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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:500/120
First address
2c19:dd:c25:c25d:dd:dd:dd:500
Last address
2c19:dd:c25:c25d:dd:dd:dd:5ff
Addresses
256
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:0c25:c25d:00dd:00dd:00dd:0500
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
5.0.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:500/120 makes 256 subnets of /128.

Subnets
#SubnetLast address
12c19:dd:c25:c25d:dd:dd:dd:500/1282c19:dd:c25:c25d:dd:dd:dd:500
22c19:dd:c25:c25d:dd:dd:dd:501/1282c19:dd:c25:c25d:dd:dd:dd:501
32c19:dd:c25:c25d:dd:dd:dd:502/1282c19:dd:c25:c25d:dd:dd:dd:502
42c19:dd:c25:c25d:dd:dd:dd:503/1282c19:dd:c25:c25d:dd:dd:dd:503
52c19:dd:c25:c25d:dd:dd:dd:504/1282c19:dd:c25:c25d:dd:dd:dd:504
62c19:dd:c25:c25d:dd:dd:dd:505/1282c19:dd:c25:c25d:dd:dd:dd:505
72c19:dd:c25:c25d:dd:dd:dd:506/1282c19:dd:c25:c25d:dd:dd:dd:506
82c19:dd:c25:c25d:dd:dd:dd:507/1282c19:dd:c25:c25d:dd:dd:dd:507
92c19:dd:c25:c25d:dd:dd:dd:508/1282c19:dd:c25:c25d:dd:dd:dd:508
102c19:dd:c25:c25d:dd:dd:dd:509/1282c19:dd:c25:c25d:dd:dd:dd:509
112c19:dd:c25:c25d:dd:dd:dd:50a/1282c19:dd:c25:c25d:dd:dd:dd:50a
122c19:dd:c25:c25d:dd:dd:dd:50b/1282c19:dd:c25:c25d:dd:dd:dd:50b
132c19:dd:c25:c25d:dd:dd:dd:50c/1282c19:dd:c25:c25d:dd:dd:dd:50c
142c19:dd:c25:c25d:dd:dd:dd:50d/1282c19:dd:c25:c25d:dd:dd:dd:50d
152c19:dd:c25:c25d:dd:dd:dd:50e/1282c19:dd:c25:c25d:dd:dd:dd:50e
162c19:dd:c25:c25d:dd:dd:dd:50f/1282c19:dd:c25:c25d:dd:dd:dd:50f
172c19:dd:c25:c25d:dd:dd:dd:510/1282c19:dd:c25:c25d:dd:dd:dd:510
182c19:dd:c25:c25d:dd:dd:dd:511/1282c19:dd:c25:c25d:dd:dd:dd:511
192c19:dd:c25:c25d:dd:dd:dd:512/1282c19:dd:c25:c25d:dd:dd:dd:512
202c19:dd:c25:c25d:dd:dd:dd:513/1282c19:dd:c25:c25d:dd:dd:dd:513
212c19:dd:c25:c25d:dd:dd:dd:514/1282c19:dd:c25:c25d:dd:dd:dd:514
222c19:dd:c25:c25d:dd:dd:dd:515/1282c19:dd:c25:c25d:dd:dd:dd:515
232c19:dd:c25:c25d:dd:dd:dd:516/1282c19:dd:c25:c25d:dd:dd:dd:516
242c19:dd:c25:c25d:dd:dd:dd:517/1282c19:dd:c25:c25d:dd:dd:dd:517
252c19:dd:c25:c25d:dd:dd:dd:518/1282c19:dd:c25:c25d:dd:dd:dd:518
262c19:dd:c25:c25d:dd:dd:dd:519/1282c19:dd:c25:c25d:dd:dd:dd:519
