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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
3ef2::/16
First address
3ef2::
Last address
3ef2: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
3ef2:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
2.f.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)

3ef2::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
13ef2::/323ef2:0:ffff:ffff:ffff:ffff:ffff:ffff
23ef2:1::/323ef2:1:ffff:ffff:ffff:ffff:ffff:ffff
33ef2:2::/323ef2:2:ffff:ffff:ffff:ffff:ffff:ffff
43ef2:3::/323ef2:3:ffff:ffff:ffff:ffff:ffff:ffff
53ef2:4::/323ef2:4:ffff:ffff:ffff:ffff:ffff:ffff
63ef2:5::/323ef2:5:ffff:ffff:ffff:ffff:ffff:ffff
73ef2:6::/323ef2:6:ffff:ffff:ffff:ffff:ffff:ffff
83ef2:7::/323ef2:7:ffff:ffff:ffff:ffff:ffff:ffff
93ef2:8::/323ef2:8:ffff:ffff:ffff:ffff:ffff:ffff
103ef2:9::/323ef2:9:ffff:ffff:ffff:ffff:ffff:ffff
113ef2:a::/323ef2:a:ffff:ffff:ffff:ffff:ffff:ffff
123ef2:b::/323ef2:b:ffff:ffff:ffff:ffff:ffff:ffff
133ef2:c::/323ef2:c:ffff:ffff:ffff:ffff:ffff:ffff
143ef2:d::/323ef2:d:ffff:ffff:ffff:ffff:ffff:ffff
153ef2:e::/323ef2:e:ffff:ffff:ffff:ffff:ffff:ffff
163ef2:f::/323ef2:f:ffff:ffff:ffff:ffff:ffff:ffff
173ef2:10::/323ef2:10:ffff:ffff:ffff:ffff:ffff:ffff
183ef2:11::/323ef2:11:ffff:ffff:ffff:ffff:ffff:ffff
193ef2:12::/323ef2:12:ffff:ffff:ffff:ffff:ffff:ffff
203ef2:13::/323ef2:13:ffff:ffff:ffff:ffff:ffff:ffff
213ef2:14::/323ef2:14:ffff:ffff:ffff:ffff:ffff:ffff
223ef2:15::/323ef2:15:ffff:ffff:ffff:ffff:ffff:ffff
233ef2:16::/323ef2:16:ffff:ffff:ffff:ffff:ffff:ffff
243ef2:17::/323ef2:17:ffff:ffff:ffff:ffff:ffff:ffff
253ef2:18::/323ef2:18:ffff:ffff:ffff:ffff:ffff:ffff
263ef2:19::/323ef2:19:ffff:ffff:ffff:ffff:ffff:ffff
273ef2:1a::/323ef2:1a:ffff:ffff:ffff:ffff:ffff:ffff
283ef2:1b::/323ef2:1b:ffff:ffff:ffff:ffff:ffff:ffff
293ef2:1c::/323ef2:1c:ffff:ffff:ffff:ffff:ffff:ffff
303ef2:1d::/323ef2:1d:ffff:ffff:ffff:ffff:ffff:ffff
313ef2:1e::/323ef2:1e:ffff:ffff:ffff:ffff:ffff:ffff
323ef2:1f::/323ef2:1f:ffff:ffff:ffff:ffff:ffff:ffff
333ef2:20::/323ef2:20:ffff:ffff:ffff:ffff:ffff:ffff
343ef2:21::/323ef2:21:ffff:ffff:ffff:ffff:ffff:ffff
353ef2:22::/323ef2:22:ffff:ffff:ffff:ffff:ffff:ffff
363ef2:23::/323ef2:23:ffff:ffff:ffff:ffff:ffff:ffff
373ef2:24::/323ef2:24:ffff:ffff:ffff:ffff:ffff:ffff
383ef2:25::/323ef2:25:ffff:ffff:ffff:ffff:ffff:ffff
