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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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Update checkIs this computer, phone and browser up to date? With links to update.Camera and mic testCheck your webcam and microphone before a call.Test print pagePrint an A4 page to check a printer: edges, text, line art and colours.

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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
20e9::/16
First address
20e9::
Last address
20e9: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
20e9:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zone
9.e.0.2.ip6.arpa
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

20e9::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
120e9::/2420e9:ff:ffff:ffff:ffff:ffff:ffff:ffff
220e9:100::/2420e9:1ff:ffff:ffff:ffff:ffff:ffff:ffff
320e9:200::/2420e9:2ff:ffff:ffff:ffff:ffff:ffff:ffff
420e9:300::/2420e9:3ff:ffff:ffff:ffff:ffff:ffff:ffff
520e9:400::/2420e9:4ff:ffff:ffff:ffff:ffff:ffff:ffff
620e9:500::/2420e9:5ff:ffff:ffff:ffff:ffff:ffff:ffff
720e9:600::/2420e9:6ff:ffff:ffff:ffff:ffff:ffff:ffff
820e9:700::/2420e9:7ff:ffff:ffff:ffff:ffff:ffff:ffff
920e9:800::/2420e9:8ff:ffff:ffff:ffff:ffff:ffff:ffff
1020e9:900::/2420e9:9ff:ffff:ffff:ffff:ffff:ffff:ffff
1120e9:a00::/2420e9:aff:ffff:ffff:ffff:ffff:ffff:ffff
1220e9:b00::/2420e9:bff:ffff:ffff:ffff:ffff:ffff:ffff
1320e9:c00::/2420e9:cff:ffff:ffff:ffff:ffff:ffff:ffff
1420e9:d00::/2420e9:dff:ffff:ffff:ffff:ffff:ffff:ffff
1520e9:e00::/2420e9:eff:ffff:ffff:ffff:ffff:ffff:ffff
1620e9:f00::/2420e9:fff:ffff:ffff:ffff:ffff:ffff:ffff
1720e9:1000::/2420e9:10ff:ffff:ffff:ffff:ffff:ffff:ffff
1820e9:1100::/2420e9:11ff:ffff:ffff:ffff:ffff:ffff:ffff
1920e9:1200::/2420e9:12ff:ffff:ffff:ffff:ffff:ffff:ffff
2020e9:1300::/2420e9:13ff:ffff:ffff:ffff:ffff:ffff:ffff
2120e9:1400::/2420e9:14ff:ffff:ffff:ffff:ffff:ffff:ffff
2220e9:1500::/2420e9:15ff:ffff:ffff:ffff:ffff:ffff:ffff
2320e9:1600::/2420e9:16ff:ffff:ffff:ffff:ffff:ffff:ffff
2420e9:1700::/2420e9:17ff:ffff:ffff:ffff:ffff:ffff:ffff
2520e9:1800::/2420e9:18ff:ffff:ffff:ffff:ffff:ffff:ffff
2620e9:1900::/2420e9:19ff:ffff:ffff:ffff:ffff:ffff:ffff
2720e9:1a00::/2420e9:1aff:ffff:ffff:ffff:ffff:ffff:ffff
2820e9:1b00::/2420e9:1bff:ffff:ffff:ffff:ffff:ffff:ffff
2920e9:1c00::/2420e9:1cff:ffff:ffff:ffff:ffff:ffff:ffff
3020e9:1d00::/2420e9:1dff:ffff:ffff:ffff:ffff:ffff:ffff
3120e9:1e00::/2420e9:1eff:ffff:ffff:ffff:ffff:ffff:ffff
3220e9:1f00::/2420e9:1fff:ffff:ffff:ffff:ffff:ffff:ffff
3320e9:2000::/2420e9:20ff:ffff:ffff:ffff:ffff:ffff:ffff
3420e9:2100::/2420e9:21ff:ffff:ffff:ffff:ffff:ffff:ffff
3520e9:2200::/2420e9:22ff:ffff:ffff:ffff:ffff:ffff:ffff
