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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/116
Addresses4,096
/64 networksPart of one
Network
2c19:dd:d9:dd:c25:c25:a00a:5000/116
First address
2c19:dd:d9:dd:c25:c25:a00a:5000
Last address
2c19:dd:d9:dd:c25:c25:a00a:5fff
Addresses
4,096
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:a00a:5000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
5.a.0.0.a.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/124
/117 (2)/118 (4)/119 (8)/120 (16)/124 (256)/127 (2,048)/128 (4,096)

2c19:dd:d9:dd:c25:c25:a00a:5000/116 makes 256 subnets of /124.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:a00a:5000/1242c19:dd:d9:dd:c25:c25:a00a:500f
22c19:dd:d9:dd:c25:c25:a00a:5010/1242c19:dd:d9:dd:c25:c25:a00a:501f
32c19:dd:d9:dd:c25:c25:a00a:5020/1242c19:dd:d9:dd:c25:c25:a00a:502f
42c19:dd:d9:dd:c25:c25:a00a:5030/1242c19:dd:d9:dd:c25:c25:a00a:503f
52c19:dd:d9:dd:c25:c25:a00a:5040/1242c19:dd:d9:dd:c25:c25:a00a:504f
62c19:dd:d9:dd:c25:c25:a00a:5050/1242c19:dd:d9:dd:c25:c25:a00a:505f
72c19:dd:d9:dd:c25:c25:a00a:5060/1242c19:dd:d9:dd:c25:c25:a00a:506f
82c19:dd:d9:dd:c25:c25:a00a:5070/1242c19:dd:d9:dd:c25:c25:a00a:507f
92c19:dd:d9:dd:c25:c25:a00a:5080/1242c19:dd:d9:dd:c25:c25:a00a:508f
102c19:dd:d9:dd:c25:c25:a00a:5090/1242c19:dd:d9:dd:c25:c25:a00a:509f
112c19:dd:d9:dd:c25:c25:a00a:50a0/1242c19:dd:d9:dd:c25:c25:a00a:50af
122c19:dd:d9:dd:c25:c25:a00a:50b0/1242c19:dd:d9:dd:c25:c25:a00a:50bf
132c19:dd:d9:dd:c25:c25:a00a:50c0/1242c19:dd:d9:dd:c25:c25:a00a:50cf
142c19:dd:d9:dd:c25:c25:a00a:50d0/1242c19:dd:d9:dd:c25:c25:a00a:50df
152c19:dd:d9:dd:c25:c25:a00a:50e0/1242c19:dd:d9:dd:c25:c25:a00a:50ef
162c19:dd:d9:dd:c25:c25:a00a:50f0/1242c19:dd:d9:dd:c25:c25:a00a:50ff
172c19:dd:d9:dd:c25:c25:a00a:5100/1242c19:dd:d9:dd:c25:c25:a00a:510f
182c19:dd:d9:dd:c25:c25:a00a:5110/1242c19:dd:d9:dd:c25:c25:a00a:511f
192c19:dd:d9:dd:c25:c25:a00a:5120/1242c19:dd:d9:dd:c25:c25:a00a:512f
202c19:dd:d9:dd:c25:c25:a00a:5130/1242c19:dd:d9:dd:c25:c25:a00a:513f
212c19:dd:d9:dd:c25:c25:a00a:5140/1242c19:dd:d9:dd:c25:c25:a00a:514f
222c19:dd:d9:dd:c25:c25:a00a:5150/1242c19:dd:d9:dd:c25:c25:a00a:515f
232c19:dd:d9:dd:c25:c25:a00a:5160/1242c19:dd:d9:dd:c25:c25:a00a:516f
242c19:dd:d9:dd:c25:c25:a00a:5170/1242c19:dd:d9:dd:c25:c25:a00a:517f
