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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/12
Addresses2^116
/64 networks2^52
Network
2bb0::/12
First address
2bb0::
Last address
2bbf:ffff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
83,076,749,736,557,242,056,487,941,267,521,536 (2^116)
/64 networks (LANs)
4,503,599,627,370,496 (2^52)
Full form
2bb0:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
b.b.2.ip6.arpa
Split into smaller subnets/28
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

2bb0::/12 makes 65,536 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
12bb0::/282bb0:f:ffff:ffff:ffff:ffff:ffff:ffff
22bb0:10::/282bb0:1f:ffff:ffff:ffff:ffff:ffff:ffff
32bb0:20::/282bb0:2f:ffff:ffff:ffff:ffff:ffff:ffff
42bb0:30::/282bb0:3f:ffff:ffff:ffff:ffff:ffff:ffff
52bb0:40::/282bb0:4f:ffff:ffff:ffff:ffff:ffff:ffff
62bb0:50::/282bb0:5f:ffff:ffff:ffff:ffff:ffff:ffff
72bb0:60::/282bb0:6f:ffff:ffff:ffff:ffff:ffff:ffff
82bb0:70::/282bb0:7f:ffff:ffff:ffff:ffff:ffff:ffff
92bb0:80::/282bb0:8f:ffff:ffff:ffff:ffff:ffff:ffff
102bb0:90::/282bb0:9f:ffff:ffff:ffff:ffff:ffff:ffff
112bb0:a0::/282bb0:af:ffff:ffff:ffff:ffff:ffff:ffff
122bb0:b0::/282bb0:bf:ffff:ffff:ffff:ffff:ffff:ffff
132bb0:c0::/282bb0:cf:ffff:ffff:ffff:ffff:ffff:ffff
142bb0:d0::/282bb0:df:ffff:ffff:ffff:ffff:ffff:ffff
152bb0:e0::/282bb0:ef:ffff:ffff:ffff:ffff:ffff:ffff
162bb0:f0::/282bb0:ff:ffff:ffff:ffff:ffff:ffff:ffff
172bb0:100::/282bb0:10f:ffff:ffff:ffff:ffff:ffff:ffff
182bb0:110::/282bb0:11f:ffff:ffff:ffff:ffff:ffff:ffff
192bb0:120::/282bb0:12f:ffff:ffff:ffff:ffff:ffff:ffff
202bb0:130::/282bb0:13f:ffff:ffff:ffff:ffff:ffff:ffff
212bb0:140::/282bb0:14f:ffff:ffff:ffff:ffff:ffff:ffff
222bb0:150::/282bb0:15f:ffff:ffff:ffff:ffff:ffff:ffff
232bb0:160::/282bb0:16f:ffff:ffff:ffff:ffff:ffff:ffff
242bb0:170::/282bb0:17f:ffff:ffff:ffff:ffff:ffff:ffff
252bb0:180::/282bb0:18f:ffff:ffff:ffff:ffff:ffff:ffff
262bb0:190::/282bb0:19f:ffff:ffff:ffff:ffff:ffff:ffff
272bb0:1a0::/282bb0:1af:ffff:ffff:ffff:ffff:ffff:ffff
282bb0:1b0::/282bb0:1bf:ffff:ffff:ffff:ffff:ffff:ffff
