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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/16
Addresses2^112
/64 networks2^48
Network
2ea3::/16
First address
2ea3::
Last address
2ea3:ffff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
5,192,296,858,534,827,628,530,496,329,220,096 (2^112)
/64 networks (LANs)
281,474,976,710,656 (2^48)
Full form
2ea3:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
3.a.e.2.ip6.arpa
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

2ea3::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
12ea3::/282ea3:f:ffff:ffff:ffff:ffff:ffff:ffff
22ea3:10::/282ea3:1f:ffff:ffff:ffff:ffff:ffff:ffff
32ea3:20::/282ea3:2f:ffff:ffff:ffff:ffff:ffff:ffff
42ea3:30::/282ea3:3f:ffff:ffff:ffff:ffff:ffff:ffff
52ea3:40::/282ea3:4f:ffff:ffff:ffff:ffff:ffff:ffff
62ea3:50::/282ea3:5f:ffff:ffff:ffff:ffff:ffff:ffff
72ea3:60::/282ea3:6f:ffff:ffff:ffff:ffff:ffff:ffff
82ea3:70::/282ea3:7f:ffff:ffff:ffff:ffff:ffff:ffff
92ea3:80::/282ea3:8f:ffff:ffff:ffff:ffff:ffff:ffff
102ea3:90::/282ea3:9f:ffff:ffff:ffff:ffff:ffff:ffff
112ea3:a0::/282ea3:af:ffff:ffff:ffff:ffff:ffff:ffff
122ea3:b0::/282ea3:bf:ffff:ffff:ffff:ffff:ffff:ffff
132ea3:c0::/282ea3:cf:ffff:ffff:ffff:ffff:ffff:ffff
142ea3:d0::/282ea3:df:ffff:ffff:ffff:ffff:ffff:ffff
152ea3:e0::/282ea3:ef:ffff:ffff:ffff:ffff:ffff:ffff
162ea3:f0::/282ea3:ff:ffff:ffff:ffff:ffff:ffff:ffff
172ea3:100::/282ea3:10f:ffff:ffff:ffff:ffff:ffff:ffff
182ea3:110::/282ea3:11f:ffff:ffff:ffff:ffff:ffff:ffff
192ea3:120::/282ea3:12f:ffff:ffff:ffff:ffff:ffff:ffff
202ea3:130::/282ea3:13f:ffff:ffff:ffff:ffff:ffff:ffff
212ea3:140::/282ea3:14f:ffff:ffff:ffff:ffff:ffff:ffff
222ea3:150::/282ea3:15f:ffff:ffff:ffff:ffff:ffff:ffff
232ea3:160::/282ea3:16f:ffff:ffff:ffff:ffff:ffff:ffff
242ea3:170::/282ea3:17f:ffff:ffff:ffff:ffff:ffff:ffff
252ea3:180::/282ea3:18f:ffff:ffff:ffff:ffff:ffff:ffff
262ea3:190::/282ea3:19f:ffff:ffff:ffff:ffff:ffff:ffff
272ea3:1a0::/282ea3:1af:ffff:ffff:ffff:ffff:ffff:ffff
282ea3:1b0::/282ea3:1bf:ffff:ffff:ffff:ffff:ffff:ffff
292ea3:1c0::/282ea3:1cf:ffff:ffff:ffff:ffff:ffff:ffff