272c19:dd:c25:c25d:dd:dd:dd:51a/1282c19:dd:c25:c25d:dd:dd:dd:51a
282c19:dd:c25:c25d:dd:dd:dd:51b/1282c19:dd:c25:c25d:dd:dd:dd:51b
292c19:dd:c25:c25d:dd:dd:dd:51c/1282c19:dd:c25:c25d:dd:dd:dd:51c
302c19:dd:c25:c25d:dd:dd:dd:51d/1282c19:dd:c25:c25d:dd:dd:dd:51d
312c19:dd:c25:c25d:dd:dd:dd:51e/1282c19:dd:c25:c25d:dd:dd:dd:51e
322c19:dd:c25:c25d:dd:dd:dd:51f/1282c19:dd:c25:c25d:dd:dd:dd:51f
332c19:dd:c25:c25d:dd:dd:dd:520/1282c19:dd:c25:c25d:dd:dd:dd:520
342c19:dd:c25:c25d:dd:dd:dd:521/1282c19:dd:c25:c25d:dd:dd:dd:521
352c19:dd:c25:c25d:dd:dd:dd:522/1282c19:dd:c25:c25d:dd:dd:dd:522
362c19:dd:c25:c25d:dd:dd:dd:523/1282c19:dd:c25:c25d:dd:dd:dd:523
372c19:dd:c25:c25d:dd:dd:dd:524/1282c19:dd:c25:c25d:dd:dd:dd:524
382c19:dd:c25:c25d:dd:dd:dd:525/1282c19:dd:c25:c25d:dd:dd:dd:525
392c19:dd:c25:c25d:dd:dd:dd:526/1282c19:dd:c25:c25d:dd:dd:dd:526
402c19:dd:c25:c25d:dd:dd:dd:527/1282c19:dd:c25:c25d:dd:dd:dd:527
412c19:dd:c25:c25d:dd:dd:dd:528/1282c19:dd:c25:c25d:dd:dd:dd:528
422c19:dd:c25:c25d:dd:dd:dd:529/1282c19:dd:c25:c25d:dd:dd:dd:529
432c19:dd:c25:c25d:dd:dd:dd:52a/1282c19:dd:c25:c25d:dd:dd:dd:52a
442c19:dd:c25:c25d:dd:dd:dd:52b/1282c19:dd:c25:c25d:dd:dd:dd:52b
452c19:dd:c25:c25d:dd:dd:dd:52c/1282c19:dd:c25:c25d:dd:dd:dd:52c
462c19:dd:c25:c25d:dd:dd:dd:52d/1282c19:dd:c25:c25d:dd:dd:dd:52d
472c19:dd:c25:c25d:dd:dd:dd:52e/1282c19:dd:c25:c25d:dd:dd:dd:52e
482c19:dd:c25:c25d:dd:dd:dd:52f/1282c19:dd:c25:c25d:dd:dd:dd:52f
492c19:dd:c25:c25d:dd:dd:dd:530/1282c19:dd:c25:c25d:dd:dd:dd:530
502c19:dd:c25:c25d:dd:dd:dd:531/1282c19:dd:c25:c25d:dd:dd:dd:531
512c19:dd:c25:c25d:dd:dd:dd:532/1282c19:dd:c25:c25d:dd:dd:dd:532
522c19:dd:c25:c25d:dd:dd:dd:533/1282c19:dd:c25:c25d:dd:dd:dd:533
532c19:dd:c25:c25d:dd:dd:dd:534/1282c19:dd:c25:c25d:dd:dd:dd:534
542c19:dd:c25:c25d:dd:dd:dd:535/1282c19:dd:c25:c25d:dd:dd:dd:535
552c19:dd:c25:c25d:dd:dd:dd:536/1282c19:dd:c25:c25d:dd:dd:dd:536
562c19:dd:c25:c25d:dd:dd:dd:537/1282c19:dd:c25:c25d:dd:dd:dd:537
572c19:dd:c25:c25d:dd:dd:dd:538/1282c19:dd:c25:c25d:dd:dd:dd:538
582c19:dd:c25:c25d:dd:dd:dd:539/1282c19:dd:c25:c25d:dd:dd:dd:539
592c19:dd:c25:c25d:dd:dd:dd:53a/1282c19:dd:c25:c25d:dd:dd:dd:53a