292bb0:1c0::/282bb0:1cf:ffff:ffff:ffff:ffff:ffff:ffff
302bb0:1d0::/282bb0:1df:ffff:ffff:ffff:ffff:ffff:ffff
312bb0:1e0::/282bb0:1ef:ffff:ffff:ffff:ffff:ffff:ffff
322bb0:1f0::/282bb0:1ff:ffff:ffff:ffff:ffff:ffff:ffff
332bb0:200::/282bb0:20f:ffff:ffff:ffff:ffff:ffff:ffff
342bb0:210::/282bb0:21f:ffff:ffff:ffff:ffff:ffff:ffff
352bb0:220::/282bb0:22f:ffff:ffff:ffff:ffff:ffff:ffff
362bb0:230::/282bb0:23f:ffff:ffff:ffff:ffff:ffff:ffff
372bb0:240::/282bb0:24f:ffff:ffff:ffff:ffff:ffff:ffff
382bb0:250::/282bb0:25f:ffff:ffff:ffff:ffff:ffff:ffff
392bb0:260::/282bb0:26f:ffff:ffff:ffff:ffff:ffff:ffff
402bb0:270::/282bb0:27f:ffff:ffff:ffff:ffff:ffff:ffff
412bb0:280::/282bb0:28f:ffff:ffff:ffff:ffff:ffff:ffff
422bb0:290::/282bb0:29f:ffff:ffff:ffff:ffff:ffff:ffff
432bb0:2a0::/282bb0:2af:ffff:ffff:ffff:ffff:ffff:ffff
442bb0:2b0::/282bb0:2bf:ffff:ffff:ffff:ffff:ffff:ffff
452bb0:2c0::/282bb0:2cf:ffff:ffff:ffff:ffff:ffff:ffff
462bb0:2d0::/282bb0:2df:ffff:ffff:ffff:ffff:ffff:ffff
472bb0:2e0::/282bb0:2ef:ffff:ffff:ffff:ffff:ffff:ffff
482bb0:2f0::/282bb0:2ff:ffff:ffff:ffff:ffff:ffff:ffff
492bb0:300::/282bb0:30f:ffff:ffff:ffff:ffff:ffff:ffff
502bb0:310::/282bb0:31f:ffff:ffff:ffff:ffff:ffff:ffff
512bb0:320::/282bb0:32f:ffff:ffff:ffff:ffff:ffff:ffff
522bb0:330::/282bb0:33f:ffff:ffff:ffff:ffff:ffff:ffff
532bb0:340::/282bb0:34f:ffff:ffff:ffff:ffff:ffff:ffff
542bb0:350::/282bb0:35f:ffff:ffff:ffff:ffff:ffff:ffff
552bb0:360::/282bb0:36f:ffff:ffff:ffff:ffff:ffff:ffff
562bb0:370::/282bb0:37f:ffff:ffff:ffff:ffff:ffff:ffff
572bb0:380::/282bb0:38f:ffff:ffff:ffff:ffff:ffff:ffff
582bb0:390::/282bb0:39f:ffff:ffff:ffff:ffff:ffff:ffff
592bb0:3a0::/282bb0:3af:ffff:ffff:ffff:ffff:ffff:ffff
602bb0:3b0::/282bb0:3bf:ffff:ffff:ffff:ffff:ffff:ffff
612bb0:3c0::/282bb0:3cf:ffff:ffff:ffff:ffff:ffff:ffff
622bb0:3d0::/282bb0:3df:ffff:ffff:ffff:ffff:ffff:ffff
632bb0:3e0::/282bb0:3ef:ffff:ffff:ffff:ffff:ffff:ffff
642bb0:3f0::/282bb0:3ff:ffff:ffff:ffff:ffff:ffff:ffff
652bb0:400::/282bb0:40f:ffff:ffff:ffff:ffff:ffff:ffff
662bb0:410::/282bb0:41f:ffff:ffff:ffff:ffff:ffff:ffff
672bb0:420::/282bb0:42f:ffff:ffff:ffff:ffff:ffff:ffff