393ef2:26::/323ef2:26:ffff:ffff:ffff:ffff:ffff:ffff
403ef2:27::/323ef2:27:ffff:ffff:ffff:ffff:ffff:ffff
413ef2:28::/323ef2:28:ffff:ffff:ffff:ffff:ffff:ffff
423ef2:29::/323ef2:29:ffff:ffff:ffff:ffff:ffff:ffff
433ef2:2a::/323ef2:2a:ffff:ffff:ffff:ffff:ffff:ffff
443ef2:2b::/323ef2:2b:ffff:ffff:ffff:ffff:ffff:ffff
453ef2:2c::/323ef2:2c:ffff:ffff:ffff:ffff:ffff:ffff
463ef2:2d::/323ef2:2d:ffff:ffff:ffff:ffff:ffff:ffff
473ef2:2e::/323ef2:2e:ffff:ffff:ffff:ffff:ffff:ffff
483ef2:2f::/323ef2:2f:ffff:ffff:ffff:ffff:ffff:ffff
493ef2:30::/323ef2:30:ffff:ffff:ffff:ffff:ffff:ffff
503ef2:31::/323ef2:31:ffff:ffff:ffff:ffff:ffff:ffff
513ef2:32::/323ef2:32:ffff:ffff:ffff:ffff:ffff:ffff
523ef2:33::/323ef2:33:ffff:ffff:ffff:ffff:ffff:ffff
533ef2:34::/323ef2:34:ffff:ffff:ffff:ffff:ffff:ffff
543ef2:35::/323ef2:35:ffff:ffff:ffff:ffff:ffff:ffff
553ef2:36::/323ef2:36:ffff:ffff:ffff:ffff:ffff:ffff
563ef2:37::/323ef2:37:ffff:ffff:ffff:ffff:ffff:ffff
573ef2:38::/323ef2:38:ffff:ffff:ffff:ffff:ffff:ffff
583ef2:39::/323ef2:39:ffff:ffff:ffff:ffff:ffff:ffff
593ef2:3a::/323ef2:3a:ffff:ffff:ffff:ffff:ffff:ffff
603ef2:3b::/323ef2:3b:ffff:ffff:ffff:ffff:ffff:ffff
613ef2:3c::/323ef2:3c:ffff:ffff:ffff:ffff:ffff:ffff
623ef2:3d::/323ef2:3d:ffff:ffff:ffff:ffff:ffff:ffff
633ef2:3e::/323ef2:3e:ffff:ffff:ffff:ffff:ffff:ffff
643ef2:3f::/323ef2:3f:ffff:ffff:ffff:ffff:ffff:ffff
653ef2:40::/323ef2:40:ffff:ffff:ffff:ffff:ffff:ffff
663ef2:41::/323ef2:41:ffff:ffff:ffff:ffff:ffff:ffff
673ef2:42::/323ef2:42:ffff:ffff:ffff:ffff:ffff:ffff
683ef2:43::/323ef2:43:ffff:ffff:ffff:ffff:ffff:ffff
693ef2:44::/323ef2:44:ffff:ffff:ffff:ffff:ffff:ffff
703ef2:45::/323ef2:45:ffff:ffff:ffff:ffff:ffff:ffff
713ef2:46::/323ef2:46:ffff:ffff:ffff:ffff:ffff:ffff
723ef2:47::/323ef2:47:ffff:ffff:ffff:ffff:ffff:ffff
733ef2:48::/323ef2:48:ffff:ffff:ffff:ffff:ffff:ffff
743ef2:49::/323ef2:49:ffff:ffff:ffff:ffff:ffff:ffff
753ef2:4a::/323ef2:4a:ffff:ffff:ffff:ffff:ffff:ffff
763ef2:4b::/323ef2:4b:ffff:ffff:ffff:ffff:ffff:ffff
773ef2:4c::/323ef2:4c:ffff:ffff:ffff:ffff:ffff:ffff
783ef2:4d::/323ef2:4d:ffff:ffff:ffff:ffff:ffff:ffff
793ef2:4e::/323ef2:4e:ffff:ffff:ffff:ffff:ffff:ffff
803ef2:4f::/323ef2:4f:ffff:ffff:ffff:ffff:ffff:ffff
813ef2:50::/323ef2:50:ffff:ffff:ffff:ffff:ffff:ffff
823ef2:51::/323ef2:51:ffff:ffff:ffff:ffff:ffff:ffff
