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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/115
Addresses8,192
/64 networksPart of one
Network
2c19:dd:c25:c25d:dd:dd:dd:4000/115
First address
2c19:dd:c25:c25d:dd:dd:dd:4000
Last address
2c19:dd:c25:c25d:dd:dd:dd:5fff
Addresses
8,192
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:0c25:c25d:00dd:00dd:00dd:4000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zones
4.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
5.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
/115 is not on a 4-bit boundary, so it takes 2 /116 zones.
Split into smaller subnets/124
/116 (2)/117 (4)/118 (8)/119 (16)/120 (32)/124 (512)/127 (4,096)/128 (8,192)

2c19:dd:c25:c25d:dd:dd:dd:4000/115 makes 512 subnets of /124; the first 256 are listed.

Subnets
#SubnetLast address
12c19:dd:c25:c25d:dd:dd:dd:4000/1242c19:dd:c25:c25d:dd:dd:dd:400f
22c19:dd:c25:c25d:dd:dd:dd:4010/1242c19:dd:c25:c25d:dd:dd:dd:401f
32c19:dd:c25:c25d:dd:dd:dd:4020/1242c19:dd:c25:c25d:dd:dd:dd:402f
42c19:dd:c25:c25d:dd:dd:dd:4030/1242c19:dd:c25:c25d:dd:dd:dd:403f
52c19:dd:c25:c25d:dd:dd:dd:4040/1242c19:dd:c25:c25d:dd:dd:dd:404f
62c19:dd:c25:c25d:dd:dd:dd:4050/1242c19:dd:c25:c25d:dd:dd:dd:405f
72c19:dd:c25:c25d:dd:dd:dd:4060/1242c19:dd:c25:c25d:dd:dd:dd:406f
82c19:dd:c25:c25d:dd:dd:dd:4070/1242c19:dd:c25:c25d:dd:dd:dd:407f
92c19:dd:c25:c25d:dd:dd:dd:4080/1242c19:dd:c25:c25d:dd:dd:dd:408f
102c19:dd:c25:c25d:dd:dd:dd:4090/1242c19:dd:c25:c25d:dd:dd:dd:409f
112c19:dd:c25:c25d:dd:dd:dd:40a0/1242c19:dd:c25:c25d:dd:dd:dd:40af
122c19:dd:c25:c25d:dd:dd:dd:40b0/1242c19:dd:c25:c25d:dd:dd:dd:40bf
132c19:dd:c25:c25d:dd:dd:dd:40c0/1242c19:dd:c25:c25d:dd:dd:dd:40cf
142c19:dd:c25:c25d:dd:dd:dd:40d0/1242c19:dd:c25:c25d:dd:dd:dd:40df
152c19:dd:c25:c25d:dd:dd:dd:40e0/1242c19:dd:c25:c25d:dd:dd:dd:40ef
162c19:dd:c25:c25d:dd:dd:dd:40f0/1242c19:dd:c25:c25d:dd:dd:dd:40ff
172c19:dd:c25:c25d:dd:dd:dd:4100/1242c19:dd:c25:c25d:dd:dd:dd:410f
182c19:dd:c25:c25d:dd:dd:dd:4110/1242c19:dd:c25:c25d:dd:dd:dd:411f
192c19:dd:c25:c25d:dd:dd:dd:4120/1242c19:dd:c25:c25d:dd:dd:dd:412f
202c19:dd:c25:c25d:dd:dd:dd:4130/1242c19:dd:c25:c25d:dd:dd:dd:413f
212c19:dd:c25:c25d:dd:dd:dd:4140/1242c19:dd:c25:c25d:dd:dd:dd:414f
222c19:dd:c25:c25d:dd:dd:dd:4150/1242c19:dd:c25:c25d:dd:dd:dd:415f
