dd:dd:35f
972c19:dd:c25:c25d:dd:dd:dd:360/1282c19:dd:c25:c25d:dd:dd:dd:360
982c19:dd:c25:c25d:dd:dd:dd:361/1282c19:dd:c25:c25d:dd:dd:dd:361
992c19:dd:c25:c25d:dd:dd:dd:362/1282c19:dd:c25:c25d:dd:dd:dd:362
1002c19:dd:c25:c25d:dd:dd:dd:363/1282c19:dd:c25:c25d:dd:dd:dd:363
1012c19:dd:c25:c25d:dd:dd:dd:364/1282c19:dd:c25:c25d:dd:dd:dd:364
1022c19:dd:c25:c25d:dd:dd:dd:365/1282c19:dd:c25:c25d:dd:dd:dd:365
1032c19:dd:c25:c25d:dd:dd:dd:366/1282c19:dd:c25:c25d:dd:dd:dd:366
1042c19:dd:c25:c25d:dd:dd:dd:367/1282c19:dd:c25:c25d:dd:dd:dd:367
1052c19:dd:c25:c25d:dd:dd:dd:368/1282c19:dd:c25:c25d:dd:dd:dd:368
1062c19:dd:c25:c25d:dd:dd:dd:369/1282c19:dd:c25:c25d:dd:dd:dd:369
1072c19:dd:c25:c25d:dd:dd:dd:36a/1282c19:dd:c25:c25d:dd:dd:dd:36a
1082c19:dd:c25:c25d:dd:dd:dd:36b/1282c19:dd:c25:c25d:dd:dd:dd:36b
1092c19:dd:c25:c25d:dd:dd:dd:36c/1282c19:dd:c25:c25d:dd:dd:dd:36c
1102c19:dd:c25:c25d:dd:dd:dd:36d/1282c19:dd:c25:c25d:dd:dd:dd:36d
1112c19:dd:c25:c25d:dd:dd:dd:36e/1282c19:dd:c25:c25d:dd:dd:dd:36e
1122c19:dd:c25:c25d:dd:dd:dd:36f/1282c19:dd:c25:c25d:dd:dd:dd:36f
1132c19:dd:c25:c25d:dd:dd:dd:370/1282c19:dd:c25:c25d:dd:dd:dd:370
1142c19:dd:c25:c25d:dd:dd:dd:371/1282c19:dd:c25:c25d:dd:dd:dd:371
1152c19:dd:c25:c25d:dd:dd:dd:372/1282c19:dd:c25:c25d:dd:dd:dd:372
1162c19:dd:c25:c25d:dd:dd:dd:373/1282c19:dd:c25:c25d:dd:dd:dd:373
1172c19:dd:c25:c25d:dd:dd:dd:374/1282c19:dd:c25:c25d:dd:dd:dd:374
1182c19:dd:c25:c25d:dd:dd:dd:375/1282c19:dd:c25:c25d:dd:dd:dd:375
1192c19:dd:c25:c25d:dd:dd:dd:376/1282c19:dd:c25:c25d:dd:dd:dd:376
1202c19:dd:c25:c25d:dd:dd:dd:377/1282c19:dd:c25:c25d:dd:dd:dd:377
1212c19:dd:c25:c25d:dd:dd:dd:378/1282c19:dd:c25:c25d:dd:dd:dd:378
1222c19:dd:c25:c25d:dd:dd:dd:379/1282c19:dd:c25:c25d:dd:dd:dd:379
1232c19:dd:c25:c25d:dd:dd:dd:37a/1282c19:dd:c25:c25d:dd:dd:dd:37a
1242c19:dd:c25:c25d:dd:dd:dd:37b/1282c19:dd:c25:c25d:dd:dd:dd:37b
1252c19:dd:c25:c25d:dd:dd:dd:37c/1282c19:dd:c25:c25d:dd:dd:dd:37c
1262c19:dd:c25:c25d:dd:dd:dd:37d/1282c19:dd:c25:c25d:dd:dd:dd:37d
1272c19:dd:c25:c25d:dd:dd:dd:37e/1282c19:dd:c25:c25d:dd:dd:dd:37e
1282c19:dd:c25:c25d:dd:dd:dd:37f/1282c19:dd:c25:c25d:dd:dd:dd:37f
