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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/12
Addresses2^116
/64 networks2^52
Network
25e0::/12
First address
25e0::
Last address
25ef:ffff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
83,076,749,736,557,242,056,487,941,267,521,536 (2^116)
/64 networks (LANs)
4,503,599,627,370,496 (2^52)
Full form
25e0:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
e.5.2.ip6.arpa
Split into smaller subnets/28
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

25e0::/12 makes 65,536 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
125e0::/2825e0:f:ffff:ffff:ffff:ffff:ffff:ffff
225e0:10::/2825e0:1f:ffff:ffff:ffff:ffff:ffff:ffff
325e0:20::/2825e0:2f:ffff:ffff:ffff:ffff:ffff:ffff
425e0:30::/2825e0:3f:ffff:ffff:ffff:ffff:ffff:ffff
525e0:40::/2825e0:4f:ffff:ffff:ffff:ffff:ffff:ffff
625e0:50::/2825e0:5f:ffff:ffff:ffff:ffff:ffff:ffff
725e0:60::/2825e0:6f:ffff:ffff:ffff:ffff:ffff:ffff
825e0:70::/2825e0:7f:ffff:ffff:ffff:ffff:ffff:ffff
925e0:80::/2825e0:8f:ffff:ffff:ffff:ffff:ffff:ffff
1025e0:90::/2825e0:9f:ffff:ffff:ffff:ffff:ffff:ffff
1125e0:a0::/2825e0:af:ffff:ffff:ffff:ffff:ffff:ffff
1225e0:b0::/2825e0:bf:ffff:ffff:ffff:ffff:ffff:ffff
1325e0:c0::/2825e0:cf:ffff:ffff:ffff:ffff:ffff:ffff
1425e0:d0::/2825e0:df:ffff:ffff:ffff:ffff:ffff:ffff
1525e0:e0::/2825e0:ef:ffff:ffff:ffff:ffff:ffff:ffff
1625e0:f0::/2825e0:ff:ffff:ffff:ffff:ffff:ffff:ffff
1725e0:100::/2825e0:10f:ffff:ffff:ffff:ffff:ffff:ffff
1825e0:110::/2825e0:11f:ffff:ffff:ffff:ffff:ffff:ffff
1925e0:120::/2825e0:12f:ffff:ffff:ffff:ffff:ffff:ffff
2025e0:130::/2825e0:13f:ffff:ffff:ffff:ffff:ffff:ffff
2125e0:140::/2825e0:14f:ffff:ffff:ffff:ffff:ffff:ffff
2225e0:150::/2825e0:15f:ffff:ffff:ffff:ffff:ffff:ffff
2325e0:160::/2825e0:16f:ffff:ffff:ffff:ffff:ffff:ffff
2425e0:170::/2825e0:17f:ffff:ffff:ffff:ffff:ffff:ffff
2525e0:180::/2825e0:18f:ffff:ffff:ffff:ffff:ffff:ffff
2625e0:190::/2825e0:19f:ffff:ffff:ffff:ffff:ffff:ffff
2725e0:1a0::/2825e0:1af:ffff:ffff:ffff:ffff:ffff:ffff
2825e0:1b0::/2825e0:1bf:ffff:ffff:ffff:ffff:ffff:ffff
2925e0:1c0::/2825e0:1cf:ffff:ffff:ffff:ffff:ffff:ffff
3025e0:1d0::/2825e0:1df:ffff:ffff:ffff:ffff:ffff:ffff
3125e0:1e0::/2825e0:1ef:ffff:ffff:ffff:ffff:ffff:ffff
3225e0:1f0::/2825e0:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3325e0:200::/2825e0:20f:ffff:ffff:ffff:ffff:ffff:ffff
3425e0:210::/2825e0:21f:ffff:ffff:ffff:ffff:ffff:ffff