232c19:dd:c25:c25d:dd:dd:dd:4160/1242c19:dd:c25:c25d:dd:dd:dd:416f
242c19:dd:c25:c25d:dd:dd:dd:4170/1242c19:dd:c25:c25d:dd:dd:dd:417f
252c19:dd:c25:c25d:dd:dd:dd:4180/1242c19:dd:c25:c25d:dd:dd:dd:418f
262c19:dd:c25:c25d:dd:dd:dd:4190/1242c19:dd:c25:c25d:dd:dd:dd:419f
272c19:dd:c25:c25d:dd:dd:dd:41a0/1242c19:dd:c25:c25d:dd:dd:dd:41af
282c19:dd:c25:c25d:dd:dd:dd:41b0/1242c19:dd:c25:c25d:dd:dd:dd:41bf
292c19:dd:c25:c25d:dd:dd:dd:41c0/1242c19:dd:c25:c25d:dd:dd:dd:41cf
302c19:dd:c25:c25d:dd:dd:dd:41d0/1242c19:dd:c25:c25d:dd:dd:dd:41df
312c19:dd:c25:c25d:dd:dd:dd:41e0/1242c19:dd:c25:c25d:dd:dd:dd:41ef
322c19:dd:c25:c25d:dd:dd:dd:41f0/1242c19:dd:c25:c25d:dd:dd:dd:41ff
332c19:dd:c25:c25d:dd:dd:dd:4200/1242c19:dd:c25:c25d:dd:dd:dd:420f
342c19:dd:c25:c25d:dd:dd:dd:4210/1242c19:dd:c25:c25d:dd:dd:dd:421f
352c19:dd:c25:c25d:dd:dd:dd:4220/1242c19:dd:c25:c25d:dd:dd:dd:422f
362c19:dd:c25:c25d:dd:dd:dd:4230/1242c19:dd:c25:c25d:dd:dd:dd:423f
372c19:dd:c25:c25d:dd:dd:dd:4240/1242c19:dd:c25:c25d:dd:dd:dd:424f
382c19:dd:c25:c25d:dd:dd:dd:4250/1242c19:dd:c25:c25d:dd:dd:dd:425f
392c19:dd:c25:c25d:dd:dd:dd:4260/1242c19:dd:c25:c25d:dd:dd:dd:426f
402c19:dd:c25:c25d:dd:dd:dd:4270/1242c19:dd:c25:c25d:dd:dd:dd:427f
412c19:dd:c25:c25d:dd:dd:dd:4280/1242c19:dd:c25:c25d:dd:dd:dd:428f
422c19:dd:c25:c25d:dd:dd:dd:4290/1242c19:dd:c25:c25d:dd:dd:dd:429f
432c19:dd:c25:c25d:dd:dd:dd:42a0/1242c19:dd:c25:c25d:dd:dd:dd:42af
442c19:dd:c25:c25d:dd:dd:dd:42b0/1242c19:dd:c25:c25d:dd:dd:dd:42bf
452c19:dd:c25:c25d:dd:dd:dd:42c0/1242c19:dd:c25:c25d:dd:dd:dd:42cf
462c19:dd:c25:c25d:dd:dd:dd:42d0/1242c19:dd:c25:c25d:dd:dd:dd:42df
472c19:dd:c25:c25d:dd:dd:dd:42e0/1242c19:dd:c25:c25d:dd:dd:dd:42ef
482c19:dd:c25:c25d:dd:dd:dd:42f0/1242c19:dd:c25:c25d:dd:dd:dd:42ff
492c19:dd:c25:c25d:dd:dd:dd:4300/1242c19:dd:c25:c25d:dd:dd:dd:430f
502c19:dd:c25:c25d:dd:dd:dd:4310/1242c19:dd:c25:c25d:dd:dd:dd:431f
512c19:dd:c25:c25d:dd:dd:dd:4320/1242c19:dd:c25:c25d:dd:dd:dd:432f
522c19:dd:c25:c25d:dd:dd:dd:4330/1242c19:dd:c25:c25d:dd:dd:dd:433f
532c19:dd:c25:c25d:dd:dd:dd:4340/1242c19:dd:c25:c25d:dd:dd:dd:434f
542c19:dd:c25:c25d:dd:dd:dd:4350/1242c19:dd:c25:c25d:dd:dd:dd:435f
552c19:dd:c25:c25d:dd:dd:dd:4360/1242c19:dd:c25:c25d:dd:dd:dd:436f
562c19:dd:c25:c25d:dd:dd:dd:4370/1242c19:dd:c25:c25d:dd:dd:dd:437f
