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

3ebb::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
13ebb::/323ebb:0:ffff:ffff:ffff:ffff:ffff:ffff
23ebb:1::/323ebb:1:ffff:ffff:ffff:ffff:ffff:ffff
33ebb:2::/323ebb:2:ffff:ffff:ffff:ffff:ffff:ffff
43ebb:3::/323ebb:3:ffff:ffff:ffff:ffff:ffff:ffff
53ebb:4::/323ebb:4:ffff:ffff:ffff:ffff:ffff:ffff
63ebb:5::/323ebb:5:ffff:ffff:ffff:ffff:ffff:ffff
73ebb:6::/323ebb:6:ffff:ffff:ffff:ffff:ffff:ffff
83ebb:7::/323ebb:7:ffff:ffff:ffff:ffff:ffff:ffff
93ebb:8::/323ebb:8:ffff:ffff:ffff:ffff:ffff:ffff
103ebb:9::/323ebb:9:ffff:ffff:ffff:ffff:ffff:ffff
113ebb:a::/323ebb:a:ffff:ffff:ffff:ffff:ffff:ffff
123ebb:b::/323ebb:b:ffff:ffff:ffff:ffff:ffff:ffff
133ebb:c::/323ebb:c:ffff:ffff:ffff:ffff:ffff:ffff
143ebb:d::/323ebb:d:ffff:ffff:ffff:ffff:ffff:ffff
153ebb:e::/323ebb:e:ffff:ffff:ffff:ffff:ffff:ffff
163ebb:f::/323ebb:f:ffff:ffff:ffff:ffff:ffff:ffff
173ebb:10::/323ebb:10:ffff:ffff:ffff:ffff:ffff:ffff
183ebb:11::/323ebb:11:ffff:ffff:ffff:ffff:ffff:ffff
193ebb:12::/323ebb:12:ffff:ffff:ffff:ffff:ffff:ffff
203ebb:13::/323ebb:13:ffff:ffff:ffff:ffff:ffff:ffff
213ebb:14::/323ebb:14:ffff:ffff:ffff:ffff:ffff:ffff
223ebb:15::/323ebb:15:ffff:ffff:ffff:ffff:ffff:ffff
233ebb:16::/323ebb:16:ffff:ffff:ffff:ffff:ffff:ffff
243ebb:17::/323ebb:17:ffff:ffff:ffff:ffff:ffff:ffff
253ebb:18::/323ebb:18:ffff:ffff:ffff:ffff:ffff:ffff
263ebb:19::/323ebb:19:ffff:ffff:ffff:ffff:ffff:ffff
273ebb:1a::/323ebb:1a:ffff:ffff:ffff:ffff:ffff:ffff
283ebb:1b::/323ebb:1b:ffff:ffff:ffff:ffff:ffff:ffff
293ebb:1c::/323ebb:1c:ffff:ffff:ffff:ffff:ffff:ffff
303ebb:1d::/323ebb:1d:ffff:ffff:ffff:ffff:ffff:ffff
313ebb:1e::/323ebb:1e:ffff:ffff:ffff:ffff:ffff:ffff
323ebb:1f::/323ebb:1f:ffff:ffff:ffff:ffff:ffff:ffff
333ebb:20::/323ebb:20:ffff:ffff:ffff:ffff:ffff:ffff
343ebb:21::/323ebb:21:ffff:ffff:ffff:ffff:ffff:ffff
353ebb:22::/323ebb:22:ffff:ffff:ffff:ffff:ffff:ffff
363ebb:23::/323ebb:23:ffff:ffff:ffff:ffff:ffff:ffff
373ebb:24::/323ebb:24:ffff:ffff:ffff:ffff:ffff:ffff
383ebb:25::/323ebb:25:ffff:ffff:ffff:ffff:ffff:ffff
393ebb:26::/323ebb:26:ffff:ffff:ffff:ffff:ffff:ffff
403ebb:27::/323ebb:27:ffff:ffff:ffff:ffff:ffff:ffff
413ebb:28::/323ebb:28:ffff:ffff:ffff:ffff:ffff:ffff
423ebb:29::/323ebb:29:ffff:ffff:ffff:ffff:ffff:ffff
