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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
29c0::/12
First address
29c0::
Last address
29cf: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
29c0:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
c.9.2.ip6.arpa
Split into smaller subnets/24
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

29c0::/12 makes 4,096 subnets of /24; the first 256 are listed.

Subnets
#SubnetLast address
129c0::/2429c0:ff:ffff:ffff:ffff:ffff:ffff:ffff
229c0:100::/2429c0:1ff:ffff:ffff:ffff:ffff:ffff:ffff
329c0:200::/2429c0:2ff:ffff:ffff:ffff:ffff:ffff:ffff
429c0:300::/2429c0:3ff:ffff:ffff:ffff:ffff:ffff:ffff
529c0:400::/2429c0:4ff:ffff:ffff:ffff:ffff:ffff:ffff
629c0:500::/2429c0:5ff:ffff:ffff:ffff:ffff:ffff:ffff
729c0:600::/2429c0:6ff:ffff:ffff:ffff:ffff:ffff:ffff
829c0:700::/2429c0:7ff:ffff:ffff:ffff:ffff:ffff:ffff
929c0:800::/2429c0:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1029c0:900::/2429c0:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1129c0:a00::/2429c0:aff:ffff:ffff:ffff:ffff:ffff:ffff
1229c0:b00::/2429c0:bff:ffff:ffff:ffff:ffff:ffff:ffff
1329c0:c00::/2429c0:cff:ffff:ffff:ffff:ffff:ffff:ffff
1429c0:d00::/2429c0:dff:ffff:ffff:ffff:ffff:ffff:ffff
1529c0:e00::/2429c0:eff:ffff:ffff:ffff:ffff:ffff:ffff
1629c0:f00::/2429c0:fff:ffff:ffff:ffff:ffff:ffff:ffff
1729c0:1000::/2429c0:10ff:ffff:ffff:ffff:ffff:ffff:ffff
1829c0:1100::/2429c0:11ff:ffff:ffff:ffff:ffff:ffff:ffff
1929c0:1200::/2429c0:12ff:ffff:ffff:ffff:ffff:ffff:ffff
2029c0:1300::/2429c0:13ff:ffff:ffff:ffff:ffff:ffff:ffff
2129c0:1400::/2429c0:14ff:ffff:ffff:ffff:ffff:ffff:ffff
2229c0:1500::/2429c0:15ff:ffff:ffff:ffff:ffff:ffff:ffff
2329c0:1600::/2429c0:16ff:ffff:ffff:ffff:ffff:ffff:ffff
2429c0:1700::/2429c0:17ff:ffff:ffff:ffff:ffff:ffff:ffff
2529c0:1800::/2429c0:18ff:ffff:ffff:ffff:ffff:ffff:ffff
2629c0:1900::/2429c0:19ff:ffff:ffff:ffff:ffff:ffff:ffff
2729c0:1a00::/2429c0:1aff:ffff:ffff:ffff:ffff:ffff:ffff
2829c0:1b00::/2429c0:1bff:ffff:ffff:ffff:ffff:ffff:ffff
2929c0:1c00::/2429c0:1cff:ffff:ffff:ffff:ffff:ffff:ffff
3029c0:1d00::/2429c0:1dff:ffff:ffff:ffff:ffff:ffff:ffff
3129c0:1e00::/2429c0:1eff:ffff:ffff:ffff:ffff:ffff:ffff
3229c0:1f00::/2429c0:1fff:ffff:ffff:ffff:ffff:ffff:ffff
3329c0:2000::/2429c0:20ff:ffff:ffff:ffff:ffff:ffff:ffff
3429c0:2100::/2429c0:21ff:ffff:ffff:ffff:ffff:ffff:ffff
3529c0:2200::/2429c0:22ff:ffff:ffff:ffff:ffff:ffff:ffff
3629c0:2300::/2429c0:23ff:ffff:ffff:ffff:ffff:ffff:ffff
3729c0:2400::/2429c0:24ff:ffff:ffff:ffff:ffff:ffff:ffff
3829c0:2500::/2429c0:25ff:ffff:ffff:ffff:ffff:ffff:ffff
3929c0:2600::/2429c0:26ff:ffff:ffff:ffff:ffff:ffff:ffff
4029c0:2700::/2429c0:27ff:ffff:ffff:ffff:ffff:ffff:ffff