572c19:dd:c25:c25d:dd:dd:dd:4380/1242c19:dd:c25:c25d:dd:dd:dd:438f
582c19:dd:c25:c25d:dd:dd:dd:4390/1242c19:dd:c25:c25d:dd:dd:dd:439f
592c19:dd:c25:c25d:dd:dd:dd:43a0/1242c19:dd:c25:c25d:dd:dd:dd:43af
602c19:dd:c25:c25d:dd:dd:dd:43b0/1242c19:dd:c25:c25d:dd:dd:dd:43bf
612c19:dd:c25:c25d:dd:dd:dd:43c0/1242c19:dd:c25:c25d:dd:dd:dd:43cf
622c19:dd:c25:c25d:dd:dd:dd:43d0/1242c19:dd:c25:c25d:dd:dd:dd:43df
632c19:dd:c25:c25d:dd:dd:dd:43e0/1242c19:dd:c25:c25d:dd:dd:dd:43ef
642c19:dd:c25:c25d:dd:dd:dd:43f0/1242c19:dd:c25:c25d:dd:dd:dd:43ff
652c19:dd:c25:c25d:dd:dd:dd:4400/1242c19:dd:c25:c25d:dd:dd:dd:440f
662c19:dd:c25:c25d:dd:dd:dd:4410/1242c19:dd:c25:c25d:dd:dd:dd:441f
672c19:dd:c25:c25d:dd:dd:dd:4420/1242c19:dd:c25:c25d:dd:dd:dd:442f
682c19:dd:c25:c25d:dd:dd:dd:4430/1242c19:dd:c25:c25d:dd:dd:dd:443f
692c19:dd:c25:c25d:dd:dd:dd:4440/1242c19:dd:c25:c25d:dd:dd:dd:444f
702c19:dd:c25:c25d:dd:dd:dd:4450/1242c19:dd:c25:c25d:dd:dd:dd:445f
712c19:dd:c25:c25d:dd:dd:dd:4460/1242c19:dd:c25:c25d:dd:dd:dd:446f
722c19:dd:c25:c25d:dd:dd:dd:4470/1242c19:dd:c25:c25d:dd:dd:dd:447f
732c19:dd:c25:c25d:dd:dd:dd:4480/1242c19:dd:c25:c25d:dd:dd:dd:448f
742c19:dd:c25:c25d:dd:dd:dd:4490/1242c19:dd:c25:c25d:dd:dd:dd:449f
752c19:dd:c25:c25d:dd:dd:dd:44a0/1242c19:dd:c25:c25d:dd:dd:dd:44af
762c19:dd:c25:c25d:dd:dd:dd:44b0/1242c19:dd:c25:c25d:dd:dd:dd:44bf
772c19:dd:c25:c25d:dd:dd:dd:44c0/1242c19:dd:c25:c25d:dd:dd:dd:44cf
782c19:dd:c25:c25d:dd:dd:dd:44d0/1242c19:dd:c25:c25d:dd:dd:dd:44df
792c19:dd:c25:c25d:dd:dd:dd:44e0/1242c19:dd:c25:c25d:dd:dd:dd:44ef
802c19:dd:c25:c25d:dd:dd:dd:44f0/1242c19:dd:c25:c25d:dd:dd:dd:44ff
812c19:dd:c25:c25d:dd:dd:dd:4500/1242c19:dd:c25:c25d:dd:dd:dd:450f
822c19:dd:c25:c25d:dd:dd:dd:4510/1242c19:dd:c25:c25d:dd:dd:dd:451f
832c19:dd:c25:c25d:dd:dd:dd:4520/1242c19:dd:c25:c25d:dd:dd:dd:452f
842c19:dd:c25:c25d:dd:dd:dd:4530/1242c19:dd:c25:c25d:dd:dd:dd:453f
852c19:dd:c25:c25d:dd:dd:dd:4540/1242c19:dd:c25:c25d:dd:dd:dd:454f
862c19:dd:c25:c25d:dd:dd:dd:4550/1242c19:dd:c25:c25d:dd:dd:dd:455f
872c19:dd:c25:c25d:dd:dd:dd:4560/1242c19:dd:c25:c25d:dd:dd:dd:456f
882c19:dd:c25:c25d:dd:dd:dd:4570/1242c19:dd:c25:c25d:dd:dd:dd:457f
892c19:dd:c25:c25d:dd:dd:dd:4580/1242c19:dd:c25:c25d:dd:dd:dd:458f
