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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
2cd4::/16
First address
2cd4::
Last address
2cd4: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
2cd4:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
4.d.c.2.ip6.arpa
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

2cd4::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
12cd4::/242cd4:ff:ffff:ffff:ffff:ffff:ffff:ffff
22cd4:100::/242cd4:1ff:ffff:ffff:ffff:ffff:ffff:ffff
32cd4:200::/242cd4:2ff:ffff:ffff:ffff:ffff:ffff:ffff
42cd4:300::/242cd4:3ff:ffff:ffff:ffff:ffff:ffff:ffff
52cd4:400::/242cd4:4ff:ffff:ffff:ffff:ffff:ffff:ffff
62cd4:500::/242cd4:5ff:ffff:ffff:ffff:ffff:ffff:ffff
72cd4:600::/242cd4:6ff:ffff:ffff:ffff:ffff:ffff:ffff
82cd4:700::/242cd4:7ff:ffff:ffff:ffff:ffff:ffff:ffff
92cd4:800::/242cd4:8ff:ffff:ffff:ffff:ffff:ffff:ffff
102cd4:900::/242cd4:9ff:ffff:ffff:ffff:ffff:ffff:ffff
112cd4:a00::/242cd4:aff:ffff:ffff:ffff:ffff:ffff:ffff
122cd4:b00::/242cd4:bff:ffff:ffff:ffff:ffff:ffff:ffff
132cd4:c00::/242cd4:cff:ffff:ffff:ffff:ffff:ffff:ffff
142cd4:d00::/242cd4:dff:ffff:ffff:ffff:ffff:ffff:ffff
152cd4:e00::/242cd4:eff:ffff:ffff:ffff:ffff:ffff:ffff
162cd4:f00::/242cd4:fff:ffff:ffff:ffff:ffff:ffff:ffff
172cd4:1000::/242cd4:10ff:ffff:ffff:ffff:ffff:ffff:ffff
182cd4:1100::/242cd4:11ff:ffff:ffff:ffff:ffff:ffff:ffff
192cd4:1200::/242cd4:12ff:ffff:ffff:ffff:ffff:ffff:ffff
202cd4:1300::/242cd4:13ff:ffff:ffff:ffff:ffff:ffff:ffff
212cd4:1400::/242cd4:14ff:ffff:ffff:ffff:ffff:ffff:ffff
222cd4:1500::/242cd4:15ff:ffff:ffff:ffff:ffff:ffff:ffff
232cd4:1600::/242cd4:16ff:ffff:ffff:ffff:ffff:ffff:ffff
242cd4:1700::/242cd4:17ff:ffff:ffff:ffff:ffff:ffff:ffff
252cd4:1800::/242cd4:18ff:ffff:ffff:ffff:ffff:ffff:ffff
262cd4:1900::/242cd4:19ff:ffff:ffff:ffff:ffff:ffff:ffff
272cd4:1a00::/242cd4:1aff:ffff:ffff:ffff:ffff:ffff:ffff
282cd4:1b00::/242cd4:1bff:ffff:ffff:ffff:ffff:ffff:ffff
292cd4:1c00::/242cd4:1cff:ffff:ffff:ffff:ffff:ffff:ffff
302cd4:1d00::/242cd4:1dff:ffff:ffff:ffff:ffff:ffff:ffff
312cd4:1e00::/242cd4:1eff:ffff:ffff:ffff:ffff:ffff:ffff
322cd4:1f00::/242cd4:1fff:ffff:ffff:ffff:ffff:ffff:ffff
332cd4:2000::/242cd4:20ff:ffff:ffff:ffff:ffff:ffff:ffff
342cd4:2100::/242cd4:21ff:ffff:ffff:ffff:ffff:ffff:ffff
352cd4:2200::/242cd4:22ff:ffff:ffff:ffff:ffff:ffff:ffff
362cd4:2300::/242cd4:23ff:ffff:ffff:ffff:ffff:ffff:ffff
372cd4:2400::/242cd4:24ff:ffff:ffff:ffff:ffff:ffff:ffff
382cd4:2500::/242cd4:25ff:ffff:ffff:ffff:ffff:ffff:ffff
392cd4:2600::/242cd4:26ff:ffff:ffff:ffff:ffff:ffff:ffff
402cd4:2700::/242cd4:27ff:ffff:ffff:ffff:ffff:ffff:ffff
412cd4:2800::/242cd4:28ff:ffff:ffff:ffff:ffff:ffff:ffff
422cd4:2900::/242cd4:29ff:ffff:ffff:ffff:ffff:ffff:ffff
