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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:d00a:c000/116
First address
2c19:dd:d9:dd:c25:c25:d00a:c000
Last address
2c19:dd:d9:dd:c25:c25:d00a:cfff
Addresses
4,096
/64 networks (LANs)
None: smaller than one /64 LAN
Full form
2c19:00dd:00d9:00dd:0c25:0c25:d00a:c000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
c.a.0.0.d.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:d00a:c000/116 makes 256 subnets of /124.

Subnets
#SubnetLast address
12c19:dd:d9:dd:c25:c25:d00a:c000/1242c19:dd:d9:dd:c25:c25:d00a:c00f
22c19:dd:d9:dd:c25:c25:d00a:c010/1242c19:dd:d9:dd:c25:c25:d00a:c01f
32c19:dd:d9:dd:c25:c25:d00a:c020/1242c19:dd:d9:dd:c25:c25:d00a:c02f
42c19:dd:d9:dd:c25:c25:d00a:c030/1242c19:dd:d9:dd:c25:c25:d00a:c03f
52c19:dd:d9:dd:c25:c25:d00a:c040/1242c19:dd:d9:dd:c25:c25:d00a:c04f
62c19:dd:d9:dd:c25:c25:d00a:c050/1242c19:dd:d9:dd:c25:c25:d00a:c05f
72c19:dd:d9:dd:c25:c25:d00a:c060/1242c19:dd:d9:dd:c25:c25:d00a:c06f
82c19:dd:d9:dd:c25:c25:d00a:c070/1242c19:dd:d9:dd:c25:c25:d00a:c07f
92c19:dd:d9:dd:c25:c25:d00a:c080/1242c19:dd:d9:dd:c25:c25:d00a:c08f
102c19:dd:d9:dd:c25:c25:d00a:c090/1242c19:dd:d9:dd:c25:c25:d00a:c09f
112c19:dd:d9:dd:c25:c25:d00a:c0a0/1242c19:dd:d9:dd:c25:c25:d00a:c0af
122c19:dd:d9:dd:c25:c25:d00a:c0b0/1242c19:dd:d9:dd:c25:c25:d00a:c0bf
132c19:dd:d9:dd:c25:c25:d00a:c0c0/1242c19:dd:d9:dd:c25:c25:d00a:c0cf
142c19:dd:d9:dd:c25:c25:d00a:c0d0/1242c19:dd:d9:dd:c25:c25:d00a:c0df
152c19:dd:d9:dd:c25:c25:d00a:c0e0/1242c19:dd:d9:dd:c25:c25:d00a:c0ef
162c19:dd:d9:dd:c25:c25:d00a:c0f0/1242c19:dd:d9:dd:c25:c25:d00a:c0ff
172c19:dd:d9:dd:c25:c25:d00a:c100/1242c19:dd:d9:dd:c25:c25:d00a:c10f
182c19:dd:d9:dd:c25:c25:d00a:c110/1242c19:dd:d9:dd:c25:c25:d00a:c11f
192c19:dd:d9:dd:c25:c25:d00a:c120/1242c19:dd:d9:dd:c25:c25:d00a:c12f
202c19:dd:d9:dd:c25:c25:d00a:c130/1242c19:dd:d9:dd:c25:c25:d00a:c13f
212c19:dd:d9:dd:c25:c25:d00a:c140/1242c19:dd:d9:dd:c25:c25:d00a:c14f
222c19:dd:d9:dd:c25:c25:d00a:c150/1242c19:dd:d9:dd:c25:c25:d00a:c15f
232c19:dd:d9:dd:c25:c25:d00a:c160/1242c19:dd:d9:dd:c25:c25:d00a:c16f
242c19:dd:d9:dd:c25:c25:d00a:c170/1242c19:dd:d9:dd:c25:c25:d00a:c17f
252c19:dd:d9:dd:c25:c25:d00a:c180/1242c19:dd:d9:dd:c25:c25:d00a:c18f
262c19:dd:d9:dd:c25:c25:d00a:c190/1242c19:dd:d9:dd:c25:c25:d00a:c19f