433ebb:2a::/323ebb:2a:ffff:ffff:ffff:ffff:ffff:ffff
443ebb:2b::/323ebb:2b:ffff:ffff:ffff:ffff:ffff:ffff
453ebb:2c::/323ebb:2c:ffff:ffff:ffff:ffff:ffff:ffff
463ebb:2d::/323ebb:2d:ffff:ffff:ffff:ffff:ffff:ffff
473ebb:2e::/323ebb:2e:ffff:ffff:ffff:ffff:ffff:ffff
483ebb:2f::/323ebb:2f:ffff:ffff:ffff:ffff:ffff:ffff
493ebb:30::/323ebb:30:ffff:ffff:ffff:ffff:ffff:ffff
503ebb:31::/323ebb:31:ffff:ffff:ffff:ffff:ffff:ffff
513ebb:32::/323ebb:32:ffff:ffff:ffff:ffff:ffff:ffff
523ebb:33::/323ebb:33:ffff:ffff:ffff:ffff:ffff:ffff
533ebb:34::/323ebb:34:ffff:ffff:ffff:ffff:ffff:ffff
543ebb:35::/323ebb:35:ffff:ffff:ffff:ffff:ffff:ffff
553ebb:36::/323ebb:36:ffff:ffff:ffff:ffff:ffff:ffff
563ebb:37::/323ebb:37:ffff:ffff:ffff:ffff:ffff:ffff
573ebb:38::/323ebb:38:ffff:ffff:ffff:ffff:ffff:ffff
583ebb:39::/323ebb:39:ffff:ffff:ffff:ffff:ffff:ffff
593ebb:3a::/323ebb:3a:ffff:ffff:ffff:ffff:ffff:ffff
603ebb:3b::/323ebb:3b:ffff:ffff:ffff:ffff:ffff:ffff
613ebb:3c::/323ebb:3c:ffff:ffff:ffff:ffff:ffff:ffff
623ebb:3d::/323ebb:3d:ffff:ffff:ffff:ffff:ffff:ffff
633ebb:3e::/323ebb:3e:ffff:ffff:ffff:ffff:ffff:ffff
643ebb:3f::/323ebb:3f:ffff:ffff:ffff:ffff:ffff:ffff
653ebb:40::/323ebb:40:ffff:ffff:ffff:ffff:ffff:ffff
663ebb:41::/323ebb:41:ffff:ffff:ffff:ffff:ffff:ffff
673ebb:42::/323ebb:42:ffff:ffff:ffff:ffff:ffff:ffff
683ebb:43::/323ebb:43:ffff:ffff:ffff:ffff:ffff:ffff
693ebb:44::/323ebb:44:ffff:ffff:ffff:ffff:ffff:ffff
703ebb:45::/323ebb:45:ffff:ffff:ffff:ffff:ffff:ffff
713ebb:46::/323ebb:46:ffff:ffff:ffff:ffff:ffff:ffff
723ebb:47::/323ebb:47:ffff:ffff:ffff:ffff:ffff:ffff
733ebb:48::/323ebb:48:ffff:ffff:ffff:ffff:ffff:ffff
743ebb:49::/323ebb:49:ffff:ffff:ffff:ffff:ffff:ffff
753ebb:4a::/323ebb:4a:ffff:ffff:ffff:ffff:ffff:ffff
763ebb:4b::/323ebb:4b:ffff:ffff:ffff:ffff:ffff:ffff
773ebb:4c::/323ebb:4c:ffff:ffff:ffff:ffff:ffff:ffff
783ebb:4d::/323ebb:4d:ffff:ffff:ffff:ffff:ffff:ffff
793ebb:4e::/323ebb:4e:ffff:ffff:ffff:ffff:ffff:ffff
803ebb:4f::/323ebb:4f:ffff:ffff:ffff:ffff:ffff:ffff
813ebb:50::/323ebb:50:ffff:ffff:ffff:ffff:ffff:ffff
823ebb:51::/323ebb:51:ffff:ffff:ffff:ffff:ffff:ffff
833ebb:52::/323ebb:52:ffff:ffff:ffff:ffff:ffff:ffff
843ebb:53::/323ebb:53:ffff:ffff:ffff:ffff:ffff:ffff
853ebb:54::/323ebb:54:ffff:ffff:ffff:ffff:ffff:ffff
863ebb:55::/323ebb:55:ffff:ffff:ffff:ffff:ffff:ffff