682bb0:430::/282bb0:43f:ffff:ffff:ffff:ffff:ffff:ffff
692bb0:440::/282bb0:44f:ffff:ffff:ffff:ffff:ffff:ffff
702bb0:450::/282bb0:45f:ffff:ffff:ffff:ffff:ffff:ffff
712bb0:460::/282bb0:46f:ffff:ffff:ffff:ffff:ffff:ffff
722bb0:470::/282bb0:47f:ffff:ffff:ffff:ffff:ffff:ffff
732bb0:480::/282bb0:48f:ffff:ffff:ffff:ffff:ffff:ffff
742bb0:490::/282bb0:49f:ffff:ffff:ffff:ffff:ffff:ffff
752bb0:4a0::/282bb0:4af:ffff:ffff:ffff:ffff:ffff:ffff
762bb0:4b0::/282bb0:4bf:ffff:ffff:ffff:ffff:ffff:ffff
772bb0:4c0::/282bb0:4cf:ffff:ffff:ffff:ffff:ffff:ffff
782bb0:4d0::/282bb0:4df:ffff:ffff:ffff:ffff:ffff:ffff
792bb0:4e0::/282bb0:4ef:ffff:ffff:ffff:ffff:ffff:ffff
802bb0:4f0::/282bb0:4ff:ffff:ffff:ffff:ffff:ffff:ffff
812bb0:500::/282bb0:50f:ffff:ffff:ffff:ffff:ffff:ffff
822bb0:510::/282bb0:51f:ffff:ffff:ffff:ffff:ffff:ffff
832bb0:520::/282bb0:52f:ffff:ffff:ffff:ffff:ffff:ffff
842bb0:530::/282bb0:53f:ffff:ffff:ffff:ffff:ffff:ffff
852bb0:540::/282bb0:54f:ffff:ffff:ffff:ffff:ffff:ffff
862bb0:550::/282bb0:55f:ffff:ffff:ffff:ffff:ffff:ffff
872bb0:560::/282bb0:56f:ffff:ffff:ffff:ffff:ffff:ffff
882bb0:570::/282bb0:57f:ffff:ffff:ffff:ffff:ffff:ffff
892bb0:580::/282bb0:58f:ffff:ffff:ffff:ffff:ffff:ffff
902bb0:590::/282bb0:59f:ffff:ffff:ffff:ffff:ffff:ffff
912bb0:5a0::/282bb0:5af:ffff:ffff:ffff:ffff:ffff:ffff
922bb0:5b0::/282bb0:5bf:ffff:ffff:ffff:ffff:ffff:ffff
932bb0:5c0::/282bb0:5cf:ffff:ffff:ffff:ffff:ffff:ffff
942bb0:5d0::/282bb0:5df:ffff:ffff:ffff:ffff:ffff:ffff
952bb0:5e0::/282bb0:5ef:ffff:ffff:ffff:ffff:ffff:ffff
962bb0:5f0::/282bb0:5ff:ffff:ffff:ffff:ffff:ffff:ffff
972bb0:600::/282bb0:60f:ffff:ffff:ffff:ffff:ffff:ffff
982bb0:610::/282bb0:61f:ffff:ffff:ffff:ffff:ffff:ffff
992bb0:620::/282bb0:62f:ffff:ffff:ffff:ffff:ffff:ffff
1002bb0:630::/282bb0:63f:ffff:ffff:ffff:ffff:ffff:ffff
1012bb0:640::/282bb0:64f:ffff:ffff:ffff:ffff:ffff:ffff
1022bb0:650::/282bb0:65f:ffff:ffff:ffff:ffff:ffff:ffff
1032bb0:660::/282bb0:66f:ffff:ffff:ffff:ffff:ffff:ffff
1042bb0:670::/282bb0:67f:ffff:ffff:ffff:ffff:ffff:ffff
1052bb0:680::/282bb0:68f:ffff:ffff:ffff:ffff:ffff:ffff
1062bb0:690::/282bb0:69f:ffff:ffff:ffff:ffff:ffff:ffff