432cd4:2a00::/242cd4:2aff:ffff:ffff:ffff:ffff:ffff:ffff
442cd4:2b00::/242cd4:2bff:ffff:ffff:ffff:ffff:ffff:ffff
452cd4:2c00::/242cd4:2cff:ffff:ffff:ffff:ffff:ffff:ffff
462cd4:2d00::/242cd4:2dff:ffff:ffff:ffff:ffff:ffff:ffff
472cd4:2e00::/242cd4:2eff:ffff:ffff:ffff:ffff:ffff:ffff
482cd4:2f00::/242cd4:2fff:ffff:ffff:ffff:ffff:ffff:ffff
492cd4:3000::/242cd4:30ff:ffff:ffff:ffff:ffff:ffff:ffff
502cd4:3100::/242cd4:31ff:ffff:ffff:ffff:ffff:ffff:ffff
512cd4:3200::/242cd4:32ff:ffff:ffff:ffff:ffff:ffff:ffff
522cd4:3300::/242cd4:33ff:ffff:ffff:ffff:ffff:ffff:ffff
532cd4:3400::/242cd4:34ff:ffff:ffff:ffff:ffff:ffff:ffff
542cd4:3500::/242cd4:35ff:ffff:ffff:ffff:ffff:ffff:ffff
552cd4:3600::/242cd4:36ff:ffff:ffff:ffff:ffff:ffff:ffff
562cd4:3700::/242cd4:37ff:ffff:ffff:ffff:ffff:ffff:ffff
572cd4:3800::/242cd4:38ff:ffff:ffff:ffff:ffff:ffff:ffff
582cd4:3900::/242cd4:39ff:ffff:ffff:ffff:ffff:ffff:ffff
592cd4:3a00::/242cd4:3aff:ffff:ffff:ffff:ffff:ffff:ffff
602cd4:3b00::/242cd4:3bff:ffff:ffff:ffff:ffff:ffff:ffff
612cd4:3c00::/242cd4:3cff:ffff:ffff:ffff:ffff:ffff:ffff
622cd4:3d00::/242cd4:3dff:ffff:ffff:ffff:ffff:ffff:ffff
632cd4:3e00::/242cd4:3eff:ffff:ffff:ffff:ffff:ffff:ffff
642cd4:3f00::/242cd4:3fff:ffff:ffff:ffff:ffff:ffff:ffff
652cd4:4000::/242cd4:40ff:ffff:ffff:ffff:ffff:ffff:ffff
662cd4:4100::/242cd4:41ff:ffff:ffff:ffff:ffff:ffff:ffff
672cd4:4200::/242cd4:42ff:ffff:ffff:ffff:ffff:ffff:ffff
682cd4:4300::/242cd4:43ff:ffff:ffff:ffff:ffff:ffff:ffff
692cd4:4400::/242cd4:44ff:ffff:ffff:ffff:ffff:ffff:ffff
702cd4:4500::/242cd4:45ff:ffff:ffff:ffff:ffff:ffff:ffff
712cd4:4600::/242cd4:46ff:ffff:ffff:ffff:ffff:ffff:ffff
722cd4:4700::/242cd4:47ff:ffff:ffff:ffff:ffff:ffff:ffff
732cd4:4800::/242cd4:48ff:ffff:ffff:ffff:ffff:ffff:ffff
742cd4:4900::/242cd4:49ff:ffff:ffff:ffff:ffff:ffff:ffff
752cd4:4a00::/242cd4:4aff:ffff:ffff:ffff:ffff:ffff:ffff
762cd4:4b00::/242cd4:4bff:ffff:ffff:ffff:ffff:ffff:ffff
772cd4:4c00::/242cd4:4cff:ffff:ffff:ffff:ffff:ffff:ffff
782cd4:4d00::/242cd4:4dff:ffff:ffff:ffff:ffff:ffff:ffff
792cd4:4e00::/242cd4:4eff:ffff:ffff:ffff:ffff:ffff:ffff
802cd4:4f00::/242cd4:4fff:ffff:ffff:ffff:ffff:ffff:ffff
812cd4:5000::/242cd4:50ff:ffff:ffff:ffff:ffff:ffff:ffff
822cd4:5100::/242cd4:51ff:ffff:ffff:ffff:ffff:ffff:ffff
832cd4:5200::/242cd4:52ff:ffff:ffff:ffff:ffff:ffff:ffff
842cd4:5300::/242cd4:53ff:ffff:ffff:ffff:ffff:ffff:ffff
852cd4:5400::/242cd4:54ff:ffff:ffff:ffff:ffff:ffff:ffff
862cd4:5500::/242cd4:55ff:ffff:ffff:ffff:ffff:ffff:ffff
872cd4:5600::/242cd4:56ff:ffff:ffff:ffff:ffff:ffff:ffff
882cd4:5700::/242cd4:57ff:ffff:ffff:ffff:ffff:ffff:ffff
892cd4:5800::/242cd4:58ff:ffff:ffff:ffff:ffff:ffff:ffff
902cd4:5900::/242cd4:59ff:ffff:ffff:ffff:ffff:ffff:ffff