1292c19:dd:c25:c25d:dd:dd:dd:380/1282c19:dd:c25:c25d:dd:dd:dd:380
1302c19:dd:c25:c25d:dd:dd:dd:381/1282c19:dd:c25:c25d:dd:dd:dd:381
1312c19:dd:c25:c25d:dd:dd:dd:382/1282c19:dd:c25:c25d:dd:dd:dd:382
1322c19:dd:c25:c25d:dd:dd:dd:383/1282c19:dd:c25:c25d:dd:dd:dd:383
1332c19:dd:c25:c25d:dd:dd:dd:384/1282c19:dd:c25:c25d:dd:dd:dd:384
1342c19:dd:c25:c25d:dd:dd:dd:385/1282c19:dd:c25:c25d:dd:dd:dd:385
1352c19:dd:c25:c25d:dd:dd:dd:386/1282c19:dd:c25:c25d:dd:dd:dd:386
1362c19:dd:c25:c25d:dd:dd:dd:387/1282c19:dd:c25:c25d:dd:dd:dd:387
1372c19:dd:c25:c25d:dd:dd:dd:388/1282c19:dd:c25:c25d:dd:dd:dd:388
1382c19:dd:c25:c25d:dd:dd:dd:389/1282c19:dd:c25:c25d:dd:dd:dd:389
1392c19:dd:c25:c25d:dd:dd:dd:38a/1282c19:dd:c25:c25d:dd:dd:dd:38a
1402c19:dd:c25:c25d:dd:dd:dd:38b/1282c19:dd:c25:c25d:dd:dd:dd:38b
1412c19:dd:c25:c25d:dd:dd:dd:38c/1282c19:dd:c25:c25d:dd:dd:dd:38c
1422c19:dd:c25:c25d:dd:dd:dd:38d/1282c19:dd:c25:c25d:dd:dd:dd:38d
1432c19:dd:c25:c25d:dd:dd:dd:38e/1282c19:dd:c25:c25d:dd:dd:dd:38e
1442c19:dd:c25:c25d:dd:dd:dd:38f/1282c19:dd:c25:c25d:dd:dd:dd:38f
1452c19:dd:c25:c25d:dd:dd:dd:390/1282c19:dd:c25:c25d:dd:dd:dd:390
1462c19:dd:c25:c25d:dd:dd:dd:391/1282c19:dd:c25:c25d:dd:dd:dd:391
1472c19:dd:c25:c25d:dd:dd:dd:392/1282c19:dd:c25:c25d:dd:dd:dd:392
1482c19:dd:c25:c25d:dd:dd:dd:393/1282c19:dd:c25:c25d:dd:dd:dd:393
1492c19:dd:c25:c25d:dd:dd:dd:394/1282c19:dd:c25:c25d:dd:dd:dd:394
1502c19:dd:c25:c25d:dd:dd:dd:395/1282c19:dd:c25:c25d:dd:dd:dd:395
1512c19:dd:c25:c25d:dd:dd:dd:396/1282c19:dd:c25:c25d:dd:dd:dd:396
1522c19:dd:c25:c25d:dd:dd:dd:397/1282c19:dd:c25:c25d:dd:dd:dd:397
1532c19:dd:c25:c25d:dd:dd:dd:398/1282c19:dd:c25:c25d:dd:dd:dd:398
1542c19:dd:c25:c25d:dd:dd:dd:399/1282c19:dd:c25:c25d:dd:dd:dd:399
1552c19:dd:c25:c25d:dd:dd:dd:39a/1282c19:dd:c25:c25d:dd:dd:dd:39a
1562c19:dd:c25:c25d:dd:dd:dd:39b/1282c19:dd:c25:c25d:dd:dd:dd:39b
1572c19:dd:c25:c25d:dd:dd:dd:39c/1282c19:dd:c25:c25d:dd:dd:dd:39c
1582c19:dd:c25:c25d:dd:dd:dd:39d/1282c19:dd:c25:c25d:dd:dd:dd:39d
1592c19:dd:c25:c25d:dd:dd:dd:39e/1282c19:dd:c25:c25d:dd:dd:dd:39e
1602c19:dd:c25:c25d:dd:dd:dd:39f/1282c19:dd:c25:c25d:dd:dd:dd:39f