252c19:dd:d9:dd:c25:c25:a00a:5180/1242c19:dd:d9:dd:c25:c25:a00a:518f
262c19:dd:d9:dd:c25:c25:a00a:5190/1242c19:dd:d9:dd:c25:c25:a00a:519f
272c19:dd:d9:dd:c25:c25:a00a:51a0/1242c19:dd:d9:dd:c25:c25:a00a:51af
282c19:dd:d9:dd:c25:c25:a00a:51b0/1242c19:dd:d9:dd:c25:c25:a00a:51bf
292c19:dd:d9:dd:c25:c25:a00a:51c0/1242c19:dd:d9:dd:c25:c25:a00a:51cf
302c19:dd:d9:dd:c25:c25:a00a:51d0/1242c19:dd:d9:dd:c25:c25:a00a:51df
312c19:dd:d9:dd:c25:c25:a00a:51e0/1242c19:dd:d9:dd:c25:c25:a00a:51ef
322c19:dd:d9:dd:c25:c25:a00a:51f0/1242c19:dd:d9:dd:c25:c25:a00a:51ff
332c19:dd:d9:dd:c25:c25:a00a:5200/1242c19:dd:d9:dd:c25:c25:a00a:520f
342c19:dd:d9:dd:c25:c25:a00a:5210/1242c19:dd:d9:dd:c25:c25:a00a:521f
352c19:dd:d9:dd:c25:c25:a00a:5220/1242c19:dd:d9:dd:c25:c25:a00a:522f
362c19:dd:d9:dd:c25:c25:a00a:5230/1242c19:dd:d9:dd:c25:c25:a00a:523f
372c19:dd:d9:dd:c25:c25:a00a:5240/1242c19:dd:d9:dd:c25:c25:a00a:524f
382c19:dd:d9:dd:c25:c25:a00a:5250/1242c19:dd:d9:dd:c25:c25:a00a:525f
392c19:dd:d9:dd:c25:c25:a00a:5260/1242c19:dd:d9:dd:c25:c25:a00a:526f
402c19:dd:d9:dd:c25:c25:a00a:5270/1242c19:dd:d9:dd:c25:c25:a00a:527f
412c19:dd:d9:dd:c25:c25:a00a:5280/1242c19:dd:d9:dd:c25:c25:a00a:528f
422c19:dd:d9:dd:c25:c25:a00a:5290/1242c19:dd:d9:dd:c25:c25:a00a:529f
432c19:dd:d9:dd:c25:c25:a00a:52a0/1242c19:dd:d9:dd:c25:c25:a00a:52af
442c19:dd:d9:dd:c25:c25:a00a:52b0/1242c19:dd:d9:dd:c25:c25:a00a:52bf
452c19:dd:d9:dd:c25:c25:a00a:52c0/1242c19:dd:d9:dd:c25:c25:a00a:52cf
462c19:dd:d9:dd:c25:c25:a00a:52d0/1242c19:dd:d9:dd:c25:c25:a00a:52df
472c19:dd:d9:dd:c25:c25:a00a:52e0/1242c19:dd:d9:dd:c25:c25:a00a:52ef
482c19:dd:d9:dd:c25:c25:a00a:52f0/1242c19:dd:d9:dd:c25:c25:a00a:52ff
492c19:dd:d9:dd:c25:c25:a00a:5300/1242c19:dd:d9:dd:c25:c25:a00a:530f
502c19:dd:d9:dd:c25:c25:a00a:5310/1242c19:dd:d9:dd:c25:c25:a00a:531f
512c19:dd:d9:dd:c25:c25:a00a:5320/1242c19:dd:d9:dd:c25:c25:a00a:532f
522c19:dd:d9:dd:c25:c25:a00a:5330/1242c19:dd:d9:dd:c25:c25:a00a:533f
532c19:dd:d9:dd:c25:c25:a00a:5340/1242c19:dd:d9:dd:c25:c25:a00a:534f
542c19:dd:d9:dd:c25:c25:a00a:5350/1242c19:dd:d9:dd:c25:c25:a00a:535f
552c19:dd:d9:dd:c25:c25:a00a:5360/1242c19:dd:d9:dd:c25:c25:a00a:536f
562c19:dd:d9:dd:c25:c25:a00a:5370/1242c19:dd:d9:dd:c25:c25:a00a:537f
572c19:dd:d9:dd:c25:c25:a00a:5380/1242c19:dd:d9:dd:c25:c25:a00a:538f
582c19:dd:d9:dd:c25:c25:a00a:5390/1242c19:dd:d9:dd:c25:c25:a00a:539f
