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

2ccd::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
12ccd::/322ccd:0:ffff:ffff:ffff:ffff:ffff:ffff
22ccd:1::/322ccd:1:ffff:ffff:ffff:ffff:ffff:ffff
32ccd:2::/322ccd:2:ffff:ffff:ffff:ffff:ffff:ffff
42ccd:3::/322ccd:3:ffff:ffff:ffff:ffff:ffff:ffff
52ccd:4::/322ccd:4:ffff:ffff:ffff:ffff:ffff:ffff
62ccd:5::/322ccd:5:ffff:ffff:ffff:ffff:ffff:ffff
72ccd:6::/322ccd:6:ffff:ffff:ffff:ffff:ffff:ffff
82ccd:7::/322ccd:7:ffff:ffff:ffff:ffff:ffff:ffff
92ccd:8::/322ccd:8:ffff:ffff:ffff:ffff:ffff:ffff
102ccd:9::/322ccd:9:ffff:ffff:ffff:ffff:ffff:ffff
112ccd:a::/322ccd:a:ffff:ffff:ffff:ffff:ffff:ffff
122ccd:b::/322ccd:b:ffff:ffff:ffff:ffff:ffff:ffff
132ccd:c::/322ccd:c:ffff:ffff:ffff:ffff:ffff:ffff
142ccd:d::/322ccd:d:ffff:ffff:ffff:ffff:ffff:ffff
152ccd:e::/322ccd:e:ffff:ffff:ffff:ffff:ffff:ffff
162ccd:f::/322ccd:f:ffff:ffff:ffff:ffff:ffff:ffff
172ccd:10::/322ccd:10:ffff:ffff:ffff:ffff:ffff:ffff
182ccd:11::/322ccd:11:ffff:ffff:ffff:ffff:ffff:ffff
192ccd:12::/322ccd:12:ffff:ffff:ffff:ffff:ffff:ffff
202ccd:13::/322ccd:13:ffff:ffff:ffff:ffff:ffff:ffff
212ccd:14::/322ccd:14:ffff:ffff:ffff:ffff:ffff:ffff
222ccd:15::/322ccd:15:ffff:ffff:ffff:ffff:ffff:ffff
232ccd:16::/322ccd:16:ffff:ffff:ffff:ffff:ffff:ffff
242ccd:17::/322ccd:17:ffff:ffff:ffff:ffff:ffff:ffff
252ccd:18::/322ccd:18:ffff:ffff:ffff:ffff:ffff:ffff
262ccd:19::/322ccd:19:ffff:ffff:ffff:ffff:ffff:ffff
272ccd:1a::/322ccd:1a:ffff:ffff:ffff:ffff:ffff:ffff
282ccd:1b::/322ccd:1b:ffff:ffff:ffff:ffff:ffff:ffff
292ccd:1c::/322ccd:1c:ffff:ffff:ffff:ffff:ffff:ffff
302ccd:1d::/322ccd:1d:ffff:ffff:ffff:ffff:ffff:ffff
312ccd:1e::/322ccd:1e:ffff:ffff:ffff:ffff:ffff:ffff
322ccd:1f::/322ccd:1f:ffff:ffff:ffff:ffff:ffff:ffff
332ccd:20::/322ccd:20:ffff:ffff:ffff:ffff:ffff:ffff
342ccd:21::/322ccd:21:ffff:ffff:ffff:ffff:ffff:ffff
352ccd:22::/322ccd:22:ffff:ffff:ffff:ffff:ffff:ffff
362ccd:23::/322ccd:23:ffff:ffff:ffff:ffff:ffff:ffff
372ccd:24::/322ccd:24:ffff:ffff:ffff:ffff:ffff:ffff
382ccd:25::/322ccd:25:ffff:ffff:ffff:ffff:ffff:ffff
392ccd:26::/322ccd:26:ffff:ffff:ffff:ffff:ffff:ffff
402ccd:27::/322ccd:27:ffff:ffff:ffff:ffff:ffff:ffff
412ccd:28::/322ccd:28:ffff:ffff:ffff:ffff:ffff:ffff
422ccd:29::/322ccd:29:ffff:ffff:ffff:ffff:ffff:ffff