912cd4:5a00::/242cd4:5aff:ffff:ffff:ffff:ffff:ffff:ffff
922cd4:5b00::/242cd4:5bff:ffff:ffff:ffff:ffff:ffff:ffff
932cd4:5c00::/242cd4:5cff:ffff:ffff:ffff:ffff:ffff:ffff
942cd4:5d00::/242cd4:5dff:ffff:ffff:ffff:ffff:ffff:ffff
952cd4:5e00::/242cd4:5eff:ffff:ffff:ffff:ffff:ffff:ffff
962cd4:5f00::/242cd4:5fff:ffff:ffff:ffff:ffff:ffff:ffff
972cd4:6000::/242cd4:60ff:ffff:ffff:ffff:ffff:ffff:ffff
982cd4:6100::/242cd4:61ff:ffff:ffff:ffff:ffff:ffff:ffff
992cd4:6200::/242cd4:62ff:ffff:ffff:ffff:ffff:ffff:ffff
1002cd4:6300::/242cd4:63ff:ffff:ffff:ffff:ffff:ffff:ffff
1012cd4:6400::/242cd4:64ff:ffff:ffff:ffff:ffff:ffff:ffff
1022cd4:6500::/242cd4:65ff:ffff:ffff:ffff:ffff:ffff:ffff
1032cd4:6600::/242cd4:66ff:ffff:ffff:ffff:ffff:ffff:ffff
1042cd4:6700::/242cd4:67ff:ffff:ffff:ffff:ffff:ffff:ffff
1052cd4:6800::/242cd4:68ff:ffff:ffff:ffff:ffff:ffff:ffff
1062cd4:6900::/242cd4:69ff:ffff:ffff:ffff:ffff:ffff:ffff
1072cd4:6a00::/242cd4:6aff:ffff:ffff:ffff:ffff:ffff:ffff
1082cd4:6b00::/242cd4:6bff:ffff:ffff:ffff:ffff:ffff:ffff
1092cd4:6c00::/242cd4:6cff:ffff:ffff:ffff:ffff:ffff:ffff
1102cd4:6d00::/242cd4:6dff:ffff:ffff:ffff:ffff:ffff:ffff
1112cd4:6e00::/242cd4:6eff:ffff:ffff:ffff:ffff:ffff:ffff
1122cd4:6f00::/242cd4:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1132cd4:7000::/242cd4:70ff:ffff:ffff:ffff:ffff:ffff:ffff
1142cd4:7100::/242cd4:71ff:ffff:ffff:ffff:ffff:ffff:ffff
1152cd4:7200::/242cd4:72ff:ffff:ffff:ffff:ffff:ffff:ffff
1162cd4:7300::/242cd4:73ff:ffff:ffff:ffff:ffff:ffff:ffff
1172cd4:7400::/242cd4:74ff:ffff:ffff:ffff:ffff:ffff:ffff
1182cd4:7500::/242cd4:75ff:ffff:ffff:ffff:ffff:ffff:ffff
1192cd4:7600::/242cd4:76ff:ffff:ffff:ffff:ffff:ffff:ffff
1202cd4:7700::/242cd4:77ff:ffff:ffff:ffff:ffff:ffff:ffff
1212cd4:7800::/242cd4:78ff:ffff:ffff:ffff:ffff:ffff:ffff
1222cd4:7900::/242cd4:79ff:ffff:ffff:ffff:ffff:ffff:ffff
1232cd4:7a00::/242cd4:7aff:ffff:ffff:ffff:ffff:ffff:ffff
1242cd4:7b00::/242cd4:7bff:ffff:ffff:ffff:ffff:ffff:ffff
1252cd4:7c00::/242cd4:7cff:ffff:ffff:ffff:ffff:ffff:ffff
1262cd4:7d00::/242cd4:7dff:ffff:ffff:ffff:ffff:ffff:ffff
1272cd4:7e00::/242cd4:7eff:ffff:ffff:ffff:ffff:ffff:ffff
1282cd4:7f00::/242cd4:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1292cd4:8000::/242cd4:80ff:ffff:ffff:ffff:ffff:ffff:ffff
1302cd4:8100::/242cd4:81ff:ffff:ffff:ffff:ffff:ffff:ffff
1312cd4:8200::/242cd4:82ff:ffff:ffff:ffff:ffff:ffff:ffff
1322cd4:8300::/242cd4:83ff:ffff:ffff:ffff:ffff:ffff:ffff
1332cd4:8400::/242cd4:84ff:ffff:ffff:ffff:ffff:ffff:ffff
1342cd4:8500::/242cd4:85ff:ffff:ffff:ffff:ffff:ffff:ffff
1352cd4:8600::/242cd4:86ff:ffff:ffff:ffff:ffff:ffff:ffff
1362cd4:8700::/242cd4:87ff:ffff:ffff:ffff:ffff:ffff:ffff
