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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
29b0::/12
First address
29b0::
Last address
29bf: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
29b0:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
b.9.2.ip6.arpa
Split into smaller subnets/28
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

29b0::/12 makes 65,536 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
129b0::/2829b0:f:ffff:ffff:ffff:ffff:ffff:ffff
229b0:10::/2829b0:1f:ffff:ffff:ffff:ffff:ffff:ffff
329b0:20::/2829b0:2f:ffff:ffff:ffff:ffff:ffff:ffff
429b0:30::/2829b0:3f:ffff:ffff:ffff:ffff:ffff:ffff
529b0:40::/2829b0:4f:ffff:ffff:ffff:ffff:ffff:ffff
629b0:50::/2829b0:5f:ffff:ffff:ffff:ffff:ffff:ffff
729b0:60::/2829b0:6f:ffff:ffff:ffff:ffff:ffff:ffff
829b0:70::/2829b0:7f:ffff:ffff:ffff:ffff:ffff:ffff
929b0:80::/2829b0:8f:ffff:ffff:ffff:ffff:ffff:ffff
1029b0:90::/2829b0:9f:ffff:ffff:ffff:ffff:ffff:ffff
1129b0:a0::/2829b0:af:ffff:ffff:ffff:ffff:ffff:ffff
1229b0:b0::/2829b0:bf:ffff:ffff:ffff:ffff:ffff:ffff
1329b0:c0::/2829b0:cf:ffff:ffff:ffff:ffff:ffff:ffff
1429b0:d0::/2829b0:df:ffff:ffff:ffff:ffff:ffff:ffff
1529b0:e0::/2829b0:ef:ffff:ffff:ffff:ffff:ffff:ffff
1629b0:f0::/2829b0:ff:ffff:ffff:ffff:ffff:ffff:ffff
1729b0:100::/2829b0:10f:ffff:ffff:ffff:ffff:ffff:ffff
1829b0:110::/2829b0:11f:ffff:ffff:ffff:ffff:ffff:ffff
1929b0:120::/2829b0:12f:ffff:ffff:ffff:ffff:ffff:ffff
2029b0:130::/2829b0:13f:ffff:ffff:ffff:ffff:ffff:ffff
2129b0:140::/2829b0:14f:ffff:ffff:ffff:ffff:ffff:ffff
2229b0:150::/2829b0:15f:ffff:ffff:ffff:ffff:ffff:ffff
2329b0:160::/2829b0:16f:ffff:ffff:ffff:ffff:ffff:ffff
2429b0:170::/2829b0:17f:ffff:ffff:ffff:ffff:ffff:ffff
2529b0:180::/2829b0:18f:ffff:ffff:ffff:ffff:ffff:ffff
2629b0:190::/2829b0:19f:ffff:ffff:ffff:ffff:ffff:ffff
2729b0:1a0::/2829b0:1af:ffff:ffff:ffff:ffff:ffff:ffff
2829b0:1b0::/2829b0:1bf:ffff:ffff:ffff:ffff:ffff:ffff
2929b0:1c0::/2829b0:1cf:ffff:ffff:ffff:ffff:ffff:ffff
3029b0:1d0::/2829b0:1df:ffff:ffff:ffff:ffff:ffff:ffff
3129b0:1e0::/2829b0:1ef:ffff:ffff:ffff:ffff:ffff:ffff
3229b0:1f0::/2829b0:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3329b0:200::/2829b0:20f:ffff:ffff:ffff:ffff:ffff:ffff
3429b0:210::/2829b0:21f:ffff:ffff:ffff:ffff:ffff:ffff
3529b0:220::/2829b0:22f:ffff:ffff:ffff:ffff:ffff:ffff
3629b0:230::/2829b0:23f:ffff:ffff:ffff:ffff:ffff:ffff
3729b0:240::/2829b0:24f:ffff:ffff:ffff:ffff:ffff:ffff