432ccd:2a::/322ccd:2a:ffff:ffff:ffff:ffff:ffff:ffff
442ccd:2b::/322ccd:2b:ffff:ffff:ffff:ffff:ffff:ffff
452ccd:2c::/322ccd:2c:ffff:ffff:ffff:ffff:ffff:ffff
462ccd:2d::/322ccd:2d:ffff:ffff:ffff:ffff:ffff:ffff
472ccd:2e::/322ccd:2e:ffff:ffff:ffff:ffff:ffff:ffff
482ccd:2f::/322ccd:2f:ffff:ffff:ffff:ffff:ffff:ffff
492ccd:30::/322ccd:30:ffff:ffff:ffff:ffff:ffff:ffff
502ccd:31::/322ccd:31:ffff:ffff:ffff:ffff:ffff:ffff
512ccd:32::/322ccd:32:ffff:ffff:ffff:ffff:ffff:ffff
522ccd:33::/322ccd:33:ffff:ffff:ffff:ffff:ffff:ffff
532ccd:34::/322ccd:34:ffff:ffff:ffff:ffff:ffff:ffff
542ccd:35::/322ccd:35:ffff:ffff:ffff:ffff:ffff:ffff
552ccd:36::/322ccd:36:ffff:ffff:ffff:ffff:ffff:ffff
562ccd:37::/322ccd:37:ffff:ffff:ffff:ffff:ffff:ffff
572ccd:38::/322ccd:38:ffff:ffff:ffff:ffff:ffff:ffff
582ccd:39::/322ccd:39:ffff:ffff:ffff:ffff:ffff:ffff
592ccd:3a::/322ccd:3a:ffff:ffff:ffff:ffff:ffff:ffff
602ccd:3b::/322ccd:3b:ffff:ffff:ffff:ffff:ffff:ffff
612ccd:3c::/322ccd:3c:ffff:ffff:ffff:ffff:ffff:ffff
622ccd:3d::/322ccd:3d:ffff:ffff:ffff:ffff:ffff:ffff
632ccd:3e::/322ccd:3e:ffff:ffff:ffff:ffff:ffff:ffff
642ccd:3f::/322ccd:3f:ffff:ffff:ffff:ffff:ffff:ffff
652ccd:40::/322ccd:40:ffff:ffff:ffff:ffff:ffff:ffff
662ccd:41::/322ccd:41:ffff:ffff:ffff:ffff:ffff:ffff
672ccd:42::/322ccd:42:ffff:ffff:ffff:ffff:ffff:ffff
682ccd:43::/322ccd:43:ffff:ffff:ffff:ffff:ffff:ffff
692ccd:44::/322ccd:44:ffff:ffff:ffff:ffff:ffff:ffff
702ccd:45::/322ccd:45:ffff:ffff:ffff:ffff:ffff:ffff
712ccd:46::/322ccd:46:ffff:ffff:ffff:ffff:ffff:ffff
722ccd:47::/322ccd:47:ffff:ffff:ffff:ffff:ffff:ffff
732ccd:48::/322ccd:48:ffff:ffff:ffff:ffff:ffff:ffff
742ccd:49::/322ccd:49:ffff:ffff:ffff:ffff:ffff:ffff
752ccd:4a::/322ccd:4a:ffff:ffff:ffff:ffff:ffff:ffff
762ccd:4b::/322ccd:4b:ffff:ffff:ffff:ffff:ffff:ffff
772ccd:4c::/322ccd:4c:ffff:ffff:ffff:ffff:ffff:ffff
782ccd:4d::/322ccd:4d:ffff:ffff:ffff:ffff:ffff:ffff
792ccd:4e::/322ccd:4e:ffff:ffff:ffff:ffff:ffff:ffff
802ccd:4f::/322ccd:4f:ffff:ffff:ffff:ffff:ffff:ffff
812ccd:50::/322ccd:50:ffff:ffff:ffff:ffff:ffff:ffff
822ccd:51::/322ccd:51:ffff:ffff:ffff:ffff:ffff:ffff
832ccd:52::/322ccd:52:ffff:ffff:ffff:ffff:ffff:ffff
842ccd:53::/322ccd:53:ffff:ffff:ffff:ffff:ffff:ffff
852ccd:54::/322ccd:54:ffff:ffff:ffff:ffff:ffff:ffff
862ccd:55::/322ccd:55:ffff:ffff:ffff:ffff:ffff:ffff