592c19:dd:d9:dd:c25:c25:a00a:53a0/1242c19:dd:d9:dd:c25:c25:a00a:53af
602c19:dd:d9:dd:c25:c25:a00a:53b0/1242c19:dd:d9:dd:c25:c25:a00a:53bf
612c19:dd:d9:dd:c25:c25:a00a:53c0/1242c19:dd:d9:dd:c25:c25:a00a:53cf
622c19:dd:d9:dd:c25:c25:a00a:53d0/1242c19:dd:d9:dd:c25:c25:a00a:53df
632c19:dd:d9:dd:c25:c25:a00a:53e0/1242c19:dd:d9:dd:c25:c25:a00a:53ef
642c19:dd:d9:dd:c25:c25:a00a:53f0/1242c19:dd:d9:dd:c25:c25:a00a:53ff
652c19:dd:d9:dd:c25:c25:a00a:5400/1242c19:dd:d9:dd:c25:c25:a00a:540f
662c19:dd:d9:dd:c25:c25:a00a:5410/1242c19:dd:d9:dd:c25:c25:a00a:541f
672c19:dd:d9:dd:c25:c25:a00a:5420/1242c19:dd:d9:dd:c25:c25:a00a:542f
682c19:dd:d9:dd:c25:c25:a00a:5430/1242c19:dd:d9:dd:c25:c25:a00a:543f
692c19:dd:d9:dd:c25:c25:a00a:5440/1242c19:dd:d9:dd:c25:c25:a00a:544f
702c19:dd:d9:dd:c25:c25:a00a:5450/1242c19:dd:d9:dd:c25:c25:a00a:545f
712c19:dd:d9:dd:c25:c25:a00a:5460/1242c19:dd:d9:dd:c25:c25:a00a:546f
722c19:dd:d9:dd:c25:c25:a00a:5470/1242c19:dd:d9:dd:c25:c25:a00a:547f
732c19:dd:d9:dd:c25:c25:a00a:5480/1242c19:dd:d9:dd:c25:c25:a00a:548f
742c19:dd:d9:dd:c25:c25:a00a:5490/1242c19:dd:d9:dd:c25:c25:a00a:549f
752c19:dd:d9:dd:c25:c25:a00a:54a0/1242c19:dd:d9:dd:c25:c25:a00a:54af
762c19:dd:d9:dd:c25:c25:a00a:54b0/1242c19:dd:d9:dd:c25:c25:a00a:54bf
772c19:dd:d9:dd:c25:c25:a00a:54c0/1242c19:dd:d9:dd:c25:c25:a00a:54cf
782c19:dd:d9:dd:c25:c25:a00a:54d0/1242c19:dd:d9:dd:c25:c25:a00a:54df
792c19:dd:d9:dd:c25:c25:a00a:54e0/1242c19:dd:d9:dd:c25:c25:a00a:54ef
802c19:dd:d9:dd:c25:c25:a00a:54f0/1242c19:dd:d9:dd:c25:c25:a00a:54ff
812c19:dd:d9:dd:c25:c25:a00a:5500/1242c19:dd:d9:dd:c25:c25:a00a:550f
822c19:dd:d9:dd:c25:c25:a00a:5510/1242c19:dd:d9:dd:c25:c25:a00a:551f
832c19:dd:d9:dd:c25:c25:a00a:5520/1242c19:dd:d9:dd:c25:c25:a00a:552f
842c19:dd:d9:dd:c25:c25:a00a:5530/1242c19:dd:d9:dd:c25:c25:a00a:553f
852c19:dd:d9:dd:c25:c25:a00a:5540/1242c19:dd:d9:dd:c25:c25:a00a:554f
862c19:dd:d9:dd:c25:c25:a00a:5550/1242c19:dd:d9:dd:c25:c25:a00a:555f
872c19:dd:d9:dd:c25:c25:a00a:5560/1242c19:dd:d9:dd:c25:c25:a00a:556f
882c19:dd:d9:dd:c25:c25:a00a:5570/1242c19:dd:d9:dd:c25:c25:a00a:557f
892c19:dd:d9:dd:c25:c25:a00a:5580/1242c19:dd:d9:dd:c25:c25:a00a:558f
902c19:dd:d9:dd:c25:c25:a00a:5590/1242c19:dd:d9:dd:c25:c25:a00a:559f
912c19:dd:d9:dd:c25:c25:a00a:55a0/1242c19:dd:d9:dd:c25:c25:a00a:55af
