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Speed and call quality testTest delay, jitter and speed, with a focus on phone calls.My IP addressYour public IPv4 and IPv6 addresses, provider and address range.WhoIs lookupWho owns a domain or IP address, when it expires, and its DNS.DNS reportEvery DNS record for a domain, with email setup checked.IP subnet calculatorWork out a network's range, mask and hosts, and split it into subnets.

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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
2a2f::/16
First address
2a2f::
Last address
2a2f: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
2a2f:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
f.2.a.2.ip6.arpa
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

2a2f::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
12a2f::/282a2f:f:ffff:ffff:ffff:ffff:ffff:ffff
22a2f:10::/282a2f:1f:ffff:ffff:ffff:ffff:ffff:ffff
32a2f:20::/282a2f:2f:ffff:ffff:ffff:ffff:ffff:ffff
42a2f:30::/282a2f:3f:ffff:ffff:ffff:ffff:ffff:ffff
52a2f:40::/282a2f:4f:ffff:ffff:ffff:ffff:ffff:ffff
62a2f:50::/282a2f:5f:ffff:ffff:ffff:ffff:ffff:ffff
72a2f:60::/282a2f:6f:ffff:ffff:ffff:ffff:ffff:ffff
82a2f:70::/282a2f:7f:ffff:ffff:ffff:ffff:ffff:ffff
92a2f:80::/282a2f:8f:ffff:ffff:ffff:ffff:ffff:ffff
102a2f:90::/282a2f:9f:ffff:ffff:ffff:ffff:ffff:ffff
112a2f:a0::/282a2f:af:ffff:ffff:ffff:ffff:ffff:ffff
122a2f:b0::/282a2f:bf:ffff:ffff:ffff:ffff:ffff:ffff
132a2f:c0::/282a2f:cf:ffff:ffff:ffff:ffff:ffff:ffff
142a2f:d0::/282a2f:df:ffff:ffff:ffff:ffff:ffff:ffff
152a2f:e0::/282a2f:ef:ffff:ffff:ffff:ffff:ffff:ffff
162a2f:f0::/282a2f:ff:ffff:ffff:ffff:ffff:ffff:ffff
172a2f:100::/282a2f:10f:ffff:ffff:ffff:ffff:ffff:ffff
182a2f:110::/282a2f:11f:ffff:ffff:ffff:ffff:ffff:ffff
192a2f:120::/282a2f:12f:ffff:ffff:ffff:ffff:ffff:ffff
202a2f:130::/282a2f:13f:ffff:ffff:ffff:ffff:ffff:ffff
212a2f:140::/282a2f:14f:ffff:ffff:ffff:ffff:ffff:ffff
222a2f:150::/282a2f:15f:ffff:ffff:ffff:ffff:ffff:ffff
232a2f:160::/282a2f:16f:ffff:ffff:ffff:ffff:ffff:ffff
242a2f:170::/282a2f:17f:ffff:ffff:ffff:ffff:ffff:ffff
