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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
fcc2::/16
First address
fcc2::
Last address
fcc2: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
fcc2:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
2.c.c.f.ip6.arpa
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

fcc2::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
1fcc2::/24fcc2:ff:ffff:ffff:ffff:ffff:ffff:ffff
2fcc2:100::/24fcc2:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3fcc2:200::/24fcc2:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4fcc2:300::/24fcc2:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5fcc2:400::/24fcc2:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6fcc2:500::/24fcc2:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7fcc2:600::/24fcc2:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8fcc2:700::/24fcc2:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9fcc2:800::/24fcc2:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10fcc2:900::/24fcc2:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11fcc2:a00::/24fcc2:aff:ffff:ffff:ffff:ffff:ffff:ffff
12fcc2:b00::/24fcc2:bff:ffff:ffff:ffff:ffff:ffff:ffff
13fcc2:c00::/24fcc2:cff:ffff:ffff:ffff:ffff:ffff:ffff
14fcc2:d00::/24fcc2:dff:ffff:ffff:ffff:ffff:ffff:ffff
15fcc2:e00::/24fcc2:eff:ffff:ffff:ffff:ffff:ffff:ffff
16fcc2:f00::/24fcc2:fff:ffff:ffff:ffff:ffff:ffff:ffff
17fcc2:1000::/24fcc2:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18fcc2:1100::/24fcc2:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19fcc2:1200::/24fcc2:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20fcc2:1300::/24fcc2:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21fcc2:1400::/24fcc2:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22fcc2:1500::/24fcc2:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23fcc2:1600::/24fcc2:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24fcc2:1700::/24fcc2:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25fcc2:1800::/24fcc2:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26fcc2:1900::/24fcc2:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27fcc2:1a00::/24fcc2:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28fcc2:1b00::/24fcc2:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29fcc2:1c00::/24fcc2:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30fcc2:1d00::/24fcc2:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31fcc2:1e00::/24fcc2:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32fcc2:1f00::/24fcc2:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33fcc2:2000::/24fcc2:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34fcc2:2100::/24fcc2:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35fcc2:2200::/24fcc2:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36fcc2:2300::/24fcc2:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37fcc2:2400::/24fcc2:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38fcc2:2500::/24fcc2:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39fcc2:2600::/24fcc2:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40fcc2:2700::/24fcc2:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41fcc2:2800::/24fcc2:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42fcc2:2900::/24fcc2:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43fcc2:2a00::/24fcc2:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44fcc2:2b00::/24fcc2:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45fcc2:2c00::/24fcc2:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46fcc2:2d00::/24fcc2:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47fcc2:2e00::/24fcc2:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48fcc2:2f00::/24fcc2:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49fcc2:3000::/24fcc2:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50fcc2:3100::/24fcc2:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51fcc2:3200::/24fcc2:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52fcc2:3300::/24fcc2:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53fcc2:3400::/24fcc2:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54fcc2:3500::/24fcc2:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55fcc2:3600::/24fcc2:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56fcc2:3700::/24fcc2:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57fcc2:3800::/24fcc2:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58fcc2:3900::/24fcc2:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59fcc2:3a00::/24fcc2:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60fcc2:3b00::/24fcc2:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61fcc2:3c00::/24fcc2:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62fcc2:3d00::/24fcc2:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63fcc2:3e00::/24fcc2:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64fcc2:3f00::/24fcc2:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65fcc2:4000::/24fcc2:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66fcc2:4100::/24fcc2:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67fcc2:4200::/24fcc2:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68fcc2:4300::/24fcc2:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69fcc2:4400::/24fcc2:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70fcc2:4500::/24fcc2:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71fcc2:4600::/24fcc2:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72fcc2:4700::/24fcc2:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73fcc2:4800::/24fcc2:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74fcc2:4900::/24fcc2:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75fcc2:4a00::/24fcc2:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76fcc2:4b00::/24fcc2:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77fcc2:4c00::/24fcc2:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78fcc2:4d00::/24fcc2:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79fcc2:4e00::/24fcc2:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80fcc2:4f00::/24fcc2:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81fcc2:5000::/24fcc2:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82fcc2:5100::/24fcc2:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83fcc2:5200::/24fcc2:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