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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
22cd::/16
First address
22cd::
Last address
22cd: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
22cd:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
d.c.2.2.ip6.arpa
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

22cd::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
122cd::/2822cd:f:ffff:ffff:ffff:ffff:ffff:ffff
222cd:10::/2822cd:1f:ffff:ffff:ffff:ffff:ffff:ffff
322cd:20::/2822cd:2f:ffff:ffff:ffff:ffff:ffff:ffff
422cd:30::/2822cd:3f:ffff:ffff:ffff:ffff:ffff:ffff
522cd:40::/2822cd:4f:ffff:ffff:ffff:ffff:ffff:ffff
622cd:50::/2822cd:5f:ffff:ffff:ffff:ffff:ffff:ffff
722cd:60::/2822cd:6f:ffff:ffff:ffff:ffff:ffff:ffff
822cd:70::/2822cd:7f:ffff:ffff:ffff:ffff:ffff:ffff
922cd:80::/2822cd:8f:ffff:ffff:ffff:ffff:ffff:ffff
1022cd:90::/2822cd:9f:ffff:ffff:ffff:ffff:ffff:ffff
1122cd:a0::/2822cd:af:ffff:ffff:ffff:ffff:ffff:ffff
1222cd:b0::/2822cd:bf:ffff:ffff:ffff:ffff:ffff:ffff
1322cd:c0::/2822cd:cf:ffff:ffff:ffff:ffff:ffff:ffff
1422cd:d0::/2822cd:df:ffff:ffff:ffff:ffff:ffff:ffff
1522cd:e0::/2822cd:ef:ffff:ffff:ffff:ffff:ffff:ffff
1622cd:f0::/2822cd:ff:ffff:ffff:ffff:ffff:ffff:ffff
1722cd:100::/2822cd:10f:ffff:ffff:ffff:ffff:ffff:ffff
1822cd:110::/2822cd:11f:ffff:ffff:ffff:ffff:ffff:ffff
1922cd:120::/2822cd:12f:ffff:ffff:ffff:ffff:ffff:ffff
2022cd:130::/2822cd:13f:ffff:ffff:ffff:ffff:ffff:ffff
2122cd:140::/2822cd:14f:ffff:ffff:ffff:ffff:ffff:ffff
2222cd:150::/2822cd:15f:ffff:ffff:ffff:ffff:ffff:ffff
2322cd:160::/2822cd:16f:ffff:ffff:ffff:ffff:ffff:ffff
2422cd:170::/2822cd:17f:ffff:ffff:ffff:ffff:ffff:ffff
2522cd:180::/2822cd:18f:ffff:ffff:ffff:ffff:ffff:ffff
2622cd:190::/2822cd:19f:ffff:ffff:ffff:ffff:ffff:ffff
2722cd:1a0::/2822cd:1af:ffff:ffff:ffff:ffff:ffff:ffff
2822cd:1b0::/2822cd:1bf:ffff:ffff:ffff:ffff:ffff:ffff
2922cd:1c0::/2822cd:1cf:ffff:ffff:ffff:ffff:ffff:ffff
3022cd:1d0::/2822cd:1df:ffff:ffff:ffff:ffff:ffff:ffff
3122cd:1e0::/2822cd:1ef:ffff:ffff:ffff:ffff:ffff:ffff
3222cd:1f0::/2822cd:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3322cd:200::/2822cd:20f:ffff:ffff:ffff:ffff:ffff:ffff
3422cd:210::/2822cd:21f:ffff:ffff:ffff:ffff:ffff:ffff
3522cd:220::/2822cd:22f:ffff:ffff:ffff:ffff:ffff:ffff
3622cd:230::/2822cd:23f:ffff:ffff:ffff:ffff:ffff:ffff
3722cd:240::/2822cd:24f:ffff:ffff:ffff:ffff:ffff:ffff