1372cd4:8800::/242cd4:88ff:ffff:ffff:ffff:ffff:ffff:ffff
1382cd4:8900::/242cd4:89ff:ffff:ffff:ffff:ffff:ffff:ffff
1392cd4:8a00::/242cd4:8aff:ffff:ffff:ffff:ffff:ffff:ffff
1402cd4:8b00::/242cd4:8bff:ffff:ffff:ffff:ffff:ffff:ffff
1412cd4:8c00::/242cd4:8cff:ffff:ffff:ffff:ffff:ffff:ffff
1422cd4:8d00::/242cd4:8dff:ffff:ffff:ffff:ffff:ffff:ffff
1432cd4:8e00::/242cd4:8eff:ffff:ffff:ffff:ffff:ffff:ffff
1442cd4:8f00::/242cd4:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1452cd4:9000::/242cd4:90ff:ffff:ffff:ffff:ffff:ffff:ffff
1462cd4:9100::/242cd4:91ff:ffff:ffff:ffff:ffff:ffff:ffff
1472cd4:9200::/242cd4:92ff:ffff:ffff:ffff:ffff:ffff:ffff
1482cd4:9300::/242cd4:93ff:ffff:ffff:ffff:ffff:ffff:ffff
1492cd4:9400::/242cd4:94ff:ffff:ffff:ffff:ffff:ffff:ffff
1502cd4:9500::/242cd4:95ff:ffff:ffff:ffff:ffff:ffff:ffff
1512cd4:9600::/242cd4:96ff:ffff:ffff:ffff:ffff:ffff:ffff
1522cd4:9700::/242cd4:97ff:ffff:ffff:ffff:ffff:ffff:ffff
1532cd4:9800::/242cd4:98ff:ffff:ffff:ffff:ffff:ffff:ffff
1542cd4:9900::/242cd4:99ff:ffff:ffff:ffff:ffff:ffff:ffff
1552cd4:9a00::/242cd4:9aff:ffff:ffff:ffff:ffff:ffff:ffff
1562cd4:9b00::/242cd4:9bff:ffff:ffff:ffff:ffff:ffff:ffff
1572cd4:9c00::/242cd4:9cff:ffff:ffff:ffff:ffff:ffff:ffff
1582cd4:9d00::/242cd4:9dff:ffff:ffff:ffff:ffff:ffff:ffff
1592cd4:9e00::/242cd4:9eff:ffff:ffff:ffff:ffff:ffff:ffff
1602cd4:9f00::/242cd4:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1612cd4:a000::/242cd4:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
1622cd4:a100::/242cd4:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
1632cd4:a200::/242cd4:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
1642cd4:a300::/242cd4:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
1652cd4:a400::/242cd4:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
1662cd4:a500::/242cd4:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
1672cd4:a600::/242cd4:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
1682cd4:a700::/242cd4:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
1692cd4:a800::/242cd4:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
1702cd4:a900::/242cd4:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
1712cd4:aa00::/242cd4:aaff:ffff:ffff:ffff:ffff:ffff:ffff
1722cd4:ab00::/242cd4:abff:ffff:ffff:ffff:ffff:ffff:ffff
1732cd4:ac00::/242cd4:acff:ffff:ffff:ffff:ffff:ffff:ffff
1742cd4:ad00::/242cd4:adff:ffff:ffff:ffff:ffff:ffff:ffff
1752cd4:ae00::/242cd4:aeff:ffff:ffff:ffff:ffff:ffff:ffff
1762cd4:af00::/242cd4:afff:ffff:ffff:ffff:ffff:ffff:ffff
1772cd4:b000::/242cd4:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
1782cd4:b100::/242cd4:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
