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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
ffd0::/12
First address
ffd0::
Last address
ffdf: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
ffd0:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
d.f.f.ip6.arpa
Split into smaller subnets/24
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

ffd0::/12 makes 4,096 subnets of /24; the first 256 are listed.

Subnets
#SubnetLast address
1ffd0::/24ffd0:ff:ffff:ffff:ffff:ffff:ffff:ffff
2ffd0:100::/24ffd0:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3ffd0:200::/24ffd0:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4ffd0:300::/24ffd0:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5ffd0:400::/24ffd0:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6ffd0:500::/24ffd0:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7ffd0:600::/24ffd0:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8ffd0:700::/24ffd0:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9ffd0:800::/24ffd0:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10ffd0:900::/24ffd0:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11ffd0:a00::/24ffd0:aff:ffff:ffff:ffff:ffff:ffff:ffff
12ffd0:b00::/24ffd0:bff:ffff:ffff:ffff:ffff:ffff:ffff
13ffd0:c00::/24ffd0:cff:ffff:ffff:ffff:ffff:ffff:ffff
14ffd0:d00::/24ffd0:dff:ffff:ffff:ffff:ffff:ffff:ffff
15ffd0:e00::/24ffd0:eff:ffff:ffff:ffff:ffff:ffff:ffff
16ffd0:f00::/24ffd0:fff:ffff:ffff:ffff:ffff:ffff:ffff
17ffd0:1000::/24ffd0:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18ffd0:1100::/24ffd0:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19ffd0:1200::/24ffd0:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20ffd0:1300::/24ffd0:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21ffd0:1400::/24ffd0:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22ffd0:1500::/24ffd0:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23ffd0:1600::/24ffd0:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24ffd0:1700::/24ffd0:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25ffd0:1800::/24ffd0:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26ffd0:1900::/24ffd0:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27ffd0:1a00::/24ffd0:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28ffd0:1b00::/24ffd0:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29ffd0:1c00::/24ffd0:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30ffd0:1d00::/24ffd0:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31ffd0:1e00::/24ffd0:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32ffd0:1f00::/24ffd0:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33ffd0:2000::/24ffd0:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34ffd0:2100::/24ffd0:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35ffd0:2200::/24ffd0:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36ffd0:2300::/24ffd0:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37ffd0:2400::/24ffd0:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38ffd0:2500::/24ffd0:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39ffd0:2600::/24ffd0:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40ffd0:2700::/24ffd0:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41ffd0:2800::/24ffd0:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42ffd0:2900::/24ffd0:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43ffd0:2a00::/24ffd0:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44ffd0:2b00::/24ffd0:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45ffd0:2c00::/24ffd0:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46ffd0:2d00::/24ffd0:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47ffd0:2e00::/24ffd0:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48ffd0:2f00::/24ffd0:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49ffd0:3000::/24ffd0:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50ffd0:3100::/24ffd0:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51ffd0:3200::/24ffd0:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52ffd0:3300::/24ffd0:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53ffd0:3400::/24ffd0:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54ffd0:3500::/24ffd0:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55ffd0:3600::/24ffd0:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56ffd0:3700::/24ffd0:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57ffd0:3800::/24ffd0:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58ffd0:3900::/24ffd0:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59ffd0:3a00::/24ffd0:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60ffd0:3b00::/24ffd0:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61ffd0:3c00::/24ffd0:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62ffd0:3d00::/24ffd0:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63ffd0:3e00::/24ffd0:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64ffd0:3f00::/24ffd0:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65ffd0:4000::/24ffd0:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66ffd0:4100::/24ffd0:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67ffd0:4200::/24ffd0:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68ffd0:4300::/24ffd0:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69ffd0:4400::/24ffd0:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70ffd0:4500::/24ffd0:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71ffd0:4600::/24ffd0:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72ffd0:4700::/24ffd0:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73ffd0:4800::/24ffd0:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74ffd0:4900::/24ffd0:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75ffd0:4a00::/24ffd0:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76ffd0:4b00::/24ffd0:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77ffd0:4c00::/24ffd0:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78ffd0:4d00::/24ffd0:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79ffd0:4e00::/24ffd0:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80ffd0:4f00::/24ffd0:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81ffd0:5000::/24ffd0:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82ffd0:5100::/24ffd0:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83ffd0:5200::/24ffd0:