1612c19:dd:c25:c25d:dd:dd:dd:3a0/1282c19:dd:c25:c25d:dd:dd:dd:3a0
1622c19:dd:c25:c25d:dd:dd:dd:3a1/1282c19:dd:c25:c25d:dd:dd:dd:3a1
1632c19:dd:c25:c25d:dd:dd:dd:3a2/1282c19:dd:c25:c25d:dd:dd:dd:3a2
1642c19:dd:c25:c25d:dd:dd:dd:3a3/1282c19:dd:c25:c25d:dd:dd:dd:3a3
1652c19:dd:c25:c25d:dd:dd:dd:3a4/1282c19:dd:c25:c25d:dd:dd:dd:3a4
1662c19:dd:c25:c25d:dd:dd:dd:3a5/1282c19:dd:c25:c25d:dd:dd:dd:3a5
1672c19:dd:c25:c25d:dd:dd:dd:3a6/1282c19:dd:c25:c25d:dd:dd:dd:3a6
1682c19:dd:c25:c25d:dd:dd:dd:3a7/1282c19:dd:c25:c25d:dd:dd:dd:3a7
1692c19:dd:c25:c25d:dd:dd:dd:3a8/1282c19:dd:c25:c25d:dd:dd:dd:3a8
1702c19:dd:c25:c25d:dd:dd:dd:3a9/1282c19:dd:c25:c25d:dd:dd:dd:3a9
1712c19:dd:c25:c25d:dd:dd:dd:3aa/1282c19:dd:c25:c25d:dd:dd:dd:3aa
1722c19:dd:c25:c25d:dd:dd:dd:3ab/1282c19:dd:c25:c25d:dd:dd:dd:3ab
1732c19:dd:c25:c25d:dd:dd:dd:3ac/1282c19:dd:c25:c25d:dd:dd:dd:3ac
1742c19:dd:c25:c25d:dd:dd:dd:3ad/1282c19:dd:c25:c25d:dd:dd:dd:3ad
1752c19:dd:c25:c25d:dd:dd:dd:3ae/1282c19:dd:c25:c25d:dd:dd:dd:3ae
1762c19:dd:c25:c25d:dd:dd:dd:3af/1282c19:dd:c25:c25d:dd:dd:dd:3af
1772c19:dd:c25:c25d:dd:dd:dd:3b0/1282c19:dd:c25:c25d:dd:dd:dd:3b0
1782c19:dd:c25:c25d:dd:dd:dd:3b1/1282c19:dd:c25:c25d:dd:dd:dd:3b1
1792c19:dd:c25:c25d:dd:dd:dd:3b2/1282c19:dd:c25:c25d:dd:dd:dd:3b2
1802c19:dd:c25:c25d:dd:dd:dd:3b3/1282c19:dd:c25:c25d:dd:dd:dd:3b3
1812c19:dd:c25:c25d:dd:dd:dd:3b4/1282c19:dd:c25:c25d:dd:dd:dd:3b4
1822c19:dd:c25:c25d:dd:dd:dd:3b5/1282c19:dd:c25:c25d:dd:dd:dd:3b5
1832c19:dd:c25:c25d:dd:dd:dd:3b6/1282c19:dd:c25:c25d:dd:dd:dd:3b6
1842c19:dd:c25:c25d:dd:dd:dd:3b7/1282c19:dd:c25:c25d:dd:dd:dd:3b7
1852c19:dd:c25:c25d:dd:dd:dd:3b8/1282c19:dd:c25:c25d:dd:dd:dd:3b8
1862c19:dd:c25:c25d:dd:dd:dd:3b9/1282c19:dd:c25:c25d:dd:dd:dd:3b9
1872c19:dd:c25:c25d:dd:dd:dd:3ba/1282c19:dd:c25:c25d:dd:dd:dd:3ba
1882c19:dd:c25:c25d:dd:dd:dd:3bb/1282c19:dd:c25:c25d:dd:dd:dd:3bb
1892c19:dd:c25:c25d:dd:dd:dd:3bc/1282c19:dd:c25:c25d:dd:dd:dd:3bc
1902c19:dd:c25:c25d:dd:dd:dd:3bd/1282c19:dd:c25:c25d:dd:dd:dd:3bd
1912c19:dd:c25:c25d:dd:dd:dd:3be/1282c19:dd:c25:c25d:dd:dd:dd:3be
1922c19:dd:c25:c25d:dd:dd:dd:3bf/1282c19:dd:c25:c25d:dd:dd:dd:3bf
