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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/28
Addresses2^100
/64 networks2^36
Network
24ef:dd0::/28
First address
24ef:dd0::
Last address
24ef:ddf:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
1,267,650,600,228,229,401,496,703,205,376 (2^100)
/64 networks (LANs)
68,719,476,736 (2^36)
Full form
24ef:0dd0:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
d.d.0.f.e.4.2.ip6.arpa
Split into smaller subnets/44
/29 (2)/30 (4)/31 (8)/32 (16)/36 (256)/40 (4,096)/44 (65,536)

24ef:dd0::/28 makes 65,536 subnets of /44; the first 256 are listed.

Subnets
#SubnetLast address
124ef:dd0::/4424ef:dd0:f:ffff:ffff:ffff:ffff:ffff
224ef:dd0:10::/4424ef:dd0:1f:ffff:ffff:ffff:ffff:ffff
324ef:dd0:20::/4424ef:dd0:2f:ffff:ffff:ffff:ffff:ffff
424ef:dd0:30::/4424ef:dd0:3f:ffff:ffff:ffff:ffff:ffff
524ef:dd0:40::/4424ef:dd0:4f:ffff:ffff:ffff:ffff:ffff
624ef:dd0:50::/4424ef:dd0:5f:ffff:ffff:ffff:ffff:ffff
724ef:dd0:60::/4424ef:dd0:6f:ffff:ffff:ffff:ffff:ffff
824ef:dd0:70::/4424ef:dd0:7f:ffff:ffff:ffff:ffff:ffff
924ef:dd0:80::/4424ef:dd0:8f:ffff:ffff:ffff:ffff:ffff
1024ef:dd0:90::/4424ef:dd0:9f:ffff:ffff:ffff:ffff:ffff
1124ef:dd0:a0::/4424ef:dd0:af:ffff:ffff:ffff:ffff:ffff
1224ef:dd0:b0::/4424ef:dd0:bf:ffff:ffff:ffff:ffff:ffff
1324ef:dd0:c0::/4424ef:dd0:cf:ffff:ffff:ffff:ffff:ffff
1424ef:dd0:d0::/4424ef:dd0:df:ffff:ffff:ffff:ffff:ffff
1524ef:dd0:e0::/4424ef:dd0:ef:ffff:ffff:ffff:ffff:ffff
1624ef:dd0:f0::/4424ef:dd0:ff:ffff:ffff:ffff:ffff:ffff
1724ef:dd0:100::/4424ef:dd0:10f:ffff:ffff:ffff:ffff:ffff
1824ef:dd0:110::/4424ef:dd0:11f:ffff:ffff:ffff:ffff:ffff
1924ef:dd0:120::/4424ef:dd0:12f:ffff:ffff:ffff:ffff:ffff
2024ef:dd0:130::/4424ef:dd0:13f:ffff:ffff:ffff:ffff:ffff
2124ef:dd0:140::/4424ef:dd0:14f:ffff:ffff:ffff:ffff:ffff
2224ef:dd0:150::/4424ef:dd0:15f:ffff:ffff:ffff:ffff:ffff
2324ef:dd0:160::/4424ef:dd0:16f:ffff:ffff:ffff:ffff:ffff
2424ef:dd0:170::/4424ef:dd0:17f:ffff:ffff:ffff:ffff:ffff
2524ef:dd0:180::/4424ef:dd0:18f:ffff:ffff:ffff:ffff:ffff
2624ef:dd0:190::/4424ef:dd0:19f:ffff:ffff:ffff:ffff:ffff
2724ef:dd0:1a0::/4424ef:dd0:1af:ffff:ffff:ffff:ffff:ffff
2824ef:dd0:1b0::/4424ef:dd0:1bf:ffff:ffff:ffff:ffff:ffff