902c19:dd:c25:c25d:dd:dd:dd:4590/1242c19:dd:c25:c25d:dd:dd:dd:459f
912c19:dd:c25:c25d:dd:dd:dd:45a0/1242c19:dd:c25:c25d:dd:dd:dd:45af
922c19:dd:c25:c25d:dd:dd:dd:45b0/1242c19:dd:c25:c25d:dd:dd:dd:45bf
932c19:dd:c25:c25d:dd:dd:dd:45c0/1242c19:dd:c25:c25d:dd:dd:dd:45cf
942c19:dd:c25:c25d:dd:dd:dd:45d0/1242c19:dd:c25:c25d:dd:dd:dd:45df
952c19:dd:c25:c25d:dd:dd:dd:45e0/1242c19:dd:c25:c25d:dd:dd:dd:45ef
962c19:dd:c25:c25d:dd:dd:dd:45f0/1242c19:dd:c25:c25d:dd:dd:dd:45ff
972c19:dd:c25:c25d:dd:dd:dd:4600/1242c19:dd:c25:c25d:dd:dd:dd:460f
982c19:dd:c25:c25d:dd:dd:dd:4610/1242c19:dd:c25:c25d:dd:dd:dd:461f
992c19:dd:c25:c25d:dd:dd:dd:4620/1242c19:dd:c25:c25d:dd:dd:dd:462f
1002c19:dd:c25:c25d:dd:dd:dd:4630/1242c19:dd:c25:c25d:dd:dd:dd:463f
1012c19:dd:c25:c25d:dd:dd:dd:4640/1242c19:dd:c25:c25d:dd:dd:dd:464f
1022c19:dd:c25:c25d:dd:dd:dd:4650/1242c19:dd:c25:c25d:dd:dd:dd:465f
1032c19:dd:c25:c25d:dd:dd:dd:4660/1242c19:dd:c25:c25d:dd:dd:dd:466f
1042c19:dd:c25:c25d:dd:dd:dd:4670/1242c19:dd:c25:c25d:dd:dd:dd:467f
1052c19:dd:c25:c25d:dd:dd:dd:4680/1242c19:dd:c25:c25d:dd:dd:dd:468f
1062c19:dd:c25:c25d:dd:dd:dd:4690/1242c19:dd:c25:c25d:dd:dd:dd:469f
1072c19:dd:c25:c25d:dd:dd:dd:46a0/1242c19:dd:c25:c25d:dd:dd:dd:46af
1082c19:dd:c25:c25d:dd:dd:dd:46b0/1242c19:dd:c25:c25d:dd:dd:dd:46bf
1092c19:dd:c25:c25d:dd:dd:dd:46c0/1242c19:dd:c25:c25d:dd:dd:dd:46cf
1102c19:dd:c25:c25d:dd:dd:dd:46d0/1242c19:dd:c25:c25d:dd:dd:dd:46df
1112c19:dd:c25:c25d:dd:dd:dd:46e0/1242c19:dd:c25:c25d:dd:dd:dd:46ef
1122c19:dd:c25:c25d:dd:dd:dd:46f0/1242c19:dd:c25:c25d:dd:dd:dd:46ff
1132c19:dd:c25:c25d:dd:dd:dd:4700/1242c19:dd:c25:c25d:dd:dd:dd:470f
1142c19:dd:c25:c25d:dd:dd:dd:4710/1242c19:dd:c25:c25d:dd:dd:dd:471f
1152c19:dd:c25:c25d:dd:dd:dd:4720/1242c19:dd:c25:c25d:dd:dd:dd:472f
1162c19:dd:c25:c25d:dd:dd:dd:4730/1242c19:dd:c25:c25d:dd:dd:dd:473f
1172c19:dd:c25:c25d:dd:dd:dd:4740/1242c19:dd:c25:c25d:dd:dd:dd:474f
1182c19:dd:c25:c25d:dd:dd:dd:4750/1242c19:dd:c25:c25d:dd:dd:dd:475f
1192c19:dd:c25:c25d:dd:dd:dd:4760/1242c19:dd:c25:c25d:dd:dd:dd:476f
1202c19:dd:c25:c25d:dd:dd:dd:4770/1242c19:dd:c25:c25d:dd:dd:dd:477f
1212c19:dd:c25:c25d:dd:dd:dd:4780/1242c19:dd:c25:c25d:dd:dd:dd:478f
1222c19:dd:c25:c25d:dd:dd:dd:4790/1242c19:dd:c25:c25d:dd:dd:dd:479f
1232c19:dd:c25:c25d:dd:dd:dd:47a0/1242c19:dd:c25:c25d:dd:dd:dd:47af