3620e9:2300::/2420e9:23ff:ffff:ffff:ffff:ffff:ffff:ffff
3720e9:2400::/2420e9:24ff:ffff:ffff:ffff:ffff:ffff:ffff
3820e9:2500::/2420e9:25ff:ffff:ffff:ffff:ffff:ffff:ffff
3920e9:2600::/2420e9:26ff:ffff:ffff:ffff:ffff:ffff:ffff
4020e9:2700::/2420e9:27ff:ffff:ffff:ffff:ffff:ffff:ffff
4120e9:2800::/2420e9:28ff:ffff:ffff:ffff:ffff:ffff:ffff
4220e9:2900::/2420e9:29ff:ffff:ffff:ffff:ffff:ffff:ffff
4320e9:2a00::/2420e9:2aff:ffff:ffff:ffff:ffff:ffff:ffff
4420e9:2b00::/2420e9:2bff:ffff:ffff:ffff:ffff:ffff:ffff
4520e9:2c00::/2420e9:2cff:ffff:ffff:ffff:ffff:ffff:ffff
4620e9:2d00::/2420e9:2dff:ffff:ffff:ffff:ffff:ffff:ffff
4720e9:2e00::/2420e9:2eff:ffff:ffff:ffff:ffff:ffff:ffff
4820e9:2f00::/2420e9:2fff:ffff:ffff:ffff:ffff:ffff:ffff
4920e9:3000::/2420e9:30ff:ffff:ffff:ffff:ffff:ffff:ffff
5020e9:3100::/2420e9:31ff:ffff:ffff:ffff:ffff:ffff:ffff
5120e9:3200::/2420e9:32ff:ffff:ffff:ffff:ffff:ffff:ffff
5220e9:3300::/2420e9:33ff:ffff:ffff:ffff:ffff:ffff:ffff
5320e9:3400::/2420e9:34ff:ffff:ffff:ffff:ffff:ffff:ffff
5420e9:3500::/2420e9:35ff:ffff:ffff:ffff:ffff:ffff:ffff
5520e9:3600::/2420e9:36ff:ffff:ffff:ffff:ffff:ffff:ffff
5620e9:3700::/2420e9:37ff:ffff:ffff:ffff:ffff:ffff:ffff
5720e9:3800::/2420e9:38ff:ffff:ffff:ffff:ffff:ffff:ffff
5820e9:3900::/2420e9:39ff:ffff:ffff:ffff:ffff:ffff:ffff
5920e9:3a00::/2420e9:3aff:ffff:ffff:ffff:ffff:ffff:ffff
6020e9:3b00::/2420e9:3bff:ffff:ffff:ffff:ffff:ffff:ffff
6120e9:3c00::/2420e9:3cff:ffff:ffff:ffff:ffff:ffff:ffff
6220e9:3d00::/2420e9:3dff:ffff:ffff:ffff:ffff:ffff:ffff
6320e9:3e00::/2420e9:3eff:ffff:ffff:ffff:ffff:ffff:ffff
6420e9:3f00::/2420e9:3fff:ffff:ffff:ffff:ffff:ffff:ffff
6520e9:4000::/2420e9:40ff:ffff:ffff:ffff:ffff:ffff:ffff
6620e9:4100::/2420e9:41ff:ffff:ffff:ffff:ffff:ffff:ffff
6720e9:4200::/2420e9:42ff:ffff:ffff:ffff:ffff:ffff:ffff
6820e9:4300::/2420e9:43ff:ffff:ffff:ffff:ffff:ffff:ffff
6920e9:4400::/2420e9:44ff:ffff:ffff:ffff:ffff:ffff:ffff
7020e9:4500::/2420e9:45ff:ffff:ffff:ffff:ffff:ffff:ffff
7120e9:4600::/2420e9:46ff:ffff:ffff:ffff:ffff:ffff:ffff
7220e9:4700::/2420e9:47ff:ffff:ffff:ffff:ffff:ffff:ffff
7320e9:4800::/2420e9:48ff:ffff:ffff:ffff:ffff:ffff:ffff
7420e9:4900::/2420e9:49ff:ffff:ffff:ffff:ffff:ffff:ffff
7520e9:4a00::/2420e9:4aff:ffff:ffff:ffff:ffff:ffff:ffff
7620e9:4b00::/2420e9:4bff:ffff:ffff:ffff:ffff:ffff:ffff
7720e9:4c00::/2420e9:4cff:ffff:ffff:ffff:ffff:ffff:ffff
7820e9:4d00::/2420e9:4dff:ffff:ffff:ffff:ffff:ffff:ffff
7920e9:4e00::/2420e9:4eff:ffff:ffff:ffff:ffff:ffff:ffff
8020e9:4f00::/2420e9:4fff:ffff:ffff:ffff:ffff:ffff:ffff
8120e9:5000::/2420e9:50ff:ffff:ffff:ffff:ffff:ffff:ffff
8220e9:5100::/2420e9:51ff:ffff:ffff:ffff:ffff:ffff:ffff
8320e9:5200::/2420e9:52ff:ffff:ffff:ffff:ffff:ffff:ffff
8420e9:5300::/2420e9:53ff:ffff:ffff:ffff:ffff:ffff:ffff