2924ef:dd0:1c0::/4424ef:dd0:1cf:ffff:ffff:ffff:ffff:ffff
3024ef:dd0:1d0::/4424ef:dd0:1df:ffff:ffff:ffff:ffff:ffff
3124ef:dd0:1e0::/4424ef:dd0:1ef:ffff:ffff:ffff:ffff:ffff
3224ef:dd0:1f0::/4424ef:dd0:1ff:ffff:ffff:ffff:ffff:ffff
3324ef:dd0:200::/4424ef:dd0:20f:ffff:ffff:ffff:ffff:ffff
3424ef:dd0:210::/4424ef:dd0:21f:ffff:ffff:ffff:ffff:ffff
3524ef:dd0:220::/4424ef:dd0:22f:ffff:ffff:ffff:ffff:ffff
3624ef:dd0:230::/4424ef:dd0:23f:ffff:ffff:ffff:ffff:ffff
3724ef:dd0:240::/4424ef:dd0:24f:ffff:ffff:ffff:ffff:ffff
3824ef:dd0:250::/4424ef:dd0:25f:ffff:ffff:ffff:ffff:ffff
3924ef:dd0:260::/4424ef:dd0:26f:ffff:ffff:ffff:ffff:ffff
4024ef:dd0:270::/4424ef:dd0:27f:ffff:ffff:ffff:ffff:ffff
4124ef:dd0:280::/4424ef:dd0:28f:ffff:ffff:ffff:ffff:ffff
4224ef:dd0:290::/4424ef:dd0:29f:ffff:ffff:ffff:ffff:ffff
4324ef:dd0:2a0::/4424ef:dd0:2af:ffff:ffff:ffff:ffff:ffff
4424ef:dd0:2b0::/4424ef:dd0:2bf:ffff:ffff:ffff:ffff:ffff
4524ef:dd0:2c0::/4424ef:dd0:2cf:ffff:ffff:ffff:ffff:ffff
4624ef:dd0:2d0::/4424ef:dd0:2df:ffff:ffff:ffff:ffff:ffff
4724ef:dd0:2e0::/4424ef:dd0:2ef:ffff:ffff:ffff:ffff:ffff
4824ef:dd0:2f0::/4424ef:dd0:2ff:ffff:ffff:ffff:ffff:ffff
4924ef:dd0:300::/4424ef:dd0:30f:ffff:ffff:ffff:ffff:ffff
5024ef:dd0:310::/4424ef:dd0:31f:ffff:ffff:ffff:ffff:ffff
5124ef:dd0:320::/4424ef:dd0:32f:ffff:ffff:ffff:ffff:ffff
5224ef:dd0:330::/4424ef:dd0:33f:ffff:ffff:ffff:ffff:ffff
5324ef:dd0:340::/4424ef:dd0:34f:ffff:ffff:ffff:ffff:ffff
5424ef:dd0:350::/4424ef:dd0:35f:ffff:ffff:ffff:ffff:ffff
5524ef:dd0:360::/4424ef:dd0:36f:ffff:ffff:ffff:ffff:ffff
5624ef:dd0:370::/4424ef:dd0:37f:ffff:ffff:ffff:ffff:ffff
5724ef:dd0:380::/4424ef:dd0:38f:ffff:ffff:ffff:ffff:ffff
5824ef:dd0:390::/4424ef:dd0:39f:ffff:ffff:ffff:ffff:ffff
5924ef:dd0:3a0::/4424ef:dd0:3af:ffff:ffff:ffff:ffff:ffff
6024ef:dd0:3b0::/4424ef:dd0:3bf:ffff:ffff:ffff:ffff:ffff
6124ef:dd0:3c0::/4424ef:dd0:3cf:ffff:ffff:ffff:ffff:ffff
6224ef:dd0:3d0::/4424ef:dd0:3df:ffff:ffff:ffff:ffff:ffff
6324ef:dd0:3e0::/4424ef:dd0:3ef:ffff:ffff:ffff:ffff:ffff
6424ef:dd0:3f0::/4424ef:dd0:3ff:ffff:ffff:ffff:ffff:ffff
6524ef:dd0:400::/4424ef:dd0:40f:ffff:ffff:ffff:ffff:ffff
6624ef:dd0:410::/4424ef:dd0:41f:ffff:ffff:ffff:ffff:ffff
6724ef:dd0:420::/4424ef:dd0:42f:ffff:ffff:ffff:ffff:ffff
