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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
2130::/12
First address
2130::
Last address
213f: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
2130:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
3.1.2.ip6.arpa
Split into smaller subnets/24
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

2130::/12 makes 4,096 subnets of /24; the first 256 are listed.

Subnets
#SubnetLast address
12130::/242130:ff:ffff:ffff:ffff:ffff:ffff:ffff
22130:100::/242130:1ff:ffff:ffff:ffff:ffff:ffff:ffff
32130:200::/242130:2ff:ffff:ffff:ffff:ffff:ffff:ffff
42130:300::/242130:3ff:ffff:ffff:ffff:ffff:ffff:ffff
52130:400::/242130:4ff:ffff:ffff:ffff:ffff:ffff:ffff
62130:500::/242130:5ff:ffff:ffff:ffff:ffff:ffff:ffff
72130:600::/242130:6ff:ffff:ffff:ffff:ffff:ffff:ffff
82130:700::/242130:7ff:ffff:ffff:ffff:ffff:ffff:ffff
92130:800::/242130:8ff:ffff:ffff:ffff:ffff:ffff:ffff
102130:900::/242130:9ff:ffff:ffff:ffff:ffff:ffff:ffff
112130:a00::/242130:aff:ffff:ffff:ffff:ffff:ffff:ffff
122130:b00::/242130:bff:ffff:ffff:ffff:ffff:ffff:ffff
132130:c00::/242130:cff:ffff:ffff:ffff:ffff:ffff:ffff
142130:d00::/242130:dff:ffff:ffff:ffff:ffff:ffff:ffff
152130:e00::/242130:eff:ffff:ffff:ffff:ffff:ffff:ffff
162130:f00::/242130:fff:ffff:ffff:ffff:ffff:ffff:ffff
172130:1000::/242130:10ff:ffff:ffff:ffff:ffff:ffff:ffff
182130:1100::/242130:11ff:ffff:ffff:ffff:ffff:ffff:ffff
192130:1200::/242130:12ff:ffff:ffff:ffff:ffff:ffff:ffff
202130:1300::/242130:13ff:ffff:ffff:ffff:ffff:ffff:ffff
212130:1400::/242130:14ff:ffff:ffff:ffff:ffff:ffff:ffff
222130:1500::/242130:15ff:ffff:ffff:ffff:ffff:ffff:ffff
232130:1600::/242130:16ff:ffff:ffff:ffff:ffff:ffff:ffff
242130:1700::/242130:17ff:ffff:ffff:ffff:ffff:ffff:ffff
252130:1800::/242130:18ff:ffff:ffff:ffff:ffff:ffff:ffff
262130:1900::/242130:19ff:ffff:ffff:ffff:ffff:ffff:ffff
272130:1a00::/242130:1aff:ffff:ffff:ffff:ffff:ffff:ffff
282130:1b00::/242130:1bff:ffff:ffff:ffff:ffff:ffff:ffff
292130:1c00::/242130:1cff:ffff:ffff:ffff:ffff:ffff:ffff
302130:1d00::/242130:1dff:ffff:ffff:ffff:ffff:ffff:ffff
312130:1e00::/242130:1eff:ffff:ffff:ffff:ffff:ffff:ffff
322130:1f00::/242130:1fff:ffff:ffff:ffff:ffff:ffff:ffff
332130:2000::/242130:20ff:ffff:ffff:ffff:ffff:ffff:ffff
342130:2100::/242130:21ff:ffff:ffff:ffff:ffff:ffff:ffff
352130:2200::/242130:22ff:ffff:ffff:ffff:ffff:ffff:ffff
362130:2300::/242130:23ff:ffff:ffff:ffff:ffff:ffff:ffff
372130:2400::/242130:24ff:ffff:ffff:ffff:ffff:ffff:ffff
382130:2500::/242130:25ff:ffff:ffff:ffff:ffff:ffff:ffff
392130:2600::/242130:26ff:ffff:ffff:ffff:ffff:ffff:ffff
402130:2700::/242130:27ff:ffff:ffff:ffff:ffff:ffff:ffff
412130:2800::/242130:28ff:ffff:ffff:ffff:ffff:ffff:ffff
422130:2900::/242130:29ff:ffff:ffff:ffff:ffff:ffff:ffff
432130:2a00::/242130:2aff:ffff:ffff:ffff:ffff:ffff:ffff
442130:2b00::/242130:2bff:ffff:ffff:ffff:ffff:ffff:ffff
452130:2c00::/242130:2cff:ffff:ffff:ffff:ffff:ffff:ffff
462130:2d00::/242130:2dff:ffff:ffff:ffff:ffff:ffff:ffff
472130:2e00::/242130:2eff:ffff:ffff:ffff:ffff:ffff:ffff
482130:2f00::/242130:2fff:ffff:ffff:ffff:ffff:ffff:ffff
492130:3000::/242130:30ff:ffff:ffff:ffff:ffff:ffff:ffff
502130:3100::/242130:31ff:ffff:ffff:ffff:ffff:ffff:ffff