272c19:dd:d9:dd:c25:c25:d00a:c1a0/1242c19:dd:d9:dd:c25:c25:d00a:c1af
282c19:dd:d9:dd:c25:c25:d00a:c1b0/1242c19:dd:d9:dd:c25:c25:d00a:c1bf
292c19:dd:d9:dd:c25:c25:d00a:c1c0/1242c19:dd:d9:dd:c25:c25:d00a:c1cf
302c19:dd:d9:dd:c25:c25:d00a:c1d0/1242c19:dd:d9:dd:c25:c25:d00a:c1df
312c19:dd:d9:dd:c25:c25:d00a:c1e0/1242c19:dd:d9:dd:c25:c25:d00a:c1ef
322c19:dd:d9:dd:c25:c25:d00a:c1f0/1242c19:dd:d9:dd:c25:c25:d00a:c1ff
332c19:dd:d9:dd:c25:c25:d00a:c200/1242c19:dd:d9:dd:c25:c25:d00a:c20f
342c19:dd:d9:dd:c25:c25:d00a:c210/1242c19:dd:d9:dd:c25:c25:d00a:c21f
352c19:dd:d9:dd:c25:c25:d00a:c220/1242c19:dd:d9:dd:c25:c25:d00a:c22f
362c19:dd:d9:dd:c25:c25:d00a:c230/1242c19:dd:d9:dd:c25:c25:d00a:c23f
372c19:dd:d9:dd:c25:c25:d00a:c240/1242c19:dd:d9:dd:c25:c25:d00a:c24f
382c19:dd:d9:dd:c25:c25:d00a:c250/1242c19:dd:d9:dd:c25:c25:d00a:c25f
392c19:dd:d9:dd:c25:c25:d00a:c260/1242c19:dd:d9:dd:c25:c25:d00a:c26f
402c19:dd:d9:dd:c25:c25:d00a:c270/1242c19:dd:d9:dd:c25:c25:d00a:c27f
412c19:dd:d9:dd:c25:c25:d00a:c280/1242c19:dd:d9:dd:c25:c25:d00a:c28f
422c19:dd:d9:dd:c25:c25:d00a:c290/1242c19:dd:d9:dd:c25:c25:d00a:c29f
432c19:dd:d9:dd:c25:c25:d00a:c2a0/1242c19:dd:d9:dd:c25:c25:d00a:c2af
442c19:dd:d9:dd:c25:c25:d00a:c2b0/1242c19:dd:d9:dd:c25:c25:d00a:c2bf
452c19:dd:d9:dd:c25:c25:d00a:c2c0/1242c19:dd:d9:dd:c25:c25:d00a:c2cf
462c19:dd:d9:dd:c25:c25:d00a:c2d0/1242c19:dd:d9:dd:c25:c25:d00a:c2df
472c19:dd:d9:dd:c25:c25:d00a:c2e0/1242c19:dd:d9:dd:c25:c25:d00a:c2ef
482c19:dd:d9:dd:c25:c25:d00a:c2f0/1242c19:dd:d9:dd:c25:c25:d00a:c2ff
492c19:dd:d9:dd:c25:c25:d00a:c300/1242c19:dd:d9:dd:c25:c25:d00a:c30f
502c19:dd:d9:dd:c25:c25:d00a:c310/1242c19:dd:d9:dd:c25:c25:d00a:c31f
512c19:dd:d9:dd:c25:c25:d00a:c320/1242c19:dd:d9:dd:c25:c25:d00a:c32f
522c19:dd:d9:dd:c25:c25:d00a:c330/1242c19:dd:d9:dd:c25:c25:d00a:c33f
532c19:dd:d9:dd:c25:c25:d00a:c340/1242c19:dd:d9:dd:c25:c25:d00a:c34f
542c19:dd:d9:dd:c25:c25:d00a:c350/1242c19:dd:d9:dd:c25:c25:d00a:c35f
552c19:dd:d9:dd:c25:c25:d00a:c360/1242c19:dd:d9:dd:c25:c25:d00a:c36f
562c19:dd:d9:dd:c25:c25:d00a:c370/1242c19:dd:d9:dd:c25:c25:d00a:c37f
572c19:dd:d9:dd:c25:c25:d00a:c380/1242c19:dd:d9:dd:c25:c25:d00a:c38f
582c19:dd:d9:dd:c25:c25:d00a:c390/1242c19:dd:d9:dd:c25:c25:d00a:c39f
592c19:dd:d9:dd:c25:c25:d00a:c3a0/1242c19:dd:d9:dd:c25:c25:d00a:c3af