4129c0:2800::/2429c0:28ff:ffff:ffff:ffff:ffff:ffff:ffff
4229c0:2900::/2429c0:29ff:ffff:ffff:ffff:ffff:ffff:ffff
4329c0:2a00::/2429c0:2aff:ffff:ffff:ffff:ffff:ffff:ffff
4429c0:2b00::/2429c0:2bff:ffff:ffff:ffff:ffff:ffff:ffff
4529c0:2c00::/2429c0:2cff:ffff:ffff:ffff:ffff:ffff:ffff
4629c0:2d00::/2429c0:2dff:ffff:ffff:ffff:ffff:ffff:ffff
4729c0:2e00::/2429c0:2eff:ffff:ffff:ffff:ffff:ffff:ffff
4829c0:2f00::/2429c0:2fff:ffff:ffff:ffff:ffff:ffff:ffff
4929c0:3000::/2429c0:30ff:ffff:ffff:ffff:ffff:ffff:ffff
5029c0:3100::/2429c0:31ff:ffff:ffff:ffff:ffff:ffff:ffff
5129c0:3200::/2429c0:32ff:ffff:ffff:ffff:ffff:ffff:ffff
5229c0:3300::/2429c0:33ff:ffff:ffff:ffff:ffff:ffff:ffff
5329c0:3400::/2429c0:34ff:ffff:ffff:ffff:ffff:ffff:ffff
5429c0:3500::/2429c0:35ff:ffff:ffff:ffff:ffff:ffff:ffff
5529c0:3600::/2429c0:36ff:ffff:ffff:ffff:ffff:ffff:ffff
5629c0:3700::/2429c0:37ff:ffff:ffff:ffff:ffff:ffff:ffff
5729c0:3800::/2429c0:38ff:ffff:ffff:ffff:ffff:ffff:ffff
5829c0:3900::/2429c0:39ff:ffff:ffff:ffff:ffff:ffff:ffff
5929c0:3a00::/2429c0:3aff:ffff:ffff:ffff:ffff:ffff:ffff
6029c0:3b00::/2429c0:3bff:ffff:ffff:ffff:ffff:ffff:ffff
6129c0:3c00::/2429c0:3cff:ffff:ffff:ffff:ffff:ffff:ffff
6229c0:3d00::/2429c0:3dff:ffff:ffff:ffff:ffff:ffff:ffff
6329c0:3e00::/2429c0:3eff:ffff:ffff:ffff:ffff:ffff:ffff
6429c0:3f00::/2429c0:3fff:ffff:ffff:ffff:ffff:ffff:ffff
6529c0:4000::/2429c0:40ff:ffff:ffff:ffff:ffff:ffff:ffff
6629c0:4100::/2429c0:41ff:ffff:ffff:ffff:ffff:ffff:ffff
6729c0:4200::/2429c0:42ff:ffff:ffff:ffff:ffff:ffff:ffff
6829c0:4300::/2429c0:43ff:ffff:ffff:ffff:ffff:ffff:ffff
6929c0:4400::/2429c0:44ff:ffff:ffff:ffff:ffff:ffff:ffff
7029c0:4500::/2429c0:45ff:ffff:ffff:ffff:ffff:ffff:ffff
7129c0:4600::/2429c0:46ff:ffff:ffff:ffff:ffff:ffff:ffff
7229c0:4700::/2429c0:47ff:ffff:ffff:ffff:ffff:ffff:ffff
7329c0:4800::/2429c0:48ff:ffff:ffff:ffff:ffff:ffff:ffff
7429c0:4900::/2429c0:49ff:ffff:ffff:ffff:ffff:ffff:ffff
7529c0:4a00::/2429c0:4aff:ffff:ffff:ffff:ffff:ffff:ffff
7629c0:4b00::/2429c0:4bff:ffff:ffff:ffff:ffff:ffff:ffff
7729c0:4c00::/2429c0:4cff:ffff:ffff:ffff:ffff:ffff:ffff
7829c0:4d00::/2429c0:4dff:ffff:ffff:ffff:ffff:ffff:ffff
7929c0:4e00::/2429c0:4eff:ffff:ffff:ffff:ffff:ffff:ffff
8029c0:4f00::/2429c0:4fff:ffff:ffff:ffff:ffff:ffff:ffff
8129c0:5000::/2429c0:50ff:ffff:ffff:ffff:ffff:ffff:ffff
8229c0:5100::/2429c0:51ff:ffff:ffff:ffff:ffff:ffff:ffff
8329c0:5200::/2429c0:52ff:ffff:ffff:ffff:ffff:ffff:ffff
8429c0:5300::/2429c0:53ff:ffff:ffff:ffff:ffff:ffff:ffff
8529c0:5400::/2429c0:54ff:ffff:ffff:ffff:ffff:ffff:ffff
8629c0:5500::/2429c0:55ff:ffff:ffff:ffff:ffff:ffff:ffff
8729c0:5600::/2429c0:56ff:ffff:ffff:ffff:ffff:ffff:ffff
8829c0:5700::/2429c0:57ff:ffff:ffff:ffff:ffff:ffff:ffff