512130:3200::/242130:32ff:ffff:ffff:ffff:ffff:ffff:ffff
522130:3300::/242130:33ff:ffff:ffff:ffff:ffff:ffff:ffff
532130:3400::/242130:34ff:ffff:ffff:ffff:ffff:ffff:ffff
542130:3500::/242130:35ff:ffff:ffff:ffff:ffff:ffff:ffff
552130:3600::/242130:36ff:ffff:ffff:ffff:ffff:ffff:ffff
562130:3700::/242130:37ff:ffff:ffff:ffff:ffff:ffff:ffff
572130:3800::/242130:38ff:ffff:ffff:ffff:ffff:ffff:ffff
582130:3900::/242130:39ff:ffff:ffff:ffff:ffff:ffff:ffff
592130:3a00::/242130:3aff:ffff:ffff:ffff:ffff:ffff:ffff
602130:3b00::/242130:3bff:ffff:ffff:ffff:ffff:ffff:ffff
612130:3c00::/242130:3cff:ffff:ffff:ffff:ffff:ffff:ffff
622130:3d00::/242130:3dff:ffff:ffff:ffff:ffff:ffff:ffff
632130:3e00::/242130:3eff:ffff:ffff:ffff:ffff:ffff:ffff
642130:3f00::/242130:3fff:ffff:ffff:ffff:ffff:ffff:ffff
652130:4000::/242130:40ff:ffff:ffff:ffff:ffff:ffff:ffff
662130:4100::/242130:41ff:ffff:ffff:ffff:ffff:ffff:ffff
672130:4200::/242130:42ff:ffff:ffff:ffff:ffff:ffff:ffff
682130:4300::/242130:43ff:ffff:ffff:ffff:ffff:ffff:ffff
692130:4400::/242130:44ff:ffff:ffff:ffff:ffff:ffff:ffff
702130:4500::/242130:45ff:ffff:ffff:ffff:ffff:ffff:ffff
712130:4600::/242130:46ff:ffff:ffff:ffff:ffff:ffff:ffff
722130:4700::/242130:47ff:ffff:ffff:ffff:ffff:ffff:ffff
732130:4800::/242130:48ff:ffff:ffff:ffff:ffff:ffff:ffff
742130:4900::/242130:49ff:ffff:ffff:ffff:ffff:ffff:ffff
752130:4a00::/242130:4aff:ffff:ffff:ffff:ffff:ffff:ffff
762130:4b00::/242130:4bff:ffff:ffff:ffff:ffff:ffff:ffff
772130:4c00::/242130:4cff:ffff:ffff:ffff:ffff:ffff:ffff
782130:4d00::/242130:4dff:ffff:ffff:ffff:ffff:ffff:ffff
792130:4e00::/242130:4eff:ffff:ffff:ffff:ffff:ffff:ffff
802130:4f00::/242130:4fff:ffff:ffff:ffff:ffff:ffff:ffff
812130:5000::/242130:50ff:ffff:ffff:ffff:ffff:ffff:ffff
822130:5100::/242130:51ff:ffff:ffff:ffff:ffff:ffff:ffff
832130:5200::/242130:52ff:ffff:ffff:ffff:ffff:ffff:ffff
842130:5300::/242130:53ff:ffff:ffff:ffff:ffff:ffff:ffff
852130:5400::/242130:54ff:ffff:ffff:ffff:ffff:ffff:ffff
862130:5500::/242130:55ff:ffff:ffff:ffff:ffff:ffff:ffff
872130:5600::/242130:56ff:ffff:ffff:ffff:ffff:ffff:ffff
882130:5700::/242130:57ff:ffff:ffff:ffff:ffff:ffff:ffff
892130:5800::/242130:58ff:ffff:ffff:ffff:ffff:ffff:ffff
902130:5900::/242130:59ff:ffff:ffff:ffff:ffff:ffff:ffff
912130:5a00::/242130:5aff:ffff:ffff:ffff:ffff:ffff:ffff
922130:5b00::/242130:5bff:ffff:ffff:ffff:ffff:ffff:ffff
932130:5c00::/242130:5cff:ffff:ffff:ffff:ffff:ffff:ffff
942130:5d00::/242130:5dff:ffff:ffff:ffff:ffff:ffff:ffff
952130:5e00::/242130:5eff:ffff:ffff:ffff:ffff:ffff:ffff
962130:5f00::/242130:5fff:ffff:ffff:ffff:ffff:ffff:ffff
972130:6000::/242130:60ff:ffff:ffff:ffff:ffff:ffff:ffff
982130:6100::/242130:61ff:ffff:ffff:ffff:ffff:ffff:ffff
992130:6200::/242130:62ff:ffff:ffff:ffff:ffff:ffff:ffff
1002130:6300::/242130:63ff:ffff:ffff:ffff:ffff:ffff:ffff
1012130:6400::/242130:64ff:ffff:ffff:ffff:ffff:ffff:ffff
1022130:6500::/242130:65ff:ffff:ffff:ffff:ffff:ffff:ffff
1032130:6600::/242130:66ff:ffff:ffff:ffff:ffff:ffff:ffff
1042130:6700::/242130:67ff:ffff:ffff:ffff:ffff:ffff:ffff
1052130:6800::/242130:68ff:ffff:ffff:ffff:ffff:ffff:ffff
1062130:6900::/242130:69ff:ffff:ffff:ffff:ffff:ffff:ffff
1072130:6a00::/242130:6aff:ffff:ffff:ffff:ffff:ffff:ffff