602c19:dd:d9:dd:c25:c25:d00a:c3b0/1242c19:dd:d9:dd:c25:c25:d00a:c3bf
612c19:dd:d9:dd:c25:c25:d00a:c3c0/1242c19:dd:d9:dd:c25:c25:d00a:c3cf
622c19:dd:d9:dd:c25:c25:d00a:c3d0/1242c19:dd:d9:dd:c25:c25:d00a:c3df
632c19:dd:d9:dd:c25:c25:d00a:c3e0/1242c19:dd:d9:dd:c25:c25:d00a:c3ef
642c19:dd:d9:dd:c25:c25:d00a:c3f0/1242c19:dd:d9:dd:c25:c25:d00a:c3ff
652c19:dd:d9:dd:c25:c25:d00a:c400/1242c19:dd:d9:dd:c25:c25:d00a:c40f
662c19:dd:d9:dd:c25:c25:d00a:c410/1242c19:dd:d9:dd:c25:c25:d00a:c41f
672c19:dd:d9:dd:c25:c25:d00a:c420/1242c19:dd:d9:dd:c25:c25:d00a:c42f
682c19:dd:d9:dd:c25:c25:d00a:c430/1242c19:dd:d9:dd:c25:c25:d00a:c43f
692c19:dd:d9:dd:c25:c25:d00a:c440/1242c19:dd:d9:dd:c25:c25:d00a:c44f
702c19:dd:d9:dd:c25:c25:d00a:c450/1242c19:dd:d9:dd:c25:c25:d00a:c45f
712c19:dd:d9:dd:c25:c25:d00a:c460/1242c19:dd:d9:dd:c25:c25:d00a:c46f
722c19:dd:d9:dd:c25:c25:d00a:c470/1242c19:dd:d9:dd:c25:c25:d00a:c47f
732c19:dd:d9:dd:c25:c25:d00a:c480/1242c19:dd:d9:dd:c25:c25:d00a:c48f
742c19:dd:d9:dd:c25:c25:d00a:c490/1242c19:dd:d9:dd:c25:c25:d00a:c49f
752c19:dd:d9:dd:c25:c25:d00a:c4a0/1242c19:dd:d9:dd:c25:c25:d00a:c4af
762c19:dd:d9:dd:c25:c25:d00a:c4b0/1242c19:dd:d9:dd:c25:c25:d00a:c4bf
772c19:dd:d9:dd:c25:c25:d00a:c4c0/1242c19:dd:d9:dd:c25:c25:d00a:c4cf
782c19:dd:d9:dd:c25:c25:d00a:c4d0/1242c19:dd:d9:dd:c25:c25:d00a:c4df
792c19:dd:d9:dd:c25:c25:d00a:c4e0/1242c19:dd:d9:dd:c25:c25:d00a:c4ef
802c19:dd:d9:dd:c25:c25:d00a:c4f0/1242c19:dd:d9:dd:c25:c25:d00a:c4ff
812c19:dd:d9:dd:c25:c25:d00a:c500/1242c19:dd:d9:dd:c25:c25:d00a:c50f
822c19:dd:d9:dd:c25:c25:d00a:c510/1242c19:dd:d9:dd:c25:c25:d00a:c51f
832c19:dd:d9:dd:c25:c25:d00a:c520/1242c19:dd:d9:dd:c25:c25:d00a:c52f
842c19:dd:d9:dd:c25:c25:d00a:c530/1242c19:dd:d9:dd:c25:c25:d00a:c53f
852c19:dd:d9:dd:c25:c25:d00a:c540/1242c19:dd:d9:dd:c25:c25:d00a:c54f
862c19:dd:d9:dd:c25:c25:d00a:c550/1242c19:dd:d9:dd:c25:c25:d00a:c55f
872c19:dd:d9:dd:c25:c25:d00a:c560/1242c19:dd:d9:dd:c25:c25:d00a:c56f
882c19:dd:d9:dd:c25:c25:d00a:c570/1242c19:dd:d9:dd:c25:c25:d00a:c57f
892c19:dd:d9:dd:c25:c25:d00a:c580/1242c19:dd:d9:dd:c25:c25:d00a:c58f
902c19:dd:d9:dd:c25:c25:d00a:c590/1242c19:dd:d9:dd:c25:c25:d00a:c59f
912c19:dd:d9:dd:c25:c25:d00a:c5a0/1242c19:dd:d9:dd:c25:c25:d00a:c5af
922c19:dd:d9:dd:c25:c25:d00a:c5b0/1242c19:dd:d9:dd:c25:c25:d00a:c5bf
932c19:dd:d9:dd:c25:c25:d00a:c5c0/1242c19:dd:d9:dd:c25:c25:d00a:c5cf