3822cd:250::/2822cd:25f:ffff:ffff:ffff:ffff:ffff:ffff
3922cd:260::/2822cd:26f:ffff:ffff:ffff:ffff:ffff:ffff
4022cd:270::/2822cd:27f:ffff:ffff:ffff:ffff:ffff:ffff
4122cd:280::/2822cd:28f:ffff:ffff:ffff:ffff:ffff:ffff
4222cd:290::/2822cd:29f:ffff:ffff:ffff:ffff:ffff:ffff
4322cd:2a0::/2822cd:2af:ffff:ffff:ffff:ffff:ffff:ffff
4422cd:2b0::/2822cd:2bf:ffff:ffff:ffff:ffff:ffff:ffff
4522cd:2c0::/2822cd:2cf:ffff:ffff:ffff:ffff:ffff:ffff
4622cd:2d0::/2822cd:2df:ffff:ffff:ffff:ffff:ffff:ffff
4722cd:2e0::/2822cd:2ef:ffff:ffff:ffff:ffff:ffff:ffff
4822cd:2f0::/2822cd:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4922cd:300::/2822cd:30f:ffff:ffff:ffff:ffff:ffff:ffff
5022cd:310::/2822cd:31f:ffff:ffff:ffff:ffff:ffff:ffff
5122cd:320::/2822cd:32f:ffff:ffff:ffff:ffff:ffff:ffff
5222cd:330::/2822cd:33f:ffff:ffff:ffff:ffff:ffff:ffff
5322cd:340::/2822cd:34f:ffff:ffff:ffff:ffff:ffff:ffff
5422cd:350::/2822cd:35f:ffff:ffff:ffff:ffff:ffff:ffff
5522cd:360::/2822cd:36f:ffff:ffff:ffff:ffff:ffff:ffff
5622cd:370::/2822cd:37f:ffff:ffff:ffff:ffff:ffff:ffff
5722cd:380::/2822cd:38f:ffff:ffff:ffff:ffff:ffff:ffff
5822cd:390::/2822cd:39f:ffff:ffff:ffff:ffff:ffff:ffff
5922cd:3a0::/2822cd:3af:ffff:ffff:ffff:ffff:ffff:ffff
6022cd:3b0::/2822cd:3bf:ffff:ffff:ffff:ffff:ffff:ffff
6122cd:3c0::/2822cd:3cf:ffff:ffff:ffff:ffff:ffff:ffff
6222cd:3d0::/2822cd:3df:ffff:ffff:ffff:ffff:ffff:ffff
6322cd:3e0::/2822cd:3ef:ffff:ffff:ffff:ffff:ffff:ffff
6422cd:3f0::/2822cd:3ff:ffff:ffff:ffff:ffff:ffff:ffff
6522cd:400::/2822cd:40f:ffff:ffff:ffff:ffff:ffff:ffff
6622cd:410::/2822cd:41f:ffff:ffff:ffff:ffff:ffff:ffff
6722cd:420::/2822cd:42f:ffff:ffff:ffff:ffff:ffff:ffff
6822cd:430::/2822cd:43f:ffff:ffff:ffff:ffff:ffff:ffff
6922cd:440::/2822cd:44f:ffff:ffff:ffff:ffff:ffff:ffff
7022cd:450::/2822cd:45f:ffff:ffff:ffff:ffff:ffff:ffff
7122cd:460::/2822cd:46f:ffff:ffff:ffff:ffff:ffff:ffff
7222cd:470::/2822cd:47f:ffff:ffff:ffff:ffff:ffff:ffff
7322cd:480::/2822cd:48f:ffff:ffff:ffff:ffff:ffff:ffff
7422cd:490::/2822cd:49f:ffff:ffff:ffff:ffff:ffff:ffff
7522cd:4a0::/2822cd:4af:ffff:ffff:ffff:ffff:ffff:ffff
7622cd:4b0::/2822cd:4bf:ffff:ffff:ffff:ffff:ffff:ffff
7722cd:4c0::/2822cd:4cf:ffff:ffff:ffff:ffff:ffff:ffff
7822cd:4d0::/2822cd:4df:ffff:ffff:ffff:ffff:ffff:ffff
7922cd:4e0::/2822cd:4ef:ffff:ffff:ffff:ffff:ffff:ffff
8022cd:4f0::/2822cd:4ff:ffff:ffff:ffff:ffff:ffff:ffff
8122cd:500::/2822cd:50f:ffff:ffff:ffff:ffff:ffff:ffff
8222cd:510::/2822cd:51f:ffff:ffff:ffff:ffff:ffff:ffff