1082130:6b00::/242130:6bff:ffff:ffff:ffff:ffff:ffff:ffff
1092130:6c00::/242130:6cff:ffff:ffff:ffff:ffff:ffff:ffff
1102130:6d00::/242130:6dff:ffff:ffff:ffff:ffff:ffff:ffff
1112130:6e00::/242130:6eff:ffff:ffff:ffff:ffff:ffff:ffff
1122130:6f00::/242130:6fff:ffff:ffff:ffff:ffff:ffff:ffff
1132130:7000::/242130:70ff:ffff:ffff:ffff:ffff:ffff:ffff
1142130:7100::/242130:71ff:ffff:ffff:ffff:ffff:ffff:ffff
1152130:7200::/242130:72ff:ffff:ffff:ffff:ffff:ffff:ffff
1162130:7300::/242130:73ff:ffff:ffff:ffff:ffff:ffff:ffff
1172130:7400::/242130:74ff:ffff:ffff:ffff:ffff:ffff:ffff
1182130:7500::/242130:75ff:ffff:ffff:ffff:ffff:ffff:ffff
1192130:7600::/242130:76ff:ffff:ffff:ffff:ffff:ffff:ffff
1202130:7700::/242130:77ff:ffff:ffff:ffff:ffff:ffff:ffff
1212130:7800::/242130:78ff:ffff:ffff:ffff:ffff:ffff:ffff
1222130:7900::/242130:79ff:ffff:ffff:ffff:ffff:ffff:ffff
1232130:7a00::/242130:7aff:ffff:ffff:ffff:ffff:ffff:ffff
1242130:7b00::/242130:7bff:ffff:ffff:ffff:ffff:ffff:ffff
1252130:7c00::/242130:7cff:ffff:ffff:ffff:ffff:ffff:ffff
1262130:7d00::/242130:7dff:ffff:ffff:ffff:ffff:ffff:ffff
1272130:7e00::/242130:7eff:ffff:ffff:ffff:ffff:ffff:ffff
1282130:7f00::/242130:7fff:ffff:ffff:ffff:ffff:ffff:ffff
1292130:8000::/242130:80ff:ffff:ffff:ffff:ffff:ffff:ffff
1302130:8100::/242130:81ff:ffff:ffff:ffff:ffff:ffff:ffff
1312130:8200::/242130:82ff:ffff:ffff:ffff:ffff:ffff:ffff
1322130:8300::/242130:83ff:ffff:ffff:ffff:ffff:ffff:ffff
1332130:8400::/242130:84ff:ffff:ffff:ffff:ffff:ffff:ffff
1342130:8500::/242130:85ff:ffff:ffff:ffff:ffff:ffff:ffff
1352130:8600::/242130:86ff:ffff:ffff:ffff:ffff:ffff:ffff
1362130:8700::/242130:87ff:ffff:ffff:ffff:ffff:ffff:ffff
1372130:8800::/242130:88ff:ffff:ffff:ffff:ffff:ffff:ffff
1382130:8900::/242130:89ff:ffff:ffff:ffff:ffff:ffff:ffff
1392130:8a00::/242130:8aff:ffff:ffff:ffff:ffff:ffff:ffff
1402130:8b00::/242130:8bff:ffff:ffff:ffff:ffff:ffff:ffff
1412130:8c00::/242130:8cff:ffff:ffff:ffff:ffff:ffff:ffff
1422130:8d00::/242130:8dff:ffff:ffff:ffff:ffff:ffff:ffff
1432130:8e00::/242130:8eff:ffff:ffff:ffff:ffff:ffff:ffff
1442130:8f00::/242130:8fff:ffff:ffff:ffff:ffff:ffff:ffff
1452130:9000::/242130:90ff:ffff:ffff:ffff:ffff:ffff:ffff
1462130:9100::/242130:91ff:ffff:ffff:ffff:ffff:ffff:ffff
1472130:9200::/242130:92ff:ffff:ffff:ffff:ffff:ffff:ffff
1482130:9300::/242130:93ff:ffff:ffff:ffff:ffff:ffff:ffff
1492130:9400::/242130:94ff:ffff:ffff:ffff:ffff:ffff:ffff
1502130:9500::/242130:95ff:ffff:ffff:ffff:ffff:ffff:ffff
1512130:9600::/242130:96ff:ffff:ffff:ffff:ffff:ffff:ffff
1522130:9700::/242130:97ff:ffff:ffff:ffff:ffff:ffff:ffff
1532130:9800::/242130:98ff:ffff:ffff:ffff:ffff:ffff:ffff
1542130:9900::/242130:99ff:ffff:ffff:ffff:ffff:ffff:ffff
1552130:9a00::/242130:9aff:ffff:ffff:ffff:ffff:ffff:ffff
1562130:9b00::/242130:9bff:ffff:ffff:ffff:ffff:ffff:ffff
1572130:9c00::/242130:9cff:ffff:ffff:ffff:ffff:ffff:ffff
1582130:9d00::/242130:9dff:ffff:ffff:ffff:ffff:ffff:ffff
1592130:9e00::/242130:9eff:ffff:ffff:ffff:ffff:ffff:ffff
1602130:9f00::/242130:9fff:ffff:ffff:ffff:ffff:ffff:ffff
1612130:a000::/242130:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
1622130:a100::/242130:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
1632130:a200::/242130:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