942c19:dd:d9:dd:c25:c25:d00a:c5d0/1242c19:dd:d9:dd:c25:c25:d00a:c5df
952c19:dd:d9:dd:c25:c25:d00a:c5e0/1242c19:dd:d9:dd:c25:c25:d00a:c5ef
962c19:dd:d9:dd:c25:c25:d00a:c5f0/1242c19:dd:d9:dd:c25:c25:d00a:c5ff
972c19:dd:d9:dd:c25:c25:d00a:c600/1242c19:dd:d9:dd:c25:c25:d00a:c60f
982c19:dd:d9:dd:c25:c25:d00a:c610/1242c19:dd:d9:dd:c25:c25:d00a:c61f
992c19:dd:d9:dd:c25:c25:d00a:c620/1242c19:dd:d9:dd:c25:c25:d00a:c62f
1002c19:dd:d9:dd:c25:c25:d00a:c630/1242c19:dd:d9:dd:c25:c25:d00a:c63f
1012c19:dd:d9:dd:c25:c25:d00a:c640/1242c19:dd:d9:dd:c25:c25:d00a:c64f
1022c19:dd:d9:dd:c25:c25:d00a:c650/1242c19:dd:d9:dd:c25:c25:d00a:c65f
1032c19:dd:d9:dd:c25:c25:d00a:c660/1242c19:dd:d9:dd:c25:c25:d00a:c66f
1042c19:dd:d9:dd:c25:c25:d00a:c670/1242c19:dd:d9:dd:c25:c25:d00a:c67f
1052c19:dd:d9:dd:c25:c25:d00a:c680/1242c19:dd:d9:dd:c25:c25:d00a:c68f
1062c19:dd:d9:dd:c25:c25:d00a:c690/1242c19:dd:d9:dd:c25:c25:d00a:c69f
1072c19:dd:d9:dd:c25:c25:d00a:c6a0/1242c19:dd:d9:dd:c25:c25:d00a:c6af
1082c19:dd:d9:dd:c25:c25:d00a:c6b0/1242c19:dd:d9:dd:c25:c25:d00a:c6bf
1092c19:dd:d9:dd:c25:c25:d00a:c6c0/1242c19:dd:d9:dd:c25:c25:d00a:c6cf
1102c19:dd:d9:dd:c25:c25:d00a:c6d0/1242c19:dd:d9:dd:c25:c25:d00a:c6df
1112c19:dd:d9:dd:c25:c25:d00a:c6e0/1242c19:dd:d9:dd:c25:c25:d00a:c6ef
1122c19:dd:d9:dd:c25:c25:d00a:c6f0/1242c19:dd:d9:dd:c25:c25:d00a:c6ff
1132c19:dd:d9:dd:c25:c25:d00a:c700/1242c19:dd:d9:dd:c25:c25:d00a:c70f
1142c19:dd:d9:dd:c25:c25:d00a:c710/1242c19:dd:d9:dd:c25:c25:d00a:c71f
1152c19:dd:d9:dd:c25:c25:d00a:c720/1242c19:dd:d9:dd:c25:c25:d00a:c72f
1162c19:dd:d9:dd:c25:c25:d00a:c730/1242c19:dd:d9:dd:c25:c25:d00a:c73f
1172c19:dd:d9:dd:c25:c25:d00a:c740/1242c19:dd:d9:dd:c25:c25:d00a:c74f
1182c19:dd:d9:dd:c25:c25:d00a:c750/1242c19:dd:d9:dd:c25:c25:d00a:c75f
1192c19:dd:d9:dd:c25:c25:d00a:c760/1242c19:dd:d9:dd:c25:c25:d00a:c76f
1202c19:dd:d9:dd:c25:c25:d00a:c770/1242c19:dd:d9:dd:c25:c25:d00a:c77f
1212c19:dd:d9:dd:c25:c25:d00a:c780/1242c19:dd:d9:dd:c25:c25:d00a:c78f
1222c19:dd:d9:dd:c25:c25:d00a:c790/1242c19:dd:d9:dd:c25:c25:d00a:c79f
1232c19:dd:d9:dd:c25:c25:d00a:c7a0/1242c19:dd:d9:dd:c25:c25:d00a:c7af
1242c19:dd:d9:dd:c25:c25:d00a:c7b0/1242c19:dd:d9:dd:c25:c25:d00a:c7bf
1252c19:dd:d9:dd:c25:c25:d00a:c7c0/1242c19:dd:d9:dd:c25:c25:d00a:c7cf