252a2f:180::/282a2f:18f:ffff:ffff:ffff:ffff:ffff:ffff
262a2f:190::/282a2f:19f:ffff:ffff:ffff:ffff:ffff:ffff
272a2f:1a0::/282a2f:1af:ffff:ffff:ffff:ffff:ffff:ffff
282a2f:1b0::/282a2f:1bf:ffff:ffff:ffff:ffff:ffff:ffff
292a2f:1c0::/282a2f:1cf:ffff:ffff:ffff:ffff:ffff:ffff
302a2f:1d0::/282a2f:1df:ffff:ffff:ffff:ffff:ffff:ffff
312a2f:1e0::/282a2f:1ef:ffff:ffff:ffff:ffff:ffff:ffff
322a2f:1f0::/282a2f:1ff:ffff:ffff:ffff:ffff:ffff:ffff
332a2f:200::/282a2f:20f:ffff:ffff:ffff:ffff:ffff:ffff
342a2f:210::/282a2f:21f:ffff:ffff:ffff:ffff:ffff:ffff
352a2f:220::/282a2f:22f:ffff:ffff:ffff:ffff:ffff:ffff
362a2f:230::/282a2f:23f:ffff:ffff:ffff:ffff:ffff:ffff
372a2f:240::/282a2f:24f:ffff:ffff:ffff:ffff:ffff:ffff
382a2f:250::/282a2f:25f:ffff:ffff:ffff:ffff:ffff:ffff
392a2f:260::/282a2f:26f:ffff:ffff:ffff:ffff:ffff:ffff
402a2f:270::/282a2f:27f:ffff:ffff:ffff:ffff:ffff:ffff
412a2f:280::/282a2f:28f:ffff:ffff:ffff:ffff:ffff:ffff
422a2f:290::/282a2f:29f:ffff:ffff:ffff:ffff:ffff:ffff
432a2f:2a0::/282a2f:2af:ffff:ffff:ffff:ffff:ffff:ffff
442a2f:2b0::/282a2f:2bf:ffff:ffff:ffff:ffff:ffff:ffff
452a2f:2c0::/282a2f:2cf:ffff:ffff:ffff:ffff:ffff:ffff
462a2f:2d0::/282a2f:2df:ffff:ffff:ffff:ffff:ffff:ffff
472a2f:2e0::/282a2f:2ef:ffff:ffff:ffff:ffff:ffff:ffff
482a2f:2f0::/282a2f:2ff:ffff:ffff:ffff:ffff:ffff:ffff
492a2f:300::/282a2f:30f:ffff:ffff:ffff:ffff:ffff:ffff
502a2f:310::/282a2f:31f:ffff:ffff:ffff:ffff:ffff:ffff
512a2f:320::/282a2f:32f:ffff:ffff:ffff:ffff:ffff:ffff
522a2f:330::/282a2f:33f:ffff:ffff:ffff:ffff:ffff:ffff
532a2f:340::/282a2f:34f:ffff:ffff:ffff:ffff:ffff:ffff
542a2f:350::/282a2f:35f:ffff:ffff:ffff:ffff:ffff:ffff
552a2f:360::/282a2f:36f:ffff:ffff:ffff:ffff:ffff:ffff
562a2f:370::/282a2f:37f:ffff:ffff:ffff:ffff:ffff:ffff
572a2f:380::/282a2f:38f:ffff:ffff:ffff:ffff:ffff:ffff
582a2f:390::/282a2f:39f:ffff:ffff:ffff:ffff:ffff:ffff
592a2f:3a0::/282a2f:3af:ffff:ffff:ffff:ffff:ffff:ffff
602a2f:3b0::/282a2f:3bf:ffff:ffff:ffff:ffff:ffff:ffff
612a2f:3c0::/282a2f:3cf:ffff:ffff:ffff:ffff:ffff:ffff
622a2f:3d0::/282a2f:3df:ffff:ffff:ffff:ffff:ffff:ffff
632a2f:3e0::/282a2f:3ef:ffff:ffff:ffff:ffff:ffff:ffff
642a2f:3f0::/282a2f:3ff:ffff:ffff:ffff:ffff:ffff:ffff