302ea3:1d0::/282ea3:1df:ffff:ffff:ffff:ffff:ffff:ffff
312ea3:1e0::/282ea3:1ef:ffff:ffff:ffff:ffff:ffff:ffff
322ea3:1f0::/282ea3:1ff:ffff:ffff:ffff:ffff:ffff:ffff
332ea3:200::/282ea3:20f:ffff:ffff:ffff:ffff:ffff:ffff
342ea3:210::/282ea3:21f:ffff:ffff:ffff:ffff:ffff:ffff
352ea3:220::/282ea3:22f:ffff:ffff:ffff:ffff:ffff:ffff
362ea3:230::/282ea3:23f:ffff:ffff:ffff:ffff:ffff:ffff
372ea3:240::/282ea3:24f:ffff:ffff:ffff:ffff:ffff:ffff
382ea3:250::/282ea3:25f:ffff:ffff:ffff:ffff:ffff:ffff
392ea3:260::/282ea3:26f:ffff:ffff:ffff:ffff:ffff:ffff
402ea3:270::/282ea3:27f:ffff:ffff:ffff:ffff:ffff:ffff
412ea3:280::/282ea3:28f:ffff:ffff:ffff:ffff:ffff:ffff
422ea3:290::/282ea3:29f:ffff:ffff:ffff:ffff:ffff:ffff
432ea3:2a0::/282ea3:2af:ffff:ffff:ffff:ffff:ffff:ffff
442ea3:2b0::/282ea3:2bf:ffff:ffff:ffff:ffff:ffff:ffff
452ea3:2c0::/282ea3:2cf:ffff:ffff:ffff:ffff:ffff:ffff
462ea3:2d0::/282ea3:2df:ffff:ffff:ffff:ffff:ffff:ffff
472ea3:2e0::/282ea3:2ef:ffff:ffff:ffff:ffff:ffff:ffff
482ea3:2f0::/282ea3:2ff:ffff:ffff:ffff:ffff:ffff:ffff
492ea3:300::/282ea3:30f:ffff:ffff:ffff:ffff:ffff:ffff
502ea3:310::/282ea3:31f:ffff:ffff:ffff:ffff:ffff:ffff
512ea3:320::/282ea3:32f:ffff:ffff:ffff:ffff:ffff:ffff
522ea3:330::/282ea3:33f:ffff:ffff:ffff:ffff:ffff:ffff
532ea3:340::/282ea3:34f:ffff:ffff:ffff:ffff:ffff:ffff
542ea3:350::/282ea3:35f:ffff:ffff:ffff:ffff:ffff:ffff
552ea3:360::/282ea3:36f:ffff:ffff:ffff:ffff:ffff:ffff
562ea3:370::/282ea3:37f:ffff:ffff:ffff:ffff:ffff:ffff
572ea3:380::/282ea3:38f:ffff:ffff:ffff:ffff:ffff:ffff
582ea3:390::/282ea3:39f:ffff:ffff:ffff:ffff:ffff:ffff
592ea3:3a0::/282ea3:3af:ffff:ffff:ffff:ffff:ffff:ffff
602ea3:3b0::/282ea3:3bf:ffff:ffff:ffff:ffff:ffff:ffff
612ea3:3c0::/282ea3:3cf:ffff:ffff:ffff:ffff:ffff:ffff
622ea3:3d0::/282ea3:3df:ffff:ffff:ffff:ffff:ffff:ffff
632ea3:3e0::/282ea3:3ef:ffff:ffff:ffff:ffff:ffff:ffff
642ea3:3f0::/282ea3:3ff:ffff:ffff:ffff:ffff:ffff:ffff
652ea3:400::/282ea3:40f:ffff:ffff:ffff:ffff:ffff:ffff
662ea3:410::/282ea3:41f:ffff:ffff:ffff:ffff:ffff:ffff
672ea3:420::/282ea3:42f:ffff:ffff:ffff:ffff:ffff:ffff