3525e0:220::/2825e0:22f:ffff:ffff:ffff:ffff:ffff:ffff
3625e0:230::/2825e0:23f:ffff:ffff:ffff:ffff:ffff:ffff
3725e0:240::/2825e0:24f:ffff:ffff:ffff:ffff:ffff:ffff
3825e0:250::/2825e0:25f:ffff:ffff:ffff:ffff:ffff:ffff
3925e0:260::/2825e0:26f:ffff:ffff:ffff:ffff:ffff:ffff
4025e0:270::/2825e0:27f:ffff:ffff:ffff:ffff:ffff:ffff
4125e0:280::/2825e0:28f:ffff:ffff:ffff:ffff:ffff:ffff
4225e0:290::/2825e0:29f:ffff:ffff:ffff:ffff:ffff:ffff
4325e0:2a0::/2825e0:2af:ffff:ffff:ffff:ffff:ffff:ffff
4425e0:2b0::/2825e0:2bf:ffff:ffff:ffff:ffff:ffff:ffff
4525e0:2c0::/2825e0:2cf:ffff:ffff:ffff:ffff:ffff:ffff
4625e0:2d0::/2825e0:2df:ffff:ffff:ffff:ffff:ffff:ffff
4725e0:2e0::/2825e0:2ef:ffff:ffff:ffff:ffff:ffff:ffff
4825e0:2f0::/2825e0:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4925e0:300::/2825e0:30f:ffff:ffff:ffff:ffff:ffff:ffff
5025e0:310::/2825e0:31f:ffff:ffff:ffff:ffff:ffff:ffff
5125e0:320::/2825e0:32f:ffff:ffff:ffff:ffff:ffff:ffff
5225e0:330::/2825e0:33f:ffff:ffff:ffff:ffff:ffff:ffff
5325e0:340::/2825e0:34f:ffff:ffff:ffff:ffff:ffff:ffff
5425e0:350::/2825e0:35f:ffff:ffff:ffff:ffff:ffff:ffff
5525e0:360::/2825e0:36f:ffff:ffff:ffff:ffff:ffff:ffff
5625e0:370::/2825e0:37f:ffff:ffff:ffff:ffff:ffff:ffff
5725e0:380::/2825e0:38f:ffff:ffff:ffff:ffff:ffff:ffff
5825e0:390::/2825e0:39f:ffff:ffff:ffff:ffff:ffff:ffff
5925e0:3a0::/2825e0:3af:ffff:ffff:ffff:ffff:ffff:ffff
6025e0:3b0::/2825e0:3bf:ffff:ffff:ffff:ffff:ffff:ffff
6125e0:3c0::/2825e0:3cf:ffff:ffff:ffff:ffff:ffff:ffff
6225e0:3d0::/2825e0:3df:ffff:ffff:ffff:ffff:ffff:ffff
6325e0:3e0::/2825e0:3ef:ffff:ffff:ffff:ffff:ffff:ffff
6425e0:3f0::/2825e0:3ff:ffff:ffff:ffff:ffff:ffff:ffff
6525e0:400::/2825e0:40f:ffff:ffff:ffff:ffff:ffff:ffff
6625e0:410::/2825e0:41f:ffff:ffff:ffff:ffff:ffff:ffff
6725e0:420::/2825e0:42f:ffff:ffff:ffff:ffff:ffff:ffff
6825e0:430::/2825e0:43f:ffff:ffff:ffff:ffff:ffff:ffff
6925e0:440::/2825e0:44f:ffff:ffff:ffff:ffff:ffff:ffff
7025e0:450::/2825e0:45f:ffff:ffff:ffff:ffff:ffff:ffff
7125e0:460::/2825e0:46f:ffff:ffff:ffff:ffff:ffff:ffff
7225e0:470::/2825e0:47f:ffff:ffff:ffff:ffff:ffff:ffff
7325e0:480::/2825e0:48f:ffff:ffff:ffff:ffff:ffff:ffff
7425e0:490::/2825e0:49f:ffff:ffff:ffff:ffff:ffff:ffff
7525e0:4a0::/2825e0:4af:ffff:ffff:ffff:ffff:ffff:ffff
7625e0:4b0::/2825e0:4bf:ffff:ffff:ffff:ffff:ffff:ffff
7725e0:4c0::/2825e0:4cf:ffff:ffff:ffff:ffff:ffff:ffff
7825e0:4d0::/2825e0:4df:ffff:ffff:ffff:ffff:ffff:ffff
7925e0:4e0::/2825e0:4ef:ffff:ffff:ffff:ffff:ffff:ffff