1072bb0:6a0::/282bb0:6af:ffff:ffff:ffff:ffff:ffff:ffff
1082bb0:6b0::/282bb0:6bf:ffff:ffff:ffff:ffff:ffff:ffff
1092bb0:6c0::/282bb0:6cf:ffff:ffff:ffff:ffff:ffff:ffff
1102bb0:6d0::/282bb0:6df:ffff:ffff:ffff:ffff:ffff:ffff
1112bb0:6e0::/282bb0:6ef:ffff:ffff:ffff:ffff:ffff:ffff
1122bb0:6f0::/282bb0:6ff:ffff:ffff:ffff:ffff:ffff:ffff
1132bb0:700::/282bb0:70f:ffff:ffff:ffff:ffff:ffff:ffff
1142bb0:710::/282bb0:71f:ffff:ffff:ffff:ffff:ffff:ffff
1152bb0:720::/282bb0:72f:ffff:ffff:ffff:ffff:ffff:ffff
1162bb0:730::/282bb0:73f:ffff:ffff:ffff:ffff:ffff:ffff
1172bb0:740::/282bb0:74f:ffff:ffff:ffff:ffff:ffff:ffff
1182bb0:750::/282bb0:75f:ffff:ffff:ffff:ffff:ffff:ffff
1192bb0:760::/282bb0:76f:ffff:ffff:ffff:ffff:ffff:ffff
1202bb0:770::/282bb0:77f:ffff:ffff:ffff:ffff:ffff:ffff
1212bb0:780::/282bb0:78f:ffff:ffff:ffff:ffff:ffff:ffff
1222bb0:790::/282bb0:79f:ffff:ffff:ffff:ffff:ffff:ffff
1232bb0:7a0::/282bb0:7af:ffff:ffff:ffff:ffff:ffff:ffff
1242bb0:7b0::/282bb0:7bf:ffff:ffff:ffff:ffff:ffff:ffff
1252bb0:7c0::/282bb0:7cf:ffff:ffff:ffff:ffff:ffff:ffff
1262bb0:7d0::/282bb0:7df:ffff:ffff:ffff:ffff:ffff:ffff
1272bb0:7e0::/282bb0:7ef:ffff:ffff:ffff:ffff:ffff:ffff
1282bb0:7f0::/282bb0:7ff:ffff:ffff:ffff:ffff:ffff:ffff
1292bb0:800::/282bb0:80f:ffff:ffff:ffff:ffff:ffff:ffff
1302bb0:810::/282bb0:81f:ffff:ffff:ffff:ffff:ffff:ffff
1312bb0:820::/282bb0:82f:ffff:ffff:ffff:ffff:ffff:ffff
1322bb0:830::/282bb0:83f:ffff:ffff:ffff:ffff:ffff:ffff
1332bb0:840::/282bb0:84f:ffff:ffff:ffff:ffff:ffff:ffff
1342bb0:850::/282bb0:85f:ffff:ffff:ffff:ffff:ffff:ffff
1352bb0:860::/282bb0:86f:ffff:ffff:ffff:ffff:ffff:ffff
1362bb0:870::/282bb0:87f:ffff:ffff:ffff:ffff:ffff:ffff
1372bb0:880::/282bb0:88f:ffff:ffff:ffff:ffff:ffff:ffff
1382bb0:890::/282bb0:89f:ffff:ffff:ffff:ffff:ffff:ffff
1392bb0:8a0::/282bb0:8af:ffff:ffff:ffff:ffff:ffff:ffff
1402bb0:8b0::/282bb0:8bf:ffff:ffff:ffff:ffff:ffff:ffff
1412bb0:8c0::/282bb0:8cf:ffff:ffff:ffff:ffff:ffff:ffff
1422bb0:8d0::/282bb0:8df:ffff:ffff:ffff:ffff:ffff:ffff
1432bb0:8e0::/282bb0:8ef:ffff:ffff:ffff:ffff:ffff:ffff