682ea3:430::/282ea3:43f:ffff:ffff:ffff:ffff:ffff:ffff
692ea3:440::/282ea3:44f:ffff:ffff:ffff:ffff:ffff:ffff
702ea3:450::/282ea3:45f:ffff:ffff:ffff:ffff:ffff:ffff
712ea3:460::/282ea3:46f:ffff:ffff:ffff:ffff:ffff:ffff
722ea3:470::/282ea3:47f:ffff:ffff:ffff:ffff:ffff:ffff
732ea3:480::/282ea3:48f:ffff:ffff:ffff:ffff:ffff:ffff
742ea3:490::/282ea3:49f:ffff:ffff:ffff:ffff:ffff:ffff
752ea3:4a0::/282ea3:4af:ffff:ffff:ffff:ffff:ffff:ffff
762ea3:4b0::/282ea3:4bf:ffff:ffff:ffff:ffff:ffff:ffff
772ea3:4c0::/282ea3:4cf:ffff:ffff:ffff:ffff:ffff:ffff
782ea3:4d0::/282ea3:4df:ffff:ffff:ffff:ffff:ffff:ffff
792ea3:4e0::/282ea3:4ef:ffff:ffff:ffff:ffff:ffff:ffff
802ea3:4f0::/282ea3:4ff:ffff:ffff:ffff:ffff:ffff:ffff
812ea3:500::/282ea3:50f:ffff:ffff:ffff:ffff:ffff:ffff
822ea3:510::/282ea3:51f:ffff:ffff:ffff:ffff:ffff:ffff
832ea3:520::/282ea3:52f:ffff:ffff:ffff:ffff:ffff:ffff
842ea3:530::/282ea3:53f:ffff:ffff:ffff:ffff:ffff:ffff
852ea3:540::/282ea3:54f:ffff:ffff:ffff:ffff:ffff:ffff
862ea3:550::/282ea3:55f:ffff:ffff:ffff:ffff:ffff:ffff
872ea3:560::/282ea3:56f:ffff:ffff:ffff:ffff:ffff:ffff
882ea3:570::/282ea3:57f:ffff:ffff:ffff:ffff:ffff:ffff
892ea3:580::/282ea3:58f:ffff:ffff:ffff:ffff:ffff:ffff
902ea3:590::/282ea3:59f:ffff:ffff:ffff:ffff:ffff:ffff
912ea3:5a0::/282ea3:5af:ffff:ffff:ffff:ffff:ffff:ffff
922ea3:5b0::/282ea3:5bf:ffff:ffff:ffff:ffff:ffff:ffff
932ea3:5c0::/282ea3:5cf:ffff:ffff:ffff:ffff:ffff:ffff
942ea3:5d0::/282ea3:5df:ffff:ffff:ffff:ffff:ffff:ffff
952ea3:5e0::/282ea3:5ef:ffff:ffff:ffff:ffff:ffff:ffff
962ea3:5f0::/282ea3:5ff:ffff:ffff:ffff:ffff:ffff:ffff
972ea3:600::/282ea3:60f:ffff:ffff:ffff:ffff:ffff:ffff
982ea3:610::/282ea3:61f:ffff:ffff:ffff:ffff:ffff:ffff
992ea3:620::/282ea3:62f:ffff:ffff:ffff:ffff:ffff:ffff
1002ea3:630::/282ea3:63f:ffff:ffff:ffff:ffff:ffff:ffff
1012ea3:640::/282ea3:64f:ffff:ffff:ffff:ffff:ffff:ffff
1022ea3:650::/282ea3:65f:ffff:ffff:ffff:ffff:ffff:ffff
1032ea3:660::/282ea3:66f:ffff:ffff:ffff:ffff:ffff:ffff
1042ea3:670::/282ea3:67f:ffff:ffff:ffff:ffff:ffff:ffff
1052ea3:680::/282ea3:68f:ffff:ffff:ffff:ffff:ffff:ffff
1062ea3:690::/282ea3:69f:ffff:ffff:ffff:ffff:ffff:ffff