922c19:dd:d9:dd:c25:c25:a00a:55b0/1242c19:dd:d9:dd:c25:c25:a00a:55bf
932c19:dd:d9:dd:c25:c25:a00a:55c0/1242c19:dd:d9:dd:c25:c25:a00a:55cf
942c19:dd:d9:dd:c25:c25:a00a:55d0/1242c19:dd:d9:dd:c25:c25:a00a:55df
952c19:dd:d9:dd:c25:c25:a00a:55e0/1242c19:dd:d9:dd:c25:c25:a00a:55ef
962c19:dd:d9:dd:c25:c25:a00a:55f0/1242c19:dd:d9:dd:c25:c25:a00a:55ff
972c19:dd:d9:dd:c25:c25:a00a:5600/1242c19:dd:d9:dd:c25:c25:a00a:560f
982c19:dd:d9:dd:c25:c25:a00a:5610/1242c19:dd:d9:dd:c25:c25:a00a:561f
992c19:dd:d9:dd:c25:c25:a00a:5620/1242c19:dd:d9:dd:c25:c25:a00a:562f
1002c19:dd:d9:dd:c25:c25:a00a:5630/1242c19:dd:d9:dd:c25:c25:a00a:563f
1012c19:dd:d9:dd:c25:c25:a00a:5640/1242c19:dd:d9:dd:c25:c25:a00a:564f
1022c19:dd:d9:dd:c25:c25:a00a:5650/1242c19:dd:d9:dd:c25:c25:a00a:565f
1032c19:dd:d9:dd:c25:c25:a00a:5660/1242c19:dd:d9:dd:c25:c25:a00a:566f
1042c19:dd:d9:dd:c25:c25:a00a:5670/1242c19:dd:d9:dd:c25:c25:a00a:567f
1052c19:dd:d9:dd:c25:c25:a00a:5680/1242c19:dd:d9:dd:c25:c25:a00a:568f
1062c19:dd:d9:dd:c25:c25:a00a:5690/1242c19:dd:d9:dd:c25:c25:a00a:569f
1072c19:dd:d9:dd:c25:c25:a00a:56a0/1242c19:dd:d9:dd:c25:c25:a00a:56af
1082c19:dd:d9:dd:c25:c25:a00a:56b0/1242c19:dd:d9:dd:c25:c25:a00a:56bf
1092c19:dd:d9:dd:c25:c25:a00a:56c0/1242c19:dd:d9:dd:c25:c25:a00a:56cf
1102c19:dd:d9:dd:c25:c25:a00a:56d0/1242c19:dd:d9:dd:c25:c25:a00a:56df
1112c19:dd:d9:dd:c25:c25:a00a:56e0/1242c19:dd:d9:dd:c25:c25:a00a:56ef
1122c19:dd:d9:dd:c25:c25:a00a:56f0/1242c19:dd:d9:dd:c25:c25:a00a:56ff
1132c19:dd:d9:dd:c25:c25:a00a:5700/1242c19:dd:d9:dd:c25:c25:a00a:570f
1142c19:dd:d9:dd:c25:c25:a00a:5710/1242c19:dd:d9:dd:c25:c25:a00a:571f
1152c19:dd:d9:dd:c25:c25:a00a:5720/1242c19:dd:d9:dd:c25:c25:a00a:572f
1162c19:dd:d9:dd:c25:c25:a00a:5730/1242c19:dd:d9:dd:c25:c25:a00a:573f
1172c19:dd:d9:dd:c25:c25:a00a:5740/1242c19:dd:d9:dd:c25:c25:a00a:574f
1182c19:dd:d9:dd:c25:c25:a00a:5750/1242c19:dd:d9:dd:c25:c25:a00a:575f
1192c19:dd:d9:dd:c25:c25:a00a:5760/1242c19:dd:d9:dd:c25:c25:a00a:576f
1202c19:dd:d9:dd:c25:c25:a00a:5770/1242c19:dd:d9:dd:c25:c25:a00a:577f
1212c19:dd:d9:dd:c25:c25:a00a:5780/1242c19:dd:d9:dd:c25:c25:a00a:578f
1222c19:dd:d9:dd:c25:c25:a00a:5790/1242c19:dd:d9:dd:c25:c25:a00a:579f
1232c19:dd:d9:dd:c25:c25:a00a:57a0/1242c19:dd:d9:dd:c25:c25:a00a:57af
1242c19:dd:d9:dd:c25:c25:a00a:57b0/1242c19:dd:d9:dd:c25:c25:a00a:57bf
1252c19:dd:d9:dd:c25:c25:a00a:57c0/1242c19:dd:d9:dd:c25:c25:a00a:57cf