1932c19:dd:c25:c25d:dd:dd:dd:3c0/1282c19:dd:c25:c25d:dd:dd:dd:3c0
1942c19:dd:c25:c25d:dd:dd:dd:3c1/1282c19:dd:c25:c25d:dd:dd:dd:3c1
1952c19:dd:c25:c25d:dd:dd:dd:3c2/1282c19:dd:c25:c25d:dd:dd:dd:3c2
1962c19:dd:c25:c25d:dd:dd:dd:3c3/1282c19:dd:c25:c25d:dd:dd:dd:3c3
1972c19:dd:c25:c25d:dd:dd:dd:3c4/1282c19:dd:c25:c25d:dd:dd:dd:3c4
1982c19:dd:c25:c25d:dd:dd:dd:3c5/1282c19:dd:c25:c25d:dd:dd:dd:3c5
1992c19:dd:c25:c25d:dd:dd:dd:3c6/1282c19:dd:c25:c25d:dd:dd:dd:3c6
2002c19:dd:c25:c25d:dd:dd:dd:3c7/1282c19:dd:c25:c25d:dd:dd:dd:3c7
2012c19:dd:c25:c25d:dd:dd:dd:3c8/1282c19:dd:c25:c25d:dd:dd:dd:3c8
2022c19:dd:c25:c25d:dd:dd:dd:3c9/1282c19:dd:c25:c25d:dd:dd:dd:3c9
2032c19:dd:c25:c25d:dd:dd:dd:3ca/1282c19:dd:c25:c25d:dd:dd:dd:3ca
2042c19:dd:c25:c25d:dd:dd:dd:3cb/1282c19:dd:c25:c25d:dd:dd:dd:3cb
2052c19:dd:c25:c25d:dd:dd:dd:3cc/1282c19:dd:c25:c25d:dd:dd:dd:3cc
2062c19:dd:c25:c25d:dd:dd:dd:3cd/1282c19:dd:c25:c25d:dd:dd:dd:3cd
2072c19:dd:c25:c25d:dd:dd:dd:3ce/1282c19:dd:c25:c25d:dd:dd:dd:3ce
2082c19:dd:c25:c25d:dd:dd:dd:3cf/1282c19:dd:c25:c25d:dd:dd:dd:3cf
2092c19:dd:c25:c25d:dd:dd:dd:3d0/1282c19:dd:c25:c25d:dd:dd:dd:3d0
2102c19:dd:c25:c25d:dd:dd:dd:3d1/1282c19:dd:c25:c25d:dd:dd:dd:3d1
2112c19:dd:c25:c25d:dd:dd:dd:3d2/1282c19:dd:c25:c25d:dd:dd:dd:3d2
2122c19:dd:c25:c25d:dd:dd:dd:3d3/1282c19:dd:c25:c25d:dd:dd:dd:3d3
2132c19:dd:c25:c25d:dd:dd:dd:3d4/1282c19:dd:c25:c25d:dd:dd:dd:3d4
2142c19:dd:c25:c25d:dd:dd:dd:3d5/1282c19:dd:c25:c25d:dd:dd:dd:3d5
2152c19:dd:c25:c25d:dd:dd:dd:3d6/1282c19:dd:c25:c25d:dd:dd:dd:3d6
2162c19:dd:c25:c25d:dd:dd:dd:3d7/1282c19:dd:c25:c25d:dd:dd:dd:3d7
2172c19:dd:c25:c25d:dd:dd:dd:3d8/1282c19:dd:c25:c25d:dd:dd:dd:3d8
2182c19:dd:c25:c25d:dd:dd:dd:3d9/1282c19:dd:c25:c25d:dd:dd:dd:3d9
2192c19:dd:c25:c25d:dd:dd:dd:3da/1282c19:dd:c25:c25d:dd:dd:dd:3da
2202c19:dd:c25:c25d:dd:dd:dd:3db/1282c19:dd:c25:c25d:dd:dd:dd:3db
2212c19:dd:c25:c25d:dd:dd:dd:3dc/1282c19:dd:c25:c25d:dd:dd:dd:3dc
2222c19:dd:c25:c25d:dd:dd:dd:3dd/1282c19:dd:c25:c25d:dd:dd:dd:3dd
2232c19:dd:c25:c25d:dd:dd:dd:3de/1282c19:dd:c25:c25d:dd:dd:dd:3de
2242c19:dd:c25:c25d:dd:dd:dd:3df/1282c19:dd:c25:c25d:dd:dd:dd:3df
2252c19:dd:c25:c25d:dd:dd:dd:3e0/1282c19:dd:c25:c25d:dd:dd:dd:3e0