1072ea3:6a0::/282ea3:6af:ffff:ffff:ffff:ffff:ffff:ffff
1082ea3:6b0::/282ea3:6bf:ffff:ffff:ffff:ffff:ffff:ffff
1092ea3:6c0::/282ea3:6cf:ffff:ffff:ffff:ffff:ffff:ffff
1102ea3:6d0::/282ea3:6df:ffff:ffff:ffff:ffff:ffff:ffff
1112ea3:6e0::/282ea3:6ef:ffff:ffff:ffff:ffff:ffff:ffff
1122ea3:6f0::/282ea3:6ff:ffff:ffff:ffff:ffff:ffff:ffff
1132ea3:700::/282ea3:70f:ffff:ffff:ffff:ffff:ffff:ffff
1142ea3:710::/282ea3:71f:ffff:ffff:ffff:ffff:ffff:ffff
1152ea3:720::/282ea3:72f:ffff:ffff:ffff:ffff:ffff:ffff
1162ea3:730::/282ea3:73f:ffff:ffff:ffff:ffff:ffff:ffff
1172ea3:740::/282ea3:74f:ffff:ffff:ffff:ffff:ffff:ffff
1182ea3:750::/282ea3:75f:ffff:ffff:ffff:ffff:ffff:ffff
1192ea3:760::/282ea3:76f:ffff:ffff:ffff:ffff:ffff:ffff
1202ea3:770::/282ea3:77f:ffff:ffff:ffff:ffff:ffff:ffff
1212ea3:780::/282ea3:78f:ffff:ffff:ffff:ffff:ffff:ffff
1222ea3:790::/282ea3:79f:ffff:ffff:ffff:ffff:ffff:ffff
1232ea3:7a0::/282ea3:7af:ffff:ffff:ffff:ffff:ffff:ffff
1242ea3:7b0::/282ea3:7bf:ffff:ffff:ffff:ffff:ffff:ffff
1252ea3:7c0::/282ea3:7cf:ffff:ffff:ffff:ffff:ffff:ffff
1262ea3:7d0::/282ea3:7df:ffff:ffff:ffff:ffff:ffff:ffff
1272ea3:7e0::/282ea3:7ef:ffff:ffff:ffff:ffff:ffff:ffff
1282ea3:7f0::/282ea3:7ff:ffff:ffff:ffff:ffff:ffff:ffff
1292ea3:800::/282ea3:80f:ffff:ffff:ffff:ffff:ffff:ffff
1302ea3:810::/282ea3:81f:ffff:ffff:ffff:ffff:ffff:ffff
1312ea3:820::/282ea3:82f:ffff:ffff:ffff:ffff:ffff:ffff
1322ea3:830::/282ea3:83f:ffff:ffff:ffff:ffff:ffff:ffff
1332ea3:840::/282ea3:84f:ffff:ffff:ffff:ffff:ffff:ffff
1342ea3:850::/282ea3:85f:ffff:ffff:ffff:ffff:ffff:ffff
1352ea3:860::/282ea3:86f:ffff:ffff:ffff:ffff:ffff:ffff
1362ea3:870::/282ea3:87f:ffff:ffff:ffff:ffff:ffff:ffff
1372ea3:880::/282ea3:88f:ffff:ffff:ffff:ffff:ffff:ffff
1382ea3:890::/282ea3:89f:ffff:ffff:ffff:ffff:ffff:ffff
1392ea3:8a0::/282ea3:8af:ffff:ffff:ffff:ffff:ffff:ffff
1402ea3:8b0::/282ea3:8bf:ffff:ffff:ffff:ffff:ffff:ffff
1412ea3:8c0::/282ea3:8cf:ffff:ffff:ffff:ffff:ffff:ffff
1422ea3:8d0::/282ea3:8df:ffff:ffff:ffff:ffff:ffff:ffff
1432ea3:8e0::/282ea3:8ef:ffff:ffff:ffff:ffff:ffff:ffff