1442bb0:8f0::/282bb0:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1452bb0:900::/282bb0:90f:ffff:ffff:ffff:ffff:ffff:ffff
1462bb0:910::/282bb0:91f:ffff:ffff:ffff:ffff:ffff:ffff
1472bb0:920::/282bb0:92f:ffff:ffff:ffff:ffff:ffff:ffff
1482bb0:930::/282bb0:93f:ffff:ffff:ffff:ffff:ffff:ffff
1492bb0:940::/282bb0:94f:ffff:ffff:ffff:ffff:ffff:ffff
1502bb0:950::/282bb0:95f:ffff:ffff:ffff:ffff:ffff:ffff
1512bb0:960::/282bb0:96f:ffff:ffff:ffff:ffff:ffff:ffff
1522bb0:970::/282bb0:97f:ffff:ffff:ffff:ffff:ffff:ffff
1532bb0:980::/282bb0:98f:ffff:ffff:ffff:ffff:ffff:ffff
1542bb0:990::/282bb0:99f:ffff:ffff:ffff:ffff:ffff:ffff
1552bb0:9a0::/282bb0:9af:ffff:ffff:ffff:ffff:ffff:ffff
1562bb0:9b0::/282bb0:9bf:ffff:ffff:ffff:ffff:ffff:ffff
1572bb0:9c0::/282bb0:9cf:ffff:ffff:ffff:ffff:ffff:ffff
1582bb0:9d0::/282bb0:9df:ffff:ffff:ffff:ffff:ffff:ffff
1592bb0:9e0::/282bb0:9ef:ffff:ffff:ffff:ffff:ffff:ffff
1602bb0:9f0::/282bb0:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1612bb0:a00::/282bb0:a0f:ffff:ffff:ffff:ffff:ffff:ffff
1622bb0:a10::/282bb0:a1f:ffff:ffff:ffff:ffff:ffff:ffff
1632bb0:a20::/282bb0:a2f:ffff:ffff:ffff:ffff:ffff:ffff
1642bb0:a30::/282bb0:a3f:ffff:ffff:ffff:ffff:ffff:ffff
1652bb0:a40::/282bb0:a4f:ffff:ffff:ffff:ffff:ffff:ffff
1662bb0:a50::/282bb0:a5f:ffff:ffff:ffff:ffff:ffff:ffff
1672bb0:a60::/282bb0:a6f:ffff:ffff:ffff:ffff:ffff:ffff
1682bb0:a70::/282bb0:a7f:ffff:ffff:ffff:ffff:ffff:ffff
1692bb0:a80::/282bb0:a8f:ffff:ffff:ffff:ffff:ffff:ffff
1702bb0:a90::/282bb0:a9f:ffff:ffff:ffff:ffff:ffff:ffff
1712bb0:aa0::/282bb0:aaf:ffff:ffff:ffff:ffff:ffff:ffff
1722bb0:ab0::/282bb0:abf:ffff:ffff:ffff:ffff:ffff:ffff
1732bb0:ac0::/282bb0:acf:ffff:ffff:ffff:ffff:ffff:ffff
1742bb0:ad0::/282bb0:adf:ffff:ffff:ffff:ffff:ffff:ffff
1752bb0:ae0::/282bb0:aef:ffff:ffff:ffff:ffff:ffff:ffff
1762bb0:af0::/282bb0:aff:ffff:ffff:ffff:ffff:ffff:ffff
1772bb0:b00::/282bb0:b0f:ffff:ffff:ffff:ffff:ffff:ffff
1782bb0:b10::/282bb0:b1f:ffff:ffff:ffff:ffff:ffff:ffff
1792bb0:b20::/282bb0:b2f:ffff:ffff:ffff:ffff:ffff:ffff
1802bb0:b30::/282bb0:b3f:ffff:ffff:ffff:ffff:ffff:ffff
1812bb0:b40::/282bb0:b4f:ffff:ffff:ffff:ffff:ffff:ffff