833ef2:52::/323ef2:52:ffff:ffff:ffff:ffff:ffff:ffff
843ef2:53::/323ef2:53:ffff:ffff:ffff:ffff:ffff:ffff
853ef2:54::/323ef2:54:ffff:ffff:ffff:ffff:ffff:ffff
863ef2:55::/323ef2:55:ffff:ffff:ffff:ffff:ffff:ffff
873ef2:56::/323ef2:56:ffff:ffff:ffff:ffff:ffff:ffff
883ef2:57::/323ef2:57:ffff:ffff:ffff:ffff:ffff:ffff
893ef2:58::/323ef2:58:ffff:ffff:ffff:ffff:ffff:ffff
903ef2:59::/323ef2:59:ffff:ffff:ffff:ffff:ffff:ffff
913ef2:5a::/323ef2:5a:ffff:ffff:ffff:ffff:ffff:ffff
923ef2:5b::/323ef2:5b:ffff:ffff:ffff:ffff:ffff:ffff
933ef2:5c::/323ef2:5c:ffff:ffff:ffff:ffff:ffff:ffff
943ef2:5d::/323ef2:5d:ffff:ffff:ffff:ffff:ffff:ffff
953ef2:5e::/323ef2:5e:ffff:ffff:ffff:ffff:ffff:ffff
963ef2:5f::/323ef2:5f:ffff:ffff:ffff:ffff:ffff:ffff
973ef2:60::/323ef2:60:ffff:ffff:ffff:ffff:ffff:ffff
983ef2:61::/323ef2:61:ffff:ffff:ffff:ffff:ffff:ffff
993ef2:62::/323ef2:62:ffff:ffff:ffff:ffff:ffff:ffff
1003ef2:63::/323ef2:63:ffff:ffff:ffff:ffff:ffff:ffff
1013ef2:64::/323ef2:64:ffff:ffff:ffff:ffff:ffff:ffff
1023ef2:65::/323ef2:65:ffff:ffff:ffff:ffff:ffff:ffff
1033ef2:66::/323ef2:66:ffff:ffff:ffff:ffff:ffff:ffff
1043ef2:67::/323ef2:67:ffff:ffff:ffff:ffff:ffff:ffff
1053ef2:68::/323ef2:68:ffff:ffff:ffff:ffff:ffff:ffff
1063ef2:69::/323ef2:69:ffff:ffff:ffff:ffff:ffff:ffff
1073ef2:6a::/323ef2:6a:ffff:ffff:ffff:ffff:ffff:ffff
1083ef2:6b::/323ef2:6b:ffff:ffff:ffff:ffff:ffff:ffff
1093ef2:6c::/323ef2:6c:ffff:ffff:ffff:ffff:ffff:ffff
1103ef2:6d::/323ef2:6d:ffff:ffff:ffff:ffff:ffff:ffff
1113ef2:6e::/323ef2:6e:ffff:ffff:ffff:ffff:ffff:ffff
1123ef2:6f::/323ef2:6f:ffff:ffff:ffff:ffff:ffff:ffff
1133ef2:70::/323ef2:70:ffff:ffff:ffff:ffff:ffff:ffff
1143ef2:71::/323ef2:71:ffff:ffff:ffff:ffff:ffff:ffff
1153ef2:72::/323ef2:72:ffff:ffff:ffff:ffff:ffff:ffff
1163ef2:73::/323ef2:73:ffff:ffff:ffff:ffff:ffff:ffff
1173ef2:74::/323ef2:74:ffff:ffff:ffff:ffff:ffff:ffff
1183ef2:75::/323ef2:75:ffff:ffff:ffff:ffff:ffff:ffff
1193ef2:76::/323ef2:76:ffff:ffff:ffff:ffff:ffff:ffff
1203ef2:77::/323ef2:77:ffff:ffff:ffff:ffff:ffff:ffff
1213ef2:78::/323ef2:78:ffff:ffff:ffff:ffff:ffff:ffff
1223ef2:79::/323ef2:79:ffff:ffff:ffff:ffff:ffff:ffff
1233ef2:7a::/323ef2:7a:ffff:ffff:ffff:ffff:ffff:ffff
1243ef2:7b::/323ef2:7b:ffff:ffff:ffff:ffff:ffff:ffff
1253ef2:7c::/323ef2:7c:ffff:ffff:ffff:ffff:ffff:ffff
1263ef2:7d::/323ef2:7d:ffff:ffff:ffff:ffff:ffff:ffff