1442ea3:8f0::/282ea3:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1452ea3:900::/282ea3:90f:ffff:ffff:ffff:ffff:ffff:ffff
1462ea3:910::/282ea3:91f:ffff:ffff:ffff:ffff:ffff:ffff
1472ea3:920::/282ea3:92f:ffff:ffff:ffff:ffff:ffff:ffff
1482ea3:930::/282ea3:93f:ffff:ffff:ffff:ffff:ffff:ffff
1492ea3:940::/282ea3:94f:ffff:ffff:ffff:ffff:ffff:ffff
1502ea3:950::/282ea3:95f:ffff:ffff:ffff:ffff:ffff:ffff
1512ea3:960::/282ea3:96f:ffff:ffff:ffff:ffff:ffff:ffff
1522ea3:970::/282ea3:97f:ffff:ffff:ffff:ffff:ffff:ffff
1532ea3:980::/282ea3:98f:ffff:ffff:ffff:ffff:ffff:ffff
1542ea3:990::/282ea3:99f:ffff:ffff:ffff:ffff:ffff:ffff
1552ea3:9a0::/282ea3:9af:ffff:ffff:ffff:ffff:ffff:ffff
1562ea3:9b0::/282ea3:9bf:ffff:ffff:ffff:ffff:ffff:ffff
1572ea3:9c0::/282ea3:9cf:ffff:ffff:ffff:ffff:ffff:ffff
1582ea3:9d0::/282ea3:9df:ffff:ffff:ffff:ffff:ffff:ffff
1592ea3:9e0::/282ea3:9ef:ffff:ffff:ffff:ffff:ffff:ffff
1602ea3:9f0::/282ea3:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1612ea3:a00::/282ea3:a0f:ffff:ffff:ffff:ffff:ffff:ffff
1622ea3:a10::/282ea3:a1f:ffff:ffff:ffff:ffff:ffff:ffff
1632ea3:a20::/282ea3:a2f:ffff:ffff:ffff:ffff:ffff:ffff
1642ea3:a30::/282ea3:a3f:ffff:ffff:ffff:ffff:ffff:ffff
1652ea3:a40::/282ea3:a4f:ffff:ffff:ffff:ffff:ffff:ffff
1662ea3:a50::/282ea3:a5f:ffff:ffff:ffff:ffff:ffff:ffff
1672ea3:a60::/282ea3:a6f:ffff:ffff:ffff:ffff:ffff:ffff
1682ea3:a70::/282ea3:a7f:ffff:ffff:ffff:ffff:ffff:ffff
1692ea3:a80::/282ea3:a8f:ffff:ffff:ffff:ffff:ffff:ffff
1702ea3:a90::/282ea3:a9f:ffff:ffff:ffff:ffff:ffff:ffff
1712ea3:aa0::/282ea3:aaf:ffff:ffff:ffff:ffff:ffff:ffff
1722ea3:ab0::/282ea3:abf:ffff:ffff:ffff:ffff:ffff:ffff
1732ea3:ac0::/282ea3:acf:ffff:ffff:ffff:ffff:ffff:ffff
1742ea3:ad0::/282ea3:adf:ffff:ffff:ffff:ffff:ffff:ffff
1752ea3:ae0::/282ea3:aef:ffff:ffff:ffff:ffff:ffff:ffff
1762ea3:af0::/282ea3:aff:ffff:ffff:ffff:ffff:ffff:ffff
1772ea3:b00::/282ea3:b0f:ffff:ffff:ffff:ffff:ffff:ffff
1782ea3:b10::/282ea3:b1f:ffff:ffff:ffff:ffff:ffff:ffff
1792ea3:b20::/282ea3:b2f:ffff:ffff:ffff:ffff:ffff:ffff
1802ea3:b30::/282ea3:b3f:ffff:ffff:ffff:ffff:ffff:ffff
1812ea3:b40::/282ea3:b4f:ffff:ffff:ffff:ffff:ffff:ffff