602c19:dd:c25:c25d:dd:dd:dd:53b/1282c19:dd:c25:c25d:dd:dd:dd:53b
612c19:dd:c25:c25d:dd:dd:dd:53c/1282c19:dd:c25:c25d:dd:dd:dd:53c
622c19:dd:c25:c25d:dd:dd:dd:53d/1282c19:dd:c25:c25d:dd:dd:dd:53d
632c19:dd:c25:c25d:dd:dd:dd:53e/1282c19:dd:c25:c25d:dd:dd:dd:53e
642c19:dd:c25:c25d:dd:dd:dd:53f/1282c19:dd:c25:c25d:dd:dd:dd:53f
652c19:dd:c25:c25d:dd:dd:dd:540/1282c19:dd:c25:c25d:dd:dd:dd:540
662c19:dd:c25:c25d:dd:dd:dd:541/1282c19:dd:c25:c25d:dd:dd:dd:541
672c19:dd:c25:c25d:dd:dd:dd:542/1282c19:dd:c25:c25d:dd:dd:dd:542
682c19:dd:c25:c25d:dd:dd:dd:543/1282c19:dd:c25:c25d:dd:dd:dd:543
692c19:dd:c25:c25d:dd:dd:dd:544/1282c19:dd:c25:c25d:dd:dd:dd:544
702c19:dd:c25:c25d:dd:dd:dd:545/1282c19:dd:c25:c25d:dd:dd:dd:545
712c19:dd:c25:c25d:dd:dd:dd:546/1282c19:dd:c25:c25d:dd:dd:dd:546
722c19:dd:c25:c25d:dd:dd:dd:547/1282c19:dd:c25:c25d:dd:dd:dd:547
732c19:dd:c25:c25d:dd:dd:dd:548/1282c19:dd:c25:c25d:dd:dd:dd:548
742c19:dd:c25:c25d:dd:dd:dd:549/1282c19:dd:c25:c25d:dd:dd:dd:549
752c19:dd:c25:c25d:dd:dd:dd:54a/1282c19:dd:c25:c25d:dd:dd:dd:54a
762c19:dd:c25:c25d:dd:dd:dd:54b/1282c19:dd:c25:c25d:dd:dd:dd:54b
772c19:dd:c25:c25d:dd:dd:dd:54c/1282c19:dd:c25:c25d:dd:dd:dd:54c
782c19:dd:c25:c25d:dd:dd:dd:54d/1282c19:dd:c25:c25d:dd:dd:dd:54d
792c19:dd:c25:c25d:dd:dd:dd:54e/1282c19:dd:c25:c25d:dd:dd:dd:54e
802c19:dd:c25:c25d:dd:dd:dd:54f/1282c19:dd:c25:c25d:dd:dd:dd:54f
812c19:dd:c25:c25d:dd:dd:dd:550/1282c19:dd:c25:c25d:dd:dd:dd:550
822c19:dd:c25:c25d:dd:dd:dd:551/1282c19:dd:c25:c25d:dd:dd:dd:551
832c19:dd:c25:c25d:dd:dd:dd:552/1282c19:dd:c25:c25d:dd:dd:dd:552
842c19:dd:c25:c25d:dd:dd:dd:553/1282c19:dd:c25:c25d:dd:dd:dd:553
852c19:dd:c25:c25d:dd:dd:dd:554/1282c19:dd:c25:c25d:dd:dd:dd:554
862c19:dd:c25:c25d:dd:dd:dd:555/1282c19:dd:c25:c25d:dd:dd:dd:555
872c19:dd:c25:c25d:dd:dd:dd:556/1282c19:dd:c25:c25d:dd:dd:dd:556
882c19:dd:c25:c25d:dd:dd:dd:557/1282c19:dd:c25:c25d:dd:dd:dd:557
892c19:dd:c25:c25d:dd:dd:dd:558/1282c19:dd:c25:c25d:dd:dd:dd:558
902c19:dd:c25:c25d:dd:dd:dd:559/1282c19:dd:c25:c25d:dd:dd:dd:559
912c19:dd:c25:c25d:dd:dd:dd:55a/1282c19:dd:c25:c25d:dd:dd:dd:55a
922c19:dd:c25:c25d:dd:dd:dd:55b/1282c19:dd:c25:c25d:dd:dd:dd:55b
932c19:dd:c25:c25d:dd:dd:dd:55c/1282c19:dd:c25:c25d:dd:dd:dd:55c