8025e0:4f0::/2825e0:4ff:ffff:ffff:ffff:ffff:ffff:ffff
8125e0:500::/2825e0:50f:ffff:ffff:ffff:ffff:ffff:ffff
8225e0:510::/2825e0:51f:ffff:ffff:ffff:ffff:ffff:ffff
8325e0:520::/2825e0:52f:ffff:ffff:ffff:ffff:ffff:ffff
8425e0:530::/2825e0:53f:ffff:ffff:ffff:ffff:ffff:ffff
8525e0:540::/2825e0:54f:ffff:ffff:ffff:ffff:ffff:ffff
8625e0:550::/2825e0:55f:ffff:ffff:ffff:ffff:ffff:ffff
8725e0:560::/2825e0:56f:ffff:ffff:ffff:ffff:ffff:ffff
8825e0:570::/2825e0:57f:ffff:ffff:ffff:ffff:ffff:ffff
8925e0:580::/2825e0:58f:ffff:ffff:ffff:ffff:ffff:ffff
9025e0:590::/2825e0:59f:ffff:ffff:ffff:ffff:ffff:ffff
9125e0:5a0::/2825e0:5af:ffff:ffff:ffff:ffff:ffff:ffff
9225e0:5b0::/2825e0:5bf:ffff:ffff:ffff:ffff:ffff:ffff
9325e0:5c0::/2825e0:5cf:ffff:ffff:ffff:ffff:ffff:ffff
9425e0:5d0::/2825e0:5df:ffff:ffff:ffff:ffff:ffff:ffff
9525e0:5e0::/2825e0:5ef:ffff:ffff:ffff:ffff:ffff:ffff
9625e0:5f0::/2825e0:5ff:ffff:ffff:ffff:ffff:ffff:ffff
9725e0:600::/2825e0:60f:ffff:ffff:ffff:ffff:ffff:ffff
9825e0:610::/2825e0:61f:ffff:ffff:ffff:ffff:ffff:ffff
9925e0:620::/2825e0:62f:ffff:ffff:ffff:ffff:ffff:ffff
10025e0:630::/2825e0:63f:ffff:ffff:ffff:ffff:ffff:ffff
10125e0:640::/2825e0:64f:ffff:ffff:ffff:ffff:ffff:ffff
10225e0:650::/2825e0:65f:ffff:ffff:ffff:ffff:ffff:ffff
10325e0:660::/2825e0:66f:ffff:ffff:ffff:ffff:ffff:ffff
10425e0:670::/2825e0:67f:ffff:ffff:ffff:ffff:ffff:ffff
10525e0:680::/2825e0:68f:ffff:ffff:ffff:ffff:ffff:ffff
10625e0:690::/2825e0:69f:ffff:ffff:ffff:ffff:ffff:ffff
10725e0:6a0::/2825e0:6af:ffff:ffff:ffff:ffff:ffff:ffff
10825e0:6b0::/2825e0:6bf:ffff:ffff:ffff:ffff:ffff:ffff
10925e0:6c0::/2825e0:6cf:ffff:ffff:ffff:ffff:ffff:ffff
11025e0:6d0::/2825e0:6df:ffff:ffff:ffff:ffff:ffff:ffff
11125e0:6e0::/2825e0:6ef:ffff:ffff:ffff:ffff:ffff:ffff
11225e0:6f0::/2825e0:6ff:ffff:ffff:ffff:ffff:ffff:ffff
11325e0:700::/2825e0:70f:ffff:ffff:ffff:ffff:ffff:ffff
11425e0:710::/2825e0:71f:ffff:ffff:ffff:ffff:ffff:ffff
11525e0:720::/2825e0:72f:ffff:ffff:ffff:ffff:ffff:ffff
11625e0:730::/2825e0:73f:ffff:ffff:ffff:ffff:ffff:ffff
11725e0:740::/2825e0:74f:ffff:ffff:ffff:ffff:ffff:ffff
11825e0:750::/2825e0:75f:ffff:ffff:ffff:ffff:ffff:ffff
11925e0:760::/2825e0:76f:ffff:ffff:ffff:ffff:ffff:ffff
12025e0:770::/2825e0:77f:ffff:ffff:ffff:ffff:ffff:ffff
12125e0:780::/2825e0:78f:ffff:ffff:ffff:ffff:ffff:ffff
12225e0:790::/2825e0:79f:ffff:ffff:ffff:ffff:ffff:ffff
12325e0:7a0::/2825e0:7af:ffff:ffff:ffff:ffff:ffff:ffff
12425e0:7b0::/2825e0:7bf:ffff:ffff:ffff:ffff:ffff:ffff