8322cd:520::/2822cd:52f:ffff:ffff:ffff:ffff:ffff:ffff
8422cd:530::/2822cd:53f:ffff:ffff:ffff:ffff:ffff:ffff
8522cd:540::/2822cd:54f:ffff:ffff:ffff:ffff:ffff:ffff
8622cd:550::/2822cd:55f:ffff:ffff:ffff:ffff:ffff:ffff
8722cd:560::/2822cd:56f:ffff:ffff:ffff:ffff:ffff:ffff
8822cd:570::/2822cd:57f:ffff:ffff:ffff:ffff:ffff:ffff
8922cd:580::/2822cd:58f:ffff:ffff:ffff:ffff:ffff:ffff
9022cd:590::/2822cd:59f:ffff:ffff:ffff:ffff:ffff:ffff
9122cd:5a0::/2822cd:5af:ffff:ffff:ffff:ffff:ffff:ffff
9222cd:5b0::/2822cd:5bf:ffff:ffff:ffff:ffff:ffff:ffff
9322cd:5c0::/2822cd:5cf:ffff:ffff:ffff:ffff:ffff:ffff
9422cd:5d0::/2822cd:5df:ffff:ffff:ffff:ffff:ffff:ffff
9522cd:5e0::/2822cd:5ef:ffff:ffff:ffff:ffff:ffff:ffff
9622cd:5f0::/2822cd:5ff:ffff:ffff:ffff:ffff:ffff:ffff
9722cd:600::/2822cd:60f:ffff:ffff:ffff:ffff:ffff:ffff
9822cd:610::/2822cd:61f:ffff:ffff:ffff:ffff:ffff:ffff
9922cd:620::/2822cd:62f:ffff:ffff:ffff:ffff:ffff:ffff
10022cd:630::/2822cd:63f:ffff:ffff:ffff:ffff:ffff:ffff
10122cd:640::/2822cd:64f:ffff:ffff:ffff:ffff:ffff:ffff
10222cd:650::/2822cd:65f:ffff:ffff:ffff:ffff:ffff:ffff
10322cd:660::/2822cd:66f:ffff:ffff:ffff:ffff:ffff:ffff
10422cd:670::/2822cd:67f:ffff:ffff:ffff:ffff:ffff:ffff
10522cd:680::/2822cd:68f:ffff:ffff:ffff:ffff:ffff:ffff
10622cd:690::/2822cd:69f:ffff:ffff:ffff:ffff:ffff:ffff
10722cd:6a0::/2822cd:6af:ffff:ffff:ffff:ffff:ffff:ffff
10822cd:6b0::/2822cd:6bf:ffff:ffff:ffff:ffff:ffff:ffff
10922cd:6c0::/2822cd:6cf:ffff:ffff:ffff:ffff:ffff:ffff
11022cd:6d0::/2822cd:6df:ffff:ffff:ffff:ffff:ffff:ffff
11122cd:6e0::/2822cd:6ef:ffff:ffff:ffff:ffff:ffff:ffff
11222cd:6f0::/2822cd:6ff:ffff:ffff:ffff:ffff:ffff:ffff
11322cd:700::/2822cd:70f:ffff:ffff:ffff:ffff:ffff:ffff
11422cd:710::/2822cd:71f:ffff:ffff:ffff:ffff:ffff:ffff
11522cd:720::/2822cd:72f:ffff:ffff:ffff:ffff:ffff:ffff
11622cd:730::/2822cd:73f:ffff:ffff:ffff:ffff:ffff:ffff
11722cd:740::/2822cd:74f:ffff:ffff:ffff:ffff:ffff:ffff
11822cd:750::/2822cd:75f:ffff:ffff:ffff:ffff:ffff:ffff
11922cd:760::/2822cd:76f:ffff:ffff:ffff:ffff:ffff:ffff
12022cd:770::/2822cd:77f:ffff:ffff:ffff:ffff:ffff:ffff
12122cd:780::/2822cd:78f:ffff:ffff:ffff:ffff:ffff:ffff
12222cd:790::/2822cd:79f:ffff:ffff:ffff:ffff:ffff:ffff
12322cd:7a0::/2822cd:7af:ffff:ffff:ffff:ffff:ffff:ffff
12422cd:7b0::/2822cd:7bf:ffff:ffff:ffff:ffff:ffff:ffff
12522cd:7c0::/2822cd:7cf:ffff:ffff:ffff:ffff:ffff:ffff