942c19:dd:c25:c25d:dd:dd:dd:55d/1282c19:dd:c25:c25d:dd:dd:dd:55d
952c19:dd:c25:c25d:dd:dd:dd:55e/1282c19:dd:c25:c25d:dd:dd:dd:55e
962c19:dd:c25:c25d:dd:dd:dd:55f/1282c19:dd:c25:c25d:dd:dd:dd:55f
972c19:dd:c25:c25d:dd:dd:dd:560/1282c19:dd:c25:c25d:dd:dd:dd:560
982c19:dd:c25:c25d:dd:dd:dd:561/1282c19:dd:c25:c25d:dd:dd:dd:561
992c19:dd:c25:c25d:dd:dd:dd:562/1282c19:dd:c25:c25d:dd:dd:dd:562
1002c19:dd:c25:c25d:dd:dd:dd:563/1282c19:dd:c25:c25d:dd:dd:dd:563
1012c19:dd:c25:c25d:dd:dd:dd:564/1282c19:dd:c25:c25d:dd:dd:dd:564
1022c19:dd:c25:c25d:dd:dd:dd:565/1282c19:dd:c25:c25d:dd:dd:dd:565
1032c19:dd:c25:c25d:dd:dd:dd:566/1282c19:dd:c25:c25d:dd:dd:dd:566
1042c19:dd:c25:c25d:dd:dd:dd:567/1282c19:dd:c25:c25d:dd:dd:dd:567
1052c19:dd:c25:c25d:dd:dd:dd:568/1282c19:dd:c25:c25d:dd:dd:dd:568
1062c19:dd:c25:c25d:dd:dd:dd:569/1282c19:dd:c25:c25d:dd:dd:dd:569
1072c19:dd:c25:c25d:dd:dd:dd:56a/1282c19:dd:c25:c25d:dd:dd:dd:56a
1082c19:dd:c25:c25d:dd:dd:dd:56b/1282c19:dd:c25:c25d:dd:dd:dd:56b
1092c19:dd:c25:c25d:dd:dd:dd:56c/1282c19:dd:c25:c25d:dd:dd:dd:56c
1102c19:dd:c25:c25d:dd:dd:dd:56d/1282c19:dd:c25:c25d:dd:dd:dd:56d
1112c19:dd:c25:c25d:dd:dd:dd:56e/1282c19:dd:c25:c25d:dd:dd:dd:56e
1122c19:dd:c25:c25d:dd:dd:dd:56f/1282c19:dd:c25:c25d:dd:dd:dd:56f
1132c19:dd:c25:c25d:dd:dd:dd:570/1282c19:dd:c25:c25d:dd:dd:dd:570
1142c19:dd:c25:c25d:dd:dd:dd:571/1282c19:dd:c25:c25d:dd:dd:dd:571
1152c19:dd:c25:c25d:dd:dd:dd:572/1282c19:dd:c25:c25d:dd:dd:dd:572
1162c19:dd:c25:c25d:dd:dd:dd:573/1282c19:dd:c25:c25d:dd:dd:dd:573
1172c19:dd:c25:c25d:dd:dd:dd:574/1282c19:dd:c25:c25d:dd:dd:dd:574
1182c19:dd:c25:c25d:dd:dd:dd:575/1282c19:dd:c25:c25d:dd:dd:dd:575
1192c19:dd:c25:c25d:dd:dd:dd:576/1282c19:dd:c25:c25d:dd:dd:dd:576
1202c19:dd:c25:c25d:dd:dd:dd:577/1282c19:dd:c25:c25d:dd:dd:dd:577
1212c19:dd:c25:c25d:dd:dd:dd:578/1282c19:dd:c25:c25d:dd:dd:dd:578
1222c19:dd:c25:c25d:dd:dd:dd:579/1282c19:dd:c25:c25d:dd:dd:dd:579
1232c19:dd:c25:c25d:dd:dd:dd:57a/1282c19:dd:c25:c25d:dd:dd:dd:57a
1242c19:dd:c25:c25d:dd:dd:dd:57b/1282c19:dd:c25:c25d:dd:dd:dd:57b
1252c19:dd:c25:c25d:dd:dd:dd:57c/1282c19:dd:c25:c25d:dd:dd:dd:57c
1262c19:dd:c25:c25d:dd:dd:dd:57d/1282c19:dd:c25:c25d:dd:dd:dd:57d