1262c19:dd:d9:dd:c25:c25:d00a:c7d0/1242c19:dd:d9:dd:c25:c25:d00a:c7df
1272c19:dd:d9:dd:c25:c25:d00a:c7e0/1242c19:dd:d9:dd:c25:c25:d00a:c7ef
1282c19:dd:d9:dd:c25:c25:d00a:c7f0/1242c19:dd:d9:dd:c25:c25:d00a:c7ff
1292c19:dd:d9:dd:c25:c25:d00a:c800/1242c19:dd:d9:dd:c25:c25:d00a:c80f
1302c19:dd:d9:dd:c25:c25:d00a:c810/1242c19:dd:d9:dd:c25:c25:d00a:c81f
1312c19:dd:d9:dd:c25:c25:d00a:c820/1242c19:dd:d9:dd:c25:c25:d00a:c82f
1322c19:dd:d9:dd:c25:c25:d00a:c830/1242c19:dd:d9:dd:c25:c25:d00a:c83f
1332c19:dd:d9:dd:c25:c25:d00a:c840/1242c19:dd:d9:dd:c25:c25:d00a:c84f
1342c19:dd:d9:dd:c25:c25:d00a:c850/1242c19:dd:d9:dd:c25:c25:d00a:c85f
1352c19:dd:d9:dd:c25:c25:d00a:c860/1242c19:dd:d9:dd:c25:c25:d00a:c86f
1362c19:dd:d9:dd:c25:c25:d00a:c870/1242c19:dd:d9:dd:c25:c25:d00a:c87f
1372c19:dd:d9:dd:c25:c25:d00a:c880/1242c19:dd:d9:dd:c25:c25:d00a:c88f
1382c19:dd:d9:dd:c25:c25:d00a:c890/1242c19:dd:d9:dd:c25:c25:d00a:c89f
1392c19:dd:d9:dd:c25:c25:d00a:c8a0/1242c19:dd:d9:dd:c25:c25:d00a:c8af
1402c19:dd:d9:dd:c25:c25:d00a:c8b0/1242c19:dd:d9:dd:c25:c25:d00a:c8bf
1412c19:dd:d9:dd:c25:c25:d00a:c8c0/1242c19:dd:d9:dd:c25:c25:d00a:c8cf
1422c19:dd:d9:dd:c25:c25:d00a:c8d0/1242c19:dd:d9:dd:c25:c25:d00a:c8df
1432c19:dd:d9:dd:c25:c25:d00a:c8e0/1242c19:dd:d9:dd:c25:c25:d00a:c8ef
1442c19:dd:d9:dd:c25:c25:d00a:c8f0/1242c19:dd:d9:dd:c25:c25:d00a:c8ff
1452c19:dd:d9:dd:c25:c25:d00a:c900/1242c19:dd:d9:dd:c25:c25:d00a:c90f
1462c19:dd:d9:dd:c25:c25:d00a:c910/1242c19:dd:d9:dd:c25:c25:d00a:c91f
1472c19:dd:d9:dd:c25:c25:d00a:c920/1242c19:dd:d9:dd:c25:c25:d00a:c92f
1482c19:dd:d9:dd:c25:c25:d00a:c930/1242c19:dd:d9:dd:c25:c25:d00a:c93f
1492c19:dd:d9:dd:c25:c25:d00a:c940/1242c19:dd:d9:dd:c25:c25:d00a:c94f
1502c19:dd:d9:dd:c25:c25:d00a:c950/1242c19:dd:d9:dd:c25:c25:d00a:c95f
1512c19:dd:d9:dd:c25:c25:d00a:c960/1242c19:dd:d9:dd:c25:c25:d00a:c96f
1522c19:dd:d9:dd:c25:c25:d00a:c970/1242c19:dd:d9:dd:c25:c25:d00a:c97f
1532c19:dd:d9:dd:c25:c25:d00a:c980/1242c19:dd:d9:dd:c25:c25:d00a:c98f
1542c19:dd:d9:dd:c25:c25:d00a:c990/1242c19:dd:d9:dd:c25:c25:d00a:c99f
1552c19:dd:d9:dd:c25:c25:d00a:c9a0/1242c19:dd:d9:dd:c25:c25:d00a:c9af
1562c19:dd:d9:dd:c25:c25:d00a:c9b0/1242c19:dd:d9:dd:c25:c25:d00a:c9bf
1572c19:dd:d9:dd:c25:c25:d00a:c9c0/1242c19:dd:d9:dd:c25:c25:d00a:c9cf
1582c19:dd:d9:dd:c25:c25:d00a:c9d0/1242c19:dd:d9:dd:c25:c25:d00a:c9df