84fcc2:5300::/24fcc2:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85fcc2:5400::/24fcc2:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86fcc2:5500::/24fcc2:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87fcc2:5600::/24fcc2:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88fcc2:5700::/24fcc2:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89fcc2:5800::/24fcc2:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90fcc2:5900::/24fcc2:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91fcc2:5a00::/24fcc2:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92fcc2:5b00::/24fcc2:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93fcc2:5c00::/24fcc2:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94fcc2:5d00::/24fcc2:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95fcc2:5e00::/24fcc2:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96fcc2:5f00::/24fcc2:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97fcc2:6000::/24fcc2:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98fcc2:6100::/24fcc2:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99fcc2:6200::/24fcc2:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100fcc2:6300::/24fcc2:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101fcc2:6400::/24fcc2:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102fcc2:6500::/24fcc2:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103fcc2:6600::/24fcc2:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104fcc2:6700::/24fcc2:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105fcc2:6800::/24fcc2:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106fcc2:6900::/24fcc2:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107fcc2:6a00::/24fcc2:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108fcc2:6b00::/24fcc2:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109fcc2:6c00::/24fcc2:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110fcc2:6d00::/24fcc2:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111fcc2:6e00::/24fcc2:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112fcc2:6f00::/24fcc2:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113fcc2:7000::/24fcc2:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114fcc2:7100::/24fcc2:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115fcc2:7200::/24fcc2:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116fcc2:7300::/24fcc2:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117fcc2:7400::/24fcc2:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118fcc2:7500::/24fcc2:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119fcc2:7600::/24fcc2:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120fcc2:7700::/24fcc2:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121fcc2:7800::/24fcc2:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122fcc2:7900::/24fcc2:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123fcc2:7a00::/24fcc2:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124fcc2:7b00::/24fcc2:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125fcc2:7c00::/24fcc2:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126fcc2:7d00::/24fcc2:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127fcc2:7e00::/24fcc2:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128fcc2:7f00::/24fcc2:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129fcc2:8000::/24fcc2:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130fcc2:8100::/24fcc2:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131fcc2:8200::/24fcc2:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132fcc2:8300::/24fcc2:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133fcc2:8400::/24fcc2:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134fcc2:8500::/24fcc2:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135fcc2:8600::/24fcc2:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136fcc2:8700::/24fcc2:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137fcc2:8800::/24fcc2:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138fcc2:8900::/24fcc2:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139fcc2:8a00::/24fcc2:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140fcc2:8b00::/24fcc2:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141fcc2:8c00::/24fcc2:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142fcc2:8d00::/24fcc2:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143fcc2:8e00::/24fcc2:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144fcc2:8f00::/24fcc2:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145fcc2:9000::/24fcc2:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146fcc2:9100::/24fcc2:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147fcc2:9200::/24fcc2:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148fcc2:9300::/24fcc2:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149fcc2:9400::/24fcc2:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150fcc2:9500::/24fcc2:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151fcc2:9600::/24fcc2:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152fcc2:9700::/24fcc2:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153fcc2:9800::/24fcc2:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154fcc2:9900::/24fcc2:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155fcc2:9a00::/24fcc2:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156fcc2:9b00::/24fcc2:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157fcc2:9c00::/24fcc2:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158fcc2:9d00::/24fcc2:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159fcc2:9e00::/24fcc2:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160fcc2:9f00::/24fcc2:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161fcc2:a000::/24fcc2:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162fcc2:a100::/24fcc2:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163fcc2:a200::/24fcc2:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164fcc2:a300::/24fcc2:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165fcc2:a400::/24fcc2:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166fcc2:a500::/24fcc2:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167fcc2:a600::/24fcc2:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168fcc2:a700::/24fcc2:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169fcc2:a800::/24fcc2:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170fcc2:a900::/24fcc2:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171fcc2:aa00::/24fcc2:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172fcc2:ab00::/24fcc2:abff:ffff:ffff:ffff:ffff:ffff:ffff