3829b0:250::/2829b0:25f:ffff:ffff:ffff:ffff:ffff:ffff
3929b0:260::/2829b0:26f:ffff:ffff:ffff:ffff:ffff:ffff
4029b0:270::/2829b0:27f:ffff:ffff:ffff:ffff:ffff:ffff
4129b0:280::/2829b0:28f:ffff:ffff:ffff:ffff:ffff:ffff
4229b0:290::/2829b0:29f:ffff:ffff:ffff:ffff:ffff:ffff
4329b0:2a0::/2829b0:2af:ffff:ffff:ffff:ffff:ffff:ffff
4429b0:2b0::/2829b0:2bf:ffff:ffff:ffff:ffff:ffff:ffff
4529b0:2c0::/2829b0:2cf:ffff:ffff:ffff:ffff:ffff:ffff
4629b0:2d0::/2829b0:2df:ffff:ffff:ffff:ffff:ffff:ffff
4729b0:2e0::/2829b0:2ef:ffff:ffff:ffff:ffff:ffff:ffff
4829b0:2f0::/2829b0:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4929b0:300::/2829b0:30f:ffff:ffff:ffff:ffff:ffff:ffff
5029b0:310::/2829b0:31f:ffff:ffff:ffff:ffff:ffff:ffff
5129b0:320::/2829b0:32f:ffff:ffff:ffff:ffff:ffff:ffff
5229b0:330::/2829b0:33f:ffff:ffff:ffff:ffff:ffff:ffff
5329b0:340::/2829b0:34f:ffff:ffff:ffff:ffff:ffff:ffff
5429b0:350::/2829b0:35f:ffff:ffff:ffff:ffff:ffff:ffff
5529b0:360::/2829b0:36f:ffff:ffff:ffff:ffff:ffff:ffff
5629b0:370::/2829b0:37f:ffff:ffff:ffff:ffff:ffff:ffff
5729b0:380::/2829b0:38f:ffff:ffff:ffff:ffff:ffff:ffff
5829b0:390::/2829b0:39f:ffff:ffff:ffff:ffff:ffff:ffff
5929b0:3a0::/2829b0:3af:ffff:ffff:ffff:ffff:ffff:ffff
6029b0:3b0::/2829b0:3bf:ffff:ffff:ffff:ffff:ffff:ffff
6129b0:3c0::/2829b0:3cf:ffff:ffff:ffff:ffff:ffff:ffff
6229b0:3d0::/2829b0:3df:ffff:ffff:ffff:ffff:ffff:ffff
6329b0:3e0::/2829b0:3ef:ffff:ffff:ffff:ffff:ffff:ffff
6429b0:3f0::/2829b0:3ff:ffff:ffff:ffff:ffff:ffff:ffff
6529b0:400::/2829b0:40f:ffff:ffff:ffff:ffff:ffff:ffff
6629b0:410::/2829b0:41f:ffff:ffff:ffff:ffff:ffff:ffff
6729b0:420::/2829b0:42f:ffff:ffff:ffff:ffff:ffff:ffff
6829b0:430::/2829b0:43f:ffff:ffff:ffff:ffff:ffff:ffff
6929b0:440::/2829b0:44f:ffff:ffff:ffff:ffff:ffff:ffff
7029b0:450::/2829b0:45f:ffff:ffff:ffff:ffff:ffff:ffff
7129b0:460::/2829b0:46f:ffff:ffff:ffff:ffff:ffff:ffff
7229b0:470::/2829b0:47f:ffff:ffff:ffff:ffff:ffff:ffff
7329b0:480::/2829b0:48f:ffff:ffff:ffff:ffff:ffff:ffff
7429b0:490::/2829b0:49f:ffff:ffff:ffff:ffff:ffff:ffff
7529b0:4a0::/2829b0:4af:ffff:ffff:ffff:ffff:ffff:ffff
7629b0:4b0::/2829b0:4bf:ffff:ffff:ffff:ffff:ffff:ffff
7729b0:4c0::/2829b0:4cf:ffff:ffff:ffff:ffff:ffff:ffff
7829b0:4d0::/2829b0:4df:ffff:ffff:ffff:ffff:ffff:ffff
7929b0:4e0::/2829b0:4ef:ffff:ffff:ffff:ffff:ffff:ffff
8029b0:4f0::/2829b0:4ff:ffff:ffff:ffff:ffff:ffff:ffff
8129b0:500::/2829b0:50f:ffff:ffff:ffff:ffff:ffff:ffff