1792cd4:b200::/242cd4:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
1802cd4:b300::/242cd4:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
1812cd4:b400::/242cd4:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
1822cd4:b500::/242cd4:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
1832cd4:b600::/242cd4:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
1842cd4:b700::/242cd4:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
1852cd4:b800::/242cd4:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
1862cd4:b900::/242cd4:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
1872cd4:ba00::/242cd4:baff:ffff:ffff:ffff:ffff:ffff:ffff
1882cd4:bb00::/242cd4:bbff:ffff:ffff:ffff:ffff:ffff:ffff
1892cd4:bc00::/242cd4:bcff:ffff:ffff:ffff:ffff:ffff:ffff
1902cd4:bd00::/242cd4:bdff:ffff:ffff:ffff:ffff:ffff:ffff
1912cd4:be00::/242cd4:beff:ffff:ffff:ffff:ffff:ffff:ffff
1922cd4:bf00::/242cd4:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1932cd4:c000::/242cd4:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
1942cd4:c100::/242cd4:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
1952cd4:c200::/242cd4:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
1962cd4:c300::/242cd4:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
1972cd4:c400::/242cd4:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
1982cd4:c500::/242cd4:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
1992cd4:c600::/242cd4:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
2002cd4:c700::/242cd4:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
2012cd4:c800::/242cd4:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
2022cd4:c900::/242cd4:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
2032cd4:ca00::/242cd4:caff:ffff:ffff:ffff:ffff:ffff:ffff
2042cd4:cb00::/242cd4:cbff:ffff:ffff:ffff:ffff:ffff:ffff
2052cd4:cc00::/242cd4:ccff:ffff:ffff:ffff:ffff:ffff:ffff
2062cd4:cd00::/242cd4:cdff:ffff:ffff:ffff:ffff:ffff:ffff
2072cd4:ce00::/242cd4:ceff:ffff:ffff:ffff:ffff:ffff:ffff
2082cd4:cf00::/242cd4:cfff:ffff:ffff:ffff:ffff:ffff:ffff
2092cd4:d000::/242cd4:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
2102cd4:d100::/242cd4:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
2112cd4:d200::/242cd4:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
2122cd4:d300::/242cd4:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
2132cd4:d400::/242cd4:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
2142cd4:d500::/242cd4:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
2152cd4:d600::/242cd4:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
2162cd4:d700::/242cd4:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
2172cd4:d800::/242cd4:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