652a2f:400::/282a2f:40f:ffff:ffff:ffff:ffff:ffff:ffff
662a2f:410::/282a2f:41f:ffff:ffff:ffff:ffff:ffff:ffff
672a2f:420::/282a2f:42f:ffff:ffff:ffff:ffff:ffff:ffff
682a2f:430::/282a2f:43f:ffff:ffff:ffff:ffff:ffff:ffff
692a2f:440::/282a2f:44f:ffff:ffff:ffff:ffff:ffff:ffff
702a2f:450::/282a2f:45f:ffff:ffff:ffff:ffff:ffff:ffff
712a2f:460::/282a2f:46f:ffff:ffff:ffff:ffff:ffff:ffff
722a2f:470::/282a2f:47f:ffff:ffff:ffff:ffff:ffff:ffff
732a2f:480::/282a2f:48f:ffff:ffff:ffff:ffff:ffff:ffff
742a2f:490::/282a2f:49f:ffff:ffff:ffff:ffff:ffff:ffff
752a2f:4a0::/282a2f:4af:ffff:ffff:ffff:ffff:ffff:ffff
762a2f:4b0::/282a2f:4bf:ffff:ffff:ffff:ffff:ffff:ffff
772a2f:4c0::/282a2f:4cf:ffff:ffff:ffff:ffff:ffff:ffff
782a2f:4d0::/282a2f:4df:ffff:ffff:ffff:ffff:ffff:ffff
792a2f:4e0::/282a2f:4ef:ffff:ffff:ffff:ffff:ffff:ffff
802a2f:4f0::/282a2f:4ff:ffff:ffff:ffff:ffff:ffff:ffff
812a2f:500::/282a2f:50f:ffff:ffff:ffff:ffff:ffff:ffff
822a2f:510::/282a2f:51f:ffff:ffff:ffff:ffff:ffff:ffff
832a2f:520::/282a2f:52f:ffff:ffff:ffff:ffff:ffff:ffff
842a2f:530::/282a2f:53f:ffff:ffff:ffff:ffff:ffff:ffff
852a2f:540::/282a2f:54f:ffff:ffff:ffff:ffff:ffff:ffff
862a2f:550::/282a2f:55f:ffff:ffff:ffff:ffff:ffff:ffff
872a2f:560::/282a2f:56f:ffff:ffff:ffff:ffff:ffff:ffff
882a2f:570::/282a2f:57f:ffff:ffff:ffff:ffff:ffff:ffff
892a2f:580::/282a2f:58f:ffff:ffff:ffff:ffff:ffff:ffff
902a2f:590::/282a2f:59f:ffff:ffff:ffff:ffff:ffff:ffff
912a2f:5a0::/282a2f:5af:ffff:ffff:ffff:ffff:ffff:ffff
922a2f:5b0::/282a2f:5bf:ffff:ffff:ffff:ffff:ffff:ffff
932a2f:5c0::/282a2f:5cf:ffff:ffff:ffff:ffff:ffff:ffff
942a2f:5d0::/282a2f:5df:ffff:ffff:ffff:ffff:ffff:ffff
952a2f:5e0::/282a2f:5ef:ffff:ffff:ffff:ffff:ffff:ffff
962a2f:5f0::/282a2f:5ff:ffff:ffff:ffff:ffff:ffff:ffff
972a2f:600::/282a2f:60f:ffff:ffff:ffff:ffff:ffff:ffff
982a2f:610::/282a2f:61f:ffff:ffff:ffff:ffff:ffff:ffff
992a2f:620::/282a2f:62f:ffff:ffff:ffff:ffff:ffff:ffff
1002a2f:630::/282a2f:63f:ffff:ffff:ffff:ffff:ffff:ffff
1012a2f:640::/282a2f:64f:ffff:ffff:ffff:ffff:ffff:ffff
1022a2f:650::/282a2f:65f:ffff:ffff:ffff:ffff:ffff:ffff
1032a2f:660::/282a2f:66f:ffff:ffff:ffff:ffff:ffff:ffff