872ccd:56::/322ccd:56:ffff:ffff:ffff:ffff:ffff:ffff
882ccd:57::/322ccd:57:ffff:ffff:ffff:ffff:ffff:ffff
892ccd:58::/322ccd:58:ffff:ffff:ffff:ffff:ffff:ffff
902ccd:59::/322ccd:59:ffff:ffff:ffff:ffff:ffff:ffff
912ccd:5a::/322ccd:5a:ffff:ffff:ffff:ffff:ffff:ffff
922ccd:5b::/322ccd:5b:ffff:ffff:ffff:ffff:ffff:ffff
932ccd:5c::/322ccd:5c:ffff:ffff:ffff:ffff:ffff:ffff
942ccd:5d::/322ccd:5d:ffff:ffff:ffff:ffff:ffff:ffff
952ccd:5e::/322ccd:5e:ffff:ffff:ffff:ffff:ffff:ffff
962ccd:5f::/322ccd:5f:ffff:ffff:ffff:ffff:ffff:ffff
972ccd:60::/322ccd:60:ffff:ffff:ffff:ffff:ffff:ffff
982ccd:61::/322ccd:61:ffff:ffff:ffff:ffff:ffff:ffff
992ccd:62::/322ccd:62:ffff:ffff:ffff:ffff:ffff:ffff
1002ccd:63::/322ccd:63:ffff:ffff:ffff:ffff:ffff:ffff
1012ccd:64::/322ccd:64:ffff:ffff:ffff:ffff:ffff:ffff
1022ccd:65::/322ccd:65:ffff:ffff:ffff:ffff:ffff:ffff
1032ccd:66::/322ccd:66:ffff:ffff:ffff:ffff:ffff:ffff
1042ccd:67::/322ccd:67:ffff:ffff:ffff:ffff:ffff:ffff
1052ccd:68::/322ccd:68:ffff:ffff:ffff:ffff:ffff:ffff
1062ccd:69::/322ccd:69:ffff:ffff:ffff:ffff:ffff:ffff
1072ccd:6a::/322ccd:6a:ffff:ffff:ffff:ffff:ffff:ffff
1082ccd:6b::/322ccd:6b:ffff:ffff:ffff:ffff:ffff:ffff
1092ccd:6c::/322ccd:6c:ffff:ffff:ffff:ffff:ffff:ffff
1102ccd:6d::/322ccd:6d:ffff:ffff:ffff:ffff:ffff:ffff
1112ccd:6e::/322ccd:6e:ffff:ffff:ffff:ffff:ffff:ffff
1122ccd:6f::/322ccd:6f:ffff:ffff:ffff:ffff:ffff:ffff
1132ccd:70::/322ccd:70:ffff:ffff:ffff:ffff:ffff:ffff
1142ccd:71::/322ccd:71:ffff:ffff:ffff:ffff:ffff:ffff
1152ccd:72::/322ccd:72:ffff:ffff:ffff:ffff:ffff:ffff
1162ccd:73::/322ccd:73:ffff:ffff:ffff:ffff:ffff:ffff
1172ccd:74::/322ccd:74:ffff:ffff:ffff:ffff:ffff:ffff
1182ccd:75::/322ccd:75:ffff:ffff:ffff:ffff:ffff:ffff
1192ccd:76::/322ccd:76:ffff:ffff:ffff:ffff:ffff:ffff
1202ccd:77::/322ccd:77:ffff:ffff:ffff:ffff:ffff:ffff
1212ccd:78::/322ccd:78:ffff:ffff:ffff:ffff:ffff:ffff
1222ccd:79::/322ccd:79:ffff:ffff:ffff:ffff:ffff:ffff
1232ccd:7a::/322ccd:7a:ffff:ffff:ffff:ffff:ffff:ffff
1242ccd:7b::/322ccd:7b:ffff:ffff:ffff:ffff:ffff:ffff
1252ccd:7c::/322ccd:7c:ffff:ffff:ffff:ffff:ffff:ffff
1262ccd:7d::/322ccd:7d:ffff:ffff:ffff:ffff:ffff:ffff
1272ccd:7e::/322ccd:7e:ffff:ffff:ffff:ffff:ffff:ffff
1282ccd:7f::/322ccd:7f:ffff:ffff:ffff:ffff:ffff:ffff