8929c0:5800::/2429c0:58ff:ffff:ffff:ffff:ffff:ffff:ffff
9029c0:5900::/2429c0:59ff:ffff:ffff:ffff:ffff:ffff:ffff
9129c0:5a00::/2429c0:5aff:ffff:ffff:ffff:ffff:ffff:ffff
9229c0:5b00::/2429c0:5bff:ffff:ffff:ffff:ffff:ffff:ffff
9329c0:5c00::/2429c0:5cff:ffff:ffff:ffff:ffff:ffff:ffff
9429c0:5d00::/2429c0:5dff:ffff:ffff:ffff:ffff:ffff:ffff
9529c0:5e00::/2429c0:5eff:ffff:ffff:ffff:ffff:ffff:ffff
9629c0:5f00::/2429c0:5fff:ffff:ffff:ffff:ffff:ffff:ffff
9729c0:6000::/2429c0:60ff:ffff:ffff:ffff:ffff:ffff:ffff
9829c0:6100::/2429c0:61ff:ffff:ffff:ffff:ffff:ffff:ffff
9929c0:6200::/2429c0:62ff:ffff:ffff:ffff:ffff:ffff:ffff
10029c0:6300::/2429c0:63ff:ffff:ffff:ffff:ffff:ffff:ffff
10129c0:6400::/2429c0:64ff:ffff:ffff:ffff:ffff:ffff:ffff
10229c0:6500::/2429c0:65ff:ffff:ffff:ffff:ffff:ffff:ffff
10329c0:6600::/2429c0:66ff:ffff:ffff:ffff:ffff:ffff:ffff
10429c0:6700::/2429c0:67ff:ffff:ffff:ffff:ffff:ffff:ffff
10529c0:6800::/2429c0:68ff:ffff:ffff:ffff:ffff:ffff:ffff
10629c0:6900::/2429c0:69ff:ffff:ffff:ffff:ffff:ffff:ffff
10729c0:6a00::/2429c0:6aff:ffff:ffff:ffff:ffff:ffff:ffff
10829c0:6b00::/2429c0:6bff:ffff:ffff:ffff:ffff:ffff:ffff
10929c0:6c00::/2429c0:6cff:ffff:ffff:ffff:ffff:ffff:ffff
11029c0:6d00::/2429c0:6dff:ffff:ffff:ffff:ffff:ffff:ffff
11129c0:6e00::/2429c0:6eff:ffff:ffff:ffff:ffff:ffff:ffff
11229c0:6f00::/2429c0:6fff:ffff:ffff:ffff:ffff:ffff:ffff
11329c0:7000::/2429c0:70ff:ffff:ffff:ffff:ffff:ffff:ffff
11429c0:7100::/2429c0:71ff:ffff:ffff:ffff:ffff:ffff:ffff
11529c0:7200::/2429c0:72ff:ffff:ffff:ffff:ffff:ffff:ffff
11629c0:7300::/2429c0:73ff:ffff:ffff:ffff:ffff:ffff:ffff
11729c0:7400::/2429c0:74ff:ffff:ffff:ffff:ffff:ffff:ffff
11829c0:7500::/2429c0:75ff:ffff:ffff:ffff:ffff:ffff:ffff
11929c0:7600::/2429c0:76ff:ffff:ffff:ffff:ffff:ffff:ffff
12029c0:7700::/2429c0:77ff:ffff:ffff:ffff:ffff:ffff:ffff
12129c0:7800::/2429c0:78ff:ffff:ffff:ffff:ffff:ffff:ffff
12229c0:7900::/2429c0:79ff:ffff:ffff:ffff:ffff:ffff:ffff
12329c0:7a00::/2429c0:7aff:ffff:ffff:ffff:ffff:ffff:ffff
12429c0:7b00::/2429c0:7bff:ffff:ffff:ffff:ffff:ffff:ffff
12529c0:7c00::/2429c0:7cff:ffff:ffff:ffff:ffff:ffff:ffff
12629c0:7d00::/2429c0:7dff:ffff:ffff:ffff:ffff:ffff:ffff
12729c0:7e00::/2429c0:7eff:ffff:ffff:ffff:ffff:ffff:ffff
12829c0:7f00::/2429c0:7fff:ffff:ffff:ffff:ffff:ffff:ffff
12929c0:8000::/2429c0:80ff:ffff:ffff:ffff:ffff:ffff:ffff
13029c0:8100::/2429c0:81ff:ffff:ffff:ffff:ffff:ffff:ffff
13129c0:8200::/2429c0:82ff:ffff:ffff:ffff:ffff:ffff:ffff
13229c0:8300::/2429c0:83ff:ffff:ffff:ffff:ffff:ffff:ffff
13329c0:8400::/2429c0:84ff:ffff:ffff:ffff:ffff:ffff:ffff
13429c0:8500::/2429c0:85ff:ffff:ffff:ffff:ffff:ffff:ffff
13529c0:8600::/2429c0:86ff:ffff:ffff:ffff:ffff:ffff:ffff