1042a2f:670::/282a2f:67f:ffff:ffff:ffff:ffff:ffff:ffff
1052a2f:680::/282a2f:68f:ffff:ffff:ffff:ffff:ffff:ffff
1062a2f:690::/282a2f:69f:ffff:ffff:ffff:ffff:ffff:ffff
1072a2f:6a0::/282a2f:6af:ffff:ffff:ffff:ffff:ffff:ffff
1082a2f:6b0::/282a2f:6bf:ffff:ffff:ffff:ffff:ffff:ffff
1092a2f:6c0::/282a2f:6cf:ffff:ffff:ffff:ffff:ffff:ffff
1102a2f:6d0::/282a2f:6df:ffff:ffff:ffff:ffff:ffff:ffff
1112a2f:6e0::/282a2f:6ef:ffff:ffff:ffff:ffff:ffff:ffff
1122a2f:6f0::/282a2f:6ff:ffff:ffff:ffff:ffff:ffff:ffff
1132a2f:700::/282a2f:70f:ffff:ffff:ffff:ffff:ffff:ffff
1142a2f:710::/282a2f:71f:ffff:ffff:ffff:ffff:ffff:ffff
1152a2f:720::/282a2f:72f:ffff:ffff:ffff:ffff:ffff:ffff
1162a2f:730::/282a2f:73f:ffff:ffff:ffff:ffff:ffff:ffff
1172a2f:740::/282a2f:74f:ffff:ffff:ffff:ffff:ffff:ffff
1182a2f:750::/282a2f:75f:ffff:ffff:ffff:ffff:ffff:ffff
1192a2f:760::/282a2f:76f:ffff:ffff:ffff:ffff:ffff:ffff
1202a2f:770::/282a2f:77f:ffff:ffff:ffff:ffff:ffff:ffff
1212a2f:780::/282a2f:78f:ffff:ffff:ffff:ffff:ffff:ffff
1222a2f:790::/282a2f:79f:ffff:ffff:ffff:ffff:ffff:ffff
1232a2f:7a0::/282a2f:7af:ffff:ffff:ffff:ffff:ffff:ffff
1242a2f:7b0::/282a2f:7bf:ffff:ffff:ffff:ffff:ffff:ffff
1252a2f:7c0::/282a2f:7cf:ffff:ffff:ffff:ffff:ffff:ffff
1262a2f:7d0::/282a2f:7df:ffff:ffff:ffff:ffff:ffff:ffff
1272a2f:7e0::/282a2f:7ef:ffff:ffff:ffff:ffff:ffff:ffff
1282a2f:7f0::/282a2f:7ff:ffff:ffff:ffff:ffff:ffff:ffff
1292a2f:800::/282a2f:80f:ffff:ffff:ffff:ffff:ffff:ffff
1302a2f:810::/282a2f:81f:ffff:ffff:ffff:ffff:ffff:ffff
1312a2f:820::/282a2f:82f:ffff:ffff:ffff:ffff:ffff:ffff
1322a2f:830::/282a2f:83f:ffff:ffff:ffff:ffff:ffff:ffff
1332a2f:840::/282a2f:84f:ffff:ffff:ffff:ffff:ffff:ffff
1342a2f:850::/282a2f:85f:ffff:ffff:ffff:ffff:ffff:ffff
1352a2f:860::/282a2f:86f:ffff:ffff:ffff:ffff:ffff:ffff
1362a2f:870::/282a2f:87f:ffff:ffff:ffff:ffff:ffff:ffff
1372a2f:880::/282a2f:88f:ffff:ffff:ffff:ffff:ffff:ffff
1382a2f:890::/282a2f:89f:ffff:ffff:ffff:ffff:ffff:ffff
1392a2f:8a0::/282a2f:8af:ffff:ffff:ffff:ffff:ffff:ffff
1402a2f:8b0::/282a2f:8bf:ffff:ffff:ffff:ffff:ffff:ffff
1412a2f:8c0::/282a2f:8cf:ffff:ffff:ffff:ffff:ffff:ffff