1822bb0:b50::/282bb0:b5f:ffff:ffff:ffff:ffff:ffff:ffff
1832bb0:b60::/282bb0:b6f:ffff:ffff:ffff:ffff:ffff:ffff
1842bb0:b70::/282bb0:b7f:ffff:ffff:ffff:ffff:ffff:ffff
1852bb0:b80::/282bb0:b8f:ffff:ffff:ffff:ffff:ffff:ffff
1862bb0:b90::/282bb0:b9f:ffff:ffff:ffff:ffff:ffff:ffff
1872bb0:ba0::/282bb0:baf:ffff:ffff:ffff:ffff:ffff:ffff
1882bb0:bb0::/282bb0:bbf:ffff:ffff:ffff:ffff:ffff:ffff
1892bb0:bc0::/282bb0:bcf:ffff:ffff:ffff:ffff:ffff:ffff
1902bb0:bd0::/282bb0:bdf:ffff:ffff:ffff:ffff:ffff:ffff
1912bb0:be0::/282bb0:bef:ffff:ffff:ffff:ffff:ffff:ffff
1922bb0:bf0::/282bb0:bff:ffff:ffff:ffff:ffff:ffff:ffff
1932bb0:c00::/282bb0:c0f:ffff:ffff:ffff:ffff:ffff:ffff
1942bb0:c10::/282bb0:c1f:ffff:ffff:ffff:ffff:ffff:ffff
1952bb0:c20::/282bb0:c2f:ffff:ffff:ffff:ffff:ffff:ffff
1962bb0:c30::/282bb0:c3f:ffff:ffff:ffff:ffff:ffff:ffff
1972bb0:c40::/282bb0:c4f:ffff:ffff:ffff:ffff:ffff:ffff
1982bb0:c50::/282bb0:c5f:ffff:ffff:ffff:ffff:ffff:ffff
1992bb0:c60::/282bb0:c6f:ffff:ffff:ffff:ffff:ffff:ffff
2002bb0:c70::/282bb0:c7f:ffff:ffff:ffff:ffff:ffff:ffff
2012bb0:c80::/282bb0:c8f:ffff:ffff:ffff:ffff:ffff:ffff
2022bb0:c90::/282bb0:c9f:ffff:ffff:ffff:ffff:ffff:ffff
2032bb0:ca0::/282bb0:caf:ffff:ffff:ffff:ffff:ffff:ffff
2042bb0:cb0::/282bb0:cbf:ffff:ffff:ffff:ffff:ffff:ffff
2052bb0:cc0::/282bb0:ccf:ffff:ffff:ffff:ffff:ffff:ffff
2062bb0:cd0::/282bb0:cdf:ffff:ffff:ffff:ffff:ffff:ffff
2072bb0:ce0::/282bb0:cef:ffff:ffff:ffff:ffff:ffff:ffff
2082bb0:cf0::/282bb0:cff:ffff:ffff:ffff:ffff:ffff:ffff
2092bb0:d00::/282bb0:d0f:ffff:ffff:ffff:ffff:ffff:ffff
2102bb0:d10::/282bb0:d1f:ffff:ffff:ffff:ffff:ffff:ffff
2112bb0:d20::/282bb0:d2f:ffff:ffff:ffff:ffff:ffff:ffff
2122bb0:d30::/282bb0:d3f:ffff:ffff:ffff:ffff:ffff:ffff
2132bb0:d40::/282bb0:d4f:ffff:ffff:ffff:ffff:ffff:ffff
2142bb0:d50::/282bb0:d5f:ffff:ffff:ffff:ffff:ffff:ffff
2152bb0:d60::/282bb0:d6f:ffff:ffff:ffff:ffff:ffff:ffff
2162bb0:d70::/282bb0:d7f:ffff:ffff:ffff:ffff:ffff:ffff
2172bb0:d80::/282bb0:d8f:ffff:ffff:ffff:ffff:ffff:ffff
2182bb0:d90::/282bb0:d9f:ffff:ffff:ffff:ffff:ffff:ffff
2192bb0:da0::/282bb0:daf:ffff:ffff:ffff:ffff:ffff:ffff