8229b0:510::/2829b0:51f:ffff:ffff:ffff:ffff:ffff:ffff
8329b0:520::/2829b0:52f:ffff:ffff:ffff:ffff:ffff:ffff
8429b0:530::/2829b0:53f:ffff:ffff:ffff:ffff:ffff:ffff
8529b0:540::/2829b0:54f:ffff:ffff:ffff:ffff:ffff:ffff
8629b0:550::/2829b0:55f:ffff:ffff:ffff:ffff:ffff:ffff
8729b0:560::/2829b0:56f:ffff:ffff:ffff:ffff:ffff:ffff
8829b0:570::/2829b0:57f:ffff:ffff:ffff:ffff:ffff:ffff
8929b0:580::/2829b0:58f:ffff:ffff:ffff:ffff:ffff:ffff
9029b0:590::/2829b0:59f:ffff:ffff:ffff:ffff:ffff:ffff
9129b0:5a0::/2829b0:5af:ffff:ffff:ffff:ffff:ffff:ffff
9229b0:5b0::/2829b0:5bf:ffff:ffff:ffff:ffff:ffff:ffff
9329b0:5c0::/2829b0:5cf:ffff:ffff:ffff:ffff:ffff:ffff
9429b0:5d0::/2829b0:5df:ffff:ffff:ffff:ffff:ffff:ffff
9529b0:5e0::/2829b0:5ef:ffff:ffff:ffff:ffff:ffff:ffff
9629b0:5f0::/2829b0:5ff:ffff:ffff:ffff:ffff:ffff:ffff
9729b0:600::/2829b0:60f:ffff:ffff:ffff:ffff:ffff:ffff
9829b0:610::/2829b0:61f:ffff:ffff:ffff:ffff:ffff:ffff
9929b0:620::/2829b0:62f:ffff:ffff:ffff:ffff:ffff:ffff
10029b0:630::/2829b0:63f:ffff:ffff:ffff:ffff:ffff:ffff
10129b0:640::/2829b0:64f:ffff:ffff:ffff:ffff:ffff:ffff
10229b0:650::/2829b0:65f:ffff:ffff:ffff:ffff:ffff:ffff
10329b0:660::/2829b0:66f:ffff:ffff:ffff:ffff:ffff:ffff
10429b0:670::/2829b0:67f:ffff:ffff:ffff:ffff:ffff:ffff
10529b0:680::/2829b0:68f:ffff:ffff:ffff:ffff:ffff:ffff
10629b0:690::/2829b0:69f:ffff:ffff:ffff:ffff:ffff:ffff
10729b0:6a0::/2829b0:6af:ffff:ffff:ffff:ffff:ffff:ffff
10829b0:6b0::/2829b0:6bf:ffff:ffff:ffff:ffff:ffff:ffff
10929b0:6c0::/2829b0:6cf:ffff:ffff:ffff:ffff:ffff:ffff
11029b0:6d0::/2829b0:6df:ffff:ffff:ffff:ffff:ffff:ffff
11129b0:6e0::/2829b0:6ef:ffff:ffff:ffff:ffff:ffff:ffff
11229b0:6f0::/2829b0:6ff:ffff:ffff:ffff:ffff:ffff:ffff
11329b0:700::/2829b0:70f:ffff:ffff:ffff:ffff:ffff:ffff
11429b0:710::/2829b0:71f:ffff:ffff:ffff:ffff:ffff:ffff
11529b0:720::/2829b0:72f:ffff:ffff:ffff:ffff:ffff:ffff
11629b0:730::/2829b0:73f:ffff:ffff:ffff:ffff:ffff:ffff
11729b0:740::/2829b0:74f:ffff:ffff:ffff:ffff:ffff:ffff
11829b0:750::/2829b0:75f:ffff:ffff:ffff:ffff:ffff:ffff
11929b0:760::/2829b0:76f:ffff:ffff:ffff:ffff:ffff:ffff
12029b0:770::/2829b0:77f:ffff:ffff:ffff:ffff:ffff:ffff
12129b0:780::/2829b0:78f:ffff:ffff:ffff:ffff:ffff:ffff
12229b0:790::/2829b0:79f:ffff:ffff:ffff:ffff:ffff:ffff
12329b0:7a0::/2829b0:7af:ffff:ffff:ffff:ffff:ffff:ffff
12429b0:7b0::/2829b0:7bf:ffff:ffff:ffff:ffff:ffff:ffff
12529b0:7c0::/2829b0:7cf:ffff:ffff:ffff:ffff:ffff:ffff