1642130:a300::/242130:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
1652130:a400::/242130:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
1662130:a500::/242130:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
1672130:a600::/242130:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
1682130:a700::/242130:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
1692130:a800::/242130:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
1702130:a900::/242130:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
1712130:aa00::/242130:aaff:ffff:ffff:ffff:ffff:ffff:ffff
1722130:ab00::/242130:abff:ffff:ffff:ffff:ffff:ffff:ffff
1732130:ac00::/242130:acff:ffff:ffff:ffff:ffff:ffff:ffff
1742130:ad00::/242130:adff:ffff:ffff:ffff:ffff:ffff:ffff
1752130:ae00::/242130:aeff:ffff:ffff:ffff:ffff:ffff:ffff
1762130:af00::/242130:afff:ffff:ffff:ffff:ffff:ffff:ffff
1772130:b000::/242130:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
1782130:b100::/242130:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
1792130:b200::/242130:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
1802130:b300::/242130:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
1812130:b400::/242130:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
1822130:b500::/242130:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
1832130:b600::/242130:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
1842130:b700::/242130:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
1852130:b800::/242130:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
1862130:b900::/242130:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
1872130:ba00::/242130:baff:ffff:ffff:ffff:ffff:ffff:ffff
1882130:bb00::/242130:bbff:ffff:ffff:ffff:ffff:ffff:ffff
1892130:bc00::/242130:bcff:ffff:ffff:ffff:ffff:ffff:ffff
1902130:bd00::/242130:bdff:ffff:ffff:ffff:ffff:ffff:ffff
1912130:be00::/242130:beff:ffff:ffff:ffff:ffff:ffff:ffff
1922130:bf00::/242130:bfff:ffff:ffff:ffff:ffff:ffff:ffff
1932130:c000::/242130:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
1942130:c100::/242130:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
1952130:c200::/242130:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
1962130:c300::/242130:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
1972130:c400::/242130:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
1982130:c500::/242130:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
1992130:c600::/242130:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
2002130:c700::/242130:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
2012130:c800::/242130:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
2022130:c900::/242130:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
2032130:ca00::/242130:caff:ffff:ffff:ffff:ffff:ffff:ffff
2042130:cb00::/242130:cbff:ffff:ffff:ffff:ffff:ffff:ffff
2052130:cc00::/242130:ccff:ffff:ffff:ffff:ffff:ffff:ffff
2062130:cd00::/242130:cdff:ffff:ffff:ffff:ffff:ffff:ffff
2072130:ce00::/242130:ceff:ffff:ffff:ffff:ffff:ffff:ffff
2082130:cf00::/242130:cfff:ffff:ffff:ffff:ffff:ffff:ffff
2092130:d000::/242130:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