12622cd:7d0::/2822cd:7df:ffff:ffff:ffff:ffff:ffff:ffff
12722cd:7e0::/2822cd:7ef:ffff:ffff:ffff:ffff:ffff:ffff
12822cd:7f0::/2822cd:7ff:ffff:ffff:ffff:ffff:ffff:ffff
12922cd:800::/2822cd:80f:ffff:ffff:ffff:ffff:ffff:ffff
13022cd:810::/2822cd:81f:ffff:ffff:ffff:ffff:ffff:ffff
13122cd:820::/2822cd:82f:ffff:ffff:ffff:ffff:ffff:ffff
13222cd:830::/2822cd:83f:ffff:ffff:ffff:ffff:ffff:ffff
13322cd:840::/2822cd:84f:ffff:ffff:ffff:ffff:ffff:ffff
13422cd:850::/2822cd:85f:ffff:ffff:ffff:ffff:ffff:ffff
13522cd:860::/2822cd:86f:ffff:ffff:ffff:ffff:ffff:ffff
13622cd:870::/2822cd:87f:ffff:ffff:ffff:ffff:ffff:ffff
13722cd:880::/2822cd:88f:ffff:ffff:ffff:ffff:ffff:ffff
13822cd:890::/2822cd:89f:ffff:ffff:ffff:ffff:ffff:ffff
13922cd:8a0::/2822cd:8af:ffff:ffff:ffff:ffff:ffff:ffff
14022cd:8b0::/2822cd:8bf:ffff:ffff:ffff:ffff:ffff:ffff
14122cd:8c0::/2822cd:8cf:ffff:ffff:ffff:ffff:ffff:ffff
14222cd:8d0::/2822cd:8df:ffff:ffff:ffff:ffff:ffff:ffff
14322cd:8e0::/2822cd:8ef:ffff:ffff:ffff:ffff:ffff:ffff
14422cd:8f0::/2822cd:8ff:ffff:ffff:ffff:ffff:ffff:ffff
14522cd:900::/2822cd:90f:ffff:ffff:ffff:ffff:ffff:ffff
14622cd:910::/2822cd:91f:ffff:ffff:ffff:ffff:ffff:ffff
14722cd:920::/2822cd:92f:ffff:ffff:ffff:ffff:ffff:ffff
14822cd:930::/2822cd:93f:ffff:ffff:ffff:ffff:ffff:ffff
14922cd:940::/2822cd:94f:ffff:ffff:ffff:ffff:ffff:ffff
15022cd:950::/2822cd:95f:ffff:ffff:ffff:ffff:ffff:ffff
15122cd:960::/2822cd:96f:ffff:ffff:ffff:ffff:ffff:ffff
15222cd:970::/2822cd:97f:ffff:ffff:ffff:ffff:ffff:ffff
15322cd:980::/2822cd:98f:ffff:ffff:ffff:ffff:ffff:ffff
15422cd:990::/2822cd:99f:ffff:ffff:ffff:ffff:ffff:ffff
15522cd:9a0::/2822cd:9af:ffff:ffff:ffff:ffff:ffff:ffff
15622cd:9b0::/2822cd:9bf:ffff:ffff:ffff:ffff:ffff:ffff
15722cd:9c0::/2822cd:9cf:ffff:ffff:ffff:ffff:ffff:ffff
15822cd:9d0::/2822cd:9df:ffff:ffff:ffff:ffff:ffff:ffff
15922cd:9e0::/2822cd:9ef:ffff:ffff:ffff:ffff:ffff:ffff
16022cd:9f0::/2822cd:9ff:ffff:ffff:ffff:ffff:ffff:ffff
16122cd:a00::/2822cd:a0f:ffff:ffff:ffff:ffff:ffff:ffff
16222cd:a10::/2822cd:a1f:ffff:ffff:ffff:ffff:ffff:ffff
16322cd:a20::/2822cd:a2f:ffff:ffff:ffff:ffff:ffff:ffff
16422cd:a30::/2822cd:a3f:ffff:ffff:ffff:ffff:ffff:ffff
16522cd:a40::/2822cd:a4f:ffff:ffff:ffff:ffff:ffff:ffff
16622cd:a50::/2822cd:a5f:ffff:ffff:ffff:ffff:ffff:ffff
16722cd:a60::/2822cd:a6f:ffff:ffff:ffff:ffff:ffff:ffff
16822cd:a70::/2822cd:a7f:ffff:ffff:ffff:ffff:ffff:ffff
16922cd:a80::/2822cd:a8f:ffff:ffff:ffff:ffff:ffff:ffff