1272c19:dd:c25:c25d:dd:dd:dd:57e/1282c19:dd:c25:c25d:dd:dd:dd:57e
1282c19:dd:c25:c25d:dd:dd:dd:57f/1282c19:dd:c25:c25d:dd:dd:dd:57f
1292c19:dd:c25:c25d:dd:dd:dd:580/1282c19:dd:c25:c25d:dd:dd:dd:580
1302c19:dd:c25:c25d:dd:dd:dd:581/1282c19:dd:c25:c25d:dd:dd:dd:581
1312c19:dd:c25:c25d:dd:dd:dd:582/1282c19:dd:c25:c25d:dd:dd:dd:582
1322c19:dd:c25:c25d:dd:dd:dd:583/1282c19:dd:c25:c25d:dd:dd:dd:583
1332c19:dd:c25:c25d:dd:dd:dd:584/1282c19:dd:c25:c25d:dd:dd:dd:584
1342c19:dd:c25:c25d:dd:dd:dd:585/1282c19:dd:c25:c25d:dd:dd:dd:585
1352c19:dd:c25:c25d:dd:dd:dd:586/1282c19:dd:c25:c25d:dd:dd:dd:586
1362c19:dd:c25:c25d:dd:dd:dd:587/1282c19:dd:c25:c25d:dd:dd:dd:587
1372c19:dd:c25:c25d:dd:dd:dd:588/1282c19:dd:c25:c25d:dd:dd:dd:588
1382c19:dd:c25:c25d:dd:dd:dd:589/1282c19:dd:c25:c25d:dd:dd:dd:589
1392c19:dd:c25:c25d:dd:dd:dd:58a/1282c19:dd:c25:c25d:dd:dd:dd:58a
1402c19:dd:c25:c25d:dd:dd:dd:58b/1282c19:dd:c25:c25d:dd:dd:dd:58b
1412c19:dd:c25:c25d:dd:dd:dd:58c/1282c19:dd:c25:c25d:dd:dd:dd:58c
1422c19:dd:c25:c25d:dd:dd:dd:58d/1282c19:dd:c25:c25d:dd:dd:dd:58d
1432c19:dd:c25:c25d:dd:dd:dd:58e/1282c19:dd:c25:c25d:dd:dd:dd:58e
1442c19:dd:c25:c25d:dd:dd:dd:58f/1282c19:dd:c25:c25d:dd:dd:dd:58f
1452c19:dd:c25:c25d:dd:dd:dd:590/1282c19:dd:c25:c25d:dd:dd:dd:590
1462c19:dd:c25:c25d:dd:dd:dd:591/1282c19:dd:c25:c25d:dd:dd:dd:591
1472c19:dd:c25:c25d:dd:dd:dd:592/1282c19:dd:c25:c25d:dd:dd:dd:592
1482c19:dd:c25:c25d:dd:dd:dd:593/1282c19:dd:c25:c25d:dd:dd:dd:593
1492c19:dd:c25:c25d:dd:dd:dd:594/1282c19:dd:c25:c25d:dd:dd:dd:594
1502c19:dd:c25:c25d:dd:dd:dd:595/1282c19:dd:c25:c25d:dd:dd:dd:595
1512c19:dd:c25:c25d:dd:dd:dd:596/1282c19:dd:c25:c25d:dd:dd:dd:596
1522c19:dd:c25:c25d:dd:dd:dd:597/1282c19:dd:c25:c25d:dd:dd:dd:597
1532c19:dd:c25:c25d:dd:dd:dd:598/1282c19:dd:c25:c25d:dd:dd:dd:598
1542c19:dd:c25:c25d:dd:dd:dd:599/1282c19:dd:c25:c25d:dd:dd:dd:599
1552c19:dd:c25:c25d:dd:dd:dd:59a/1282c19:dd:c25:c25d:dd:dd:dd:59a
1562c19:dd:c25:c25d:dd:dd:dd:59b/1282c19:dd:c25:c25d:dd:dd:dd:59b
1572c19:dd:c25:c25d:dd:dd:dd:59c/1282c19:dd:c25:c25d:dd:dd:dd:59c
1582c19:dd:c25:c25d:dd:dd:dd:59d/1282c19:dd:c25:c25d:dd:dd:dd:59d