6824ef:dd0:430::/4424ef:dd0:43f:ffff:ffff:ffff:ffff:ffff
6924ef:dd0:440::/4424ef:dd0:44f:ffff:ffff:ffff:ffff:ffff
7024ef:dd0:450::/4424ef:dd0:45f:ffff:ffff:ffff:ffff:ffff
7124ef:dd0:460::/4424ef:dd0:46f:ffff:ffff:ffff:ffff:ffff
7224ef:dd0:470::/4424ef:dd0:47f:ffff:ffff:ffff:ffff:ffff
7324ef:dd0:480::/4424ef:dd0:48f:ffff:ffff:ffff:ffff:ffff
7424ef:dd0:490::/4424ef:dd0:49f:ffff:ffff:ffff:ffff:ffff
7524ef:dd0:4a0::/4424ef:dd0:4af:ffff:ffff:ffff:ffff:ffff
7624ef:dd0:4b0::/4424ef:dd0:4bf:ffff:ffff:ffff:ffff:ffff
7724ef:dd0:4c0::/4424ef:dd0:4cf:ffff:ffff:ffff:ffff:ffff
7824ef:dd0:4d0::/4424ef:dd0:4df:ffff:ffff:ffff:ffff:ffff
7924ef:dd0:4e0::/4424ef:dd0:4ef:ffff:ffff:ffff:ffff:ffff
8024ef:dd0:4f0::/4424ef:dd0:4ff:ffff:ffff:ffff:ffff:ffff
8124ef:dd0:500::/4424ef:dd0:50f:ffff:ffff:ffff:ffff:ffff
8224ef:dd0:510::/4424ef:dd0:51f:ffff:ffff:ffff:ffff:ffff
8324ef:dd0:520::/4424ef:dd0:52f:ffff:ffff:ffff:ffff:ffff
8424ef:dd0:530::/4424ef:dd0:53f:ffff:ffff:ffff:ffff:ffff
8524ef:dd0:540::/4424ef:dd0:54f:ffff:ffff:ffff:ffff:ffff
8624ef:dd0:550::/4424ef:dd0:55f:ffff:ffff:ffff:ffff:ffff
8724ef:dd0:560::/4424ef:dd0:56f:ffff:ffff:ffff:ffff:ffff
8824ef:dd0:570::/4424ef:dd0:57f:ffff:ffff:ffff:ffff:ffff
8924ef:dd0:580::/4424ef:dd0:58f:ffff:ffff:ffff:ffff:ffff
9024ef:dd0:590::/4424ef:dd0:59f:ffff:ffff:ffff:ffff:ffff
9124ef:dd0:5a0::/4424ef:dd0:5af:ffff:ffff:ffff:ffff:ffff
9224ef:dd0:5b0::/4424ef:dd0:5bf:ffff:ffff:ffff:ffff:ffff
9324ef:dd0:5c0::/4424ef:dd0:5cf:ffff:ffff:ffff:ffff:ffff
9424ef:dd0:5d0::/4424ef:dd0:5df:ffff:ffff:ffff:ffff:ffff
9524ef:dd0:5e0::/4424ef:dd0:5ef:ffff:ffff:ffff:ffff:ffff
9624ef:dd0:5f0::/4424ef:dd0:5ff:ffff:ffff:ffff:ffff:ffff
9724ef:dd0:600::/4424ef:dd0:60f:ffff:ffff:ffff:ffff:ffff
9824ef:dd0:610::/4424ef:dd0:61f:ffff:ffff:ffff:ffff:ffff
9924ef:dd0:620::/4424ef:dd0:62f:ffff:ffff:ffff:ffff:ffff
10024ef:dd0:630::/4424ef:dd0:63f:ffff:ffff:ffff:ffff:ffff
10124ef:dd0:640::/4424ef:dd0:64f:ffff:ffff:ffff:ffff:ffff
10224ef:dd0:650::/4424ef:dd0:65f:ffff:ffff:ffff:ffff:ffff
10324ef:dd0:660::/4424ef:dd0:66f:ffff:ffff:ffff:ffff:ffff
10424ef:dd0:670::/4424ef:dd0:67f:ffff:ffff:ffff:ffff:ffff
10524ef:dd0:680::/4424ef:dd0:68f:ffff:ffff:ffff:ffff:ffff