1292ccd:80::/322ccd:80:ffff:ffff:ffff:ffff:ffff:ffff
1302ccd:81::/322ccd:81:ffff:ffff:ffff:ffff:ffff:ffff
1312ccd:82::/322ccd:82:ffff:ffff:ffff:ffff:ffff:ffff
1322ccd:83::/322ccd:83:ffff:ffff:ffff:ffff:ffff:ffff
1332ccd:84::/322ccd:84:ffff:ffff:ffff:ffff:ffff:ffff
1342ccd:85::/322ccd:85:ffff:ffff:ffff:ffff:ffff:ffff
1352ccd:86::/322ccd:86:ffff:ffff:ffff:ffff:ffff:ffff
1362ccd:87::/322ccd:87:ffff:ffff:ffff:ffff:ffff:ffff
1372ccd:88::/322ccd:88:ffff:ffff:ffff:ffff:ffff:ffff
1382ccd:89::/322ccd:89:ffff:ffff:ffff:ffff:ffff:ffff
1392ccd:8a::/322ccd:8a:ffff:ffff:ffff:ffff:ffff:ffff
1402ccd:8b::/322ccd:8b:ffff:ffff:ffff:ffff:ffff:ffff
1412ccd:8c::/322ccd:8c:ffff:ffff:ffff:ffff:ffff:ffff
1422ccd:8d::/322ccd:8d:ffff:ffff:ffff:ffff:ffff:ffff
1432ccd:8e::/322ccd:8e:ffff:ffff:ffff:ffff:ffff:ffff
1442ccd:8f::/322ccd:8f:ffff:ffff:ffff:ffff:ffff:ffff
1452ccd:90::/322ccd:90:ffff:ffff:ffff:ffff:ffff:ffff
1462ccd:91::/322ccd:91:ffff:ffff:ffff:ffff:ffff:ffff
1472ccd:92::/322ccd:92:ffff:ffff:ffff:ffff:ffff:ffff
1482ccd:93::/322ccd:93:ffff:ffff:ffff:ffff:ffff:ffff
1492ccd:94::/322ccd:94:ffff:ffff:ffff:ffff:ffff:ffff
1502ccd:95::/322ccd:95:ffff:ffff:ffff:ffff:ffff:ffff
1512ccd:96::/322ccd:96:ffff:ffff:ffff:ffff:ffff:ffff
1522ccd:97::/322ccd:97:ffff:ffff:ffff:ffff:ffff:ffff
1532ccd:98::/322ccd:98:ffff:ffff:ffff:ffff:ffff:ffff
1542ccd:99::/322ccd:99:ffff:ffff:ffff:ffff:ffff:ffff
1552ccd:9a::/322ccd:9a:ffff:ffff:ffff:ffff:ffff:ffff
1562ccd:9b::/322ccd:9b:ffff:ffff:ffff:ffff:ffff:ffff
1572ccd:9c::/322ccd:9c:ffff:ffff:ffff:ffff:ffff:ffff
1582ccd:9d::/322ccd:9d:ffff:ffff:ffff:ffff:ffff:ffff
1592ccd:9e::/322ccd:9e:ffff:ffff:ffff:ffff:ffff:ffff
1602ccd:9f::/322ccd:9f:ffff:ffff:ffff:ffff:ffff:ffff
1612ccd:a0::/322ccd:a0:ffff:ffff:ffff:ffff:ffff:ffff
1622ccd:a1::/322ccd:a1:ffff:ffff:ffff:ffff:ffff:ffff
1632ccd:a2::/322ccd:a2:ffff:ffff:ffff:ffff:ffff:ffff
1642ccd:a3::/322ccd:a3:ffff:ffff:ffff:ffff:ffff:ffff
1652ccd:a4::/322ccd:a4:ffff:ffff:ffff:ffff:ffff:ffff
1662ccd:a5::/322ccd:a5:ffff:ffff:ffff:ffff:ffff:ffff
1672ccd:a6::/322ccd:a6:ffff:ffff:ffff:ffff:ffff:ffff
1682ccd:a7::/322ccd:a7:ffff:ffff:ffff:ffff:ffff:ffff
1692ccd:a8::/322ccd:a8:ffff:ffff:ffff:ffff:ffff:ffff
1702ccd:a9::/322ccd:a9:ffff:ffff:ffff:ffff:ffff:ffff
1712ccd:aa::/322ccd:aa:ffff:ffff:ffff:ffff:ffff:ffff