2182cd4:d900::/242cd4:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
2192cd4:da00::/242cd4:daff:ffff:ffff:ffff:ffff:ffff:ffff
2202cd4:db00::/242cd4:dbff:ffff:ffff:ffff:ffff:ffff:ffff
2212cd4:dc00::/242cd4:dcff:ffff:ffff:ffff:ffff:ffff:ffff
2222cd4:dd00::/242cd4:ddff:ffff:ffff:ffff:ffff:ffff:ffff
2232cd4:de00::/242cd4:deff:ffff:ffff:ffff:ffff:ffff:ffff
2242cd4:df00::/242cd4:dfff:ffff:ffff:ffff:ffff:ffff:ffff
2252cd4:e000::/242cd4:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
2262cd4:e100::/242cd4:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
2272cd4:e200::/242cd4:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
2282cd4:e300::/242cd4:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
2292cd4:e400::/242cd4:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
2302cd4:e500::/242cd4:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
2312cd4:e600::/242cd4:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
2322cd4:e700::/242cd4:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
2332cd4:e800::/242cd4:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
2342cd4:e900::/242cd4:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
2352cd4:ea00::/242cd4:eaff:ffff:ffff:ffff:ffff:ffff:ffff
2362cd4:eb00::/242cd4:ebff:ffff:ffff:ffff:ffff:ffff:ffff
2372cd4:ec00::/242cd4:ecff:ffff:ffff:ffff:ffff:ffff:ffff
2382cd4:ed00::/242cd4:edff:ffff:ffff:ffff:ffff:ffff:ffff
2392cd4:ee00::/242cd4:eeff:ffff:ffff:ffff:ffff:ffff:ffff
2402cd4:ef00::/242cd4:efff:ffff:ffff:ffff:ffff:ffff:ffff
2412cd4:f000::/242cd4:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
2422cd4:f100::/242cd4:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
2432cd4:f200::/242cd4:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
2442cd4:f300::/242cd4:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
2452cd4:f400::/242cd4:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
2462cd4:f500::/242cd4:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
2472cd4:f600::/242cd4:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
2482cd4:f700::/242cd4:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
2492cd4:f800::/242cd4:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
2502cd4:f900::/242cd4:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
2512cd4:fa00::/242cd4:faff:ffff:ffff:ffff:ffff:ffff:ffff
2522cd4:fb00::/242cd4:fbff:ffff:ffff:ffff:ffff:ffff:ffff
2532cd4:fc00::/242cd4:fcff:ffff:ffff:ffff:ffff:ffff:ffff
2542cd4:fd00::/242cd4:fdff:ffff:ffff:ffff:ffff:ffff:ffff
2552cd4:fe00::/242cd4:feff:ffff:ffff:ffff:ffff:ffff:ffff
2562cd4:ff00::/242cd4:ffff: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.