1592c19:dd:c25:c25d:dd:dd:dd:59e/1282c19:dd:c25:c25d:dd:dd:dd:59e
1602c19:dd:c25:c25d:dd:dd:dd:59f/1282c19:dd:c25:c25d:dd:dd:dd:59f
1612c19:dd:c25:c25d:dd:dd:dd:5a0/1282c19:dd:c25:c25d:dd:dd:dd:5a0
1622c19:dd:c25:c25d:dd:dd:dd:5a1/1282c19:dd:c25:c25d:dd:dd:dd:5a1
1632c19:dd:c25:c25d:dd:dd:dd:5a2/1282c19:dd:c25:c25d:dd:dd:dd:5a2
1642c19:dd:c25:c25d:dd:dd:dd:5a3/1282c19:dd:c25:c25d:dd:dd:dd:5a3
1652c19:dd:c25:c25d:dd:dd:dd:5a4/1282c19:dd:c25:c25d:dd:dd:dd:5a4
1662c19:dd:c25:c25d:dd:dd:dd:5a5/1282c19:dd:c25:c25d:dd:dd:dd:5a5
1672c19:dd:c25:c25d:dd:dd:dd:5a6/1282c19:dd:c25:c25d:dd:dd:dd:5a6
1682c19:dd:c25:c25d:dd:dd:dd:5a7/1282c19:dd:c25:c25d:dd:dd:dd:5a7
1692c19:dd:c25:c25d:dd:dd:dd:5a8/1282c19:dd:c25:c25d:dd:dd:dd:5a8
1702c19:dd:c25:c25d:dd:dd:dd:5a9/1282c19:dd:c25:c25d:dd:dd:dd:5a9
1712c19:dd:c25:c25d:dd:dd:dd:5aa/1282c19:dd:c25:c25d:dd:dd:dd:5aa
1722c19:dd:c25:c25d:dd:dd:dd:5ab/1282c19:dd:c25:c25d:dd:dd:dd:5ab
1732c19:dd:c25:c25d:dd:dd:dd:5ac/1282c19:dd:c25:c25d:dd:dd:dd:5ac
1742c19:dd:c25:c25d:dd:dd:dd:5ad/1282c19:dd:c25:c25d:dd:dd:dd:5ad
1752c19:dd:c25:c25d:dd:dd:dd:5ae/1282c19:dd:c25:c25d:dd:dd:dd:5ae
1762c19:dd:c25:c25d:dd:dd:dd:5af/1282c19:dd:c25:c25d:dd:dd:dd:5af
1772c19:dd:c25:c25d:dd:dd:dd:5b0/1282c19:dd:c25:c25d:dd:dd:dd:5b0
1782c19:dd:c25:c25d:dd:dd:dd:5b1/1282c19:dd:c25:c25d:dd:dd:dd:5b1
1792c19:dd:c25:c25d:dd:dd:dd:5b2/1282c19:dd:c25:c25d:dd:dd:dd:5b2
1802c19:dd:c25:c25d:dd:dd:dd:5b3/1282c19:dd:c25:c25d:dd:dd:dd:5b3
1812c19:dd:c25:c25d:dd:dd:dd:5b4/1282c19:dd:c25:c25d:dd:dd:dd:5b4
1822c19:dd:c25:c25d:dd:dd:dd:5b5/1282c19:dd:c25:c25d:dd:dd:dd:5b5
1832c19:dd:c25:c25d:dd:dd:dd:5b6/1282c19:dd:c25:c25d:dd:dd:dd:5b6
1842c19:dd:c25:c25d:dd:dd:dd:5b7/1282c19:dd:c25:c25d:dd:dd:dd:5b7
1852c19:dd:c25:c25d:dd:dd:dd:5b8/1282c19:dd:c25:c25d:dd:dd:dd:5b8
1862c19:dd:c25:c25d:dd:dd:dd:5b9/1282c19:dd:c25:c25d:dd:dd:dd:5b9
1872c19:dd:c25:c25d:dd:dd:dd:5ba/1282c19:dd:c25:c25d:dd:dd:dd:5ba
1882c19:dd:c25:c25d:dd:dd:dd:5bb/1282c19:dd:c25:c25d:dd:dd:dd:5bb
1892c19:dd:c25:c25d:dd:dd:dd:5bc/1282c19:dd:c25:c25d:dd:dd:dd:5bc
1902c19:dd:c25:c25d:dd:dd:dd:5bd/1282c19:dd:c25:c25d:dd:dd:dd:5bd
1912c19:dd:c25:c25d:dd:dd:dd:5be/1282c19:dd:c25:c25d:dd:dd:dd:5be