1822ea3:b50::/282ea3:b5f:ffff:ffff:ffff:ffff:ffff:ffff
1832ea3:b60::/282ea3:b6f:ffff:ffff:ffff:ffff:ffff:ffff
1842ea3:b70::/282ea3:b7f:ffff:ffff:ffff:ffff:ffff:ffff
1852ea3:b80::/282ea3:b8f:ffff:ffff:ffff:ffff:ffff:ffff
1862ea3:b90::/282ea3:b9f:ffff:ffff:ffff:ffff:ffff:ffff
1872ea3:ba0::/282ea3:baf:ffff:ffff:ffff:ffff:ffff:ffff
1882ea3:bb0::/282ea3:bbf:ffff:ffff:ffff:ffff:ffff:ffff
1892ea3:bc0::/282ea3:bcf:ffff:ffff:ffff:ffff:ffff:ffff
1902ea3:bd0::/282ea3:bdf:ffff:ffff:ffff:ffff:ffff:ffff
1912ea3:be0::/282ea3:bef:ffff:ffff:ffff:ffff:ffff:ffff
1922ea3:bf0::/282ea3:bff:ffff:ffff:ffff:ffff:ffff:ffff
1932ea3:c00::/282ea3:c0f:ffff:ffff:ffff:ffff:ffff:ffff
1942ea3:c10::/282ea3:c1f:ffff:ffff:ffff:ffff:ffff:ffff
1952ea3:c20::/282ea3:c2f:ffff:ffff:ffff:ffff:ffff:ffff
1962ea3:c30::/282ea3:c3f:ffff:ffff:ffff:ffff:ffff:ffff
1972ea3:c40::/282ea3:c4f:ffff:ffff:ffff:ffff:ffff:ffff
1982ea3:c50::/282ea3:c5f:ffff:ffff:ffff:ffff:ffff:ffff
1992ea3:c60::/282ea3:c6f:ffff:ffff:ffff:ffff:ffff:ffff
2002ea3:c70::/282ea3:c7f:ffff:ffff:ffff:ffff:ffff:ffff
2012ea3:c80::/282ea3:c8f:ffff:ffff:ffff:ffff:ffff:ffff
2022ea3:c90::/282ea3:c9f:ffff:ffff:ffff:ffff:ffff:ffff
2032ea3:ca0::/282ea3:caf:ffff:ffff:ffff:ffff:ffff:ffff
2042ea3:cb0::/282ea3:cbf:ffff:ffff:ffff:ffff:ffff:ffff
2052ea3:cc0::/282ea3:ccf:ffff:ffff:ffff:ffff:ffff:ffff
2062ea3:cd0::/282ea3:cdf:ffff:ffff:ffff:ffff:ffff:ffff
2072ea3:ce0::/282ea3:cef:ffff:ffff:ffff:ffff:ffff:ffff
2082ea3:cf0::/282ea3:cff:ffff:ffff:ffff:ffff:ffff:ffff
2092ea3:d00::/282ea3:d0f:ffff:ffff:ffff:ffff:ffff:ffff
2102ea3:d10::/282ea3:d1f:ffff:ffff:ffff:ffff:ffff:ffff
2112ea3:d20::/282ea3:d2f:ffff:ffff:ffff:ffff:ffff:ffff
2122ea3:d30::/282ea3:d3f:ffff:ffff:ffff:ffff:ffff:ffff
2132ea3:d40::/282ea3:d4f:ffff:ffff:ffff:ffff:ffff:ffff
2142ea3:d50::/282ea3:d5f:ffff:ffff:ffff:ffff:ffff:ffff
2152ea3:d60::/282ea3:d6f:ffff:ffff:ffff:ffff:ffff:ffff
2162ea3:d70::/282ea3:d7f:ffff:ffff:ffff:ffff:ffff:ffff
2172ea3:d80::/282ea3:d8f:ffff:ffff:ffff:ffff:ffff:ffff
2182ea3:d90::/282ea3:d9f:ffff:ffff:ffff:ffff:ffff:ffff
2192ea3:da0::/282ea3:daf:ffff:ffff:ffff:ffff:ffff:ffff