10624ef:dd0:690::/4424ef:dd0:69f:ffff:ffff:ffff:ffff:ffff
10724ef:dd0:6a0::/4424ef:dd0:6af:ffff:ffff:ffff:ffff:ffff
10824ef:dd0:6b0::/4424ef:dd0:6bf:ffff:ffff:ffff:ffff:ffff
10924ef:dd0:6c0::/4424ef:dd0:6cf:ffff:ffff:ffff:ffff:ffff
11024ef:dd0:6d0::/4424ef:dd0:6df:ffff:ffff:ffff:ffff:ffff
11124ef:dd0:6e0::/4424ef:dd0:6ef:ffff:ffff:ffff:ffff:ffff
11224ef:dd0:6f0::/4424ef:dd0:6ff:ffff:ffff:ffff:ffff:ffff
11324ef:dd0:700::/4424ef:dd0:70f:ffff:ffff:ffff:ffff:ffff
11424ef:dd0:710::/4424ef:dd0:71f:ffff:ffff:ffff:ffff:ffff
11524ef:dd0:720::/4424ef:dd0:72f:ffff:ffff:ffff:ffff:ffff
11624ef:dd0:730::/4424ef:dd0:73f:ffff:ffff:ffff:ffff:ffff
11724ef:dd0:740::/4424ef:dd0:74f:ffff:ffff:ffff:ffff:ffff
11824ef:dd0:750::/4424ef:dd0:75f:ffff:ffff:ffff:ffff:ffff
11924ef:dd0:760::/4424ef:dd0:76f:ffff:ffff:ffff:ffff:ffff
12024ef:dd0:770::/4424ef:dd0:77f:ffff:ffff:ffff:ffff:ffff
12124ef:dd0:780::/4424ef:dd0:78f:ffff:ffff:ffff:ffff:ffff
12224ef:dd0:790::/4424ef:dd0:79f:ffff:ffff:ffff:ffff:ffff
12324ef:dd0:7a0::/4424ef:dd0:7af:ffff:ffff:ffff:ffff:ffff
12424ef:dd0:7b0::/4424ef:dd0:7bf:ffff:ffff:ffff:ffff:ffff
12524ef:dd0:7c0::/4424ef:dd0:7cf:ffff:ffff:ffff:ffff:ffff
12624ef:dd0:7d0::/4424ef:dd0:7df:ffff:ffff:ffff:ffff:ffff
12724ef:dd0:7e0::/4424ef:dd0:7ef:ffff:ffff:ffff:ffff:ffff
12824ef:dd0:7f0::/4424ef:dd0:7ff:ffff:ffff:ffff:ffff:ffff
12924ef:dd0:800::/4424ef:dd0:80f:ffff:ffff:ffff:ffff:ffff
13024ef:dd0:810::/4424ef:dd0:81f:ffff:ffff:ffff:ffff:ffff
13124ef:dd0:820::/4424ef:dd0:82f:ffff:ffff:ffff:ffff:ffff
13224ef:dd0:830::/4424ef:dd0:83f:ffff:ffff:ffff:ffff:ffff
13324ef:dd0:840::/4424ef:dd0:84f:ffff:ffff:ffff:ffff:ffff
13424ef:dd0:850::/4424ef:dd0:85f:ffff:ffff:ffff:ffff:ffff
13524ef:dd0:860::/4424ef:dd0:86f:ffff:ffff:ffff:ffff:ffff
13624ef:dd0:870::/4424ef:dd0:87f:ffff:ffff:ffff:ffff:ffff
13724ef:dd0:880::/4424ef:dd0:88f:ffff:ffff:ffff:ffff:ffff
13824ef:dd0:890::/4424ef:dd0:89f:ffff:ffff:ffff:ffff:ffff
13924ef:dd0:8a0::/4424ef:dd0:8af:ffff:ffff:ffff:ffff:ffff
14024ef:dd0:8b0::/4424ef:dd0:8bf:ffff:ffff:ffff:ffff:ffff
14124ef:dd0:8c0::/4424ef:dd0:8cf:ffff:ffff:ffff:ffff:ffff
14224ef:dd0:8d0::/4424ef:dd0:8df:ffff:ffff:ffff:ffff:ffff
14324ef:dd0:8e0::/4424ef:dd0:8ef:ffff:ffff:ffff:ffff:ffff