12525e0:7c0::/2825e0:7cf:ffff:ffff:ffff:ffff:ffff:ffff
12625e0:7d0::/2825e0:7df:ffff:ffff:ffff:ffff:ffff:ffff
12725e0:7e0::/2825e0:7ef:ffff:ffff:ffff:ffff:ffff:ffff
12825e0:7f0::/2825e0:7ff:ffff:ffff:ffff:ffff:ffff:ffff
12925e0:800::/2825e0:80f:ffff:ffff:ffff:ffff:ffff:ffff
13025e0:810::/2825e0:81f:ffff:ffff:ffff:ffff:ffff:ffff
13125e0:820::/2825e0:82f:ffff:ffff:ffff:ffff:ffff:ffff
13225e0:830::/2825e0:83f:ffff:ffff:ffff:ffff:ffff:ffff
13325e0:840::/2825e0:84f:ffff:ffff:ffff:ffff:ffff:ffff
13425e0:850::/2825e0:85f:ffff:ffff:ffff:ffff:ffff:ffff
13525e0:860::/2825e0:86f:ffff:ffff:ffff:ffff:ffff:ffff
13625e0:870::/2825e0:87f:ffff:ffff:ffff:ffff:ffff:ffff
13725e0:880::/2825e0:88f:ffff:ffff:ffff:ffff:ffff:ffff
13825e0:890::/2825e0:89f:ffff:ffff:ffff:ffff:ffff:ffff
13925e0:8a0::/2825e0:8af:ffff:ffff:ffff:ffff:ffff:ffff
14025e0:8b0::/2825e0:8bf:ffff:ffff:ffff:ffff:ffff:ffff
14125e0:8c0::/2825e0:8cf:ffff:ffff:ffff:ffff:ffff:ffff
14225e0:8d0::/2825e0:8df:ffff:ffff:ffff:ffff:ffff:ffff
14325e0:8e0::/2825e0:8ef:ffff:ffff:ffff:ffff:ffff:ffff
14425e0:8f0::/2825e0:8ff:ffff:ffff:ffff:ffff:ffff:ffff
14525e0:900::/2825e0:90f:ffff:ffff:ffff:ffff:ffff:ffff
14625e0:910::/2825e0:91f:ffff:ffff:ffff:ffff:ffff:ffff
14725e0:920::/2825e0:92f:ffff:ffff:ffff:ffff:ffff:ffff
14825e0:930::/2825e0:93f:ffff:ffff:ffff:ffff:ffff:ffff
14925e0:940::/2825e0:94f:ffff:ffff:ffff:ffff:ffff:ffff
15025e0:950::/2825e0:95f:ffff:ffff:ffff:ffff:ffff:ffff
15125e0:960::/2825e0:96f:ffff:ffff:ffff:ffff:ffff:ffff
15225e0:970::/2825e0:97f:ffff:ffff:ffff:ffff:ffff:ffff
15325e0:980::/2825e0:98f:ffff:ffff:ffff:ffff:ffff:ffff
15425e0:990::/2825e0:99f:ffff:ffff:ffff:ffff:ffff:ffff
15525e0:9a0::/2825e0:9af:ffff:ffff:ffff:ffff:ffff:ffff
15625e0:9b0::/2825e0:9bf:ffff:ffff:ffff:ffff:ffff:ffff
15725e0:9c0::/2825e0:9cf:ffff:ffff:ffff:ffff:ffff:ffff
15825e0:9d0::/2825e0:9df:ffff:ffff:ffff:ffff:ffff:ffff
15925e0:9e0::/2825e0:9ef:ffff:ffff:ffff:ffff:ffff:ffff
16025e0:9f0::/2825e0:9ff:ffff:ffff:ffff:ffff:ffff:ffff
16125e0:a00::/2825e0:a0f:ffff:ffff:ffff:ffff:ffff:ffff
16225e0:a10::/2825e0:a1f:ffff:ffff:ffff:ffff:ffff:ffff
16325e0:a20::/2825e0:a2f:ffff:ffff:ffff:ffff:ffff:ffff
16425e0:a30::/2825e0:a3f:ffff:ffff:ffff:ffff:ffff:ffff
16525e0:a40::/2825e0:a4f:ffff:ffff:ffff:ffff:ffff:ffff
16625e0:a50::/2825e0:a5f:ffff:ffff:ffff:ffff:ffff:ffff
16725e0:a60::/2825e0:a6f:ffff:ffff:ffff:ffff:ffff:ffff
16825e0:a70::/2825e0:a7f:ffff:ffff:ffff:ffff:ffff:ffff