2262c19:dd:c25:c25d:dd:dd:dd:3e1/1282c19:dd:c25:c25d:dd:dd:dd:3e1
2272c19:dd:c25:c25d:dd:dd:dd:3e2/1282c19:dd:c25:c25d:dd:dd:dd:3e2
2282c19:dd:c25:c25d:dd:dd:dd:3e3/1282c19:dd:c25:c25d:dd:dd:dd:3e3
2292c19:dd:c25:c25d:dd:dd:dd:3e4/1282c19:dd:c25:c25d:dd:dd:dd:3e4
2302c19:dd:c25:c25d:dd:dd:dd:3e5/1282c19:dd:c25:c25d:dd:dd:dd:3e5
2312c19:dd:c25:c25d:dd:dd:dd:3e6/1282c19:dd:c25:c25d:dd:dd:dd:3e6
2322c19:dd:c25:c25d:dd:dd:dd:3e7/1282c19:dd:c25:c25d:dd:dd:dd:3e7
2332c19:dd:c25:c25d:dd:dd:dd:3e8/1282c19:dd:c25:c25d:dd:dd:dd:3e8
2342c19:dd:c25:c25d:dd:dd:dd:3e9/1282c19:dd:c25:c25d:dd:dd:dd:3e9
2352c19:dd:c25:c25d:dd:dd:dd:3ea/1282c19:dd:c25:c25d:dd:dd:dd:3ea
2362c19:dd:c25:c25d:dd:dd:dd:3eb/1282c19:dd:c25:c25d:dd:dd:dd:3eb
2372c19:dd:c25:c25d:dd:dd:dd:3ec/1282c19:dd:c25:c25d:dd:dd:dd:3ec
2382c19:dd:c25:c25d:dd:dd:dd:3ed/1282c19:dd:c25:c25d:dd:dd:dd:3ed
2392c19:dd:c25:c25d:dd:dd:dd:3ee/1282c19:dd:c25:c25d:dd:dd:dd:3ee
2402c19:dd:c25:c25d:dd:dd:dd:3ef/1282c19:dd:c25:c25d:dd:dd:dd:3ef
2412c19:dd:c25:c25d:dd:dd:dd:3f0/1282c19:dd:c25:c25d:dd:dd:dd:3f0
2422c19:dd:c25:c25d:dd:dd:dd:3f1/1282c19:dd:c25:c25d:dd:dd:dd:3f1
2432c19:dd:c25:c25d:dd:dd:dd:3f2/1282c19:dd:c25:c25d:dd:dd:dd:3f2
2442c19:dd:c25:c25d:dd:dd:dd:3f3/1282c19:dd:c25:c25d:dd:dd:dd:3f3
2452c19:dd:c25:c25d:dd:dd:dd:3f4/1282c19:dd:c25:c25d:dd:dd:dd:3f4
2462c19:dd:c25:c25d:dd:dd:dd:3f5/1282c19:dd:c25:c25d:dd:dd:dd:3f5
2472c19:dd:c25:c25d:dd:dd:dd:3f6/1282c19:dd:c25:c25d:dd:dd:dd:3f6
2482c19:dd:c25:c25d:dd:dd:dd:3f7/1282c19:dd:c25:c25d:dd:dd:dd:3f7
2492c19:dd:c25:c25d:dd:dd:dd:3f8/1282c19:dd:c25:c25d:dd:dd:dd:3f8
2502c19:dd:c25:c25d:dd:dd:dd:3f9/1282c19:dd:c25:c25d:dd:dd:dd:3f9
2512c19:dd:c25:c25d:dd:dd:dd:3fa/1282c19:dd:c25:c25d:dd:dd:dd:3fa
2522c19:dd:c25:c25d:dd:dd:dd:3fb/1282c19:dd:c25:c25d:dd:dd:dd:3fb
2532c19:dd:c25:c25d:dd:dd:dd:3fc/1282c19:dd:c25:c25d:dd:dd:dd:3fc
2542c19:dd:c25:c25d:dd:dd:dd:3fd/1282c19:dd:c25:c25d:dd:dd:dd:3fd
2552c19:dd:c25:c25d:dd:dd:dd:3fe/1282c19:dd:c25:c25d:dd:dd:dd:3fe
2562c19:dd:c25:c25d:dd:dd:dd:3ff/1282c19:dd:c25:c25d:dd:dd:dd:3ff

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.