1262c19:dd:d9:dd:c25:c25:a00a:57d0/1242c19:dd:d9:dd:c25:c25:a00a:57df
1272c19:dd:d9:dd:c25:c25:a00a:57e0/1242c19:dd:d9:dd:c25:c25:a00a:57ef
1282c19:dd:d9:dd:c25:c25:a00a:57f0/1242c19:dd:d9:dd:c25:c25:a00a:57ff
1292c19:dd:d9:dd:c25:c25:a00a:5800/1242c19:dd:d9:dd:c25:c25:a00a:580f
1302c19:dd:d9:dd:c25:c25:a00a:5810/1242c19:dd:d9:dd:c25:c25:a00a:581f
1312c19:dd:d9:dd:c25:c25:a00a:5820/1242c19:dd:d9:dd:c25:c25:a00a:582f
1322c19:dd:d9:dd:c25:c25:a00a:5830/1242c19:dd:d9:dd:c25:c25:a00a:583f
1332c19:dd:d9:dd:c25:c25:a00a:5840/1242c19:dd:d9:dd:c25:c25:a00a:584f
1342c19:dd:d9:dd:c25:c25:a00a:5850/1242c19:dd:d9:dd:c25:c25:a00a:585f
1352c19:dd:d9:dd:c25:c25:a00a:5860/1242c19:dd:d9:dd:c25:c25:a00a:586f
1362c19:dd:d9:dd:c25:c25:a00a:5870/1242c19:dd:d9:dd:c25:c25:a00a:587f
1372c19:dd:d9:dd:c25:c25:a00a:5880/1242c19:dd:d9:dd:c25:c25:a00a:588f
1382c19:dd:d9:dd:c25:c25:a00a:5890/1242c19:dd:d9:dd:c25:c25:a00a:589f
1392c19:dd:d9:dd:c25:c25:a00a:58a0/1242c19:dd:d9:dd:c25:c25:a00a:58af
1402c19:dd:d9:dd:c25:c25:a00a:58b0/1242c19:dd:d9:dd:c25:c25:a00a:58bf
1412c19:dd:d9:dd:c25:c25:a00a:58c0/1242c19:dd:d9:dd:c25:c25:a00a:58cf
1422c19:dd:d9:dd:c25:c25:a00a:58d0/1242c19:dd:d9:dd:c25:c25:a00a:58df
1432c19:dd:d9:dd:c25:c25:a00a:58e0/1242c19:dd:d9:dd:c25:c25:a00a:58ef
1442c19:dd:d9:dd:c25:c25:a00a:58f0/1242c19:dd:d9:dd:c25:c25:a00a:58ff
1452c19:dd:d9:dd:c25:c25:a00a:5900/1242c19:dd:d9:dd:c25:c25:a00a:590f
1462c19:dd:d9:dd:c25:c25:a00a:5910/1242c19:dd:d9:dd:c25:c25:a00a:591f
1472c19:dd:d9:dd:c25:c25:a00a:5920/1242c19:dd:d9:dd:c25:c25:a00a:592f
1482c19:dd:d9:dd:c25:c25:a00a:5930/1242c19:dd:d9:dd:c25:c25:a00a:593f
1492c19:dd:d9:dd:c25:c25:a00a:5940/1242c19:dd:d9:dd:c25:c25:a00a:594f
1502c19:dd:d9:dd:c25:c25:a00a:5950/1242c19:dd:d9:dd:c25:c25:a00a:595f
1512c19:dd:d9:dd:c25:c25:a00a:5960/1242c19:dd:d9:dd:c25:c25:a00a:596f
1522c19:dd:d9:dd:c25:c25:a00a:5970/1242c19:dd:d9:dd:c25:c25:a00a:597f
1532c19:dd:d9:dd:c25:c25:a00a:5980/1242c19:dd:d9:dd:c25:c25:a00a:598f
1542c19:dd:d9:dd:c25:c25:a00a:5990/1242c19:dd:d9:dd:c25:c25:a00a:599f
1552c19:dd:d9:dd:c25:c25:a00a:59a0/1242c19:dd:d9:dd:c25:c25:a00a:59af
1562c19:dd:d9:dd:c25:c25:a00a:59b0/1242c19:dd:d9:dd:c25:c25:a00a:59bf
1572c19:dd:d9:dd:c25:c25:a00a:59c0/1242c19:dd:d9:dd:c25:c25:a00a:59cf
1582c19:dd:d9:dd:c25:c25:a00a:59d0/1242c19:dd:d9:dd:c25:c25:a00a:59df