16925e0:a80::/2825e0:a8f:ffff:ffff:ffff:ffff:ffff:ffff
17025e0:a90::/2825e0:a9f:ffff:ffff:ffff:ffff:ffff:ffff
17125e0:aa0::/2825e0:aaf:ffff:ffff:ffff:ffff:ffff:ffff
17225e0:ab0::/2825e0:abf:ffff:ffff:ffff:ffff:ffff:ffff
17325e0:ac0::/2825e0:acf:ffff:ffff:ffff:ffff:ffff:ffff
17425e0:ad0::/2825e0:adf:ffff:ffff:ffff:ffff:ffff:ffff
17525e0:ae0::/2825e0:aef:ffff:ffff:ffff:ffff:ffff:ffff
17625e0:af0::/2825e0:aff:ffff:ffff:ffff:ffff:ffff:ffff
17725e0:b00::/2825e0:b0f:ffff:ffff:ffff:ffff:ffff:ffff
17825e0:b10::/2825e0:b1f:ffff:ffff:ffff:ffff:ffff:ffff
17925e0:b20::/2825e0:b2f:ffff:ffff:ffff:ffff:ffff:ffff
18025e0:b30::/2825e0:b3f:ffff:ffff:ffff:ffff:ffff:ffff
18125e0:b40::/2825e0:b4f:ffff:ffff:ffff:ffff:ffff:ffff
18225e0:b50::/2825e0:b5f:ffff:ffff:ffff:ffff:ffff:ffff
18325e0:b60::/2825e0:b6f:ffff:ffff:ffff:ffff:ffff:ffff
18425e0:b70::/2825e0:b7f:ffff:ffff:ffff:ffff:ffff:ffff
18525e0:b80::/2825e0:b8f:ffff:ffff:ffff:ffff:ffff:ffff
18625e0:b90::/2825e0:b9f:ffff:ffff:ffff:ffff:ffff:ffff
18725e0:ba0::/2825e0:baf:ffff:ffff:ffff:ffff:ffff:ffff
18825e0:bb0::/2825e0:bbf:ffff:ffff:ffff:ffff:ffff:ffff
18925e0:bc0::/2825e0:bcf:ffff:ffff:ffff:ffff:ffff:ffff
19025e0:bd0::/2825e0:bdf:ffff:ffff:ffff:ffff:ffff:ffff
19125e0:be0::/2825e0:bef:ffff:ffff:ffff:ffff:ffff:ffff
19225e0:bf0::/2825e0:bff:ffff:ffff:ffff:ffff:ffff:ffff
19325e0:c00::/2825e0:c0f:ffff:ffff:ffff:ffff:ffff:ffff
19425e0:c10::/2825e0:c1f:ffff:ffff:ffff:ffff:ffff:ffff
19525e0:c20::/2825e0:c2f:ffff:ffff:ffff:ffff:ffff:ffff
19625e0:c30::/2825e0:c3f:ffff:ffff:ffff:ffff:ffff:ffff
19725e0:c40::/2825e0:c4f:ffff:ffff:ffff:ffff:ffff:ffff
19825e0:c50::/2825e0:c5f:ffff:ffff:ffff:ffff:ffff:ffff
19925e0:c60::/2825e0:c6f:ffff:ffff:ffff:ffff:ffff:ffff
20025e0:c70::/2825e0:c7f:ffff:ffff:ffff:ffff:ffff:ffff
20125e0:c80::/2825e0:c8f:ffff:ffff:ffff:ffff:ffff:ffff
20225e0:c90::/2825e0:c9f:ffff:ffff:ffff:ffff:ffff:ffff
20325e0:ca0::/2825e0:caf:ffff:ffff:ffff:ffff:ffff:ffff
20425e0:cb0::/2825e0:cbf:ffff:ffff:ffff:ffff:ffff:ffff
20525e0:cc0::/2825e0:ccf:ffff:ffff:ffff:ffff:ffff:ffff
20625e0:cd0::/2825e0:cdf:ffff:ffff:ffff:ffff:ffff:ffff
20725e0:ce0::/2825e0:cef:ffff:ffff:ffff:ffff:ffff:ffff
20825e0:cf0::/2825e0:cff:ffff:ffff:ffff:ffff:ffff:ffff
20925e0:d00::/2825e0:d0f:ffff:ffff:ffff:ffff:ffff:ffff
21025e0:d10::/2825e0:d1f:ffff:ffff:ffff:ffff:ffff:ffff
21125e0:d20::/2825e0:d2f:ffff:ffff:ffff:ffff:ffff:ffff
21225e0:d30::/2825e0:d3f:ffff:ffff:ffff:ffff:ffff:ffff