873ebb:56::/323ebb:56:ffff:ffff:ffff:ffff:ffff:ffff
883ebb:57::/323ebb:57:ffff:ffff:ffff:ffff:ffff:ffff
893ebb:58::/323ebb:58:ffff:ffff:ffff:ffff:ffff:ffff
903ebb:59::/323ebb:59:ffff:ffff:ffff:ffff:ffff:ffff
913ebb:5a::/323ebb:5a:ffff:ffff:ffff:ffff:ffff:ffff
923ebb:5b::/323ebb:5b:ffff:ffff:ffff:ffff:ffff:ffff
933ebb:5c::/323ebb:5c:ffff:ffff:ffff:ffff:ffff:ffff
943ebb:5d::/323ebb:5d:ffff:ffff:ffff:ffff:ffff:ffff
953ebb:5e::/323ebb:5e:ffff:ffff:ffff:ffff:ffff:ffff
963ebb:5f::/323ebb:5f:ffff:ffff:ffff:ffff:ffff:ffff
973ebb:60::/323ebb:60:ffff:ffff:ffff:ffff:ffff:ffff
983ebb:61::/323ebb:61:ffff:ffff:ffff:ffff:ffff:ffff
993ebb:62::/323ebb:62:ffff:ffff:ffff:ffff:ffff:ffff
1003ebb:63::/323ebb:63:ffff:ffff:ffff:ffff:ffff:ffff
1013ebb:64::/323ebb:64:ffff:ffff:ffff:ffff:ffff:ffff
1023ebb:65::/323ebb:65:ffff:ffff:ffff:ffff:ffff:ffff
1033ebb:66::/323ebb:66:ffff:ffff:ffff:ffff:ffff:ffff
1043ebb:67::/323ebb:67:ffff:ffff:ffff:ffff:ffff:ffff
1053ebb:68::/323ebb:68:ffff:ffff:ffff:ffff:ffff:ffff
1063ebb:69::/323ebb:69:ffff:ffff:ffff:ffff:ffff:ffff
1073ebb:6a::/323ebb:6a:ffff:ffff:ffff:ffff:ffff:ffff
1083ebb:6b::/323ebb:6b:ffff:ffff:ffff:ffff:ffff:ffff
1093ebb:6c::/323ebb:6c:ffff:ffff:ffff:ffff:ffff:ffff
1103ebb:6d::/323ebb:6d:ffff:ffff:ffff:ffff:ffff:ffff
1113ebb:6e::/323ebb:6e:ffff:ffff:ffff:ffff:ffff:ffff
1123ebb:6f::/323ebb:6f:ffff:ffff:ffff:ffff:ffff:ffff
1133ebb:70::/323ebb:70:ffff:ffff:ffff:ffff:ffff:ffff
1143ebb:71::/323ebb:71:ffff:ffff:ffff:ffff:ffff:ffff
1153ebb:72::/323ebb:72:ffff:ffff:ffff:ffff:ffff:ffff
1163ebb:73::/323ebb:73:ffff:ffff:ffff:ffff:ffff:ffff
1173ebb:74::/323ebb:74:ffff:ffff:ffff:ffff:ffff:ffff
1183ebb:75::/323ebb:75:ffff:ffff:ffff:ffff:ffff:ffff
1193ebb:76::/323ebb:76:ffff:ffff:ffff:ffff:ffff:ffff
1203ebb:77::/323ebb:77:ffff:ffff:ffff:ffff:ffff:ffff
1213ebb:78::/323ebb:78:ffff:ffff:ffff:ffff:ffff:ffff
1223ebb:79::/323ebb:79:ffff:ffff:ffff:ffff:ffff:ffff
1233ebb:7a::/323ebb:7a:ffff:ffff:ffff:ffff:ffff:ffff
1243ebb:7b::/323ebb:7b:ffff:ffff:ffff:ffff:ffff:ffff
1253ebb:7c::/323ebb:7c:ffff:ffff:ffff:ffff:ffff:ffff
1263ebb:7d::/323ebb:7d:ffff:ffff:ffff:ffff:ffff:ffff
1273ebb:7e::/323ebb:7e:ffff:ffff:ffff:ffff:ffff:ffff
1283ebb:7f::/323ebb:7f:ffff:ffff:ffff:ffff:ffff:ffff