1592c19:dd:d9:dd:c25:c25:d00a:c9e0/1242c19:dd:d9:dd:c25:c25:d00a:c9ef
1602c19:dd:d9:dd:c25:c25:d00a:c9f0/1242c19:dd:d9:dd:c25:c25:d00a:c9ff
1612c19:dd:d9:dd:c25:c25:d00a:ca00/1242c19:dd:d9:dd:c25:c25:d00a:ca0f
1622c19:dd:d9:dd:c25:c25:d00a:ca10/1242c19:dd:d9:dd:c25:c25:d00a:ca1f
1632c19:dd:d9:dd:c25:c25:d00a:ca20/1242c19:dd:d9:dd:c25:c25:d00a:ca2f
1642c19:dd:d9:dd:c25:c25:d00a:ca30/1242c19:dd:d9:dd:c25:c25:d00a:ca3f
1652c19:dd:d9:dd:c25:c25:d00a:ca40/1242c19:dd:d9:dd:c25:c25:d00a:ca4f
1662c19:dd:d9:dd:c25:c25:d00a:ca50/1242c19:dd:d9:dd:c25:c25:d00a:ca5f
1672c19:dd:d9:dd:c25:c25:d00a:ca60/1242c19:dd:d9:dd:c25:c25:d00a:ca6f
1682c19:dd:d9:dd:c25:c25:d00a:ca70/1242c19:dd:d9:dd:c25:c25:d00a:ca7f
1692c19:dd:d9:dd:c25:c25:d00a:ca80/1242c19:dd:d9:dd:c25:c25:d00a:ca8f
1702c19:dd:d9:dd:c25:c25:d00a:ca90/1242c19:dd:d9:dd:c25:c25:d00a:ca9f
1712c19:dd:d9:dd:c25:c25:d00a:caa0/1242c19:dd:d9:dd:c25:c25:d00a:caaf
1722c19:dd:d9:dd:c25:c25:d00a:cab0/1242c19:dd:d9:dd:c25:c25:d00a:cabf
1732c19:dd:d9:dd:c25:c25:d00a:cac0/1242c19:dd:d9:dd:c25:c25:d00a:cacf
1742c19:dd:d9:dd:c25:c25:d00a:cad0/1242c19:dd:d9:dd:c25:c25:d00a:cadf
1752c19:dd:d9:dd:c25:c25:d00a:cae0/1242c19:dd:d9:dd:c25:c25:d00a:caef
1762c19:dd:d9:dd:c25:c25:d00a:caf0/1242c19:dd:d9:dd:c25:c25:d00a:caff
1772c19:dd:d9:dd:c25:c25:d00a:cb00/1242c19:dd:d9:dd:c25:c25:d00a:cb0f
1782c19:dd:d9:dd:c25:c25:d00a:cb10/1242c19:dd:d9:dd:c25:c25:d00a:cb1f
1792c19:dd:d9:dd:c25:c25:d00a:cb20/1242c19:dd:d9:dd:c25:c25:d00a:cb2f
1802c19:dd:d9:dd:c25:c25:d00a:cb30/1242c19:dd:d9:dd:c25:c25:d00a:cb3f
1812c19:dd:d9:dd:c25:c25:d00a:cb40/1242c19:dd:d9:dd:c25:c25:d00a:cb4f
1822c19:dd:d9:dd:c25:c25:d00a:cb50/1242c19:dd:d9:dd:c25:c25:d00a:cb5f
1832c19:dd:d9:dd:c25:c25:d00a:cb60/1242c19:dd:d9:dd:c25:c25:d00a:cb6f
1842c19:dd:d9:dd:c25:c25:d00a:cb70/1242c19:dd:d9:dd:c25:c25:d00a:cb7f
1852c19:dd:d9:dd:c25:c25:d00a:cb80/1242c19:dd:d9:dd:c25:c25:d00a:cb8f
1862c19:dd:d9:dd:c25:c25:d00a:cb90/1242c19:dd:d9:dd:c25:c25:d00a:cb9f
1872c19:dd:d9:dd:c25:c25:d00a:cba0/1242c19:dd:d9:dd:c25:c25:d00a:cbaf
1882c19:dd:d9:dd:c25:c25:d00a:cbb0/1242c19:dd:d9:dd:c25:c25:d00a:cbbf
1892c19:dd:d9:dd:c25:c25:d00a:cbc0/1242c19:dd:d9:dd:c25:c25:d00a:cbcf
1902c19:dd:d9:dd:c25:c25:d00a:cbd0/1242c19:dd:d9:dd:c25:c25:d00a:cbdf
1912c19:dd:d9:dd:c25:c25:d00a:cbe0/1242c19:dd:d9:dd:c25:c25:d00a:cbef