1242c19:dd:c25:c25d:dd:dd:dd:47b0/1242c19:dd:c25:c25d:dd:dd:dd:47bf
1252c19:dd:c25:c25d:dd:dd:dd:47c0/1242c19:dd:c25:c25d:dd:dd:dd:47cf
1262c19:dd:c25:c25d:dd:dd:dd:47d0/1242c19:dd:c25:c25d:dd:dd:dd:47df
1272c19:dd:c25:c25d:dd:dd:dd:47e0/1242c19:dd:c25:c25d:dd:dd:dd:47ef
1282c19:dd:c25:c25d:dd:dd:dd:47f0/1242c19:dd:c25:c25d:dd:dd:dd:47ff
1292c19:dd:c25:c25d:dd:dd:dd:4800/1242c19:dd:c25:c25d:dd:dd:dd:480f
1302c19:dd:c25:c25d:dd:dd:dd:4810/1242c19:dd:c25:c25d:dd:dd:dd:481f
1312c19:dd:c25:c25d:dd:dd:dd:4820/1242c19:dd:c25:c25d:dd:dd:dd:482f
1322c19:dd:c25:c25d:dd:dd:dd:4830/1242c19:dd:c25:c25d:dd:dd:dd:483f
1332c19:dd:c25:c25d:dd:dd:dd:4840/1242c19:dd:c25:c25d:dd:dd:dd:484f
1342c19:dd:c25:c25d:dd:dd:dd:4850/1242c19:dd:c25:c25d:dd:dd:dd:485f
1352c19:dd:c25:c25d:dd:dd:dd:4860/1242c19:dd:c25:c25d:dd:dd:dd:486f
1362c19:dd:c25:c25d:dd:dd:dd:4870/1242c19:dd:c25:c25d:dd:dd:dd:487f
1372c19:dd:c25:c25d:dd:dd:dd:4880/1242c19:dd:c25:c25d:dd:dd:dd:488f
1382c19:dd:c25:c25d:dd:dd:dd:4890/1242c19:dd:c25:c25d:dd:dd:dd:489f
1392c19:dd:c25:c25d:dd:dd:dd:48a0/1242c19:dd:c25:c25d:dd:dd:dd:48af
1402c19:dd:c25:c25d:dd:dd:dd:48b0/1242c19:dd:c25:c25d:dd:dd:dd:48bf
1412c19:dd:c25:c25d:dd:dd:dd:48c0/1242c19:dd:c25:c25d:dd:dd:dd:48cf
1422c19:dd:c25:c25d:dd:dd:dd:48d0/1242c19:dd:c25:c25d:dd:dd:dd:48df
1432c19:dd:c25:c25d:dd:dd:dd:48e0/1242c19:dd:c25:c25d:dd:dd:dd:48ef
1442c19:dd:c25:c25d:dd:dd:dd:48f0/1242c19:dd:c25:c25d:dd:dd:dd:48ff
1452c19:dd:c25:c25d:dd:dd:dd:4900/1242c19:dd:c25:c25d:dd:dd:dd:490f
1462c19:dd:c25:c25d:dd:dd:dd:4910/1242c19:dd:c25:c25d:dd:dd:dd:491f
1472c19:dd:c25:c25d:dd:dd:dd:4920/1242c19:dd:c25:c25d:dd:dd:dd:492f
1482c19:dd:c25:c25d:dd:dd:dd:4930/1242c19:dd:c25:c25d:dd:dd:dd:493f
1492c19:dd:c25:c25d:dd:dd:dd:4940/1242c19:dd:c25:c25d:dd:dd:dd:494f
1502c19:dd:c25:c25d:dd:dd:dd:4950/1242c19:dd:c25:c25d:dd:dd:dd:495f
1512c19:dd:c25:c25d:dd:dd:dd:4960/1242c19:dd:c25:c25d:dd:dd:dd:496f
1522c19:dd:c25:c25d:dd:dd:dd:4970/1242c19:dd:c25:c25d:dd:dd:dd:497f
1532c19:dd:c25:c25d:dd:dd:dd:4980/1242c19:dd:c25:c25d:dd:dd:dd:498f
1542c19:dd:c25:c25d:dd:dd:dd:4990/1242c19:dd:c25:c25d:dd:dd:dd:499f
1552c19:dd:c25:c25d:dd:dd:dd:49a0/1242c19:dd:c25:c25d:dd:dd:dd:49af
1562c19:dd:c25:c25d:dd:dd:dd:49b0/1242c19:dd:c25:c25d:dd:dd:dd:49bf