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84ffd0:5300::/24ffd0:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85ffd0:5400::/24ffd0:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86ffd0:5500::/24ffd0:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87ffd0:5600::/24ffd0:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88ffd0:5700::/24ffd0:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89ffd0:5800::/24ffd0:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90ffd0:5900::/24ffd0:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91ffd0:5a00::/24ffd0:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92ffd0:5b00::/24ffd0:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93ffd0:5c00::/24ffd0:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94ffd0:5d00::/24ffd0:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95ffd0:5e00::/24ffd0:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96ffd0:5f00::/24ffd0:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97ffd0:6000::/24ffd0:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98ffd0:6100::/24ffd0:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99ffd0:6200::/24ffd0:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100ffd0:6300::/24ffd0:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101ffd0:6400::/24ffd0:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102ffd0:6500::/24ffd0:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103ffd0:6600::/24ffd0:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104ffd0:6700::/24ffd0:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105ffd0:6800::/24ffd0:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106ffd0:6900::/24ffd0:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107ffd0:6a00::/24ffd0:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108ffd0:6b00::/24ffd0:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109ffd0:6c00::/24ffd0:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110ffd0:6d00::/24ffd0:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111ffd0:6e00::/24ffd0:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112ffd0:6f00::/24ffd0:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113ffd0:7000::/24ffd0:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114ffd0:7100::/24ffd0:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115ffd0:7200::/24ffd0:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116ffd0:7300::/24ffd0:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117ffd0:7400::/24ffd0:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118ffd0:7500::/24ffd0:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119ffd0:7600::/24ffd0:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120ffd0:7700::/24ffd0:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121ffd0:7800::/24ffd0:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122ffd0:7900::/24ffd0:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123ffd0:7a00::/24ffd0:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124ffd0:7b00::/24ffd0:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125ffd0:7c00::/24ffd0:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126ffd0:7d00::/24ffd0:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127ffd0:7e00::/24ffd0:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128ffd0:7f00::/24ffd0:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129ffd0:8000::/24ffd0:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130ffd0:8100::/24ffd0:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131ffd0:8200::/24ffd0:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132ffd0:8300::/24ffd0:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133ffd0:8400::/24ffd0:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134ffd0:8500::/24ffd0:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135ffd0:8600::/24ffd0:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136ffd0:8700::/24ffd0:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137ffd0:8800::/24ffd0:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138ffd0:8900::/24ffd0:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139ffd0:8a00::/24ffd0:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140ffd0:8b00::/24ffd0:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141ffd0:8c00::/24ffd0:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142ffd0:8d00::/24ffd0:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143ffd0:8e00::/24ffd0:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144ffd0:8f00::/24ffd0:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145ffd0:9000::/24ffd0:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146ffd0:9100::/24ffd0:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147ffd0:9200::/24ffd0:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148ffd0:9300::/24ffd0:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149ffd0:9400::/24ffd0:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150ffd0:9500::/24ffd0:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151ffd0:9600::/24ffd0:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152ffd0:9700::/24ffd0:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153ffd0:9800::/24ffd0:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154ffd0:9900::/24ffd0:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155ffd0:9a00::/24ffd0:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156ffd0:9b00::/24ffd0:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157ffd0:9c00::/24ffd0:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158ffd0:9d00::/24ffd0:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159ffd0:9e00::/24ffd0:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160ffd0:9f00::/24ffd0:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161ffd0:a000::/24ffd0:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162ffd0:a100::/24ffd0:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163ffd0:a200::/24ffd0:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164ffd0:a300::/24ffd0:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165ffd0:a400::/24ffd0:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166ffd0:a500::/24ffd0:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167ffd0:a600::/24ffd0:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168ffd0:a700::/24ffd0:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169ffd0:a800::/24ffd0:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170ffd0:a900::/24ffd0:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171ffd0:aa00::/24ffd0:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172ffd0:ab00::/24ffd0:abff:ffff:ffff:ffff:ffff:ffff:ffff