1422a2f:8d0::/282a2f:8df:ffff:ffff:ffff:ffff:ffff:ffff
1432a2f:8e0::/282a2f:8ef:ffff:ffff:ffff:ffff:ffff:ffff
1442a2f:8f0::/282a2f:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1452a2f:900::/282a2f:90f:ffff:ffff:ffff:ffff:ffff:ffff
1462a2f:910::/282a2f:91f:ffff:ffff:ffff:ffff:ffff:ffff
1472a2f:920::/282a2f:92f:ffff:ffff:ffff:ffff:ffff:ffff
1482a2f:930::/282a2f:93f:ffff:ffff:ffff:ffff:ffff:ffff
1492a2f:940::/282a2f:94f:ffff:ffff:ffff:ffff:ffff:ffff
1502a2f:950::/282a2f:95f:ffff:ffff:ffff:ffff:ffff:ffff
1512a2f:960::/282a2f:96f:ffff:ffff:ffff:ffff:ffff:ffff
1522a2f:970::/282a2f:97f:ffff:ffff:ffff:ffff:ffff:ffff
1532a2f:980::/282a2f:98f:ffff:ffff:ffff:ffff:ffff:ffff
1542a2f:990::/282a2f:99f:ffff:ffff:ffff:ffff:ffff:ffff
1552a2f:9a0::/282a2f:9af:ffff:ffff:ffff:ffff:ffff:ffff
1562a2f:9b0::/282a2f:9bf:ffff:ffff:ffff:ffff:ffff:ffff
1572a2f:9c0::/282a2f:9cf:ffff:ffff:ffff:ffff:ffff:ffff
1582a2f:9d0::/282a2f:9df:ffff:ffff:ffff:ffff:ffff:ffff
1592a2f:9e0::/282a2f:9ef:ffff:ffff:ffff:ffff:ffff:ffff
1602a2f:9f0::/282a2f:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1612a2f:a00::/282a2f:a0f:ffff:ffff:ffff:ffff:ffff:ffff
1622a2f:a10::/282a2f:a1f:ffff:ffff:ffff:ffff:ffff:ffff
1632a2f:a20::/282a2f:a2f:ffff:ffff:ffff:ffff:ffff:ffff
1642a2f:a30::/282a2f:a3f:ffff:ffff:ffff:ffff:ffff:ffff
1652a2f:a40::/282a2f:a4f:ffff:ffff:ffff:ffff:ffff:ffff
1662a2f:a50::/282a2f:a5f:ffff:ffff:ffff:ffff:ffff:ffff
1672a2f:a60::/282a2f:a6f:ffff:ffff:ffff:ffff:ffff:ffff
1682a2f:a70::/282a2f:a7f:ffff:ffff:ffff:ffff:ffff:ffff
1692a2f:a80::/282a2f:a8f:ffff:ffff:ffff:ffff:ffff:ffff
1702a2f:a90::/282a2f:a9f:ffff:ffff:ffff:ffff:ffff:ffff
1712a2f:aa0::/282a2f:aaf:ffff:ffff:ffff:ffff:ffff:ffff
1722a2f:ab0::/282a2f:abf:ffff:ffff:ffff:ffff:ffff:ffff
1732a2f:ac0::/282a2f:acf:ffff:ffff:ffff:ffff:ffff:ffff
1742a2f:ad0::/282a2f:adf:ffff:ffff:ffff:ffff:ffff:ffff
1752a2f:ae0::/282a2f:aef:ffff:ffff:ffff:ffff:ffff:ffff
1762a2f:af0::/282a2f:aff:ffff:ffff:ffff:ffff:ffff:ffff
1772a2f:b00::/282a2f:b0f:ffff:ffff:ffff:ffff:ffff:ffff
1782a2f:b10::/282a2f:b1f:ffff:ffff:ffff:ffff:ffff:ffff
1792a2f:b20::/282a2f:b2f:ffff:ffff:ffff:ffff:ffff:ffff