1922c19:dd:d9:dd:c25:c25:d00a:cbf0/1242c19:dd:d9:dd:c25:c25:d00a:cbff
1932c19:dd:d9:dd:c25:c25:d00a:cc00/1242c19:dd:d9:dd:c25:c25:d00a:cc0f
1942c19:dd:d9:dd:c25:c25:d00a:cc10/1242c19:dd:d9:dd:c25:c25:d00a:cc1f
1952c19:dd:d9:dd:c25:c25:d00a:cc20/1242c19:dd:d9:dd:c25:c25:d00a:cc2f
1962c19:dd:d9:dd:c25:c25:d00a:cc30/1242c19:dd:d9:dd:c25:c25:d00a:cc3f
1972c19:dd:d9:dd:c25:c25:d00a:cc40/1242c19:dd:d9:dd:c25:c25:d00a:cc4f
1982c19:dd:d9:dd:c25:c25:d00a:cc50/1242c19:dd:d9:dd:c25:c25:d00a:cc5f
1992c19:dd:d9:dd:c25:c25:d00a:cc60/1242c19:dd:d9:dd:c25:c25:d00a:cc6f
2002c19:dd:d9:dd:c25:c25:d00a:cc70/1242c19:dd:d9:dd:c25:c25:d00a:cc7f
2012c19:dd:d9:dd:c25:c25:d00a:cc80/1242c19:dd:d9:dd:c25:c25:d00a:cc8f
2022c19:dd:d9:dd:c25:c25:d00a:cc90/1242c19:dd:d9:dd:c25:c25:d00a:cc9f
2032c19:dd:d9:dd:c25:c25:d00a:cca0/1242c19:dd:d9:dd:c25:c25:d00a:ccaf
2042c19:dd:d9:dd:c25:c25:d00a:ccb0/1242c19:dd:d9:dd:c25:c25:d00a:ccbf
2052c19:dd:d9:dd:c25:c25:d00a:ccc0/1242c19:dd:d9:dd:c25:c25:d00a:cccf
2062c19:dd:d9:dd:c25:c25:d00a:ccd0/1242c19:dd:d9:dd:c25:c25:d00a:ccdf
2072c19:dd:d9:dd:c25:c25:d00a:cce0/1242c19:dd:d9:dd:c25:c25:d00a:ccef
2082c19:dd:d9:dd:c25:c25:d00a:ccf0/1242c19:dd:d9:dd:c25:c25:d00a:ccff
2092c19:dd:d9:dd:c25:c25:d00a:cd00/1242c19:dd:d9:dd:c25:c25:d00a:cd0f
2102c19:dd:d9:dd:c25:c25:d00a:cd10/1242c19:dd:d9:dd:c25:c25:d00a:cd1f
2112c19:dd:d9:dd:c25:c25:d00a:cd20/1242c19:dd:d9:dd:c25:c25:d00a:cd2f
2122c19:dd:d9:dd:c25:c25:d00a:cd30/1242c19:dd:d9:dd:c25:c25:d00a:cd3f
2132c19:dd:d9:dd:c25:c25:d00a:cd40/1242c19:dd:d9:dd:c25:c25:d00a:cd4f
2142c19:dd:d9:dd:c25:c25:d00a:cd50/1242c19:dd:d9:dd:c25:c25:d00a:cd5f
2152c19:dd:d9:dd:c25:c25:d00a:cd60/1242c19:dd:d9:dd:c25:c25:d00a:cd6f
2162c19:dd:d9:dd:c25:c25:d00a:cd70/1242c19:dd:d9:dd:c25:c25:d00a:cd7f
2172c19:dd:d9:dd:c25:c25:d00a:cd80/1242c19:dd:d9:dd:c25:c25:d00a:cd8f
2182c19:dd:d9:dd:c25:c25:d00a:cd90/1242c19:dd:d9:dd:c25:c25:d00a:cd9f
2192c19:dd:d9:dd:c25:c25:d00a:cda0/1242c19:dd:d9:dd:c25:c25:d00a:cdaf
2202c19:dd:d9:dd:c25:c25:d00a:cdb0/1242c19:dd:d9:dd:c25:c25:d00a:cdbf
2212c19:dd:d9:dd:c25:c25:d00a:cdc0/1242c19:dd:d9:dd:c25:c25:d00a:cdcf
2222c19:dd:d9:dd:c25:c25:d00a:cdd0/1242c19:dd:d9:dd:c25:c25:d00a:cddf
2232c19:dd:d9:dd:c25:c25:d00a:cde0/1242c19:dd:d9:dd:c25:c25:d00a:cdef
2242c19:dd:d9:dd:c25:c25:d00a:cdf0/1242c19:dd:d9:dd:c25:c25:d00a:cdff