1922c19:dd:c25:c25d:dd:dd:dd:5bf/1282c19:dd:c25:c25d:dd:dd:dd:5bf
1932c19:dd:c25:c25d:dd:dd:dd:5c0/1282c19:dd:c25:c25d:dd:dd:dd:5c0
1942c19:dd:c25:c25d:dd:dd:dd:5c1/1282c19:dd:c25:c25d:dd:dd:dd:5c1
1952c19:dd:c25:c25d:dd:dd:dd:5c2/1282c19:dd:c25:c25d:dd:dd:dd:5c2
1962c19:dd:c25:c25d:dd:dd:dd:5c3/1282c19:dd:c25:c25d:dd:dd:dd:5c3
1972c19:dd:c25:c25d:dd:dd:dd:5c4/1282c19:dd:c25:c25d:dd:dd:dd:5c4
1982c19:dd:c25:c25d:dd:dd:dd:5c5/1282c19:dd:c25:c25d:dd:dd:dd:5c5
1992c19:dd:c25:c25d:dd:dd:dd:5c6/1282c19:dd:c25:c25d:dd:dd:dd:5c6
2002c19:dd:c25:c25d:dd:dd:dd:5c7/1282c19:dd:c25:c25d:dd:dd:dd:5c7
2012c19:dd:c25:c25d:dd:dd:dd:5c8/1282c19:dd:c25:c25d:dd:dd:dd:5c8
2022c19:dd:c25:c25d:dd:dd:dd:5c9/1282c19:dd:c25:c25d:dd:dd:dd:5c9
2032c19:dd:c25:c25d:dd:dd:dd:5ca/1282c19:dd:c25:c25d:dd:dd:dd:5ca
2042c19:dd:c25:c25d:dd:dd:dd:5cb/1282c19:dd:c25:c25d:dd:dd:dd:5cb
2052c19:dd:c25:c25d:dd:dd:dd:5cc/1282c19:dd:c25:c25d:dd:dd:dd:5cc
2062c19:dd:c25:c25d:dd:dd:dd:5cd/1282c19:dd:c25:c25d:dd:dd:dd:5cd
2072c19:dd:c25:c25d:dd:dd:dd:5ce/1282c19:dd:c25:c25d:dd:dd:dd:5ce
2082c19:dd:c25:c25d:dd:dd:dd:5cf/1282c19:dd:c25:c25d:dd:dd:dd:5cf
2092c19:dd:c25:c25d:dd:dd:dd:5d0/1282c19:dd:c25:c25d:dd:dd:dd:5d0
2102c19:dd:c25:c25d:dd:dd:dd:5d1/1282c19:dd:c25:c25d:dd:dd:dd:5d1
2112c19:dd:c25:c25d:dd:dd:dd:5d2/1282c19:dd:c25:c25d:dd:dd:dd:5d2
2122c19:dd:c25:c25d:dd:dd:dd:5d3/1282c19:dd:c25:c25d:dd:dd:dd:5d3
2132c19:dd:c25:c25d:dd:dd:dd:5d4/1282c19:dd:c25:c25d:dd:dd:dd:5d4
2142c19:dd:c25:c25d:dd:dd:dd:5d5/1282c19:dd:c25:c25d:dd:dd:dd:5d5
2152c19:dd:c25:c25d:dd:dd:dd:5d6/1282c19:dd:c25:c25d:dd:dd:dd:5d6
2162c19:dd:c25:c25d:dd:dd:dd:5d7/1282c19:dd:c25:c25d:dd:dd:dd:5d7
2172c19:dd:c25:c25d:dd:dd:dd:5d8/1282c19:dd:c25:c25d:dd:dd:dd:5d8
2182c19:dd:c25:c25d:dd:dd:dd:5d9/1282c19:dd:c25:c25d:dd:dd:dd:5d9
2192c19:dd:c25:c25d:dd:dd:dd:5da/1282c19:dd:c25:c25d:dd:dd:dd:5da
2202c19:dd:c25:c25d:dd:dd:dd:5db/1282c19:dd:c25:c25d:dd:dd:dd:5db
2212c19:dd:c25:c25d:dd:dd:dd:5dc/1282c19:dd:c25:c25d:dd:dd:dd:5dc
2222c19:dd:c25:c25d:dd:dd:dd:5dd/1282c19:dd:c25:c25d:dd:dd:dd:5dd
2232c19:dd:c25:c25d:dd:dd:dd:5de/1282c19:dd:c25:c25d:dd:dd:dd:5de
2242c19:dd:c25:c25d:dd:dd:dd:5df/1282c19:dd:c25:c25d:dd:dd:dd:5df
