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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/16
Addresses2^112
/64 networks2^48
Network
fce3::/16
First address
fce3::
Last address
fce3: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
fce3:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
3.e.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)

fce3::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
1fce3::/24fce3:ff:ffff:ffff:ffff:ffff:ffff:ffff
2fce3:100::/24fce3:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3fce3:200::/24fce3:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4fce3:300::/24fce3:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5fce3:400::/24fce3:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6fce3:500::/24fce3:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7fce3:600::/24fce3:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8fce3:700::/24fce3:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9fce3:800::/24fce3:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10fce3:900::/24fce3:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11fce3:a00::/24fce3:aff:ffff:ffff:ffff:ffff:ffff:ffff
12fce3:b00::/24fce3:bff:ffff:ffff:ffff:ffff:ffff:ffff
13fce3:c00::/24fce3:cff:ffff:ffff:ffff:ffff:ffff:ffff
14fce3:d00::/24fce3:dff:ffff:ffff:ffff:ffff:ffff:ffff
15fce3:e00::/24fce3:eff:ffff:ffff:ffff:ffff:ffff:ffff
16fce3:f00::/24fce3:fff:ffff:ffff:ffff:ffff:ffff:ffff
17fce3:1000::/24fce3:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18fce3:1100::/24fce3:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19fce3:1200::/24fce3:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20fce3:1300::/24fce3:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21fce3:1400::/24fce3:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22fce3:1500::/24fce3:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23fce3:1600::/24fce3:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24fce3:1700::/24fce3:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25fce3:1800::/24fce3:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26fce3:1900::/24fce3:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27fce3:1a00::/24fce3:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28fce3:1b00::/24fce3:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29fce3:1c00::/24fce3:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30fce3:1d00::/24fce3:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31fce3:1e00::/24fce3:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32fce3:1f00::/24fce3:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33fce3:2000::/24fce3:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34fce3:2100::/24fce3:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35fce3:2200::/24fce3:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36fce3:2300::/24fce3:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37fce3:2400::/24fce3:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38fce3:2500::/24fce3:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39fce3:2600::/24fce3:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40fce3:2700::/24fce3:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41fce3:2800::/24fce3:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42fce3:2900::/24fce3:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43fce3:2a00::/24fce3:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44fce3:2b00::/24fce3:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45fce3:2c00::/24fce3:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46fce3:2d00::/24fce3:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47fce3:2e00::/24fce3:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48fce3:2f00::/24fce3:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49fce3:3000::/24fce3:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50fce3:3100::/24fce3:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51fce3:3200::/24fce3:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52fce3:3300::/24fce3:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53fce3:3400::/24fce3:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54fce3:3500::/24fce3:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55fce3:3600::/24fce3:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56fce3:3700::/24fce3:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57fce3:3800::/24fce3:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58fce3:3900::/24fce3:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59fce3:3a00::/24fce3:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60fce3:3b00::/24fce3:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61fce3:3c00::/24fce3:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62fce3:3d00::/24fce3:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63fce3:3e00::/24fce3:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64fce3:3f00::/24fce3:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65fce3:4000::/24fce3:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66fce3:4100::/24fce3:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67fce3:4200::/24fce3:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68fce3:4300::/24fce3:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69fce3:4400::/24fce3:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70fce3:4500::/24fce3:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71fce3:4600::/24fce3:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72fce3:4700::/24fce3:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73fce3:4800::/24fce3:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74fce3:4900::/24fce3:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75fce3:4a00::/24fce3:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76fce3:4b00::/24fce3:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77fce3:4c00::/24fce3:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78fce3:4d00::/24fce3:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79fce3:4e00::/24fce3:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80fce3:4f00::/24fce3:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81fce3:5000::/24fce3:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82fce3:5100::/24fce3:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83fce3:5200::/24fce3:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84fce3:5300::/24fce3:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85fce3:5400::/24fce3:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86fce3:5500::/24fce3:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87fce3:5600::/24fce3:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88fce3:5700::/24fce3:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89fce3:5800::/24fce3:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90fce3:5900::/24fce3:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91fce3:5a00::/24fce3:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92fce3:5b00::/24fce3:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93fce3:5c00::/24fce3:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94fce3:5d00::/24fce3:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95fce3:5e00::/24fce3:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96fce3:5f00::/24fce3:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97fce3:6000::/24fce3:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98fce3:6100::/24fce3:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99fce3:6200::/24fce3:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100fce3:6300::/24fce3:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101fce3:6400::/24fce3:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102fce3:6500::/24fce3:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103fce3:6600::/24fce3:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104fce3:6700::/24fce3:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105fce3:6800::/24fce3:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106fce3:6900::/24fce3:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107fce3:6a00::/24fce3:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108fce3:6b00::/24fce3:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109fce3:6c00::/24fce3:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110fce3:6d00::/24fce3:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111fce3:6e00::/24fce3:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112fce3:6f00::/24fce3:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113fce3:7000::/24fce3:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114fce3:7100::/24fce3:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115fce3:7200::/24fce3:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116fce3:7300::/24fce3:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117fce3:7400::/24fce3:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118fce3:7500::/24fce3:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119fce3:7600::/24fce3:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120fce3:7700::/24fce3:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121fce3:7800::/24fce3:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122fce3:7900::/24fce3:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123fce3:7a00::/24fce3:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124fce3:7b00::/24fce3:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125fce3:7c00::/24fce3:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126fce3:7d00::/24fce3:