1273ef2:7e::/323ef2:7e:ffff:ffff:ffff:ffff:ffff:ffff
1283ef2:7f::/323ef2:7f:ffff:ffff:ffff:ffff:ffff:ffff
1293ef2:80::/323ef2:80:ffff:ffff:ffff:ffff:ffff:ffff
1303ef2:81::/323ef2:81:ffff:ffff:ffff:ffff:ffff:ffff
1313ef2:82::/323ef2:82:ffff:ffff:ffff:ffff:ffff:ffff
1323ef2:83::/323ef2:83:ffff:ffff:ffff:ffff:ffff:ffff
1333ef2:84::/323ef2:84:ffff:ffff:ffff:ffff:ffff:ffff
1343ef2:85::/323ef2:85:ffff:ffff:ffff:ffff:ffff:ffff
1353ef2:86::/323ef2:86:ffff:ffff:ffff:ffff:ffff:ffff
1363ef2:87::/323ef2:87:ffff:ffff:ffff:ffff:ffff:ffff
1373ef2:88::/323ef2:88:ffff:ffff:ffff:ffff:ffff:ffff
1383ef2:89::/323ef2:89:ffff:ffff:ffff:ffff:ffff:ffff
1393ef2:8a::/323ef2:8a:ffff:ffff:ffff:ffff:ffff:ffff
1403ef2:8b::/323ef2:8b:ffff:ffff:ffff:ffff:ffff:ffff
1413ef2:8c::/323ef2:8c:ffff:ffff:ffff:ffff:ffff:ffff
1423ef2:8d::/323ef2:8d:ffff:ffff:ffff:ffff:ffff:ffff
1433ef2:8e::/323ef2:8e:ffff:ffff:ffff:ffff:ffff:ffff
1443ef2:8f::/323ef2:8f:ffff:ffff:ffff:ffff:ffff:ffff
1453ef2:90::/323ef2:90:ffff:ffff:ffff:ffff:ffff:ffff
1463ef2:91::/323ef2:91:ffff:ffff:ffff:ffff:ffff:ffff
1473ef2:92::/323ef2:92:ffff:ffff:ffff:ffff:ffff:ffff
1483ef2:93::/323ef2:93:ffff:ffff:ffff:ffff:ffff:ffff
1493ef2:94::/323ef2:94:ffff:ffff:ffff:ffff:ffff:ffff
1503ef2:95::/323ef2:95:ffff:ffff:ffff:ffff:ffff:ffff
1513ef2:96::/323ef2:96:ffff:ffff:ffff:ffff:ffff:ffff
1523ef2:97::/323ef2:97:ffff:ffff:ffff:ffff:ffff:ffff
1533ef2:98::/323ef2:98:ffff:ffff:ffff:ffff:ffff:ffff
1543ef2:99::/323ef2:99:ffff:ffff:ffff:ffff:ffff:ffff
1553ef2:9a::/323ef2:9a:ffff:ffff:ffff:ffff:ffff:ffff
1563ef2:9b::/323ef2:9b:ffff:ffff:ffff:ffff:ffff:ffff
1573ef2:9c::/323ef2:9c:ffff:ffff:ffff:ffff:ffff:ffff
1583ef2:9d::/323ef2:9d:ffff:ffff:ffff:ffff:ffff:ffff
1593ef2:9e::/323ef2:9e:ffff:ffff:ffff:ffff:ffff:ffff
1603ef2:9f::/323ef2:9f:ffff:ffff:ffff:ffff:ffff:ffff
1613ef2:a0::/323ef2:a0:ffff:ffff:ffff:ffff:ffff:ffff
1623ef2:a1::/323ef2:a1:ffff:ffff:ffff:ffff:ffff:ffff
1633ef2:a2::/323ef2:a2:ffff:ffff:ffff:ffff:ffff:ffff
1643ef2:a3::/323ef2:a3:ffff:ffff:ffff:ffff:ffff:ffff
1653ef2:a4::/323ef2:a4:ffff:ffff:ffff:ffff:ffff:ffff
1663ef2:a5::/323ef2:a5:ffff:ffff:ffff:ffff:ffff:ffff
1673ef2:a6::/323ef2:a6:ffff:ffff:ffff:ffff:ffff:ffff
1683ef2:a7::/323ef2:a7:ffff:ffff:ffff:ffff:ffff:ffff
1693ef2:a8::/323ef2:a8:ffff:ffff:ffff:ffff:ffff:ffff