14424ef:dd0:8f0::/4424ef:dd0:8ff:ffff:ffff:ffff:ffff:ffff
14524ef:dd0:900::/4424ef:dd0:90f:ffff:ffff:ffff:ffff:ffff
14624ef:dd0:910::/4424ef:dd0:91f:ffff:ffff:ffff:ffff:ffff
14724ef:dd0:920::/4424ef:dd0:92f:ffff:ffff:ffff:ffff:ffff
14824ef:dd0:930::/4424ef:dd0:93f:ffff:ffff:ffff:ffff:ffff
14924ef:dd0:940::/4424ef:dd0:94f:ffff:ffff:ffff:ffff:ffff
15024ef:dd0:950::/4424ef:dd0:95f:ffff:ffff:ffff:ffff:ffff
15124ef:dd0:960::/4424ef:dd0:96f:ffff:ffff:ffff:ffff:ffff
15224ef:dd0:970::/4424ef:dd0:97f:ffff:ffff:ffff:ffff:ffff
15324ef:dd0:980::/4424ef:dd0:98f:ffff:ffff:ffff:ffff:ffff
15424ef:dd0:990::/4424ef:dd0:99f:ffff:ffff:ffff:ffff:ffff
15524ef:dd0:9a0::/4424ef:dd0:9af:ffff:ffff:ffff:ffff:ffff
15624ef:dd0:9b0::/4424ef:dd0:9bf:ffff:ffff:ffff:ffff:ffff
15724ef:dd0:9c0::/4424ef:dd0:9cf:ffff:ffff:ffff:ffff:ffff
15824ef:dd0:9d0::/4424ef:dd0:9df:ffff:ffff:ffff:ffff:ffff
15924ef:dd0:9e0::/4424ef:dd0:9ef:ffff:ffff:ffff:ffff:ffff
16024ef:dd0:9f0::/4424ef:dd0:9ff:ffff:ffff:ffff:ffff:ffff
16124ef:dd0:a00::/4424ef:dd0:a0f:ffff:ffff:ffff:ffff:ffff
16224ef:dd0:a10::/4424ef:dd0:a1f:ffff:ffff:ffff:ffff:ffff
16324ef:dd0:a20::/4424ef:dd0:a2f:ffff:ffff:ffff:ffff:ffff
16424ef:dd0:a30::/4424ef:dd0:a3f:ffff:ffff:ffff:ffff:ffff
16524ef:dd0:a40::/4424ef:dd0:a4f:ffff:ffff:ffff:ffff:ffff
16624ef:dd0:a50::/4424ef:dd0:a5f:ffff:ffff:ffff:ffff:ffff
16724ef:dd0:a60::/4424ef:dd0:a6f:ffff:ffff:ffff:ffff:ffff
16824ef:dd0:a70::/4424ef:dd0:a7f:ffff:ffff:ffff:ffff:ffff
16924ef:dd0:a80::/4424ef:dd0:a8f:ffff:ffff:ffff:ffff:ffff
17024ef:dd0:a90::/4424ef:dd0:a9f:ffff:ffff:ffff:ffff:ffff
17124ef:dd0:aa0::/4424ef:dd0:aaf:ffff:ffff:ffff:ffff:ffff
17224ef:dd0:ab0::/4424ef:dd0:abf:ffff:ffff:ffff:ffff:ffff
17324ef:dd0:ac0::/4424ef:dd0:acf:ffff:ffff:ffff:ffff:ffff
17424ef:dd0:ad0::/4424ef:dd0:adf:ffff:ffff:ffff:ffff:ffff
17524ef:dd0:ae0::/4424ef:dd0:aef:ffff:ffff:ffff:ffff:ffff
17624ef:dd0:af0::/4424ef:dd0:aff:ffff:ffff:ffff:ffff:ffff
17724ef:dd0:b00::/4424ef:dd0:b0f:ffff:ffff:ffff:ffff:ffff
17824ef:dd0:b10::/4424ef:dd0:b1f:ffff:ffff:ffff:ffff:ffff
17924ef:dd0:b20::/4424ef:dd0:b2f:ffff:ffff:ffff:ffff:ffff
18024ef:dd0:b30::/4424ef:dd0:b3f:ffff:ffff:ffff:ffff:ffff
18124ef:dd0:b40::/4424ef:dd0:b4f:ffff:ffff:ffff:ffff:ffff