1592c19:dd:d9:dd:c25:c25:a00a:59e0/1242c19:dd:d9:dd:c25:c25:a00a:59ef
1602c19:dd:d9:dd:c25:c25:a00a:59f0/1242c19:dd:d9:dd:c25:c25:a00a:59ff
1612c19:dd:d9:dd:c25:c25:a00a:5a00/1242c19:dd:d9:dd:c25:c25:a00a:5a0f
1622c19:dd:d9:dd:c25:c25:a00a:5a10/1242c19:dd:d9:dd:c25:c25:a00a:5a1f
1632c19:dd:d9:dd:c25:c25:a00a:5a20/1242c19:dd:d9:dd:c25:c25:a00a:5a2f
1642c19:dd:d9:dd:c25:c25:a00a:5a30/1242c19:dd:d9:dd:c25:c25:a00a:5a3f
1652c19:dd:d9:dd:c25:c25:a00a:5a40/1242c19:dd:d9:dd:c25:c25:a00a:5a4f
1662c19:dd:d9:dd:c25:c25:a00a:5a50/1242c19:dd:d9:dd:c25:c25:a00a:5a5f
1672c19:dd:d9:dd:c25:c25:a00a:5a60/1242c19:dd:d9:dd:c25:c25:a00a:5a6f
1682c19:dd:d9:dd:c25:c25:a00a:5a70/1242c19:dd:d9:dd:c25:c25:a00a:5a7f
1692c19:dd:d9:dd:c25:c25:a00a:5a80/1242c19:dd:d9:dd:c25:c25:a00a:5a8f
1702c19:dd:d9:dd:c25:c25:a00a:5a90/1242c19:dd:d9:dd:c25:c25:a00a:5a9f
1712c19:dd:d9:dd:c25:c25:a00a:5aa0/1242c19:dd:d9:dd:c25:c25:a00a:5aaf
1722c19:dd:d9:dd:c25:c25:a00a:5ab0/1242c19:dd:d9:dd:c25:c25:a00a:5abf
1732c19:dd:d9:dd:c25:c25:a00a:5ac0/1242c19:dd:d9:dd:c25:c25:a00a:5acf
1742c19:dd:d9:dd:c25:c25:a00a:5ad0/1242c19:dd:d9:dd:c25:c25:a00a:5adf
1752c19:dd:d9:dd:c25:c25:a00a:5ae0/1242c19:dd:d9:dd:c25:c25:a00a:5aef
1762c19:dd:d9:dd:c25:c25:a00a:5af0/1242c19:dd:d9:dd:c25:c25:a00a:5aff
1772c19:dd:d9:dd:c25:c25:a00a:5b00/1242c19:dd:d9:dd:c25:c25:a00a:5b0f
1782c19:dd:d9:dd:c25:c25:a00a:5b10/1242c19:dd:d9:dd:c25:c25:a00a:5b1f
1792c19:dd:d9:dd:c25:c25:a00a:5b20/1242c19:dd:d9:dd:c25:c25:a00a:5b2f
1802c19:dd:d9:dd:c25:c25:a00a:5b30/1242c19:dd:d9:dd:c25:c25:a00a:5b3f
1812c19:dd:d9:dd:c25:c25:a00a:5b40/1242c19:dd:d9:dd:c25:c25:a00a:5b4f
1822c19:dd:d9:dd:c25:c25:a00a:5b50/1242c19:dd:d9:dd:c25:c25:a00a:5b5f
1832c19:dd:d9:dd:c25:c25:a00a:5b60/1242c19:dd:d9:dd:c25:c25:a00a:5b6f
1842c19:dd:d9:dd:c25:c25:a00a:5b70/1242c19:dd:d9:dd:c25:c25:a00a:5b7f
1852c19:dd:d9:dd:c25:c25:a00a:5b80/1242c19:dd:d9:dd:c25:c25:a00a:5b8f
1862c19:dd:d9:dd:c25:c25:a00a:5b90/1242c19:dd:d9:dd:c25:c25:a00a:5b9f
1872c19:dd:d9:dd:c25:c25:a00a:5ba0/1242c19:dd:d9:dd:c25:c25:a00a:5baf
1882c19:dd:d9:dd:c25:c25:a00a:5bb0/1242c19:dd:d9:dd:c25:c25:a00a:5bbf
1892c19:dd:d9:dd:c25:c25:a00a:5bc0/1242c19:dd:d9:dd:c25:c25:a00a:5bcf
1902c19:dd:d9:dd:c25:c25:a00a:5bd0/1242c19:dd:d9:dd:c25:c25:a00a:5bdf
1912c19:dd:d9:dd:c25:c25:a00a:5be0/1242c19:dd:d9:dd:c25:c25:a00a:5bef