1572c19:dd:c25:c25d:dd:dd:dd:49c0/1242c19:dd:c25:c25d:dd:dd:dd:49cf
1582c19:dd:c25:c25d:dd:dd:dd:49d0/1242c19:dd:c25:c25d:dd:dd:dd:49df
1592c19:dd:c25:c25d:dd:dd:dd:49e0/1242c19:dd:c25:c25d:dd:dd:dd:49ef
1602c19:dd:c25:c25d:dd:dd:dd:49f0/1242c19:dd:c25:c25d:dd:dd:dd:49ff
1612c19:dd:c25:c25d:dd:dd:dd:4a00/1242c19:dd:c25:c25d:dd:dd:dd:4a0f
1622c19:dd:c25:c25d:dd:dd:dd:4a10/1242c19:dd:c25:c25d:dd:dd:dd:4a1f
1632c19:dd:c25:c25d:dd:dd:dd:4a20/1242c19:dd:c25:c25d:dd:dd:dd:4a2f
1642c19:dd:c25:c25d:dd:dd:dd:4a30/1242c19:dd:c25:c25d:dd:dd:dd:4a3f
1652c19:dd:c25:c25d:dd:dd:dd:4a40/1242c19:dd:c25:c25d:dd:dd:dd:4a4f
1662c19:dd:c25:c25d:dd:dd:dd:4a50/1242c19:dd:c25:c25d:dd:dd:dd:4a5f
1672c19:dd:c25:c25d:dd:dd:dd:4a60/1242c19:dd:c25:c25d:dd:dd:dd:4a6f
1682c19:dd:c25:c25d:dd:dd:dd:4a70/1242c19:dd:c25:c25d:dd:dd:dd:4a7f
1692c19:dd:c25:c25d:dd:dd:dd:4a80/1242c19:dd:c25:c25d:dd:dd:dd:4a8f
1702c19:dd:c25:c25d:dd:dd:dd:4a90/1242c19:dd:c25:c25d:dd:dd:dd:4a9f
1712c19:dd:c25:c25d:dd:dd:dd:4aa0/1242c19:dd:c25:c25d:dd:dd:dd:4aaf
1722c19:dd:c25:c25d:dd:dd:dd:4ab0/1242c19:dd:c25:c25d:dd:dd:dd:4abf
1732c19:dd:c25:c25d:dd:dd:dd:4ac0/1242c19:dd:c25:c25d:dd:dd:dd:4acf
1742c19:dd:c25:c25d:dd:dd:dd:4ad0/1242c19:dd:c25:c25d:dd:dd:dd:4adf
1752c19:dd:c25:c25d:dd:dd:dd:4ae0/1242c19:dd:c25:c25d:dd:dd:dd:4aef
1762c19:dd:c25:c25d:dd:dd:dd:4af0/1242c19:dd:c25:c25d:dd:dd:dd:4aff
1772c19:dd:c25:c25d:dd:dd:dd:4b00/1242c19:dd:c25:c25d:dd:dd:dd:4b0f
1782c19:dd:c25:c25d:dd:dd:dd:4b10/1242c19:dd:c25:c25d:dd:dd:dd:4b1f
1792c19:dd:c25:c25d:dd:dd:dd:4b20/1242c19:dd:c25:c25d:dd:dd:dd:4b2f
1802c19:dd:c25:c25d:dd:dd:dd:4b30/1242c19:dd:c25:c25d:dd:dd:dd:4b3f
1812c19:dd:c25:c25d:dd:dd:dd:4b40/1242c19:dd:c25:c25d:dd:dd:dd:4b4f
1822c19:dd:c25:c25d:dd:dd:dd:4b50/1242c19:dd:c25:c25d:dd:dd:dd:4b5f
1832c19:dd:c25:c25d:dd:dd:dd:4b60/1242c19:dd:c25:c25d:dd:dd:dd:4b6f
1842c19:dd:c25:c25d:dd:dd:dd:4b70/1242c19:dd:c25:c25d:dd:dd:dd:4b7f
1852c19:dd:c25:c25d:dd:dd:dd:4b80/1242c19:dd:c25:c25d:dd:dd:dd:4b8f
1862c19:dd:c25:c25d:dd:dd:dd:4b90/1242c19:dd:c25:c25d:dd:dd:dd:4b9f
1872c19:dd:c25:c25d:dd:dd:dd:4ba0/1242c19:dd:c25:c25d:dd:dd:dd:4baf
1882c19:dd:c25:c25d:dd:dd:dd:4bb0/1242c19:dd:c25:c25d:dd:dd:dd:4bbf
1892c19:dd:c25:c25d:dd:dd:dd:4bc0/1242c19:dd:c25:c25d:dd:dd:dd:4bcf
1902c19:dd:c25:c25d:dd:dd:dd:4bd0/1242c19:dd:c25:c25d:dd:dd:dd:4bdf