13629c0:8700::/2429c0:87ff:ffff:ffff:ffff:ffff:ffff:ffff
13729c0:8800::/2429c0:88ff:ffff:ffff:ffff:ffff:ffff:ffff
13829c0:8900::/2429c0:89ff:ffff:ffff:ffff:ffff:ffff:ffff
13929c0:8a00::/2429c0:8aff:ffff:ffff:ffff:ffff:ffff:ffff
14029c0:8b00::/2429c0:8bff:ffff:ffff:ffff:ffff:ffff:ffff
14129c0:8c00::/2429c0:8cff:ffff:ffff:ffff:ffff:ffff:ffff
14229c0:8d00::/2429c0:8dff:ffff:ffff:ffff:ffff:ffff:ffff
14329c0:8e00::/2429c0:8eff:ffff:ffff:ffff:ffff:ffff:ffff
14429c0:8f00::/2429c0:8fff:ffff:ffff:ffff:ffff:ffff:ffff
14529c0:9000::/2429c0:90ff:ffff:ffff:ffff:ffff:ffff:ffff
14629c0:9100::/2429c0:91ff:ffff:ffff:ffff:ffff:ffff:ffff
14729c0:9200::/2429c0:92ff:ffff:ffff:ffff:ffff:ffff:ffff
14829c0:9300::/2429c0:93ff:ffff:ffff:ffff:ffff:ffff:ffff
14929c0:9400::/2429c0:94ff:ffff:ffff:ffff:ffff:ffff:ffff
15029c0:9500::/2429c0:95ff:ffff:ffff:ffff:ffff:ffff:ffff
15129c0:9600::/2429c0:96ff:ffff:ffff:ffff:ffff:ffff:ffff
15229c0:9700::/2429c0:97ff:ffff:ffff:ffff:ffff:ffff:ffff
15329c0:9800::/2429c0:98ff:ffff:ffff:ffff:ffff:ffff:ffff
15429c0:9900::/2429c0:99ff:ffff:ffff:ffff:ffff:ffff:ffff
15529c0:9a00::/2429c0:9aff:ffff:ffff:ffff:ffff:ffff:ffff
15629c0:9b00::/2429c0:9bff:ffff:ffff:ffff:ffff:ffff:ffff
15729c0:9c00::/2429c0:9cff:ffff:ffff:ffff:ffff:ffff:ffff
15829c0:9d00::/2429c0:9dff:ffff:ffff:ffff:ffff:ffff:ffff
15929c0:9e00::/2429c0:9eff:ffff:ffff:ffff:ffff:ffff:ffff
16029c0:9f00::/2429c0:9fff:ffff:ffff:ffff:ffff:ffff:ffff
16129c0:a000::/2429c0:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
16229c0:a100::/2429c0:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
16329c0:a200::/2429c0:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
16429c0:a300::/2429c0:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
16529c0:a400::/2429c0:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
16629c0:a500::/2429c0:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
16729c0:a600::/2429c0:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
16829c0:a700::/2429c0:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
16929c0:a800::/2429c0:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
17029c0:a900::/2429c0:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
17129c0:aa00::/2429c0:aaff:ffff:ffff:ffff:ffff:ffff:ffff
17229c0:ab00::/2429c0:abff:ffff:ffff:ffff:ffff:ffff:ffff
17329c0:ac00::/2429c0:acff:ffff:ffff:ffff:ffff:ffff:ffff
17429c0:ad00::/2429c0:adff:ffff:ffff:ffff:ffff:ffff:ffff
17529c0:ae00::/2429c0:aeff:ffff:ffff:ffff:ffff:ffff:ffff
17629c0:af00::/2429c0:afff:ffff:ffff:ffff:ffff:ffff:ffff
17729c0:b000::/2429c0:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
17829c0:b100::/2429c0:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