8520e9:5400::/2420e9:54ff:ffff:ffff:ffff:ffff:ffff:ffff
8620e9:5500::/2420e9:55ff:ffff:ffff:ffff:ffff:ffff:ffff
8720e9:5600::/2420e9:56ff:ffff:ffff:ffff:ffff:ffff:ffff
8820e9:5700::/2420e9:57ff:ffff:ffff:ffff:ffff:ffff:ffff
8920e9:5800::/2420e9:58ff:ffff:ffff:ffff:ffff:ffff:ffff
9020e9:5900::/2420e9:59ff:ffff:ffff:ffff:ffff:ffff:ffff
9120e9:5a00::/2420e9:5aff:ffff:ffff:ffff:ffff:ffff:ffff
9220e9:5b00::/2420e9:5bff:ffff:ffff:ffff:ffff:ffff:ffff
9320e9:5c00::/2420e9:5cff:ffff:ffff:ffff:ffff:ffff:ffff
9420e9:5d00::/2420e9:5dff:ffff:ffff:ffff:ffff:ffff:ffff
9520e9:5e00::/2420e9:5eff:ffff:ffff:ffff:ffff:ffff:ffff
9620e9:5f00::/2420e9:5fff:ffff:ffff:ffff:ffff:ffff:ffff
9720e9:6000::/2420e9:60ff:ffff:ffff:ffff:ffff:ffff:ffff
9820e9:6100::/2420e9:61ff:ffff:ffff:ffff:ffff:ffff:ffff
9920e9:6200::/2420e9:62ff:ffff:ffff:ffff:ffff:ffff:ffff
10020e9:6300::/2420e9:63ff:ffff:ffff:ffff:ffff:ffff:ffff
10120e9:6400::/2420e9:64ff:ffff:ffff:ffff:ffff:ffff:ffff
10220e9:6500::/2420e9:65ff:ffff:ffff:ffff:ffff:ffff:ffff
10320e9:6600::/2420e9:66ff:ffff:ffff:ffff:ffff:ffff:ffff
10420e9:6700::/2420e9:67ff:ffff:ffff:ffff:ffff:ffff:ffff
10520e9:6800::/2420e9:68ff:ffff:ffff:ffff:ffff:ffff:ffff
10620e9:6900::/2420e9:69ff:ffff:ffff:ffff:ffff:ffff:ffff
10720e9:6a00::/2420e9:6aff:ffff:ffff:ffff:ffff:ffff:ffff
10820e9:6b00::/2420e9:6bff:ffff:ffff:ffff:ffff:ffff:ffff
10920e9:6c00::/2420e9:6cff:ffff:ffff:ffff:ffff:ffff:ffff
11020e9:6d00::/2420e9:6dff:ffff:ffff:ffff:ffff:ffff:ffff
11120e9:6e00::/2420e9:6eff:ffff:ffff:ffff:ffff:ffff:ffff
11220e9:6f00::/2420e9:6fff:ffff:ffff:ffff:ffff:ffff:ffff
11320e9:7000::/2420e9:70ff:ffff:ffff:ffff:ffff:ffff:ffff
11420e9:7100::/2420e9:71ff:ffff:ffff:ffff:ffff:ffff:ffff
11520e9:7200::/2420e9:72ff:ffff:ffff:ffff:ffff:ffff:ffff
11620e9:7300::/2420e9:73ff:ffff:ffff:ffff:ffff:ffff:ffff
11720e9:7400::/2420e9:74ff:ffff:ffff:ffff:ffff:ffff:ffff
11820e9:7500::/2420e9:75ff:ffff:ffff:ffff:ffff:ffff:ffff
11920e9:7600::/2420e9:76ff:ffff:ffff:ffff:ffff:ffff:ffff
12020e9:7700::/2420e9:77ff:ffff:ffff:ffff:ffff:ffff:ffff
12120e9:7800::/2420e9:78ff:ffff:ffff:ffff:ffff:ffff:ffff
12220e9:7900::/2420e9:79ff:ffff:ffff:ffff:ffff:ffff:ffff
12320e9:7a00::/2420e9:7aff:ffff:ffff:ffff:ffff:ffff:ffff
12420e9:7b00::/2420e9:7bff:ffff:ffff:ffff:ffff:ffff:ffff
12520e9:7c00::/2420e9:7cff:ffff:ffff:ffff:ffff:ffff:ffff
12620e9:7d00::/2420e9:7dff:ffff:ffff:ffff:ffff:ffff:ffff
12720e9:7e00::/2420e9:7eff:ffff:ffff:ffff:ffff:ffff:ffff
12820e9:7f00::/2420e9:7fff:ffff:ffff:ffff:ffff:ffff:ffff
12920e9:8000::/2420e9:80ff:ffff:ffff:ffff:ffff:ffff:ffff
13020e9:8100::/2420e9:81ff:ffff:ffff:ffff:ffff:ffff:ffff
13120e9:8200::/2420e9:82ff:ffff:ffff:ffff:ffff:ffff:ffff
13220e9:8300::/2420e9:83ff:ffff:ffff:ffff:ffff:ffff:ffff