1703ef2:a9::/323ef2:a9:ffff:ffff:ffff:ffff:ffff:ffff
1713ef2:aa::/323ef2:aa:ffff:ffff:ffff:ffff:ffff:ffff
1723ef2:ab::/323ef2:ab:ffff:ffff:ffff:ffff:ffff:ffff
1733ef2:ac::/323ef2:ac:ffff:ffff:ffff:ffff:ffff:ffff
1743ef2:ad::/323ef2:ad:ffff:ffff:ffff:ffff:ffff:ffff
1753ef2:ae::/323ef2:ae:ffff:ffff:ffff:ffff:ffff:ffff
1763ef2:af::/323ef2:af:ffff:ffff:ffff:ffff:ffff:ffff
1773ef2:b0::/323ef2:b0:ffff:ffff:ffff:ffff:ffff:ffff
1783ef2:b1::/323ef2:b1:ffff:ffff:ffff:ffff:ffff:ffff
1793ef2:b2::/323ef2:b2:ffff:ffff:ffff:ffff:ffff:ffff
1803ef2:b3::/323ef2:b3:ffff:ffff:ffff:ffff:ffff:ffff
1813ef2:b4::/323ef2:b4:ffff:ffff:ffff:ffff:ffff:ffff
1823ef2:b5::/323ef2:b5:ffff:ffff:ffff:ffff:ffff:ffff
1833ef2:b6::/323ef2:b6:ffff:ffff:ffff:ffff:ffff:ffff
1843ef2:b7::/323ef2:b7:ffff:ffff:ffff:ffff:ffff:ffff
1853ef2:b8::/323ef2:b8:ffff:ffff:ffff:ffff:ffff:ffff
1863ef2:b9::/323ef2:b9:ffff:ffff:ffff:ffff:ffff:ffff
1873ef2:ba::/323ef2:ba:ffff:ffff:ffff:ffff:ffff:ffff
1883ef2:bb::/323ef2:bb:ffff:ffff:ffff:ffff:ffff:ffff
1893ef2:bc::/323ef2:bc:ffff:ffff:ffff:ffff:ffff:ffff
1903ef2:bd::/323ef2:bd:ffff:ffff:ffff:ffff:ffff:ffff
1913ef2:be::/323ef2:be:ffff:ffff:ffff:ffff:ffff:ffff
1923ef2:bf::/323ef2:bf:ffff:ffff:ffff:ffff:ffff:ffff
1933ef2:c0::/323ef2:c0:ffff:ffff:ffff:ffff:ffff:ffff
1943ef2:c1::/323ef2:c1:ffff:ffff:ffff:ffff:ffff:ffff
1953ef2:c2::/323ef2:c2:ffff:ffff:ffff:ffff:ffff:ffff
1963ef2:c3::/323ef2:c3:ffff:ffff:ffff:ffff:ffff:ffff
1973ef2:c4::/323ef2:c4:ffff:ffff:ffff:ffff:ffff:ffff
1983ef2:c5::/323ef2:c5:ffff:ffff:ffff:ffff:ffff:ffff
1993ef2:c6::/323ef2:c6:ffff:ffff:ffff:ffff:ffff:ffff
2003ef2:c7::/323ef2:c7:ffff:ffff:ffff:ffff:ffff:ffff
2013ef2:c8::/323ef2:c8:ffff:ffff:ffff:ffff:ffff:ffff
2023ef2:c9::/323ef2:c9:ffff:ffff:ffff:ffff:ffff:ffff
2033ef2:ca::/323ef2:ca:ffff:ffff:ffff:ffff:ffff:ffff
2043ef2:cb::/323ef2:cb:ffff:ffff:ffff:ffff:ffff:ffff
2053ef2:cc::/323ef2:cc:ffff:ffff:ffff:ffff:ffff:ffff
2063ef2:cd::/323ef2:cd:ffff:ffff:ffff:ffff:ffff:ffff
2073ef2:ce::/323ef2:ce:ffff:ffff:ffff:ffff:ffff:ffff
2083ef2:cf::/323ef2:cf:ffff:ffff:ffff:ffff:ffff:ffff
2093ef2:d0::/323ef2:d0:ffff:ffff:ffff:ffff:ffff:ffff
2103ef2:d1::/323ef2:d1:ffff:ffff:ffff:ffff:ffff:ffff
2113ef2:d2::/323ef2:d2:ffff:ffff:ffff:ffff:ffff:ffff
2123ef2:d3::/323ef2:d3:ffff:ffff:ffff:ffff:ffff:ffff
2133ef2:d4::/323ef2:d4:ffff:ffff:ffff:ffff:ffff:ffff