1293ebb:80::/323ebb:80:ffff:ffff:ffff:ffff:ffff:ffff
1303ebb:81::/323ebb:81:ffff:ffff:ffff:ffff:ffff:ffff
1313ebb:82::/323ebb:82:ffff:ffff:ffff:ffff:ffff:ffff
1323ebb:83::/323ebb:83:ffff:ffff:ffff:ffff:ffff:ffff
1333ebb:84::/323ebb:84:ffff:ffff:ffff:ffff:ffff:ffff
1343ebb:85::/323ebb:85:ffff:ffff:ffff:ffff:ffff:ffff
1353ebb:86::/323ebb:86:ffff:ffff:ffff:ffff:ffff:ffff
1363ebb:87::/323ebb:87:ffff:ffff:ffff:ffff:ffff:ffff
1373ebb:88::/323ebb:88:ffff:ffff:ffff:ffff:ffff:ffff
1383ebb:89::/323ebb:89:ffff:ffff:ffff:ffff:ffff:ffff
1393ebb:8a::/323ebb:8a:ffff:ffff:ffff:ffff:ffff:ffff
1403ebb:8b::/323ebb:8b:ffff:ffff:ffff:ffff:ffff:ffff
1413ebb:8c::/323ebb:8c:ffff:ffff:ffff:ffff:ffff:ffff
1423ebb:8d::/323ebb:8d:ffff:ffff:ffff:ffff:ffff:ffff
1433ebb:8e::/323ebb:8e:ffff:ffff:ffff:ffff:ffff:ffff
1443ebb:8f::/323ebb:8f:ffff:ffff:ffff:ffff:ffff:ffff
1453ebb:90::/323ebb:90:ffff:ffff:ffff:ffff:ffff:ffff
1463ebb:91::/323ebb:91:ffff:ffff:ffff:ffff:ffff:ffff
1473ebb:92::/323ebb:92:ffff:ffff:ffff:ffff:ffff:ffff
1483ebb:93::/323ebb:93:ffff:ffff:ffff:ffff:ffff:ffff
1493ebb:94::/323ebb:94:ffff:ffff:ffff:ffff:ffff:ffff
1503ebb:95::/323ebb:95:ffff:ffff:ffff:ffff:ffff:ffff
1513ebb:96::/323ebb:96:ffff:ffff:ffff:ffff:ffff:ffff
1523ebb:97::/323ebb:97:ffff:ffff:ffff:ffff:ffff:ffff
1533ebb:98::/323ebb:98:ffff:ffff:ffff:ffff:ffff:ffff
1543ebb:99::/323ebb:99:ffff:ffff:ffff:ffff:ffff:ffff
1553ebb:9a::/323ebb:9a:ffff:ffff:ffff:ffff:ffff:ffff
1563ebb:9b::/323ebb:9b:ffff:ffff:ffff:ffff:ffff:ffff
1573ebb:9c::/323ebb:9c:ffff:ffff:ffff:ffff:ffff:ffff
1583ebb:9d::/323ebb:9d:ffff:ffff:ffff:ffff:ffff:ffff
1593ebb:9e::/323ebb:9e:ffff:ffff:ffff:ffff:ffff:ffff
1603ebb:9f::/323ebb:9f:ffff:ffff:ffff:ffff:ffff:ffff
1613ebb:a0::/323ebb:a0:ffff:ffff:ffff:ffff:ffff:ffff
1623ebb:a1::/323ebb:a1:ffff:ffff:ffff:ffff:ffff:ffff
1633ebb:a2::/323ebb:a2:ffff:ffff:ffff:ffff:ffff:ffff
1643ebb:a3::/323ebb:a3:ffff:ffff:ffff:ffff:ffff:ffff
1653ebb:a4::/323ebb:a4:ffff:ffff:ffff:ffff:ffff:ffff
1663ebb:a5::/323ebb:a5:ffff:ffff:ffff:ffff:ffff:ffff
1673ebb:a6::/323ebb:a6:ffff:ffff:ffff:ffff:ffff:ffff
1683ebb:a7::/323ebb:a7:ffff:ffff:ffff:ffff:ffff:ffff
1693ebb:a8::/323ebb:a8:ffff:ffff:ffff:ffff:ffff:ffff
1703ebb:a9::/323ebb:a9:ffff:ffff:ffff:ffff:ffff:ffff
1713ebb:aa::/323ebb:aa:ffff:ffff:ffff:ffff:ffff:ffff