1722ccd:ab::/322ccd:ab:ffff:ffff:ffff:ffff:ffff:ffff
1732ccd:ac::/322ccd:ac:ffff:ffff:ffff:ffff:ffff:ffff
1742ccd:ad::/322ccd:ad:ffff:ffff:ffff:ffff:ffff:ffff
1752ccd:ae::/322ccd:ae:ffff:ffff:ffff:ffff:ffff:ffff
1762ccd:af::/322ccd:af:ffff:ffff:ffff:ffff:ffff:ffff
1772ccd:b0::/322ccd:b0:ffff:ffff:ffff:ffff:ffff:ffff
1782ccd:b1::/322ccd:b1:ffff:ffff:ffff:ffff:ffff:ffff
1792ccd:b2::/322ccd:b2:ffff:ffff:ffff:ffff:ffff:ffff
1802ccd:b3::/322ccd:b3:ffff:ffff:ffff:ffff:ffff:ffff
1812ccd:b4::/322ccd:b4:ffff:ffff:ffff:ffff:ffff:ffff
1822ccd:b5::/322ccd:b5:ffff:ffff:ffff:ffff:ffff:ffff
1832ccd:b6::/322ccd:b6:ffff:ffff:ffff:ffff:ffff:ffff
1842ccd:b7::/322ccd:b7:ffff:ffff:ffff:ffff:ffff:ffff
1852ccd:b8::/322ccd:b8:ffff:ffff:ffff:ffff:ffff:ffff
1862ccd:b9::/322ccd:b9:ffff:ffff:ffff:ffff:ffff:ffff
1872ccd:ba::/322ccd:ba:ffff:ffff:ffff:ffff:ffff:ffff
1882ccd:bb::/322ccd:bb:ffff:ffff:ffff:ffff:ffff:ffff
1892ccd:bc::/322ccd:bc:ffff:ffff:ffff:ffff:ffff:ffff
1902ccd:bd::/322ccd:bd:ffff:ffff:ffff:ffff:ffff:ffff
1912ccd:be::/322ccd:be:ffff:ffff:ffff:ffff:ffff:ffff
1922ccd:bf::/322ccd:bf:ffff:ffff:ffff:ffff:ffff:ffff
1932ccd:c0::/322ccd:c0:ffff:ffff:ffff:ffff:ffff:ffff
1942ccd:c1::/322ccd:c1:ffff:ffff:ffff:ffff:ffff:ffff
1952ccd:c2::/322ccd:c2:ffff:ffff:ffff:ffff:ffff:ffff
1962ccd:c3::/322ccd:c3:ffff:ffff:ffff:ffff:ffff:ffff
1972ccd:c4::/322ccd:c4:ffff:ffff:ffff:ffff:ffff:ffff
1982ccd:c5::/322ccd:c5:ffff:ffff:ffff:ffff:ffff:ffff
1992ccd:c6::/322ccd:c6:ffff:ffff:ffff:ffff:ffff:ffff
2002ccd:c7::/322ccd:c7:ffff:ffff:ffff:ffff:ffff:ffff
2012ccd:c8::/322ccd:c8:ffff:ffff:ffff:ffff:ffff:ffff
2022ccd:c9::/322ccd:c9:ffff:ffff:ffff:ffff:ffff:ffff
2032ccd:ca::/322ccd:ca:ffff:ffff:ffff:ffff:ffff:ffff
2042ccd:cb::/322ccd:cb:ffff:ffff:ffff:ffff:ffff:ffff
2052ccd:cc::/322ccd:cc:ffff:ffff:ffff:ffff:ffff:ffff
2062ccd:cd::/322ccd:cd:ffff:ffff:ffff:ffff:ffff:ffff
2072ccd:ce::/322ccd:ce:ffff:ffff:ffff:ffff:ffff:ffff
2082ccd:cf::/322ccd:cf:ffff:ffff:ffff:ffff:ffff:ffff
2092ccd:d0::/322ccd:d0:ffff:ffff:ffff:ffff:ffff:ffff
2102ccd:d1::/322ccd:d1:ffff:ffff:ffff:ffff:ffff:ffff
2112ccd:d2::/322ccd:d2:ffff:ffff:ffff:ffff:ffff:ffff
2122ccd:d3::/322ccd:d3:ffff:ffff:ffff:ffff:ffff:ffff
2132ccd:d4::/322ccd:d4:ffff:ffff:ffff:ffff:ffff:ffff
2142ccd:d5::/322ccd:d5:ffff:ffff:ffff:ffff:ffff:ffff