2252c19:dd:c25:c25d:dd:dd:dd:5e0/1282c19:dd:c25:c25d:dd:dd:dd:5e0
2262c19:dd:c25:c25d:dd:dd:dd:5e1/1282c19:dd:c25:c25d:dd:dd:dd:5e1
2272c19:dd:c25:c25d:dd:dd:dd:5e2/1282c19:dd:c25:c25d:dd:dd:dd:5e2
2282c19:dd:c25:c25d:dd:dd:dd:5e3/1282c19:dd:c25:c25d:dd:dd:dd:5e3
2292c19:dd:c25:c25d:dd:dd:dd:5e4/1282c19:dd:c25:c25d:dd:dd:dd:5e4
2302c19:dd:c25:c25d:dd:dd:dd:5e5/1282c19:dd:c25:c25d:dd:dd:dd:5e5
2312c19:dd:c25:c25d:dd:dd:dd:5e6/1282c19:dd:c25:c25d:dd:dd:dd:5e6
2322c19:dd:c25:c25d:dd:dd:dd:5e7/1282c19:dd:c25:c25d:dd:dd:dd:5e7
2332c19:dd:c25:c25d:dd:dd:dd:5e8/1282c19:dd:c25:c25d:dd:dd:dd:5e8
2342c19:dd:c25:c25d:dd:dd:dd:5e9/1282c19:dd:c25:c25d:dd:dd:dd:5e9
2352c19:dd:c25:c25d:dd:dd:dd:5ea/1282c19:dd:c25:c25d:dd:dd:dd:5ea
2362c19:dd:c25:c25d:dd:dd:dd:5eb/1282c19:dd:c25:c25d:dd:dd:dd:5eb
2372c19:dd:c25:c25d:dd:dd:dd:5ec/1282c19:dd:c25:c25d:dd:dd:dd:5ec
2382c19:dd:c25:c25d:dd:dd:dd:5ed/1282c19:dd:c25:c25d:dd:dd:dd:5ed
2392c19:dd:c25:c25d:dd:dd:dd:5ee/1282c19:dd:c25:c25d:dd:dd:dd:5ee
2402c19:dd:c25:c25d:dd:dd:dd:5ef/1282c19:dd:c25:c25d:dd:dd:dd:5ef
2412c19:dd:c25:c25d:dd:dd:dd:5f0/1282c19:dd:c25:c25d:dd:dd:dd:5f0
2422c19:dd:c25:c25d:dd:dd:dd:5f1/1282c19:dd:c25:c25d:dd:dd:dd:5f1
2432c19:dd:c25:c25d:dd:dd:dd:5f2/1282c19:dd:c25:c25d:dd:dd:dd:5f2
2442c19:dd:c25:c25d:dd:dd:dd:5f3/1282c19:dd:c25:c25d:dd:dd:dd:5f3
2452c19:dd:c25:c25d:dd:dd:dd:5f4/1282c19:dd:c25:c25d:dd:dd:dd:5f4
2462c19:dd:c25:c25d:dd:dd:dd:5f5/1282c19:dd:c25:c25d:dd:dd:dd:5f5
2472c19:dd:c25:c25d:dd:dd:dd:5f6/1282c19:dd:c25:c25d:dd:dd:dd:5f6
2482c19:dd:c25:c25d:dd:dd:dd:5f7/1282c19:dd:c25:c25d:dd:dd:dd:5f7
2492c19:dd:c25:c25d:dd:dd:dd:5f8/1282c19:dd:c25:c25d:dd:dd:dd:5f8
2502c19:dd:c25:c25d:dd:dd:dd:5f9/1282c19:dd:c25:c25d:dd:dd:dd:5f9
2512c19:dd:c25:c25d:dd:dd:dd:5fa/1282c19:dd:c25:c25d:dd:dd:dd:5fa
2522c19:dd:c25:c25d:dd:dd:dd:5fb/1282c19:dd:c25:c25d:dd:dd:dd:5fb
2532c19:dd:c25:c25d:dd:dd:dd:5fc/1282c19:dd:c25:c25d:dd:dd:dd:5fc
2542c19:dd:c25:c25d:dd:dd:dd:5fd/1282c19:dd:c25:c25d:dd:dd:dd:5fd
2552c19:dd:c25:c25d:dd:dd:dd:5fe/1282c19:dd:c25:c25d:dd:dd:dd:5fe
2562c19:dd:c25:c25d:dd:dd:dd:5ff/1282c19:dd:c25:c25d:dd:dd:dd:5ff

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.