1802a2f:b30::/282a2f:b3f:ffff:ffff:ffff:ffff:ffff:ffff
1812a2f:b40::/282a2f:b4f:ffff:ffff:ffff:ffff:ffff:ffff
1822a2f:b50::/282a2f:b5f:ffff:ffff:ffff:ffff:ffff:ffff
1832a2f:b60::/282a2f:b6f:ffff:ffff:ffff:ffff:ffff:ffff
1842a2f:b70::/282a2f:b7f:ffff:ffff:ffff:ffff:ffff:ffff
1852a2f:b80::/282a2f:b8f:ffff:ffff:ffff:ffff:ffff:ffff
1862a2f:b90::/282a2f:b9f:ffff:ffff:ffff:ffff:ffff:ffff
1872a2f:ba0::/282a2f:baf:ffff:ffff:ffff:ffff:ffff:ffff
1882a2f:bb0::/282a2f:bbf:ffff:ffff:ffff:ffff:ffff:ffff
1892a2f:bc0::/282a2f:bcf:ffff:ffff:ffff:ffff:ffff:ffff
1902a2f:bd0::/282a2f:bdf:ffff:ffff:ffff:ffff:ffff:ffff
1912a2f:be0::/282a2f:bef:ffff:ffff:ffff:ffff:ffff:ffff
1922a2f:bf0::/282a2f:bff:ffff:ffff:ffff:ffff:ffff:ffff
1932a2f:c00::/282a2f:c0f:ffff:ffff:ffff:ffff:ffff:ffff
1942a2f:c10::/282a2f:c1f:ffff:ffff:ffff:ffff:ffff:ffff
1952a2f:c20::/282a2f:c2f:ffff:ffff:ffff:ffff:ffff:ffff
1962a2f:c30::/282a2f:c3f:ffff:ffff:ffff:ffff:ffff:ffff
1972a2f:c40::/282a2f:c4f:ffff:ffff:ffff:ffff:ffff:ffff
1982a2f:c50::/282a2f:c5f:ffff:ffff:ffff:ffff:ffff:ffff
1992a2f:c60::/282a2f:c6f:ffff:ffff:ffff:ffff:ffff:ffff
2002a2f:c70::/282a2f:c7f:ffff:ffff:ffff:ffff:ffff:ffff
2012a2f:c80::/282a2f:c8f:ffff:ffff:ffff:ffff:ffff:ffff
2022a2f:c90::/282a2f:c9f:ffff:ffff:ffff:ffff:ffff:ffff
2032a2f:ca0::/282a2f:caf:ffff:ffff:ffff:ffff:ffff:ffff
2042a2f:cb0::/282a2f:cbf:ffff:ffff:ffff:ffff:ffff:ffff
2052a2f:cc0::/282a2f:ccf:ffff:ffff:ffff:ffff:ffff:ffff
2062a2f:cd0::/282a2f:cdf:ffff:ffff:ffff:ffff:ffff:ffff
2072a2f:ce0::/282a2f:cef:ffff:ffff:ffff:ffff:ffff:ffff
2082a2f:cf0::/282a2f:cff:ffff:ffff:ffff:ffff:ffff:ffff
2092a2f:d00::/282a2f:d0f:ffff:ffff:ffff:ffff:ffff:ffff
2102a2f:d10::/282a2f:d1f:ffff:ffff:ffff:ffff:ffff:ffff
2112a2f:d20::/282a2f:d2f:ffff:ffff:ffff:ffff:ffff:ffff
2122a2f:d30::/282a2f:d3f:ffff:ffff:ffff:ffff:ffff:ffff
2132a2f:d40::/282a2f:d4f:ffff:ffff:ffff:ffff:ffff:ffff
2142a2f:d50::/282a2f:d5f:ffff:ffff:ffff:ffff:ffff:ffff
2152a2f:d60::/282a2f:d6f:ffff:ffff:ffff:ffff:ffff:ffff
2162a2f:d70::/282a2f:d7f:ffff:ffff:ffff:ffff:ffff:ffff
2172a2f:d80::/282a2f:d8f:ffff:ffff:ffff:ffff:ffff:ffff
2182a2f:d90::/282a2f:d9f:ffff:ffff:ffff:ffff:ffff:ffff