13320e9:8400::/2420e9:84ff:ffff:ffff:ffff:ffff:ffff:ffff
13420e9:8500::/2420e9:85ff:ffff:ffff:ffff:ffff:ffff:ffff
13520e9:8600::/2420e9:86ff:ffff:ffff:ffff:ffff:ffff:ffff
13620e9:8700::/2420e9:87ff:ffff:ffff:ffff:ffff:ffff:ffff
13720e9:8800::/2420e9:88ff:ffff:ffff:ffff:ffff:ffff:ffff
13820e9:8900::/2420e9:89ff:ffff:ffff:ffff:ffff:ffff:ffff
13920e9:8a00::/2420e9:8aff:ffff:ffff:ffff:ffff:ffff:ffff
14020e9:8b00::/2420e9:8bff:ffff:ffff:ffff:ffff:ffff:ffff
14120e9:8c00::/2420e9:8cff:ffff:ffff:ffff:ffff:ffff:ffff
14220e9:8d00::/2420e9:8dff:ffff:ffff:ffff:ffff:ffff:ffff
14320e9:8e00::/2420e9:8eff:ffff:ffff:ffff:ffff:ffff:ffff
14420e9:8f00::/2420e9:8fff:ffff:ffff:ffff:ffff:ffff:ffff
14520e9:9000::/2420e9:90ff:ffff:ffff:ffff:ffff:ffff:ffff
14620e9:9100::/2420e9:91ff:ffff:ffff:ffff:ffff:ffff:ffff
14720e9:9200::/2420e9:92ff:ffff:ffff:ffff:ffff:ffff:ffff
14820e9:9300::/2420e9:93ff:ffff:ffff:ffff:ffff:ffff:ffff
14920e9:9400::/2420e9:94ff:ffff:ffff:ffff:ffff:ffff:ffff
15020e9:9500::/2420e9:95ff:ffff:ffff:ffff:ffff:ffff:ffff
15120e9:9600::/2420e9:96ff:ffff:ffff:ffff:ffff:ffff:ffff
15220e9:9700::/2420e9:97ff:ffff:ffff:ffff:ffff:ffff:ffff
15320e9:9800::/2420e9:98ff:ffff:ffff:ffff:ffff:ffff:ffff
15420e9:9900::/2420e9:99ff:ffff:ffff:ffff:ffff:ffff:ffff
15520e9:9a00::/2420e9:9aff:ffff:ffff:ffff:ffff:ffff:ffff
15620e9:9b00::/2420e9:9bff:ffff:ffff:ffff:ffff:ffff:ffff
15720e9:9c00::/2420e9:9cff:ffff:ffff:ffff:ffff:ffff:ffff
15820e9:9d00::/2420e9:9dff:ffff:ffff:ffff:ffff:ffff:ffff
15920e9:9e00::/2420e9:9eff:ffff:ffff:ffff:ffff:ffff:ffff
16020e9:9f00::/2420e9:9fff:ffff:ffff:ffff:ffff:ffff:ffff
16120e9:a000::/2420e9:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
16220e9:a100::/2420e9:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
16320e9:a200::/2420e9:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
16420e9:a300::/2420e9:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
16520e9:a400::/2420e9:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
16620e9:a500::/2420e9:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
16720e9:a600::/2420e9:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
16820e9:a700::/2420e9:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
16920e9:a800::/2420e9:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
17020e9:a900::/2420e9:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
17120e9:aa00::/2420e9:aaff:ffff:ffff:ffff:ffff:ffff:ffff
17220e9:ab00::/2420e9:abff:ffff:ffff:ffff:ffff:ffff:ffff
17320e9:ac00::/2420e9:acff:ffff:ffff:ffff:ffff:ffff:ffff
17420e9:ad00::/2420e9:adff:ffff:ffff:ffff:ffff:ffff:ffff
17520e9:ae00::/2420e9:aeff:ffff:ffff:ffff:ffff:ffff:ffff
17620e9:af00::/2420e9:afff:ffff:ffff:ffff:ffff:ffff:ffff
17720e9:b000::/2420e9:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