17022cd:a90::/2822cd:a9f:ffff:ffff:ffff:ffff:ffff:ffff
17122cd:aa0::/2822cd:aaf:ffff:ffff:ffff:ffff:ffff:ffff
17222cd:ab0::/2822cd:abf:ffff:ffff:ffff:ffff:ffff:ffff
17322cd:ac0::/2822cd:acf:ffff:ffff:ffff:ffff:ffff:ffff
17422cd:ad0::/2822cd:adf:ffff:ffff:ffff:ffff:ffff:ffff
17522cd:ae0::/2822cd:aef:ffff:ffff:ffff:ffff:ffff:ffff
17622cd:af0::/2822cd:aff:ffff:ffff:ffff:ffff:ffff:ffff
17722cd:b00::/2822cd:b0f:ffff:ffff:ffff:ffff:ffff:ffff
17822cd:b10::/2822cd:b1f:ffff:ffff:ffff:ffff:ffff:ffff
17922cd:b20::/2822cd:b2f:ffff:ffff:ffff:ffff:ffff:ffff
18022cd:b30::/2822cd:b3f:ffff:ffff:ffff:ffff:ffff:ffff
18122cd:b40::/2822cd:b4f:ffff:ffff:ffff:ffff:ffff:ffff
18222cd:b50::/2822cd:b5f:ffff:ffff:ffff:ffff:ffff:ffff
18322cd:b60::/2822cd:b6f:ffff:ffff:ffff:ffff:ffff:ffff
18422cd:b70::/2822cd:b7f:ffff:ffff:ffff:ffff:ffff:ffff
18522cd:b80::/2822cd:b8f:ffff:ffff:ffff:ffff:ffff:ffff
18622cd:b90::/2822cd:b9f:ffff:ffff:ffff:ffff:ffff:ffff
18722cd:ba0::/2822cd:baf:ffff:ffff:ffff:ffff:ffff:ffff
18822cd:bb0::/2822cd:bbf:ffff:ffff:ffff:ffff:ffff:ffff
18922cd:bc0::/2822cd:bcf:ffff:ffff:ffff:ffff:ffff:ffff
19022cd:bd0::/2822cd:bdf:ffff:ffff:ffff:ffff:ffff:ffff
19122cd:be0::/2822cd:bef:ffff:ffff:ffff:ffff:ffff:ffff
19222cd:bf0::/2822cd:bff:ffff:ffff:ffff:ffff:ffff:ffff
19322cd:c00::/2822cd:c0f:ffff:ffff:ffff:ffff:ffff:ffff
19422cd:c10::/2822cd:c1f:ffff:ffff:ffff:ffff:ffff:ffff
19522cd:c20::/2822cd:c2f:ffff:ffff:ffff:ffff:ffff:ffff
19622cd:c30::/2822cd:c3f:ffff:ffff:ffff:ffff:ffff:ffff
19722cd:c40::/2822cd:c4f:ffff:ffff:ffff:ffff:ffff:ffff
19822cd:c50::/2822cd:c5f:ffff:ffff:ffff:ffff:ffff:ffff
19922cd:c60::/2822cd:c6f:ffff:ffff:ffff:ffff:ffff:ffff
20022cd:c70::/2822cd:c7f:ffff:ffff:ffff:ffff:ffff:ffff
20122cd:c80::/2822cd:c8f:ffff:ffff:ffff:ffff:ffff:ffff
20222cd:c90::/2822cd:c9f:ffff:ffff:ffff:ffff:ffff:ffff
20322cd:ca0::/2822cd:caf:ffff:ffff:ffff:ffff:ffff:ffff
20422cd:cb0::/2822cd:cbf:ffff:ffff:ffff:ffff:ffff:ffff
20522cd:cc0::/2822cd:ccf:ffff:ffff:ffff:ffff:ffff:ffff
20622cd:cd0::/2822cd:cdf:ffff:ffff:ffff:ffff:ffff:ffff
20722cd:ce0::/2822cd:cef:ffff:ffff:ffff:ffff:ffff:ffff
20822cd:cf0::/2822cd:cff:ffff:ffff:ffff:ffff:ffff:ffff
20922cd:d00::/2822cd:d0f:ffff:ffff:ffff:ffff:ffff:ffff
21022cd:d10::/2822cd:d1f:ffff:ffff:ffff:ffff:ffff:ffff
21122cd:d20::/2822cd:d2f:ffff:ffff:ffff:ffff:ffff:ffff
21222cd:d30::/2822cd:d3f:ffff:ffff:ffff:ffff:ffff:ffff
21322cd:d40::/2822cd:d4f:ffff:ffff:ffff:ffff:ffff:ffff