12629b0:7d0::/2829b0:7df:ffff:ffff:ffff:ffff:ffff:ffff
12729b0:7e0::/2829b0:7ef:ffff:ffff:ffff:ffff:ffff:ffff
12829b0:7f0::/2829b0:7ff:ffff:ffff:ffff:ffff:ffff:ffff
12929b0:800::/2829b0:80f:ffff:ffff:ffff:ffff:ffff:ffff
13029b0:810::/2829b0:81f:ffff:ffff:ffff:ffff:ffff:ffff
13129b0:820::/2829b0:82f:ffff:ffff:ffff:ffff:ffff:ffff
13229b0:830::/2829b0:83f:ffff:ffff:ffff:ffff:ffff:ffff
13329b0:840::/2829b0:84f:ffff:ffff:ffff:ffff:ffff:ffff
13429b0:850::/2829b0:85f:ffff:ffff:ffff:ffff:ffff:ffff
13529b0:860::/2829b0:86f:ffff:ffff:ffff:ffff:ffff:ffff
13629b0:870::/2829b0:87f:ffff:ffff:ffff:ffff:ffff:ffff
13729b0:880::/2829b0:88f:ffff:ffff:ffff:ffff:ffff:ffff
13829b0:890::/2829b0:89f:ffff:ffff:ffff:ffff:ffff:ffff
13929b0:8a0::/2829b0:8af:ffff:ffff:ffff:ffff:ffff:ffff
14029b0:8b0::/2829b0:8bf:ffff:ffff:ffff:ffff:ffff:ffff
14129b0:8c0::/2829b0:8cf:ffff:ffff:ffff:ffff:ffff:ffff
14229b0:8d0::/2829b0:8df:ffff:ffff:ffff:ffff:ffff:ffff
14329b0:8e0::/2829b0:8ef:ffff:ffff:ffff:ffff:ffff:ffff
14429b0:8f0::/2829b0:8ff:ffff:ffff:ffff:ffff:ffff:ffff
14529b0:900::/2829b0:90f:ffff:ffff:ffff:ffff:ffff:ffff
14629b0:910::/2829b0:91f:ffff:ffff:ffff:ffff:ffff:ffff
14729b0:920::/2829b0:92f:ffff:ffff:ffff:ffff:ffff:ffff
14829b0:930::/2829b0:93f:ffff:ffff:ffff:ffff:ffff:ffff
14929b0:940::/2829b0:94f:ffff:ffff:ffff:ffff:ffff:ffff
15029b0:950::/2829b0:95f:ffff:ffff:ffff:ffff:ffff:ffff
15129b0:960::/2829b0:96f:ffff:ffff:ffff:ffff:ffff:ffff
15229b0:970::/2829b0:97f:ffff:ffff:ffff:ffff:ffff:ffff
15329b0:980::/2829b0:98f:ffff:ffff:ffff:ffff:ffff:ffff
15429b0:990::/2829b0:99f:ffff:ffff:ffff:ffff:ffff:ffff
15529b0:9a0::/2829b0:9af:ffff:ffff:ffff:ffff:ffff:ffff
15629b0:9b0::/2829b0:9bf:ffff:ffff:ffff:ffff:ffff:ffff
15729b0:9c0::/2829b0:9cf:ffff:ffff:ffff:ffff:ffff:ffff
15829b0:9d0::/2829b0:9df:ffff:ffff:ffff:ffff:ffff:ffff
15929b0:9e0::/2829b0:9ef:ffff:ffff:ffff:ffff:ffff:ffff
16029b0:9f0::/2829b0:9ff:ffff:ffff:ffff:ffff:ffff:ffff
16129b0:a00::/2829b0:a0f:ffff:ffff:ffff:ffff:ffff:ffff
16229b0:a10::/2829b0:a1f:ffff:ffff:ffff:ffff:ffff:ffff
16329b0:a20::/2829b0:a2f:ffff:ffff:ffff:ffff:ffff:ffff
16429b0:a30::/2829b0:a3f:ffff:ffff:ffff:ffff:ffff:ffff
16529b0:a40::/2829b0:a4f:ffff:ffff:ffff:ffff:ffff:ffff
16629b0:a50::/2829b0:a5f:ffff:ffff:ffff:ffff:ffff:ffff
16729b0:a60::/2829b0:a6f:ffff:ffff:ffff:ffff:ffff:ffff
16829b0:a70::/2829b0:a7f:ffff:ffff:ffff:ffff:ffff:ffff
16929b0:a80::/2829b0:a8f:ffff:ffff:ffff:ffff:ffff:ffff