1912c19:dd:c25:c25d:dd:dd:dd:4be0/1242c19:dd:c25:c25d:dd:dd:dd:4bef
1922c19:dd:c25:c25d:dd:dd:dd:4bf0/1242c19:dd:c25:c25d:dd:dd:dd:4bff
1932c19:dd:c25:c25d:dd:dd:dd:4c00/1242c19:dd:c25:c25d:dd:dd:dd:4c0f
1942c19:dd:c25:c25d:dd:dd:dd:4c10/1242c19:dd:c25:c25d:dd:dd:dd:4c1f
1952c19:dd:c25:c25d:dd:dd:dd:4c20/1242c19:dd:c25:c25d:dd:dd:dd:4c2f
1962c19:dd:c25:c25d:dd:dd:dd:4c30/1242c19:dd:c25:c25d:dd:dd:dd:4c3f
1972c19:dd:c25:c25d:dd:dd:dd:4c40/1242c19:dd:c25:c25d:dd:dd:dd:4c4f
1982c19:dd:c25:c25d:dd:dd:dd:4c50/1242c19:dd:c25:c25d:dd:dd:dd:4c5f
1992c19:dd:c25:c25d:dd:dd:dd:4c60/1242c19:dd:c25:c25d:dd:dd:dd:4c6f
2002c19:dd:c25:c25d:dd:dd:dd:4c70/1242c19:dd:c25:c25d:dd:dd:dd:4c7f
2012c19:dd:c25:c25d:dd:dd:dd:4c80/1242c19:dd:c25:c25d:dd:dd:dd:4c8f
2022c19:dd:c25:c25d:dd:dd:dd:4c90/1242c19:dd:c25:c25d:dd:dd:dd:4c9f
2032c19:dd:c25:c25d:dd:dd:dd:4ca0/1242c19:dd:c25:c25d:dd:dd:dd:4caf
2042c19:dd:c25:c25d:dd:dd:dd:4cb0/1242c19:dd:c25:c25d:dd:dd:dd:4cbf
2052c19:dd:c25:c25d:dd:dd:dd:4cc0/1242c19:dd:c25:c25d:dd:dd:dd:4ccf
2062c19:dd:c25:c25d:dd:dd:dd:4cd0/1242c19:dd:c25:c25d:dd:dd:dd:4cdf
2072c19:dd:c25:c25d:dd:dd:dd:4ce0/1242c19:dd:c25:c25d:dd:dd:dd:4cef
2082c19:dd:c25:c25d:dd:dd:dd:4cf0/1242c19:dd:c25:c25d:dd:dd:dd:4cff
2092c19:dd:c25:c25d:dd:dd:dd:4d00/1242c19:dd:c25:c25d:dd:dd:dd:4d0f
2102c19:dd:c25:c25d:dd:dd:dd:4d10/1242c19:dd:c25:c25d:dd:dd:dd:4d1f
2112c19:dd:c25:c25d:dd:dd:dd:4d20/1242c19:dd:c25:c25d:dd:dd:dd:4d2f
2122c19:dd:c25:c25d:dd:dd:dd:4d30/1242c19:dd:c25:c25d:dd:dd:dd:4d3f
2132c19:dd:c25:c25d:dd:dd:dd:4d40/1242c19:dd:c25:c25d:dd:dd:dd:4d4f
2142c19:dd:c25:c25d:dd:dd:dd:4d50/1242c19:dd:c25:c25d:dd:dd:dd:4d5f
2152c19:dd:c25:c25d:dd:dd:dd:4d60/1242c19:dd:c25:c25d:dd:dd:dd:4d6f
2162c19:dd:c25:c25d:dd:dd:dd:4d70/1242c19:dd:c25:c25d:dd:dd:dd:4d7f
2172c19:dd:c25:c25d:dd:dd:dd:4d80/1242c19:dd:c25:c25d:dd:dd:dd:4d8f
2182c19:dd:c25:c25d:dd:dd:dd:4d90/1242c19:dd:c25:c25d:dd:dd:dd:4d9f
2192c19:dd:c25:c25d:dd:dd:dd:4da0/1242c19:dd:c25:c25d:dd:dd:dd:4daf
2202c19:dd:c25:c25d:dd:dd:dd:4db0/1242c19:dd:c25:c25d:dd:dd:dd:4dbf
2212c19:dd:c25:c25d:dd:dd:dd:4dc0/1242c19:dd:c25:c25d:dd:dd:dd:4dcf
2222c19:dd:c25:c25d:dd:dd:dd:4dd0/1242c19:dd:c25:c25d:dd:dd:dd:4ddf
2232c19:dd:c25:c25d:dd:dd:dd:4de0/1242c19:dd:c25:c25d:dd:dd:dd:4def