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127fce3:7e00::/24fce3:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128fce3:7f00::/24fce3:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129fce3:8000::/24fce3:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130fce3:8100::/24fce3:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131fce3:8200::/24fce3:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132fce3:8300::/24fce3:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133fce3:8400::/24fce3:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134fce3:8500::/24fce3:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135fce3:8600::/24fce3:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136fce3:8700::/24fce3:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137fce3:8800::/24fce3:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138fce3:8900::/24fce3:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139fce3:8a00::/24fce3:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140fce3:8b00::/24fce3:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141fce3:8c00::/24fce3:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142fce3:8d00::/24fce3:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143fce3:8e00::/24fce3:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144fce3:8f00::/24fce3:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145fce3:9000::/24fce3:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146fce3:9100::/24fce3:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147fce3:9200::/24fce3:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148fce3:9300::/24fce3:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149fce3:9400::/24fce3:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150fce3:9500::/24fce3:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151fce3:9600::/24fce3:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152fce3:9700::/24fce3:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153fce3:9800::/24fce3:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154fce3:9900::/24fce3:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155fce3:9a00::/24fce3:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156fce3:9b00::/24fce3:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157fce3:9c00::/24fce3:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158fce3:9d00::/24fce3:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159fce3:9e00::/24fce3:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160fce3:9f00::/24fce3:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161fce3:a000::/24fce3:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162fce3:a100::/24fce3:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163fce3:a200::/24fce3:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164fce3:a300::/24fce3:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165fce3:a400::/24fce3:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166fce3:a500::/24fce3:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167fce3:a600::/24fce3:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168fce3:a700::/24fce3:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169fce3:a800::/24fce3:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170fce3:a900::/24fce3:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171fce3:aa00::/24fce3:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172fce3:ab00::/24fce3:abff:ffff:ffff:ffff:ffff:ffff:ffff
173fce3:ac00::/24fce3:acff:ffff:ffff:ffff:ffff:ffff:ffff
174fce3:ad00::/24fce3:adff:ffff:ffff:ffff:ffff:ffff:ffff
175fce3:ae00::/24fce3:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176fce3:af00::/24fce3:afff:ffff:ffff:ffff:ffff:ffff:ffff
177fce3:b000::/24fce3:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178fce3:b100::/24fce3:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179fce3:b200::/24fce3:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180fce3:b300::/24fce3:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181fce3:b400::/24fce3:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182fce3:b500::/24fce3:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183fce3:b600::/24fce3:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184fce3:b700::/24fce3:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185fce3:b800::/24fce3:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186fce3:b900::/24fce3:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187fce3:ba00::/24fce3:baff:ffff:ffff:ffff:ffff:ffff:ffff
188fce3:bb00::/24fce3:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189fce3:bc00::/24fce3:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190fce3:bd00::/24fce3:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191fce3:be00::/24fce3:beff:ffff:ffff:ffff:ffff:ffff:ffff
192fce3:bf00::/24fce3:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193fce3:c000::/24fce3:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194fce3:c100::/24fce3:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195fce3:c200::/24fce3:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196fce3:c300::/24fce3:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197fce3:c400::/24fce3:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198fce3:c500::/24fce3:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199fce3:c600::/24fce3:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200fce3:c700::/24fce3:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201fce3:c800::/24fce3:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202fce3:c900::/24fce3:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203fce3:ca00::/24fce3:caff:ffff:ffff:ffff:ffff:ffff:ffff
204fce3:cb00::/24fce3:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205fce3:cc00::/24fce3:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206fce3:cd00::/24fce3:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207fce3:ce00::/24fce3:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208fce3:cf00::/24fce3:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209fce3:d000::/24fce3:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210fce3:d100::/24fce3:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211fce3:d200::/24fce3:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212fce3:d300::/24fce3:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213fce3:d400::/24fce3:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214fce3:d500::/24fce3:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215fce3:d600::/24fce3:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216fce3:d700::/24fce3:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217fce3:d800::/24fce3:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218fce3:d900::/24fce3:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219fce3:da00::/24fce3:daff:ffff:ffff:ffff:ffff:ffff:ffff
220fce3:db00::/24fce3:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221fce3:dc00::/24fce3:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222fce3:dd00::/24fce3:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223fce3:de00::/24fce3:deff:ffff:ffff:ffff:ffff:ffff:ffff
224fce3:df00::/24fce3:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225fce3:e000::/24fce3:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226fce3:e100::/24fce3:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227fce3:e200::/24fce3:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228fce3:e300::/24fce3:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229fce3:e400::/24fce3:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230fce3:e500::/24fce3:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231fce3:e600::/24fce3:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232fce3:e700::/24fce3:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233fce3:e800::/24fce3:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234fce3:e900::/24fce3:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235fce3:ea00::/24fce3:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236fce3:eb00::/24fce3:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237fce3:ec00::/24fce3:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238fce3:ed00::/24fce3:edff:ffff:ffff:ffff:ffff:ffff:ffff
239fce3:ee00::/24fce3:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240fce3:ef00::/24fce3:efff:ffff:ffff:ffff:ffff:ffff:ffff
241fce3:f000::/24fce3:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242fce3:f100::/24fce3:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243fce3:f200::/24fce3:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244fce3:f300::/24fce3:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245fce3:f400::/24fce3:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246fce3:f500::/24fce3:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247fce3:f600::/24fce3:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248fce3:f700::/24fce3:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249fce3:f800::/24fce3:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250fce3:f900::/24fce3:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251fce3:fa00::/24fce3:faff:ffff:ffff:ffff:ffff:ffff:ffff
252fce3:fb00::/24fce3:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253fce3:fc00::/24fce3:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254fce3:fd00::/24fce3:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255fce3:fe00::/24fce3:feff:ffff:ffff:ffff:ffff:ffff:ffff
256fce3:ff00::/24fce3: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.