17929c0:b200::/2429c0:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
18029c0:b300::/2429c0:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
18129c0:b400::/2429c0:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
18229c0:b500::/2429c0:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
18329c0:b600::/2429c0:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
18429c0:b700::/2429c0:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
18529c0:b800::/2429c0:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
18629c0:b900::/2429c0:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
18729c0:ba00::/2429c0:baff:ffff:ffff:ffff:ffff:ffff:ffff
18829c0:bb00::/2429c0:bbff:ffff:ffff:ffff:ffff:ffff:ffff
18929c0:bc00::/2429c0:bcff:ffff:ffff:ffff:ffff:ffff:ffff
19029c0:bd00::/2429c0:bdff:ffff:ffff:ffff:ffff:ffff:ffff
19129c0:be00::/2429c0:beff:ffff:ffff:ffff:ffff:ffff:ffff
19229c0:bf00::/2429c0:bfff:ffff:ffff:ffff:ffff:ffff:ffff
19329c0:c000::/2429c0:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
19429c0:c100::/2429c0:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
19529c0:c200::/2429c0:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
19629c0:c300::/2429c0:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
19729c0:c400::/2429c0:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
19829c0:c500::/2429c0:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
19929c0:c600::/2429c0:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
20029c0:c700::/2429c0:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
20129c0:c800::/2429c0:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
20229c0:c900::/2429c0:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
20329c0:ca00::/2429c0:caff:ffff:ffff:ffff:ffff:ffff:ffff
20429c0:cb00::/2429c0:cbff:ffff:ffff:ffff:ffff:ffff:ffff
20529c0:cc00::/2429c0:ccff:ffff:ffff:ffff:ffff:ffff:ffff
20629c0:cd00::/2429c0:cdff:ffff:ffff:ffff:ffff:ffff:ffff
20729c0:ce00::/2429c0:ceff:ffff:ffff:ffff:ffff:ffff:ffff
20829c0:cf00::/2429c0:cfff:ffff:ffff:ffff:ffff:ffff:ffff
20929c0:d000::/2429c0:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
21029c0:d100::/2429c0:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
21129c0:d200::/2429c0:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
21229c0:d300::/2429c0:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
21329c0:d400::/2429c0:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
21429c0:d500::/2429c0:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
21529c0:d600::/2429c0:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
21629c0:d700::/2429c0:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