2252c19:dd:d9:dd:c25:c25:d00a:ce00/1242c19:dd:d9:dd:c25:c25:d00a:ce0f
2262c19:dd:d9:dd:c25:c25:d00a:ce10/1242c19:dd:d9:dd:c25:c25:d00a:ce1f
2272c19:dd:d9:dd:c25:c25:d00a:ce20/1242c19:dd:d9:dd:c25:c25:d00a:ce2f
2282c19:dd:d9:dd:c25:c25:d00a:ce30/1242c19:dd:d9:dd:c25:c25:d00a:ce3f
2292c19:dd:d9:dd:c25:c25:d00a:ce40/1242c19:dd:d9:dd:c25:c25:d00a:ce4f
2302c19:dd:d9:dd:c25:c25:d00a:ce50/1242c19:dd:d9:dd:c25:c25:d00a:ce5f
2312c19:dd:d9:dd:c25:c25:d00a:ce60/1242c19:dd:d9:dd:c25:c25:d00a:ce6f
2322c19:dd:d9:dd:c25:c25:d00a:ce70/1242c19:dd:d9:dd:c25:c25:d00a:ce7f
2332c19:dd:d9:dd:c25:c25:d00a:ce80/1242c19:dd:d9:dd:c25:c25:d00a:ce8f
2342c19:dd:d9:dd:c25:c25:d00a:ce90/1242c19:dd:d9:dd:c25:c25:d00a:ce9f
2352c19:dd:d9:dd:c25:c25:d00a:cea0/1242c19:dd:d9:dd:c25:c25:d00a:ceaf
2362c19:dd:d9:dd:c25:c25:d00a:ceb0/1242c19:dd:d9:dd:c25:c25:d00a:cebf
2372c19:dd:d9:dd:c25:c25:d00a:cec0/1242c19:dd:d9:dd:c25:c25:d00a:cecf
2382c19:dd:d9:dd:c25:c25:d00a:ced0/1242c19:dd:d9:dd:c25:c25:d00a:cedf
2392c19:dd:d9:dd:c25:c25:d00a:cee0/1242c19:dd:d9:dd:c25:c25:d00a:ceef
2402c19:dd:d9:dd:c25:c25:d00a:cef0/1242c19:dd:d9:dd:c25:c25:d00a:ceff
2412c19:dd:d9:dd:c25:c25:d00a:cf00/1242c19:dd:d9:dd:c25:c25:d00a:cf0f
2422c19:dd:d9:dd:c25:c25:d00a:cf10/1242c19:dd:d9:dd:c25:c25:d00a:cf1f
2432c19:dd:d9:dd:c25:c25:d00a:cf20/1242c19:dd:d9:dd:c25:c25:d00a:cf2f
2442c19:dd:d9:dd:c25:c25:d00a:cf30/1242c19:dd:d9:dd:c25:c25:d00a:cf3f
2452c19:dd:d9:dd:c25:c25:d00a:cf40/1242c19:dd:d9:dd:c25:c25:d00a:cf4f
2462c19:dd:d9:dd:c25:c25:d00a:cf50/1242c19:dd:d9:dd:c25:c25:d00a:cf5f
2472c19:dd:d9:dd:c25:c25:d00a:cf60/1242c19:dd:d9:dd:c25:c25:d00a:cf6f
2482c19:dd:d9:dd:c25:c25:d00a:cf70/1242c19:dd:d9:dd:c25:c25:d00a:cf7f
2492c19:dd:d9:dd:c25:c25:d00a:cf80/1242c19:dd:d9:dd:c25:c25:d00a:cf8f
2502c19:dd:d9:dd:c25:c25:d00a:cf90/1242c19:dd:d9:dd:c25:c25:d00a:cf9f
2512c19:dd:d9:dd:c25:c25:d00a:cfa0/1242c19:dd:d9:dd:c25:c25:d00a:cfaf
2522c19:dd:d9:dd:c25:c25:d00a:cfb0/1242c19:dd:d9:dd:c25:c25:d00a:cfbf
2532c19:dd:d9:dd:c25:c25:d00a:cfc0/1242c19:dd:d9:dd:c25:c25:d00a:cfcf
2542c19:dd:d9:dd:c25:c25:d00a:cfd0/1242c19:dd:d9:dd:c25:c25:d00a:cfdf
2552c19:dd:d9:dd:c25:c25:d00a:cfe0/1242c19:dd:d9:dd:c25:c25:d00a:cfef
2562c19:dd:d9:dd:c25:c25:d00a:cff0/1242c19:dd:d9:dd:c25:c25:d00a:cfff

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.