21325e0:d40::/2825e0:d4f:ffff:ffff:ffff:ffff:ffff:ffff
21425e0:d50::/2825e0:d5f:ffff:ffff:ffff:ffff:ffff:ffff
21525e0:d60::/2825e0:d6f:ffff:ffff:ffff:ffff:ffff:ffff
21625e0:d70::/2825e0:d7f:ffff:ffff:ffff:ffff:ffff:ffff
21725e0:d80::/2825e0:d8f:ffff:ffff:ffff:ffff:ffff:ffff
21825e0:d90::/2825e0:d9f:ffff:ffff:ffff:ffff:ffff:ffff
21925e0:da0::/2825e0:daf:ffff:ffff:ffff:ffff:ffff:ffff
22025e0:db0::/2825e0:dbf:ffff:ffff:ffff:ffff:ffff:ffff
22125e0:dc0::/2825e0:dcf:ffff:ffff:ffff:ffff:ffff:ffff
22225e0:dd0::/2825e0:ddf:ffff:ffff:ffff:ffff:ffff:ffff
22325e0:de0::/2825e0:def:ffff:ffff:ffff:ffff:ffff:ffff
22425e0:df0::/2825e0:dff:ffff:ffff:ffff:ffff:ffff:ffff
22525e0:e00::/2825e0:e0f:ffff:ffff:ffff:ffff:ffff:ffff
22625e0:e10::/2825e0:e1f:ffff:ffff:ffff:ffff:ffff:ffff
22725e0:e20::/2825e0:e2f:ffff:ffff:ffff:ffff:ffff:ffff
22825e0:e30::/2825e0:e3f:ffff:ffff:ffff:ffff:ffff:ffff
22925e0:e40::/2825e0:e4f:ffff:ffff:ffff:ffff:ffff:ffff
23025e0:e50::/2825e0:e5f:ffff:ffff:ffff:ffff:ffff:ffff
23125e0:e60::/2825e0:e6f:ffff:ffff:ffff:ffff:ffff:ffff
23225e0:e70::/2825e0:e7f:ffff:ffff:ffff:ffff:ffff:ffff
23325e0:e80::/2825e0:e8f:ffff:ffff:ffff:ffff:ffff:ffff
23425e0:e90::/2825e0:e9f:ffff:ffff:ffff:ffff:ffff:ffff
23525e0:ea0::/2825e0:eaf:ffff:ffff:ffff:ffff:ffff:ffff
23625e0:eb0::/2825e0:ebf:ffff:ffff:ffff:ffff:ffff:ffff
23725e0:ec0::/2825e0:ecf:ffff:ffff:ffff:ffff:ffff:ffff
23825e0:ed0::/2825e0:edf:ffff:ffff:ffff:ffff:ffff:ffff
23925e0:ee0::/2825e0:eef:ffff:ffff:ffff:ffff:ffff:ffff
24025e0:ef0::/2825e0:eff:ffff:ffff:ffff:ffff:ffff:ffff
24125e0:f00::/2825e0:f0f:ffff:ffff:ffff:ffff:ffff:ffff
24225e0:f10::/2825e0:f1f:ffff:ffff:ffff:ffff:ffff:ffff
24325e0:f20::/2825e0:f2f:ffff:ffff:ffff:ffff:ffff:ffff
24425e0:f30::/2825e0:f3f:ffff:ffff:ffff:ffff:ffff:ffff
24525e0:f40::/2825e0:f4f:ffff:ffff:ffff:ffff:ffff:ffff
24625e0:f50::/2825e0:f5f:ffff:ffff:ffff:ffff:ffff:ffff
24725e0:f60::/2825e0:f6f:ffff:ffff:ffff:ffff:ffff:ffff
24825e0:f70::/2825e0:f7f:ffff:ffff:ffff:ffff:ffff:ffff
24925e0:f80::/2825e0:f8f:ffff:ffff:ffff:ffff:ffff:ffff
25025e0:f90::/2825e0:f9f:ffff:ffff:ffff:ffff:ffff:ffff
25125e0:fa0::/2825e0:faf:ffff:ffff:ffff:ffff:ffff:ffff
25225e0:fb0::/2825e0:fbf:ffff:ffff:ffff:ffff:ffff:ffff
25325e0:fc0::/2825e0:fcf:ffff:ffff:ffff:ffff:ffff:ffff
25425e0:fd0::/2825e0:fdf:ffff:ffff:ffff:ffff:ffff:ffff
25525e0:fe0::/2825e0:fef:ffff:ffff:ffff:ffff:ffff:ffff
25625e0:ff0::/2825e0: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.