21729c0:d800::/2429c0:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
21829c0:d900::/2429c0:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
21929c0:da00::/2429c0:daff:ffff:ffff:ffff:ffff:ffff:ffff
22029c0:db00::/2429c0:dbff:ffff:ffff:ffff:ffff:ffff:ffff
22129c0:dc00::/2429c0:dcff:ffff:ffff:ffff:ffff:ffff:ffff
22229c0:dd00::/2429c0:ddff:ffff:ffff:ffff:ffff:ffff:ffff
22329c0:de00::/2429c0:deff:ffff:ffff:ffff:ffff:ffff:ffff
22429c0:df00::/2429c0:dfff:ffff:ffff:ffff:ffff:ffff:ffff
22529c0:e000::/2429c0:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
22629c0:e100::/2429c0:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
22729c0:e200::/2429c0:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
22829c0:e300::/2429c0:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
22929c0:e400::/2429c0:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
23029c0:e500::/2429c0:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
23129c0:e600::/2429c0:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
23229c0:e700::/2429c0:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
23329c0:e800::/2429c0:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
23429c0:e900::/2429c0:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
23529c0:ea00::/2429c0:eaff:ffff:ffff:ffff:ffff:ffff:ffff
23629c0:eb00::/2429c0:ebff:ffff:ffff:ffff:ffff:ffff:ffff
23729c0:ec00::/2429c0:ecff:ffff:ffff:ffff:ffff:ffff:ffff
23829c0:ed00::/2429c0:edff:ffff:ffff:ffff:ffff:ffff:ffff
23929c0:ee00::/2429c0:eeff:ffff:ffff:ffff:ffff:ffff:ffff
24029c0:ef00::/2429c0:efff:ffff:ffff:ffff:ffff:ffff:ffff
24129c0:f000::/2429c0:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
24229c0:f100::/2429c0:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
24329c0:f200::/2429c0:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
24429c0:f300::/2429c0:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
24529c0:f400::/2429c0:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
24629c0:f500::/2429c0:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
24729c0:f600::/2429c0:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
24829c0:f700::/2429c0:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
24929c0:f800::/2429c0:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
25029c0:f900::/2429c0:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
25129c0:fa00::/2429c0:faff:ffff:ffff:ffff:ffff:ffff:ffff
25229c0:fb00::/2429c0:fbff:ffff:ffff:ffff:ffff:ffff:ffff
25329c0:fc00::/2429c0:fcff:ffff:ffff:ffff:ffff:ffff:ffff
25429c0:fd00::/2429c0:fdff:ffff:ffff:ffff:ffff:ffff:ffff
25529c0:fe00::/2429c0:feff:ffff:ffff:ffff:ffff:ffff:ffff
25629c0:ff00::/2429c0:ffff: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.