1723ebb:ab::/323ebb:ab:ffff:ffff:ffff:ffff:ffff:ffff
1733ebb:ac::/323ebb:ac:ffff:ffff:ffff:ffff:ffff:ffff
1743ebb:ad::/323ebb:ad:ffff:ffff:ffff:ffff:ffff:ffff
1753ebb:ae::/323ebb:ae:ffff:ffff:ffff:ffff:ffff:ffff
1763ebb:af::/323ebb:af:ffff:ffff:ffff:ffff:ffff:ffff
1773ebb:b0::/323ebb:b0:ffff:ffff:ffff:ffff:ffff:ffff
1783ebb:b1::/323ebb:b1:ffff:ffff:ffff:ffff:ffff:ffff
1793ebb:b2::/323ebb:b2:ffff:ffff:ffff:ffff:ffff:ffff
1803ebb:b3::/323ebb:b3:ffff:ffff:ffff:ffff:ffff:ffff
1813ebb:b4::/323ebb:b4:ffff:ffff:ffff:ffff:ffff:ffff
1823ebb:b5::/323ebb:b5:ffff:ffff:ffff:ffff:ffff:ffff
1833ebb:b6::/323ebb:b6:ffff:ffff:ffff:ffff:ffff:ffff
1843ebb:b7::/323ebb:b7:ffff:ffff:ffff:ffff:ffff:ffff
1853ebb:b8::/323ebb:b8:ffff:ffff:ffff:ffff:ffff:ffff
1863ebb:b9::/323ebb:b9:ffff:ffff:ffff:ffff:ffff:ffff
1873ebb:ba::/323ebb:ba:ffff:ffff:ffff:ffff:ffff:ffff
1883ebb:bb::/323ebb:bb:ffff:ffff:ffff:ffff:ffff:ffff
1893ebb:bc::/323ebb:bc:ffff:ffff:ffff:ffff:ffff:ffff
1903ebb:bd::/323ebb:bd:ffff:ffff:ffff:ffff:ffff:ffff
1913ebb:be::/323ebb:be:ffff:ffff:ffff:ffff:ffff:ffff
1923ebb:bf::/323ebb:bf:ffff:ffff:ffff:ffff:ffff:ffff
1933ebb:c0::/323ebb:c0:ffff:ffff:ffff:ffff:ffff:ffff
1943ebb:c1::/323ebb:c1:ffff:ffff:ffff:ffff:ffff:ffff
1953ebb:c2::/323ebb:c2:ffff:ffff:ffff:ffff:ffff:ffff
1963ebb:c3::/323ebb:c3:ffff:ffff:ffff:ffff:ffff:ffff
1973ebb:c4::/323ebb:c4:ffff:ffff:ffff:ffff:ffff:ffff
1983ebb:c5::/323ebb:c5:ffff:ffff:ffff:ffff:ffff:ffff
1993ebb:c6::/323ebb:c6:ffff:ffff:ffff:ffff:ffff:ffff
2003ebb:c7::/323ebb:c7:ffff:ffff:ffff:ffff:ffff:ffff
2013ebb:c8::/323ebb:c8:ffff:ffff:ffff:ffff:ffff:ffff
2023ebb:c9::/323ebb:c9:ffff:ffff:ffff:ffff:ffff:ffff
2033ebb:ca::/323ebb:ca:ffff:ffff:ffff:ffff:ffff:ffff
2043ebb:cb::/323ebb:cb:ffff:ffff:ffff:ffff:ffff:ffff
2053ebb:cc::/323ebb:cc:ffff:ffff:ffff:ffff:ffff:ffff
2063ebb:cd::/323ebb:cd:ffff:ffff:ffff:ffff:ffff:ffff
2073ebb:ce::/323ebb:ce:ffff:ffff:ffff:ffff:ffff:ffff
2083ebb:cf::/323ebb:cf:ffff:ffff:ffff:ffff:ffff:ffff
2093ebb:d0::/323ebb:d0:ffff:ffff:ffff:ffff:ffff:ffff
2103ebb:d1::/323ebb:d1:ffff:ffff:ffff:ffff:ffff:ffff
2113ebb:d2::/323ebb:d2:ffff:ffff:ffff:ffff:ffff:ffff
2123ebb:d3::/323ebb:d3:ffff:ffff:ffff:ffff:ffff:ffff
2133ebb:d4::/323ebb:d4:ffff:ffff:ffff:ffff:ffff:ffff
2143ebb:d5::/323ebb:d5:ffff:ffff:ffff:ffff:ffff:ffff