18224ef:dd0:b50::/4424ef:dd0:b5f:ffff:ffff:ffff:ffff:ffff
18324ef:dd0:b60::/4424ef:dd0:b6f:ffff:ffff:ffff:ffff:ffff
18424ef:dd0:b70::/4424ef:dd0:b7f:ffff:ffff:ffff:ffff:ffff
18524ef:dd0:b80::/4424ef:dd0:b8f:ffff:ffff:ffff:ffff:ffff
18624ef:dd0:b90::/4424ef:dd0:b9f:ffff:ffff:ffff:ffff:ffff
18724ef:dd0:ba0::/4424ef:dd0:baf:ffff:ffff:ffff:ffff:ffff
18824ef:dd0:bb0::/4424ef:dd0:bbf:ffff:ffff:ffff:ffff:ffff
18924ef:dd0:bc0::/4424ef:dd0:bcf:ffff:ffff:ffff:ffff:ffff
19024ef:dd0:bd0::/4424ef:dd0:bdf:ffff:ffff:ffff:ffff:ffff
19124ef:dd0:be0::/4424ef:dd0:bef:ffff:ffff:ffff:ffff:ffff
19224ef:dd0:bf0::/4424ef:dd0:bff:ffff:ffff:ffff:ffff:ffff
19324ef:dd0:c00::/4424ef:dd0:c0f:ffff:ffff:ffff:ffff:ffff
19424ef:dd0:c10::/4424ef:dd0:c1f:ffff:ffff:ffff:ffff:ffff
19524ef:dd0:c20::/4424ef:dd0:c2f:ffff:ffff:ffff:ffff:ffff
19624ef:dd0:c30::/4424ef:dd0:c3f:ffff:ffff:ffff:ffff:ffff
19724ef:dd0:c40::/4424ef:dd0:c4f:ffff:ffff:ffff:ffff:ffff
19824ef:dd0:c50::/4424ef:dd0:c5f:ffff:ffff:ffff:ffff:ffff
19924ef:dd0:c60::/4424ef:dd0:c6f:ffff:ffff:ffff:ffff:ffff
20024ef:dd0:c70::/4424ef:dd0:c7f:ffff:ffff:ffff:ffff:ffff
20124ef:dd0:c80::/4424ef:dd0:c8f:ffff:ffff:ffff:ffff:ffff
20224ef:dd0:c90::/4424ef:dd0:c9f:ffff:ffff:ffff:ffff:ffff
20324ef:dd0:ca0::/4424ef:dd0:caf:ffff:ffff:ffff:ffff:ffff
20424ef:dd0:cb0::/4424ef:dd0:cbf:ffff:ffff:ffff:ffff:ffff
20524ef:dd0:cc0::/4424ef:dd0:ccf:ffff:ffff:ffff:ffff:ffff
20624ef:dd0:cd0::/4424ef:dd0:cdf:ffff:ffff:ffff:ffff:ffff
20724ef:dd0:ce0::/4424ef:dd0:cef:ffff:ffff:ffff:ffff:ffff
20824ef:dd0:cf0::/4424ef:dd0:cff:ffff:ffff:ffff:ffff:ffff
20924ef:dd0:d00::/4424ef:dd0:d0f:ffff:ffff:ffff:ffff:ffff
21024ef:dd0:d10::/4424ef:dd0:d1f:ffff:ffff:ffff:ffff:ffff
21124ef:dd0:d20::/4424ef:dd0:d2f:ffff:ffff:ffff:ffff:ffff
21224ef:dd0:d30::/4424ef:dd0:d3f:ffff:ffff:ffff:ffff:ffff
21324ef:dd0:d40::/4424ef:dd0:d4f:ffff:ffff:ffff:ffff:ffff
21424ef:dd0:d50::/4424ef:dd0:d5f:ffff:ffff:ffff:ffff:ffff
21524ef:dd0:d60::/4424ef:dd0:d6f:ffff:ffff:ffff:ffff:ffff
21624ef:dd0:d70::/4424ef:dd0:d7f:ffff:ffff:ffff:ffff:ffff
21724ef:dd0:d80::/4424ef:dd0:d8f:ffff:ffff:ffff:ffff:ffff
21824ef:dd0:d90::/4424ef:dd0:d9f:ffff:ffff:ffff:ffff:ffff
21924ef:dd0:da0::/4424ef:dd0:daf:ffff:ffff:ffff:ffff:ffff