17029b0:a90::/2829b0:a9f:ffff:ffff:ffff:ffff:ffff:ffff
17129b0:aa0::/2829b0:aaf:ffff:ffff:ffff:ffff:ffff:ffff
17229b0:ab0::/2829b0:abf:ffff:ffff:ffff:ffff:ffff:ffff
17329b0:ac0::/2829b0:acf:ffff:ffff:ffff:ffff:ffff:ffff
17429b0:ad0::/2829b0:adf:ffff:ffff:ffff:ffff:ffff:ffff
17529b0:ae0::/2829b0:aef:ffff:ffff:ffff:ffff:ffff:ffff
17629b0:af0::/2829b0:aff:ffff:ffff:ffff:ffff:ffff:ffff
17729b0:b00::/2829b0:b0f:ffff:ffff:ffff:ffff:ffff:ffff
17829b0:b10::/2829b0:b1f:ffff:ffff:ffff:ffff:ffff:ffff
17929b0:b20::/2829b0:b2f:ffff:ffff:ffff:ffff:ffff:ffff
18029b0:b30::/2829b0:b3f:ffff:ffff:ffff:ffff:ffff:ffff
18129b0:b40::/2829b0:b4f:ffff:ffff:ffff:ffff:ffff:ffff
18229b0:b50::/2829b0:b5f:ffff:ffff:ffff:ffff:ffff:ffff
18329b0:b60::/2829b0:b6f:ffff:ffff:ffff:ffff:ffff:ffff
18429b0:b70::/2829b0:b7f:ffff:ffff:ffff:ffff:ffff:ffff
18529b0:b80::/2829b0:b8f:ffff:ffff:ffff:ffff:ffff:ffff
18629b0:b90::/2829b0:b9f:ffff:ffff:ffff:ffff:ffff:ffff
18729b0:ba0::/2829b0:baf:ffff:ffff:ffff:ffff:ffff:ffff
18829b0:bb0::/2829b0:bbf:ffff:ffff:ffff:ffff:ffff:ffff
18929b0:bc0::/2829b0:bcf:ffff:ffff:ffff:ffff:ffff:ffff
19029b0:bd0::/2829b0:bdf:ffff:ffff:ffff:ffff:ffff:ffff
19129b0:be0::/2829b0:bef:ffff:ffff:ffff:ffff:ffff:ffff
19229b0:bf0::/2829b0:bff:ffff:ffff:ffff:ffff:ffff:ffff
19329b0:c00::/2829b0:c0f:ffff:ffff:ffff:ffff:ffff:ffff
19429b0:c10::/2829b0:c1f:ffff:ffff:ffff:ffff:ffff:ffff
19529b0:c20::/2829b0:c2f:ffff:ffff:ffff:ffff:ffff:ffff
19629b0:c30::/2829b0:c3f:ffff:ffff:ffff:ffff:ffff:ffff
19729b0:c40::/2829b0:c4f:ffff:ffff:ffff:ffff:ffff:ffff
19829b0:c50::/2829b0:c5f:ffff:ffff:ffff:ffff:ffff:ffff
19929b0:c60::/2829b0:c6f:ffff:ffff:ffff:ffff:ffff:ffff
20029b0:c70::/2829b0:c7f:ffff:ffff:ffff:ffff:ffff:ffff
20129b0:c80::/2829b0:c8f:ffff:ffff:ffff:ffff:ffff:ffff
20229b0:c90::/2829b0:c9f:ffff:ffff:ffff:ffff:ffff:ffff
20329b0:ca0::/2829b0:caf:ffff:ffff:ffff:ffff:ffff:ffff
20429b0:cb0::/2829b0:cbf:ffff:ffff:ffff:ffff:ffff:ffff
20529b0:cc0::/2829b0:ccf:ffff:ffff:ffff:ffff:ffff:ffff
20629b0:cd0::/2829b0:cdf:ffff:ffff:ffff:ffff:ffff:ffff
20729b0:ce0::/2829b0:cef:ffff:ffff:ffff:ffff:ffff:ffff
20829b0:cf0::/2829b0:cff:ffff:ffff:ffff:ffff:ffff:ffff
20929b0:d00::/2829b0:d0f:ffff:ffff:ffff:ffff:ffff:ffff
21029b0:d10::/2829b0:d1f:ffff:ffff:ffff:ffff:ffff:ffff
21129b0:d20::/2829b0:d2f:ffff:ffff:ffff:ffff:ffff:ffff
21229b0:d30::/2829b0:d3f:ffff:ffff:ffff:ffff:ffff:ffff
21329b0:d40::/2829b0:d4f:ffff:ffff:ffff:ffff:ffff:ffff