2242c19:dd:c25:c25d:dd:dd:dd:4df0/1242c19:dd:c25:c25d:dd:dd:dd:4dff
2252c19:dd:c25:c25d:dd:dd:dd:4e00/1242c19:dd:c25:c25d:dd:dd:dd:4e0f
2262c19:dd:c25:c25d:dd:dd:dd:4e10/1242c19:dd:c25:c25d:dd:dd:dd:4e1f
2272c19:dd:c25:c25d:dd:dd:dd:4e20/1242c19:dd:c25:c25d:dd:dd:dd:4e2f
2282c19:dd:c25:c25d:dd:dd:dd:4e30/1242c19:dd:c25:c25d:dd:dd:dd:4e3f
2292c19:dd:c25:c25d:dd:dd:dd:4e40/1242c19:dd:c25:c25d:dd:dd:dd:4e4f
2302c19:dd:c25:c25d:dd:dd:dd:4e50/1242c19:dd:c25:c25d:dd:dd:dd:4e5f
2312c19:dd:c25:c25d:dd:dd:dd:4e60/1242c19:dd:c25:c25d:dd:dd:dd:4e6f
2322c19:dd:c25:c25d:dd:dd:dd:4e70/1242c19:dd:c25:c25d:dd:dd:dd:4e7f
2332c19:dd:c25:c25d:dd:dd:dd:4e80/1242c19:dd:c25:c25d:dd:dd:dd:4e8f
2342c19:dd:c25:c25d:dd:dd:dd:4e90/1242c19:dd:c25:c25d:dd:dd:dd:4e9f
2352c19:dd:c25:c25d:dd:dd:dd:4ea0/1242c19:dd:c25:c25d:dd:dd:dd:4eaf
2362c19:dd:c25:c25d:dd:dd:dd:4eb0/1242c19:dd:c25:c25d:dd:dd:dd:4ebf
2372c19:dd:c25:c25d:dd:dd:dd:4ec0/1242c19:dd:c25:c25d:dd:dd:dd:4ecf
2382c19:dd:c25:c25d:dd:dd:dd:4ed0/1242c19:dd:c25:c25d:dd:dd:dd:4edf
2392c19:dd:c25:c25d:dd:dd:dd:4ee0/1242c19:dd:c25:c25d:dd:dd:dd:4eef
2402c19:dd:c25:c25d:dd:dd:dd:4ef0/1242c19:dd:c25:c25d:dd:dd:dd:4eff
2412c19:dd:c25:c25d:dd:dd:dd:4f00/1242c19:dd:c25:c25d:dd:dd:dd:4f0f
2422c19:dd:c25:c25d:dd:dd:dd:4f10/1242c19:dd:c25:c25d:dd:dd:dd:4f1f
2432c19:dd:c25:c25d:dd:dd:dd:4f20/1242c19:dd:c25:c25d:dd:dd:dd:4f2f
2442c19:dd:c25:c25d:dd:dd:dd:4f30/1242c19:dd:c25:c25d:dd:dd:dd:4f3f
2452c19:dd:c25:c25d:dd:dd:dd:4f40/1242c19:dd:c25:c25d:dd:dd:dd:4f4f
2462c19:dd:c25:c25d:dd:dd:dd:4f50/1242c19:dd:c25:c25d:dd:dd:dd:4f5f
2472c19:dd:c25:c25d:dd:dd:dd:4f60/1242c19:dd:c25:c25d:dd:dd:dd:4f6f
2482c19:dd:c25:c25d:dd:dd:dd:4f70/1242c19:dd:c25:c25d:dd:dd:dd:4f7f
2492c19:dd:c25:c25d:dd:dd:dd:4f80/1242c19:dd:c25:c25d:dd:dd:dd:4f8f
2502c19:dd:c25:c25d:dd:dd:dd:4f90/1242c19:dd:c25:c25d:dd:dd:dd:4f9f
2512c19:dd:c25:c25d:dd:dd:dd:4fa0/1242c19:dd:c25:c25d:dd:dd:dd:4faf
2522c19:dd:c25:c25d:dd:dd:dd:4fb0/1242c19:dd:c25:c25d:dd:dd:dd:4fbf
2532c19:dd:c25:c25d:dd:dd:dd:4fc0/1242c19:dd:c25:c25d:dd:dd:dd:4fcf
2542c19:dd:c25:c25d:dd:dd:dd:4fd0/1242c19:dd:c25:c25d:dd:dd:dd:4fdf
2552c19:dd:c25:c25d:dd:dd:dd:4fe0/1242c19:dd:c25:c25d:dd:dd:dd:4fef
2562c19:dd:c25:c25d:dd:dd:dd:4ff0/1242c19:dd:c25:c25d:dd:dd:dd:4fff

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.