17820e9:b100::/2420e9:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
17920e9:b200::/2420e9:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
18020e9:b300::/2420e9:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
18120e9:b400::/2420e9:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
18220e9:b500::/2420e9:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
18320e9:b600::/2420e9:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
18420e9:b700::/2420e9:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
18520e9:b800::/2420e9:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
18620e9:b900::/2420e9:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
18720e9:ba00::/2420e9:baff:ffff:ffff:ffff:ffff:ffff:ffff
18820e9:bb00::/2420e9:bbff:ffff:ffff:ffff:ffff:ffff:ffff
18920e9:bc00::/2420e9:bcff:ffff:ffff:ffff:ffff:ffff:ffff
19020e9:bd00::/2420e9:bdff:ffff:ffff:ffff:ffff:ffff:ffff
19120e9:be00::/2420e9:beff:ffff:ffff:ffff:ffff:ffff:ffff
19220e9:bf00::/2420e9:bfff:ffff:ffff:ffff:ffff:ffff:ffff
19320e9:c000::/2420e9:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
19420e9:c100::/2420e9:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
19520e9:c200::/2420e9:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
19620e9:c300::/2420e9:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
19720e9:c400::/2420e9:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
19820e9:c500::/2420e9:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
19920e9:c600::/2420e9:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
20020e9:c700::/2420e9:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
20120e9:c800::/2420e9:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
20220e9:c900::/2420e9:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
20320e9:ca00::/2420e9:caff:ffff:ffff:ffff:ffff:ffff:ffff
20420e9:cb00::/2420e9:cbff:ffff:ffff:ffff:ffff:ffff:ffff
20520e9:cc00::/2420e9:ccff:ffff:ffff:ffff:ffff:ffff:ffff
20620e9:cd00::/2420e9:cdff:ffff:ffff:ffff:ffff:ffff:ffff
20720e9:ce00::/2420e9:ceff:ffff:ffff:ffff:ffff:ffff:ffff
20820e9:cf00::/2420e9:cfff:ffff:ffff:ffff:ffff:ffff:ffff
20920e9:d000::/2420e9:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
21020e9:d100::/2420e9:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
21120e9:d200::/2420e9:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
21220e9:d300::/2420e9:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
21320e9:d400::/2420e9:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
21420e9:d500::/2420e9:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
21520e9:d600::/2420e9:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
21620e9:d700::/2420e9:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