2152ccd:d6::/322ccd:d6:ffff:ffff:ffff:ffff:ffff:ffff
2162ccd:d7::/322ccd:d7:ffff:ffff:ffff:ffff:ffff:ffff
2172ccd:d8::/322ccd:d8:ffff:ffff:ffff:ffff:ffff:ffff
2182ccd:d9::/322ccd:d9:ffff:ffff:ffff:ffff:ffff:ffff
2192ccd:da::/322ccd:da:ffff:ffff:ffff:ffff:ffff:ffff
2202ccd:db::/322ccd:db:ffff:ffff:ffff:ffff:ffff:ffff
2212ccd:dc::/322ccd:dc:ffff:ffff:ffff:ffff:ffff:ffff
2222ccd:dd::/322ccd:dd:ffff:ffff:ffff:ffff:ffff:ffff
2232ccd:de::/322ccd:de:ffff:ffff:ffff:ffff:ffff:ffff
2242ccd:df::/322ccd:df:ffff:ffff:ffff:ffff:ffff:ffff
2252ccd:e0::/322ccd:e0:ffff:ffff:ffff:ffff:ffff:ffff
2262ccd:e1::/322ccd:e1:ffff:ffff:ffff:ffff:ffff:ffff
2272ccd:e2::/322ccd:e2:ffff:ffff:ffff:ffff:ffff:ffff
2282ccd:e3::/322ccd:e3:ffff:ffff:ffff:ffff:ffff:ffff
2292ccd:e4::/322ccd:e4:ffff:ffff:ffff:ffff:ffff:ffff
2302ccd:e5::/322ccd:e5:ffff:ffff:ffff:ffff:ffff:ffff
2312ccd:e6::/322ccd:e6:ffff:ffff:ffff:ffff:ffff:ffff
2322ccd:e7::/322ccd:e7:ffff:ffff:ffff:ffff:ffff:ffff
2332ccd:e8::/322ccd:e8:ffff:ffff:ffff:ffff:ffff:ffff
2342ccd:e9::/322ccd:e9:ffff:ffff:ffff:ffff:ffff:ffff
2352ccd:ea::/322ccd:ea:ffff:ffff:ffff:ffff:ffff:ffff
2362ccd:eb::/322ccd:eb:ffff:ffff:ffff:ffff:ffff:ffff
2372ccd:ec::/322ccd:ec:ffff:ffff:ffff:ffff:ffff:ffff
2382ccd:ed::/322ccd:ed:ffff:ffff:ffff:ffff:ffff:ffff
2392ccd:ee::/322ccd:ee:ffff:ffff:ffff:ffff:ffff:ffff
2402ccd:ef::/322ccd:ef:ffff:ffff:ffff:ffff:ffff:ffff
2412ccd:f0::/322ccd:f0:ffff:ffff:ffff:ffff:ffff:ffff
2422ccd:f1::/322ccd:f1:ffff:ffff:ffff:ffff:ffff:ffff
2432ccd:f2::/322ccd:f2:ffff:ffff:ffff:ffff:ffff:ffff
2442ccd:f3::/322ccd:f3:ffff:ffff:ffff:ffff:ffff:ffff
2452ccd:f4::/322ccd:f4:ffff:ffff:ffff:ffff:ffff:ffff
2462ccd:f5::/322ccd:f5:ffff:ffff:ffff:ffff:ffff:ffff
2472ccd:f6::/322ccd:f6:ffff:ffff:ffff:ffff:ffff:ffff
2482ccd:f7::/322ccd:f7:ffff:ffff:ffff:ffff:ffff:ffff
2492ccd:f8::/322ccd:f8:ffff:ffff:ffff:ffff:ffff:ffff
2502ccd:f9::/322ccd:f9:ffff:ffff:ffff:ffff:ffff:ffff
2512ccd:fa::/322ccd:fa:ffff:ffff:ffff:ffff:ffff:ffff
2522ccd:fb::/322ccd:fb:ffff:ffff:ffff:ffff:ffff:ffff
2532ccd:fc::/322ccd:fc:ffff:ffff:ffff:ffff:ffff:ffff
2542ccd:fd::/322ccd:fd:ffff:ffff:ffff:ffff:ffff:ffff
2552ccd:fe::/322ccd:fe:ffff:ffff:ffff:ffff:ffff:ffff
2562ccd:ff::/322ccd: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.