21422cd:d50::/2822cd:d5f:ffff:ffff:ffff:ffff:ffff:ffff
21522cd:d60::/2822cd:d6f:ffff:ffff:ffff:ffff:ffff:ffff
21622cd:d70::/2822cd:d7f:ffff:ffff:ffff:ffff:ffff:ffff
21722cd:d80::/2822cd:d8f:ffff:ffff:ffff:ffff:ffff:ffff
21822cd:d90::/2822cd:d9f:ffff:ffff:ffff:ffff:ffff:ffff
21922cd:da0::/2822cd:daf:ffff:ffff:ffff:ffff:ffff:ffff
22022cd:db0::/2822cd:dbf:ffff:ffff:ffff:ffff:ffff:ffff
22122cd:dc0::/2822cd:dcf:ffff:ffff:ffff:ffff:ffff:ffff
22222cd:dd0::/2822cd:ddf:ffff:ffff:ffff:ffff:ffff:ffff
22322cd:de0::/2822cd:def:ffff:ffff:ffff:ffff:ffff:ffff
22422cd:df0::/2822cd:dff:ffff:ffff:ffff:ffff:ffff:ffff
22522cd:e00::/2822cd:e0f:ffff:ffff:ffff:ffff:ffff:ffff
22622cd:e10::/2822cd:e1f:ffff:ffff:ffff:ffff:ffff:ffff
22722cd:e20::/2822cd:e2f:ffff:ffff:ffff:ffff:ffff:ffff
22822cd:e30::/2822cd:e3f:ffff:ffff:ffff:ffff:ffff:ffff
22922cd:e40::/2822cd:e4f:ffff:ffff:ffff:ffff:ffff:ffff
23022cd:e50::/2822cd:e5f:ffff:ffff:ffff:ffff:ffff:ffff
23122cd:e60::/2822cd:e6f:ffff:ffff:ffff:ffff:ffff:ffff
23222cd:e70::/2822cd:e7f:ffff:ffff:ffff:ffff:ffff:ffff
23322cd:e80::/2822cd:e8f:ffff:ffff:ffff:ffff:ffff:ffff
23422cd:e90::/2822cd:e9f:ffff:ffff:ffff:ffff:ffff:ffff
23522cd:ea0::/2822cd:eaf:ffff:ffff:ffff:ffff:ffff:ffff
23622cd:eb0::/2822cd:ebf:ffff:ffff:ffff:ffff:ffff:ffff
23722cd:ec0::/2822cd:ecf:ffff:ffff:ffff:ffff:ffff:ffff
23822cd:ed0::/2822cd:edf:ffff:ffff:ffff:ffff:ffff:ffff
23922cd:ee0::/2822cd:eef:ffff:ffff:ffff:ffff:ffff:ffff
24022cd:ef0::/2822cd:eff:ffff:ffff:ffff:ffff:ffff:ffff
24122cd:f00::/2822cd:f0f:ffff:ffff:ffff:ffff:ffff:ffff
24222cd:f10::/2822cd:f1f:ffff:ffff:ffff:ffff:ffff:ffff
24322cd:f20::/2822cd:f2f:ffff:ffff:ffff:ffff:ffff:ffff
24422cd:f30::/2822cd:f3f:ffff:ffff:ffff:ffff:ffff:ffff
24522cd:f40::/2822cd:f4f:ffff:ffff:ffff:ffff:ffff:ffff
24622cd:f50::/2822cd:f5f:ffff:ffff:ffff:ffff:ffff:ffff
24722cd:f60::/2822cd:f6f:ffff:ffff:ffff:ffff:ffff:ffff
24822cd:f70::/2822cd:f7f:ffff:ffff:ffff:ffff:ffff:ffff
24922cd:f80::/2822cd:f8f:ffff:ffff:ffff:ffff:ffff:ffff
25022cd:f90::/2822cd:f9f:ffff:ffff:ffff:ffff:ffff:ffff
25122cd:fa0::/2822cd:faf:ffff:ffff:ffff:ffff:ffff:ffff
25222cd:fb0::/2822cd:fbf:ffff:ffff:ffff:ffff:ffff:ffff
25322cd:fc0::/2822cd:fcf:ffff:ffff:ffff:ffff:ffff:ffff
25422cd:fd0::/2822cd:fdf:ffff:ffff:ffff:ffff:ffff:ffff
25522cd:fe0::/2822cd:fef:ffff:ffff:ffff:ffff:ffff:ffff
25622cd:ff0::/2822cd: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.