22024ef:dd0:db0::/4424ef:dd0:dbf:ffff:ffff:ffff:ffff:ffff
22124ef:dd0:dc0::/4424ef:dd0:dcf:ffff:ffff:ffff:ffff:ffff
22224ef:dd0:dd0::/4424ef:dd0:ddf:ffff:ffff:ffff:ffff:ffff
22324ef:dd0:de0::/4424ef:dd0:def:ffff:ffff:ffff:ffff:ffff
22424ef:dd0:df0::/4424ef:dd0:dff:ffff:ffff:ffff:ffff:ffff
22524ef:dd0:e00::/4424ef:dd0:e0f:ffff:ffff:ffff:ffff:ffff
22624ef:dd0:e10::/4424ef:dd0:e1f:ffff:ffff:ffff:ffff:ffff
22724ef:dd0:e20::/4424ef:dd0:e2f:ffff:ffff:ffff:ffff:ffff
22824ef:dd0:e30::/4424ef:dd0:e3f:ffff:ffff:ffff:ffff:ffff
22924ef:dd0:e40::/4424ef:dd0:e4f:ffff:ffff:ffff:ffff:ffff
23024ef:dd0:e50::/4424ef:dd0:e5f:ffff:ffff:ffff:ffff:ffff
23124ef:dd0:e60::/4424ef:dd0:e6f:ffff:ffff:ffff:ffff:ffff
23224ef:dd0:e70::/4424ef:dd0:e7f:ffff:ffff:ffff:ffff:ffff
23324ef:dd0:e80::/4424ef:dd0:e8f:ffff:ffff:ffff:ffff:ffff
23424ef:dd0:e90::/4424ef:dd0:e9f:ffff:ffff:ffff:ffff:ffff
23524ef:dd0:ea0::/4424ef:dd0:eaf:ffff:ffff:ffff:ffff:ffff
23624ef:dd0:eb0::/4424ef:dd0:ebf:ffff:ffff:ffff:ffff:ffff
23724ef:dd0:ec0::/4424ef:dd0:ecf:ffff:ffff:ffff:ffff:ffff
23824ef:dd0:ed0::/4424ef:dd0:edf:ffff:ffff:ffff:ffff:ffff
23924ef:dd0:ee0::/4424ef:dd0:eef:ffff:ffff:ffff:ffff:ffff
24024ef:dd0:ef0::/4424ef:dd0:eff:ffff:ffff:ffff:ffff:ffff
24124ef:dd0:f00::/4424ef:dd0:f0f:ffff:ffff:ffff:ffff:ffff
24224ef:dd0:f10::/4424ef:dd0:f1f:ffff:ffff:ffff:ffff:ffff
24324ef:dd0:f20::/4424ef:dd0:f2f:ffff:ffff:ffff:ffff:ffff
24424ef:dd0:f30::/4424ef:dd0:f3f:ffff:ffff:ffff:ffff:ffff
24524ef:dd0:f40::/4424ef:dd0:f4f:ffff:ffff:ffff:ffff:ffff
24624ef:dd0:f50::/4424ef:dd0:f5f:ffff:ffff:ffff:ffff:ffff
24724ef:dd0:f60::/4424ef:dd0:f6f:ffff:ffff:ffff:ffff:ffff
24824ef:dd0:f70::/4424ef:dd0:f7f:ffff:ffff:ffff:ffff:ffff
24924ef:dd0:f80::/4424ef:dd0:f8f:ffff:ffff:ffff:ffff:ffff
25024ef:dd0:f90::/4424ef:dd0:f9f:ffff:ffff:ffff:ffff:ffff
25124ef:dd0:fa0::/4424ef:dd0:faf:ffff:ffff:ffff:ffff:ffff
25224ef:dd0:fb0::/4424ef:dd0:fbf:ffff:ffff:ffff:ffff:ffff
25324ef:dd0:fc0::/4424ef:dd0:fcf:ffff:ffff:ffff:ffff:ffff
25424ef:dd0:fd0::/4424ef:dd0:fdf:ffff:ffff:ffff:ffff:ffff
25524ef:dd0:fe0::/4424ef:dd0:fef:ffff:ffff:ffff:ffff:ffff
25624ef:dd0:ff0::/4424ef:dd0:fff: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.