2192a2f:da0::/282a2f:daf:ffff:ffff:ffff:ffff:ffff:ffff
2202a2f:db0::/282a2f:dbf:ffff:ffff:ffff:ffff:ffff:ffff
2212a2f:dc0::/282a2f:dcf:ffff:ffff:ffff:ffff:ffff:ffff
2222a2f:dd0::/282a2f:ddf:ffff:ffff:ffff:ffff:ffff:ffff
2232a2f:de0::/282a2f:def:ffff:ffff:ffff:ffff:ffff:ffff
2242a2f:df0::/282a2f:dff:ffff:ffff:ffff:ffff:ffff:ffff
2252a2f:e00::/282a2f:e0f:ffff:ffff:ffff:ffff:ffff:ffff
2262a2f:e10::/282a2f:e1f:ffff:ffff:ffff:ffff:ffff:ffff
2272a2f:e20::/282a2f:e2f:ffff:ffff:ffff:ffff:ffff:ffff
2282a2f:e30::/282a2f:e3f:ffff:ffff:ffff:ffff:ffff:ffff
2292a2f:e40::/282a2f:e4f:ffff:ffff:ffff:ffff:ffff:ffff
2302a2f:e50::/282a2f:e5f:ffff:ffff:ffff:ffff:ffff:ffff
2312a2f:e60::/282a2f:e6f:ffff:ffff:ffff:ffff:ffff:ffff
2322a2f:e70::/282a2f:e7f:ffff:ffff:ffff:ffff:ffff:ffff
2332a2f:e80::/282a2f:e8f:ffff:ffff:ffff:ffff:ffff:ffff
2342a2f:e90::/282a2f:e9f:ffff:ffff:ffff:ffff:ffff:ffff
2352a2f:ea0::/282a2f:eaf:ffff:ffff:ffff:ffff:ffff:ffff
2362a2f:eb0::/282a2f:ebf:ffff:ffff:ffff:ffff:ffff:ffff
2372a2f:ec0::/282a2f:ecf:ffff:ffff:ffff:ffff:ffff:ffff
2382a2f:ed0::/282a2f:edf:ffff:ffff:ffff:ffff:ffff:ffff
2392a2f:ee0::/282a2f:eef:ffff:ffff:ffff:ffff:ffff:ffff
2402a2f:ef0::/282a2f:eff:ffff:ffff:ffff:ffff:ffff:ffff
2412a2f:f00::/282a2f:f0f:ffff:ffff:ffff:ffff:ffff:ffff
2422a2f:f10::/282a2f:f1f:ffff:ffff:ffff:ffff:ffff:ffff
2432a2f:f20::/282a2f:f2f:ffff:ffff:ffff:ffff:ffff:ffff
2442a2f:f30::/282a2f:f3f:ffff:ffff:ffff:ffff:ffff:ffff
2452a2f:f40::/282a2f:f4f:ffff:ffff:ffff:ffff:ffff:ffff
2462a2f:f50::/282a2f:f5f:ffff:ffff:ffff:ffff:ffff:ffff
2472a2f:f60::/282a2f:f6f:ffff:ffff:ffff:ffff:ffff:ffff
2482a2f:f70::/282a2f:f7f:ffff:ffff:ffff:ffff:ffff:ffff
2492a2f:f80::/282a2f:f8f:ffff:ffff:ffff:ffff:ffff:ffff
2502a2f:f90::/282a2f:f9f:ffff:ffff:ffff:ffff:ffff:ffff
2512a2f:fa0::/282a2f:faf:ffff:ffff:ffff:ffff:ffff:ffff
2522a2f:fb0::/282a2f:fbf:ffff:ffff:ffff:ffff:ffff:ffff
2532a2f:fc0::/282a2f:fcf:ffff:ffff:ffff:ffff:ffff:ffff
2542a2f:fd0::/282a2f:fdf:ffff:ffff:ffff:ffff:ffff:ffff
2552a2f:fe0::/282a2f:fef:ffff:ffff:ffff:ffff:ffff:ffff
2562a2f:ff0::/282a2f:fff: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.