1922c19:dd:d9:dd:c25:c25:a00a:5bf0/1242c19:dd:d9:dd:c25:c25:a00a:5bff
1932c19:dd:d9:dd:c25:c25:a00a:5c00/1242c19:dd:d9:dd:c25:c25:a00a:5c0f
1942c19:dd:d9:dd:c25:c25:a00a:5c10/1242c19:dd:d9:dd:c25:c25:a00a:5c1f
1952c19:dd:d9:dd:c25:c25:a00a:5c20/1242c19:dd:d9:dd:c25:c25:a00a:5c2f
1962c19:dd:d9:dd:c25:c25:a00a:5c30/1242c19:dd:d9:dd:c25:c25:a00a:5c3f
1972c19:dd:d9:dd:c25:c25:a00a:5c40/1242c19:dd:d9:dd:c25:c25:a00a:5c4f
1982c19:dd:d9:dd:c25:c25:a00a:5c50/1242c19:dd:d9:dd:c25:c25:a00a:5c5f
1992c19:dd:d9:dd:c25:c25:a00a:5c60/1242c19:dd:d9:dd:c25:c25:a00a:5c6f
2002c19:dd:d9:dd:c25:c25:a00a:5c70/1242c19:dd:d9:dd:c25:c25:a00a:5c7f
2012c19:dd:d9:dd:c25:c25:a00a:5c80/1242c19:dd:d9:dd:c25:c25:a00a:5c8f
2022c19:dd:d9:dd:c25:c25:a00a:5c90/1242c19:dd:d9:dd:c25:c25:a00a:5c9f
2032c19:dd:d9:dd:c25:c25:a00a:5ca0/1242c19:dd:d9:dd:c25:c25:a00a:5caf
2042c19:dd:d9:dd:c25:c25:a00a:5cb0/1242c19:dd:d9:dd:c25:c25:a00a:5cbf
2052c19:dd:d9:dd:c25:c25:a00a:5cc0/1242c19:dd:d9:dd:c25:c25:a00a:5ccf
2062c19:dd:d9:dd:c25:c25:a00a:5cd0/1242c19:dd:d9:dd:c25:c25:a00a:5cdf
2072c19:dd:d9:dd:c25:c25:a00a:5ce0/1242c19:dd:d9:dd:c25:c25:a00a:5cef
2082c19:dd:d9:dd:c25:c25:a00a:5cf0/1242c19:dd:d9:dd:c25:c25:a00a:5cff
2092c19:dd:d9:dd:c25:c25:a00a:5d00/1242c19:dd:d9:dd:c25:c25:a00a:5d0f
2102c19:dd:d9:dd:c25:c25:a00a:5d10/1242c19:dd:d9:dd:c25:c25:a00a:5d1f
2112c19:dd:d9:dd:c25:c25:a00a:5d20/1242c19:dd:d9:dd:c25:c25:a00a:5d2f
2122c19:dd:d9:dd:c25:c25:a00a:5d30/1242c19:dd:d9:dd:c25:c25:a00a:5d3f
2132c19:dd:d9:dd:c25:c25:a00a:5d40/1242c19:dd:d9:dd:c25:c25:a00a:5d4f
2142c19:dd:d9:dd:c25:c25:a00a:5d50/1242c19:dd:d9:dd:c25:c25:a00a:5d5f
2152c19:dd:d9:dd:c25:c25:a00a:5d60/1242c19:dd:d9:dd:c25:c25:a00a:5d6f
2162c19:dd:d9:dd:c25:c25:a00a:5d70/1242c19:dd:d9:dd:c25:c25:a00a:5d7f
2172c19:dd:d9:dd:c25:c25:a00a:5d80/1242c19:dd:d9:dd:c25:c25:a00a:5d8f
2182c19:dd:d9:dd:c25:c25:a00a:5d90/1242c19:dd:d9:dd:c25:c25:a00a:5d9f
2192c19:dd:d9:dd:c25:c25:a00a:5da0/1242c19:dd:d9:dd:c25:c25:a00a:5daf
2202c19:dd:d9:dd:c25:c25:a00a:5db0/1242c19:dd:d9:dd:c25:c25:a00a:5dbf
2212c19:dd:d9:dd:c25:c25:a00a:5dc0/1242c19:dd:d9:dd:c25:c25:a00a:5dcf
2222c19:dd:d9:dd:c25:c25:a00a:5dd0/1242c19:dd:d9:dd:c25:c25:a00a:5ddf
2232c19:dd:d9:dd:c25:c25:a00a:5de0/1242c19:dd:d9:dd:c25:c25:a00a:5def
2242c19:dd:d9:dd:c25:c25:a00a:5df0/1242c19:dd:d9:dd:c25:c25:a00a:5dff