173ffd0:ac00::/24ffd0:acff:ffff:ffff:ffff:ffff:ffff:ffff
174ffd0:ad00::/24ffd0:adff:ffff:ffff:ffff:ffff:ffff:ffff
175ffd0:ae00::/24ffd0:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176ffd0:af00::/24ffd0:afff:ffff:ffff:ffff:ffff:ffff:ffff
177ffd0:b000::/24ffd0:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178ffd0:b100::/24ffd0:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179ffd0:b200::/24ffd0:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180ffd0:b300::/24ffd0:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181ffd0:b400::/24ffd0:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182ffd0:b500::/24ffd0:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183ffd0:b600::/24ffd0:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184ffd0:b700::/24ffd0:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185ffd0:b800::/24ffd0:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186ffd0:b900::/24ffd0:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187ffd0:ba00::/24ffd0:baff:ffff:ffff:ffff:ffff:ffff:ffff
188ffd0:bb00::/24ffd0:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189ffd0:bc00::/24ffd0:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190ffd0:bd00::/24ffd0:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191ffd0:be00::/24ffd0:beff:ffff:ffff:ffff:ffff:ffff:ffff
192ffd0:bf00::/24ffd0:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193ffd0:c000::/24ffd0:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194ffd0:c100::/24ffd0:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195ffd0:c200::/24ffd0:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196ffd0:c300::/24ffd0:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197ffd0:c400::/24ffd0:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198ffd0:c500::/24ffd0:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199ffd0:c600::/24ffd0:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200ffd0:c700::/24ffd0:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201ffd0:c800::/24ffd0:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202ffd0:c900::/24ffd0:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203ffd0:ca00::/24ffd0:caff:ffff:ffff:ffff:ffff:ffff:ffff
204ffd0:cb00::/24ffd0:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205ffd0:cc00::/24ffd0:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206ffd0:cd00::/24ffd0:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207ffd0:ce00::/24ffd0:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208ffd0:cf00::/24ffd0:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209ffd0:d000::/24ffd0:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210ffd0:d100::/24ffd0:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211ffd0:d200::/24ffd0:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212ffd0:d300::/24ffd0:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213ffd0:d400::/24ffd0:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214ffd0:d500::/24ffd0:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215ffd0:d600::/24ffd0:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216ffd0:d700::/24ffd0:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217ffd0:d800::/24ffd0:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218ffd0:d900::/24ffd0:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219ffd0:da00::/24ffd0:daff:ffff:ffff:ffff:ffff:ffff:ffff
220ffd0:db00::/24ffd0:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221ffd0:dc00::/24ffd0:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222ffd0:dd00::/24ffd0:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223ffd0:de00::/24ffd0:deff:ffff:ffff:ffff:ffff:ffff:ffff
224ffd0:df00::/24ffd0:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225ffd0:e000::/24ffd0:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226ffd0:e100::/24ffd0:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227ffd0:e200::/24ffd0:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228ffd0:e300::/24ffd0:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229ffd0:e400::/24ffd0:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230ffd0:e500::/24ffd0:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231ffd0:e600::/24ffd0:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232ffd0:e700::/24ffd0:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233ffd0:e800::/24ffd0:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234ffd0:e900::/24ffd0:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235ffd0:ea00::/24ffd0:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236ffd0:eb00::/24ffd0:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237ffd0:ec00::/24ffd0:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238ffd0:ed00::/24ffd0:edff:ffff:ffff:ffff:ffff:ffff:ffff
239ffd0:ee00::/24ffd0:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240ffd0:ef00::/24ffd0:efff:ffff:ffff:ffff:ffff:ffff:ffff
241ffd0:f000::/24ffd0:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242ffd0:f100::/24ffd0:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243ffd0:f200::/24ffd0:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244ffd0:f300::/24ffd0:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245ffd0:f400::/24ffd0:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246ffd0:f500::/24ffd0:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247ffd0:f600::/24ffd0:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248ffd0:f700::/24ffd0:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249ffd0:f800::/24ffd0:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250ffd0:f900::/24ffd0:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251ffd0:fa00::/24ffd0:faff:ffff:ffff:ffff:ffff:ffff:ffff
252ffd0:fb00::/24ffd0:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253ffd0:fc00::/24ffd0:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254ffd0:fd00::/24ffd0:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255ffd0:fe00::/24ffd0:feff:ffff:ffff:ffff:ffff:ffff:ffff
256ffd0:ff00::/24ffd0: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.