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

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

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