2252c19:dd:d9:dd:c25:c25:a00a:5e00/1242c19:dd:d9:dd:c25:c25:a00a:5e0f
2262c19:dd:d9:dd:c25:c25:a00a:5e10/1242c19:dd:d9:dd:c25:c25:a00a:5e1f
2272c19:dd:d9:dd:c25:c25:a00a:5e20/1242c19:dd:d9:dd:c25:c25:a00a:5e2f
2282c19:dd:d9:dd:c25:c25:a00a:5e30/1242c19:dd:d9:dd:c25:c25:a00a:5e3f
2292c19:dd:d9:dd:c25:c25:a00a:5e40/1242c19:dd:d9:dd:c25:c25:a00a:5e4f
2302c19:dd:d9:dd:c25:c25:a00a:5e50/1242c19:dd:d9:dd:c25:c25:a00a:5e5f
2312c19:dd:d9:dd:c25:c25:a00a:5e60/1242c19:dd:d9:dd:c25:c25:a00a:5e6f
2322c19:dd:d9:dd:c25:c25:a00a:5e70/1242c19:dd:d9:dd:c25:c25:a00a:5e7f
2332c19:dd:d9:dd:c25:c25:a00a:5e80/1242c19:dd:d9:dd:c25:c25:a00a:5e8f
2342c19:dd:d9:dd:c25:c25:a00a:5e90/1242c19:dd:d9:dd:c25:c25:a00a:5e9f
2352c19:dd:d9:dd:c25:c25:a00a:5ea0/1242c19:dd:d9:dd:c25:c25:a00a:5eaf
2362c19:dd:d9:dd:c25:c25:a00a:5eb0/1242c19:dd:d9:dd:c25:c25:a00a:5ebf
2372c19:dd:d9:dd:c25:c25:a00a:5ec0/1242c19:dd:d9:dd:c25:c25:a00a:5ecf
2382c19:dd:d9:dd:c25:c25:a00a:5ed0/1242c19:dd:d9:dd:c25:c25:a00a:5edf
2392c19:dd:d9:dd:c25:c25:a00a:5ee0/1242c19:dd:d9:dd:c25:c25:a00a:5eef
2402c19:dd:d9:dd:c25:c25:a00a:5ef0/1242c19:dd:d9:dd:c25:c25:a00a:5eff
2412c19:dd:d9:dd:c25:c25:a00a:5f00/1242c19:dd:d9:dd:c25:c25:a00a:5f0f
2422c19:dd:d9:dd:c25:c25:a00a:5f10/1242c19:dd:d9:dd:c25:c25:a00a:5f1f
2432c19:dd:d9:dd:c25:c25:a00a:5f20/1242c19:dd:d9:dd:c25:c25:a00a:5f2f
2442c19:dd:d9:dd:c25:c25:a00a:5f30/1242c19:dd:d9:dd:c25:c25:a00a:5f3f
2452c19:dd:d9:dd:c25:c25:a00a:5f40/1242c19:dd:d9:dd:c25:c25:a00a:5f4f
2462c19:dd:d9:dd:c25:c25:a00a:5f50/1242c19:dd:d9:dd:c25:c25:a00a:5f5f
2472c19:dd:d9:dd:c25:c25:a00a:5f60/1242c19:dd:d9:dd:c25:c25:a00a:5f6f
2482c19:dd:d9:dd:c25:c25:a00a:5f70/1242c19:dd:d9:dd:c25:c25:a00a:5f7f
2492c19:dd:d9:dd:c25:c25:a00a:5f80/1242c19:dd:d9:dd:c25:c25:a00a:5f8f
2502c19:dd:d9:dd:c25:c25:a00a:5f90/1242c19:dd:d9:dd:c25:c25:a00a:5f9f
2512c19:dd:d9:dd:c25:c25:a00a:5fa0/1242c19:dd:d9:dd:c25:c25:a00a:5faf
2522c19:dd:d9:dd:c25:c25:a00a:5fb0/1242c19:dd:d9:dd:c25:c25:a00a:5fbf
2532c19:dd:d9:dd:c25:c25:a00a:5fc0/1242c19:dd:d9:dd:c25:c25:a00a:5fcf
2542c19:dd:d9:dd:c25:c25:a00a:5fd0/1242c19:dd:d9:dd:c25:c25:a00a:5fdf
2552c19:dd:d9:dd:c25:c25:a00a:5fe0/1242c19:dd:d9:dd:c25:c25:a00a:5fef
2562c19:dd:d9:dd:c25:c25:a00a:5ff0/1242c19:dd:d9:dd:c25:c25:a00a:5fff

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.