2102130:d100::/242130:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
2112130:d200::/242130:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
2122130:d300::/242130:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
2132130:d400::/242130:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
2142130:d500::/242130:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
2152130:d600::/242130:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
2162130:d700::/242130:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
2172130:d800::/242130:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
2182130:d900::/242130:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
2192130:da00::/242130:daff:ffff:ffff:ffff:ffff:ffff:ffff
2202130:db00::/242130:dbff:ffff:ffff:ffff:ffff:ffff:ffff
2212130:dc00::/242130:dcff:ffff:ffff:ffff:ffff:ffff:ffff
2222130:dd00::/242130:ddff:ffff:ffff:ffff:ffff:ffff:ffff
2232130:de00::/242130:deff:ffff:ffff:ffff:ffff:ffff:ffff
2242130:df00::/242130:dfff:ffff:ffff:ffff:ffff:ffff:ffff
2252130:e000::/242130:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
2262130:e100::/242130:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
2272130:e200::/242130:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
2282130:e300::/242130:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
2292130:e400::/242130:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
2302130:e500::/242130:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
2312130:e600::/242130:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
2322130:e700::/242130:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
2332130:e800::/242130:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
2342130:e900::/242130:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
2352130:ea00::/242130:eaff:ffff:ffff:ffff:ffff:ffff:ffff
2362130:eb00::/242130:ebff:ffff:ffff:ffff:ffff:ffff:ffff
2372130:ec00::/242130:ecff:ffff:ffff:ffff:ffff:ffff:ffff
2382130:ed00::/242130:edff:ffff:ffff:ffff:ffff:ffff:ffff
2392130:ee00::/242130:eeff:ffff:ffff:ffff:ffff:ffff:ffff
2402130:ef00::/242130:efff:ffff:ffff:ffff:ffff:ffff:ffff
2412130:f000::/242130:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
2422130:f100::/242130:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
2432130:f200::/242130:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
2442130:f300::/242130:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
2452130:f400::/242130:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
2462130:f500::/242130:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
2472130:f600::/242130:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
2482130:f700::/242130:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
2492130:f800::/242130:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
2502130:f900::/242130:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
2512130:fa00::/242130:faff:ffff:ffff:ffff:ffff:ffff:ffff
2522130:fb00::/242130:fbff:ffff:ffff:ffff:ffff:ffff:ffff
2532130:fc00::/242130:fcff:ffff:ffff:ffff:ffff:ffff:ffff
2542130:fd00::/242130:fdff:ffff:ffff:ffff:ffff:ffff:ffff
2552130:fe00::/242130:feff:ffff:ffff:ffff:ffff:ffff:ffff
2562130:ff00::/242130: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.