2202ea3:db0::/282ea3:dbf:ffff:ffff:ffff:ffff:ffff:ffff
2212ea3:dc0::/282ea3:dcf:ffff:ffff:ffff:ffff:ffff:ffff
2222ea3:dd0::/282ea3:ddf:ffff:ffff:ffff:ffff:ffff:ffff
2232ea3:de0::/282ea3:def:ffff:ffff:ffff:ffff:ffff:ffff
2242ea3:df0::/282ea3:dff:ffff:ffff:ffff:ffff:ffff:ffff
2252ea3:e00::/282ea3:e0f:ffff:ffff:ffff:ffff:ffff:ffff
2262ea3:e10::/282ea3:e1f:ffff:ffff:ffff:ffff:ffff:ffff
2272ea3:e20::/282ea3:e2f:ffff:ffff:ffff:ffff:ffff:ffff
2282ea3:e30::/282ea3:e3f:ffff:ffff:ffff:ffff:ffff:ffff
2292ea3:e40::/282ea3:e4f:ffff:ffff:ffff:ffff:ffff:ffff
2302ea3:e50::/282ea3:e5f:ffff:ffff:ffff:ffff:ffff:ffff
2312ea3:e60::/282ea3:e6f:ffff:ffff:ffff:ffff:ffff:ffff
2322ea3:e70::/282ea3:e7f:ffff:ffff:ffff:ffff:ffff:ffff
2332ea3:e80::/282ea3:e8f:ffff:ffff:ffff:ffff:ffff:ffff
2342ea3:e90::/282ea3:e9f:ffff:ffff:ffff:ffff:ffff:ffff
2352ea3:ea0::/282ea3:eaf:ffff:ffff:ffff:ffff:ffff:ffff
2362ea3:eb0::/282ea3:ebf:ffff:ffff:ffff:ffff:ffff:ffff
2372ea3:ec0::/282ea3:ecf:ffff:ffff:ffff:ffff:ffff:ffff
2382ea3:ed0::/282ea3:edf:ffff:ffff:ffff:ffff:ffff:ffff
2392ea3:ee0::/282ea3:eef:ffff:ffff:ffff:ffff:ffff:ffff
2402ea3:ef0::/282ea3:eff:ffff:ffff:ffff:ffff:ffff:ffff
2412ea3:f00::/282ea3:f0f:ffff:ffff:ffff:ffff:ffff:ffff
2422ea3:f10::/282ea3:f1f:ffff:ffff:ffff:ffff:ffff:ffff
2432ea3:f20::/282ea3:f2f:ffff:ffff:ffff:ffff:ffff:ffff
2442ea3:f30::/282ea3:f3f:ffff:ffff:ffff:ffff:ffff:ffff
2452ea3:f40::/282ea3:f4f:ffff:ffff:ffff:ffff:ffff:ffff
2462ea3:f50::/282ea3:f5f:ffff:ffff:ffff:ffff:ffff:ffff
2472ea3:f60::/282ea3:f6f:ffff:ffff:ffff:ffff:ffff:ffff
2482ea3:f70::/282ea3:f7f:ffff:ffff:ffff:ffff:ffff:ffff
2492ea3:f80::/282ea3:f8f:ffff:ffff:ffff:ffff:ffff:ffff
2502ea3:f90::/282ea3:f9f:ffff:ffff:ffff:ffff:ffff:ffff
2512ea3:fa0::/282ea3:faf:ffff:ffff:ffff:ffff:ffff:ffff
2522ea3:fb0::/282ea3:fbf:ffff:ffff:ffff:ffff:ffff:ffff
2532ea3:fc0::/282ea3:fcf:ffff:ffff:ffff:ffff:ffff:ffff
2542ea3:fd0::/282ea3:fdf:ffff:ffff:ffff:ffff:ffff:ffff
2552ea3:fe0::/282ea3:fef:ffff:ffff:ffff:ffff:ffff:ffff
2562ea3:ff0::/282ea3: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.