21720e9:d800::/2420e9:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
21820e9:d900::/2420e9:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
21920e9:da00::/2420e9:daff:ffff:ffff:ffff:ffff:ffff:ffff
22020e9:db00::/2420e9:dbff:ffff:ffff:ffff:ffff:ffff:ffff
22120e9:dc00::/2420e9:dcff:ffff:ffff:ffff:ffff:ffff:ffff
22220e9:dd00::/2420e9:ddff:ffff:ffff:ffff:ffff:ffff:ffff
22320e9:de00::/2420e9:deff:ffff:ffff:ffff:ffff:ffff:ffff
22420e9:df00::/2420e9:dfff:ffff:ffff:ffff:ffff:ffff:ffff
22520e9:e000::/2420e9:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
22620e9:e100::/2420e9:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
22720e9:e200::/2420e9:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
22820e9:e300::/2420e9:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
22920e9:e400::/2420e9:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
23020e9:e500::/2420e9:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
23120e9:e600::/2420e9:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
23220e9:e700::/2420e9:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
23320e9:e800::/2420e9:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
23420e9:e900::/2420e9:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
23520e9:ea00::/2420e9:eaff:ffff:ffff:ffff:ffff:ffff:ffff
23620e9:eb00::/2420e9:ebff:ffff:ffff:ffff:ffff:ffff:ffff
23720e9:ec00::/2420e9:ecff:ffff:ffff:ffff:ffff:ffff:ffff
23820e9:ed00::/2420e9:edff:ffff:ffff:ffff:ffff:ffff:ffff
23920e9:ee00::/2420e9:eeff:ffff:ffff:ffff:ffff:ffff:ffff
24020e9:ef00::/2420e9:efff:ffff:ffff:ffff:ffff:ffff:ffff
24120e9:f000::/2420e9:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
24220e9:f100::/2420e9:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
24320e9:f200::/2420e9:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
24420e9:f300::/2420e9:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
24520e9:f400::/2420e9:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
24620e9:f500::/2420e9:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
24720e9:f600::/2420e9:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
24820e9:f700::/2420e9:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
24920e9:f800::/2420e9:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
25020e9:f900::/2420e9:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
25120e9:fa00::/2420e9:faff:ffff:ffff:ffff:ffff:ffff:ffff
25220e9:fb00::/2420e9:fbff:ffff:ffff:ffff:ffff:ffff:ffff
25320e9:fc00::/2420e9:fcff:ffff:ffff:ffff:ffff:ffff:ffff
25420e9:fd00::/2420e9:fdff:ffff:ffff:ffff:ffff:ffff:ffff
25520e9:fe00::/2420e9:feff:ffff:ffff:ffff:ffff:ffff:ffff
25620e9:ff00::/2420e9: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.