2202bb0:db0::/282bb0:dbf:ffff:ffff:ffff:ffff:ffff:ffff
2212bb0:dc0::/282bb0:dcf:ffff:ffff:ffff:ffff:ffff:ffff
2222bb0:dd0::/282bb0:ddf:ffff:ffff:ffff:ffff:ffff:ffff
2232bb0:de0::/282bb0:def:ffff:ffff:ffff:ffff:ffff:ffff
2242bb0:df0::/282bb0:dff:ffff:ffff:ffff:ffff:ffff:ffff
2252bb0:e00::/282bb0:e0f:ffff:ffff:ffff:ffff:ffff:ffff
2262bb0:e10::/282bb0:e1f:ffff:ffff:ffff:ffff:ffff:ffff
2272bb0:e20::/282bb0:e2f:ffff:ffff:ffff:ffff:ffff:ffff
2282bb0:e30::/282bb0:e3f:ffff:ffff:ffff:ffff:ffff:ffff
2292bb0:e40::/282bb0:e4f:ffff:ffff:ffff:ffff:ffff:ffff
2302bb0:e50::/282bb0:e5f:ffff:ffff:ffff:ffff:ffff:ffff
2312bb0:e60::/282bb0:e6f:ffff:ffff:ffff:ffff:ffff:ffff
2322bb0:e70::/282bb0:e7f:ffff:ffff:ffff:ffff:ffff:ffff
2332bb0:e80::/282bb0:e8f:ffff:ffff:ffff:ffff:ffff:ffff
2342bb0:e90::/282bb0:e9f:ffff:ffff:ffff:ffff:ffff:ffff
2352bb0:ea0::/282bb0:eaf:ffff:ffff:ffff:ffff:ffff:ffff
2362bb0:eb0::/282bb0:ebf:ffff:ffff:ffff:ffff:ffff:ffff
2372bb0:ec0::/282bb0:ecf:ffff:ffff:ffff:ffff:ffff:ffff
2382bb0:ed0::/282bb0:edf:ffff:ffff:ffff:ffff:ffff:ffff
2392bb0:ee0::/282bb0:eef:ffff:ffff:ffff:ffff:ffff:ffff
2402bb0:ef0::/282bb0:eff:ffff:ffff:ffff:ffff:ffff:ffff
2412bb0:f00::/282bb0:f0f:ffff:ffff:ffff:ffff:ffff:ffff
2422bb0:f10::/282bb0:f1f:ffff:ffff:ffff:ffff:ffff:ffff
2432bb0:f20::/282bb0:f2f:ffff:ffff:ffff:ffff:ffff:ffff
2442bb0:f30::/282bb0:f3f:ffff:ffff:ffff:ffff:ffff:ffff
2452bb0:f40::/282bb0:f4f:ffff:ffff:ffff:ffff:ffff:ffff
2462bb0:f50::/282bb0:f5f:ffff:ffff:ffff:ffff:ffff:ffff
2472bb0:f60::/282bb0:f6f:ffff:ffff:ffff:ffff:ffff:ffff
2482bb0:f70::/282bb0:f7f:ffff:ffff:ffff:ffff:ffff:ffff
2492bb0:f80::/282bb0:f8f:ffff:ffff:ffff:ffff:ffff:ffff
2502bb0:f90::/282bb0:f9f:ffff:ffff:ffff:ffff:ffff:ffff
2512bb0:fa0::/282bb0:faf:ffff:ffff:ffff:ffff:ffff:ffff
2522bb0:fb0::/282bb0:fbf:ffff:ffff:ffff:ffff:ffff:ffff
2532bb0:fc0::/282bb0:fcf:ffff:ffff:ffff:ffff:ffff:ffff
2542bb0:fd0::/282bb0:fdf:ffff:ffff:ffff:ffff:ffff:ffff
2552bb0:fe0::/282bb0:fef:ffff:ffff:ffff:ffff:ffff:ffff
2562bb0:ff0::/282bb0:fff:ffff:ffff:ffff:ffff:ffff:ffff

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.