2153ebb:d6::/323ebb:d6:ffff:ffff:ffff:ffff:ffff:ffff
2163ebb:d7::/323ebb:d7:ffff:ffff:ffff:ffff:ffff:ffff
2173ebb:d8::/323ebb:d8:ffff:ffff:ffff:ffff:ffff:ffff
2183ebb:d9::/323ebb:d9:ffff:ffff:ffff:ffff:ffff:ffff
2193ebb:da::/323ebb:da:ffff:ffff:ffff:ffff:ffff:ffff
2203ebb:db::/323ebb:db:ffff:ffff:ffff:ffff:ffff:ffff
2213ebb:dc::/323ebb:dc:ffff:ffff:ffff:ffff:ffff:ffff
2223ebb:dd::/323ebb:dd:ffff:ffff:ffff:ffff:ffff:ffff
2233ebb:de::/323ebb:de:ffff:ffff:ffff:ffff:ffff:ffff
2243ebb:df::/323ebb:df:ffff:ffff:ffff:ffff:ffff:ffff
2253ebb:e0::/323ebb:e0:ffff:ffff:ffff:ffff:ffff:ffff
2263ebb:e1::/323ebb:e1:ffff:ffff:ffff:ffff:ffff:ffff
2273ebb:e2::/323ebb:e2:ffff:ffff:ffff:ffff:ffff:ffff
2283ebb:e3::/323ebb:e3:ffff:ffff:ffff:ffff:ffff:ffff
2293ebb:e4::/323ebb:e4:ffff:ffff:ffff:ffff:ffff:ffff
2303ebb:e5::/323ebb:e5:ffff:ffff:ffff:ffff:ffff:ffff
2313ebb:e6::/323ebb:e6:ffff:ffff:ffff:ffff:ffff:ffff
2323ebb:e7::/323ebb:e7:ffff:ffff:ffff:ffff:ffff:ffff
2333ebb:e8::/323ebb:e8:ffff:ffff:ffff:ffff:ffff:ffff
2343ebb:e9::/323ebb:e9:ffff:ffff:ffff:ffff:ffff:ffff
2353ebb:ea::/323ebb:ea:ffff:ffff:ffff:ffff:ffff:ffff
2363ebb:eb::/323ebb:eb:ffff:ffff:ffff:ffff:ffff:ffff
2373ebb:ec::/323ebb:ec:ffff:ffff:ffff:ffff:ffff:ffff
2383ebb:ed::/323ebb:ed:ffff:ffff:ffff:ffff:ffff:ffff
2393ebb:ee::/323ebb:ee:ffff:ffff:ffff:ffff:ffff:ffff
2403ebb:ef::/323ebb:ef:ffff:ffff:ffff:ffff:ffff:ffff
2413ebb:f0::/323ebb:f0:ffff:ffff:ffff:ffff:ffff:ffff
2423ebb:f1::/323ebb:f1:ffff:ffff:ffff:ffff:ffff:ffff
2433ebb:f2::/323ebb:f2:ffff:ffff:ffff:ffff:ffff:ffff
2443ebb:f3::/323ebb:f3:ffff:ffff:ffff:ffff:ffff:ffff
2453ebb:f4::/323ebb:f4:ffff:ffff:ffff:ffff:ffff:ffff
2463ebb:f5::/323ebb:f5:ffff:ffff:ffff:ffff:ffff:ffff
2473ebb:f6::/323ebb:f6:ffff:ffff:ffff:ffff:ffff:ffff
2483ebb:f7::/323ebb:f7:ffff:ffff:ffff:ffff:ffff:ffff
2493ebb:f8::/323ebb:f8:ffff:ffff:ffff:ffff:ffff:ffff
2503ebb:f9::/323ebb:f9:ffff:ffff:ffff:ffff:ffff:ffff
2513ebb:fa::/323ebb:fa:ffff:ffff:ffff:ffff:ffff:ffff
2523ebb:fb::/323ebb:fb:ffff:ffff:ffff:ffff:ffff:ffff
2533ebb:fc::/323ebb:fc:ffff:ffff:ffff:ffff:ffff:ffff
2543ebb:fd::/323ebb:fd:ffff:ffff:ffff:ffff:ffff:ffff
2553ebb:fe::/323ebb:fe:ffff:ffff:ffff:ffff:ffff:ffff
2563ebb:ff::/323ebb:ff: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.