2143ef2:d5::/323ef2:d5:ffff:ffff:ffff:ffff:ffff:ffff
2153ef2:d6::/323ef2:d6:ffff:ffff:ffff:ffff:ffff:ffff
2163ef2:d7::/323ef2:d7:ffff:ffff:ffff:ffff:ffff:ffff
2173ef2:d8::/323ef2:d8:ffff:ffff:ffff:ffff:ffff:ffff
2183ef2:d9::/323ef2:d9:ffff:ffff:ffff:ffff:ffff:ffff
2193ef2:da::/323ef2:da:ffff:ffff:ffff:ffff:ffff:ffff
2203ef2:db::/323ef2:db:ffff:ffff:ffff:ffff:ffff:ffff
2213ef2:dc::/323ef2:dc:ffff:ffff:ffff:ffff:ffff:ffff
2223ef2:dd::/323ef2:dd:ffff:ffff:ffff:ffff:ffff:ffff
2233ef2:de::/323ef2:de:ffff:ffff:ffff:ffff:ffff:ffff
2243ef2:df::/323ef2:df:ffff:ffff:ffff:ffff:ffff:ffff
2253ef2:e0::/323ef2:e0:ffff:ffff:ffff:ffff:ffff:ffff
2263ef2:e1::/323ef2:e1:ffff:ffff:ffff:ffff:ffff:ffff
2273ef2:e2::/323ef2:e2:ffff:ffff:ffff:ffff:ffff:ffff
2283ef2:e3::/323ef2:e3:ffff:ffff:ffff:ffff:ffff:ffff
2293ef2:e4::/323ef2:e4:ffff:ffff:ffff:ffff:ffff:ffff
2303ef2:e5::/323ef2:e5:ffff:ffff:ffff:ffff:ffff:ffff
2313ef2:e6::/323ef2:e6:ffff:ffff:ffff:ffff:ffff:ffff
2323ef2:e7::/323ef2:e7:ffff:ffff:ffff:ffff:ffff:ffff
2333ef2:e8::/323ef2:e8:ffff:ffff:ffff:ffff:ffff:ffff
2343ef2:e9::/323ef2:e9:ffff:ffff:ffff:ffff:ffff:ffff
2353ef2:ea::/323ef2:ea:ffff:ffff:ffff:ffff:ffff:ffff
2363ef2:eb::/323ef2:eb:ffff:ffff:ffff:ffff:ffff:ffff
2373ef2:ec::/323ef2:ec:ffff:ffff:ffff:ffff:ffff:ffff
2383ef2:ed::/323ef2:ed:ffff:ffff:ffff:ffff:ffff:ffff
2393ef2:ee::/323ef2:ee:ffff:ffff:ffff:ffff:ffff:ffff
2403ef2:ef::/323ef2:ef:ffff:ffff:ffff:ffff:ffff:ffff
2413ef2:f0::/323ef2:f0:ffff:ffff:ffff:ffff:ffff:ffff
2423ef2:f1::/323ef2:f1:ffff:ffff:ffff:ffff:ffff:ffff
2433ef2:f2::/323ef2:f2:ffff:ffff:ffff:ffff:ffff:ffff
2443ef2:f3::/323ef2:f3:ffff:ffff:ffff:ffff:ffff:ffff
2453ef2:f4::/323ef2:f4:ffff:ffff:ffff:ffff:ffff:ffff
2463ef2:f5::/323ef2:f5:ffff:ffff:ffff:ffff:ffff:ffff
2473ef2:f6::/323ef2:f6:ffff:ffff:ffff:ffff:ffff:ffff
2483ef2:f7::/323ef2:f7:ffff:ffff:ffff:ffff:ffff:ffff
2493ef2:f8::/323ef2:f8:ffff:ffff:ffff:ffff:ffff:ffff
2503ef2:f9::/323ef2:f9:ffff:ffff:ffff:ffff:ffff:ffff
2513ef2:fa::/323ef2:fa:ffff:ffff:ffff:ffff:ffff:ffff
2523ef2:fb::/323ef2:fb:ffff:ffff:ffff:ffff:ffff:ffff
2533ef2:fc::/323ef2:fc:ffff:ffff:ffff:ffff:ffff:ffff
2543ef2:fd::/323ef2:fd:ffff:ffff:ffff:ffff:ffff:ffff
2553ef2:fe::/323ef2:fe:ffff:ffff:ffff:ffff:ffff:ffff
2563ef2:ff::/323ef2: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.