21429b0:d50::/2829b0:d5f:ffff:ffff:ffff:ffff:ffff:ffff
21529b0:d60::/2829b0:d6f:ffff:ffff:ffff:ffff:ffff:ffff
21629b0:d70::/2829b0:d7f:ffff:ffff:ffff:ffff:ffff:ffff
21729b0:d80::/2829b0:d8f:ffff:ffff:ffff:ffff:ffff:ffff
21829b0:d90::/2829b0:d9f:ffff:ffff:ffff:ffff:ffff:ffff
21929b0:da0::/2829b0:daf:ffff:ffff:ffff:ffff:ffff:ffff
22029b0:db0::/2829b0:dbf:ffff:ffff:ffff:ffff:ffff:ffff
22129b0:dc0::/2829b0:dcf:ffff:ffff:ffff:ffff:ffff:ffff
22229b0:dd0::/2829b0:ddf:ffff:ffff:ffff:ffff:ffff:ffff
22329b0:de0::/2829b0:def:ffff:ffff:ffff:ffff:ffff:ffff
22429b0:df0::/2829b0:dff:ffff:ffff:ffff:ffff:ffff:ffff
22529b0:e00::/2829b0:e0f:ffff:ffff:ffff:ffff:ffff:ffff
22629b0:e10::/2829b0:e1f:ffff:ffff:ffff:ffff:ffff:ffff
22729b0:e20::/2829b0:e2f:ffff:ffff:ffff:ffff:ffff:ffff
22829b0:e30::/2829b0:e3f:ffff:ffff:ffff:ffff:ffff:ffff
22929b0:e40::/2829b0:e4f:ffff:ffff:ffff:ffff:ffff:ffff
23029b0:e50::/2829b0:e5f:ffff:ffff:ffff:ffff:ffff:ffff
23129b0:e60::/2829b0:e6f:ffff:ffff:ffff:ffff:ffff:ffff
23229b0:e70::/2829b0:e7f:ffff:ffff:ffff:ffff:ffff:ffff
23329b0:e80::/2829b0:e8f:ffff:ffff:ffff:ffff:ffff:ffff
23429b0:e90::/2829b0:e9f:ffff:ffff:ffff:ffff:ffff:ffff
23529b0:ea0::/2829b0:eaf:ffff:ffff:ffff:ffff:ffff:ffff
23629b0:eb0::/2829b0:ebf:ffff:ffff:ffff:ffff:ffff:ffff
23729b0:ec0::/2829b0:ecf:ffff:ffff:ffff:ffff:ffff:ffff
23829b0:ed0::/2829b0:edf:ffff:ffff:ffff:ffff:ffff:ffff
23929b0:ee0::/2829b0:eef:ffff:ffff:ffff:ffff:ffff:ffff
24029b0:ef0::/2829b0:eff:ffff:ffff:ffff:ffff:ffff:ffff
24129b0:f00::/2829b0:f0f:ffff:ffff:ffff:ffff:ffff:ffff
24229b0:f10::/2829b0:f1f:ffff:ffff:ffff:ffff:ffff:ffff
24329b0:f20::/2829b0:f2f:ffff:ffff:ffff:ffff:ffff:ffff
24429b0:f30::/2829b0:f3f:ffff:ffff:ffff:ffff:ffff:ffff
24529b0:f40::/2829b0:f4f:ffff:ffff:ffff:ffff:ffff:ffff
24629b0:f50::/2829b0:f5f:ffff:ffff:ffff:ffff:ffff:ffff
24729b0:f60::/2829b0:f6f:ffff:ffff:ffff:ffff:ffff:ffff
24829b0:f70::/2829b0:f7f:ffff:ffff:ffff:ffff:ffff:ffff
24929b0:f80::/2829b0:f8f:ffff:ffff:ffff:ffff:ffff:ffff
25029b0:f90::/2829b0:f9f:ffff:ffff:ffff:ffff:ffff:ffff
25129b0:fa0::/2829b0:faf:ffff:ffff:ffff:ffff:ffff:ffff
25229b0:fb0::/2829b0:fbf:ffff:ffff:ffff:ffff:ffff:ffff
25329b0:fc0::/2829b0:fcf:ffff:ffff:ffff:ffff:ffff:ffff
25429b0:fd0::/2829b0:fdf:ffff:ffff:ffff:ffff:ffff:ffff
25529b0:fe0::/2829b0:fef:ffff:ffff:ffff:ffff:ffff:ffff
25629b0:ff0::/2829b0: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.