173fcc2:ac00::/24fcc2:acff:ffff:ffff:ffff:ffff:ffff:ffff
174fcc2:ad00::/24fcc2:adff:ffff:ffff:ffff:ffff:ffff:ffff
175fcc2:ae00::/24fcc2:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176fcc2:af00::/24fcc2:afff:ffff:ffff:ffff:ffff:ffff:ffff
177fcc2:b000::/24fcc2:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178fcc2:b100::/24fcc2:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179fcc2:b200::/24fcc2:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180fcc2:b300::/24fcc2:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181fcc2:b400::/24fcc2:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182fcc2:b500::/24fcc2:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183fcc2:b600::/24fcc2:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184fcc2:b700::/24fcc2:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185fcc2:b800::/24fcc2:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186fcc2:b900::/24fcc2:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187fcc2:ba00::/24fcc2:baff:ffff:ffff:ffff:ffff:ffff:ffff
188fcc2:bb00::/24fcc2:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189fcc2:bc00::/24fcc2:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190fcc2:bd00::/24fcc2:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191fcc2:be00::/24fcc2:beff:ffff:ffff:ffff:ffff:ffff:ffff
192fcc2:bf00::/24fcc2:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193fcc2:c000::/24fcc2:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194fcc2:c100::/24fcc2:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195fcc2:c200::/24fcc2:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196fcc2:c300::/24fcc2:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197fcc2:c400::/24fcc2:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198fcc2:c500::/24fcc2:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199fcc2:c600::/24fcc2:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200fcc2:c700::/24fcc2:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201fcc2:c800::/24fcc2:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202fcc2:c900::/24fcc2:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203fcc2:ca00::/24fcc2:caff:ffff:ffff:ffff:ffff:ffff:ffff
204fcc2:cb00::/24fcc2:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205fcc2:cc00::/24fcc2:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206fcc2:cd00::/24fcc2:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207fcc2:ce00::/24fcc2:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208fcc2:cf00::/24fcc2:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209fcc2:d000::/24fcc2:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210fcc2:d100::/24fcc2:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211fcc2:d200::/24fcc2:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212fcc2:d300::/24fcc2:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213fcc2:d400::/24fcc2:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214fcc2:d500::/24fcc2:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215fcc2:d600::/24fcc2:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216fcc2:d700::/24fcc2:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217fcc2:d800::/24fcc2:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218fcc2:d900::/24fcc2:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219fcc2:da00::/24fcc2:daff:ffff:ffff:ffff:ffff:ffff:ffff
220fcc2:db00::/24fcc2:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221fcc2:dc00::/24fcc2:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222fcc2:dd00::/24fcc2:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223fcc2:de00::/24fcc2:deff:ffff:ffff:ffff:ffff:ffff:ffff
224fcc2:df00::/24fcc2:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225fcc2:e000::/24fcc2:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226fcc2:e100::/24fcc2:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227fcc2:e200::/24fcc2:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228fcc2:e300::/24fcc2:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229fcc2:e400::/24fcc2:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230fcc2:e500::/24fcc2:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231fcc2:e600::/24fcc2:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232fcc2:e700::/24fcc2:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233fcc2:e800::/24fcc2:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234fcc2:e900::/24fcc2:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235fcc2:ea00::/24fcc2:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236fcc2:eb00::/24fcc2:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237fcc2:ec00::/24fcc2:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238fcc2:ed00::/24fcc2:edff:ffff:ffff:ffff:ffff:ffff:ffff
239fcc2:ee00::/24fcc2:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240fcc2:ef00::/24fcc2:efff:ffff:ffff:ffff:ffff:ffff:ffff
241fcc2:f000::/24fcc2:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242fcc2:f100::/24fcc2:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243fcc2:f200::/24fcc2:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244fcc2:f300::/24fcc2:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245fcc2:f400::/24fcc2:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246fcc2:f500::/24fcc2:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247fcc2:f600::/24fcc2:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248fcc2:f700::/24fcc2:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249fcc2:f800::/24fcc2:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250fcc2:f900::/24fcc2:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251fcc2:fa00::/24fcc2:faff:ffff:ffff:ffff:ffff:ffff:ffff
252fcc2:fb00::/24fcc2:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253fcc2:fc00::/24fcc2:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254fcc2:fd00::/24fcc2:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255fcc2:fe00::/24fcc2:feff:ffff:ffff:ffff:ffff:ffff:ffff
256fcc2:ff00::/24fcc2: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.