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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
ffa0::/16
First address
ffa0::
Last address
ffa0: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
ffa0:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
0.a.f.f.ip6.arpa
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

ffa0::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
1ffa0::/24ffa0:ff:ffff:ffff:ffff:ffff:ffff:ffff
2ffa0:100::/24ffa0:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3ffa0:200::/24ffa0:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4ffa0:300::/24ffa0:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5ffa0:400::/24ffa0:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6ffa0:500::/24ffa0:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7ffa0:600::/24ffa0:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8ffa0:700::/24ffa0:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9ffa0:800::/24ffa0:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10ffa0:900::/24ffa0:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11ffa0:a00::/24ffa0:aff:ffff:ffff:ffff:ffff:ffff:ffff
12ffa0:b00::/24ffa0:bff:ffff:ffff:ffff:ffff:ffff:ffff
13ffa0:c00::/24ffa0:cff:ffff:ffff:ffff:ffff:ffff:ffff
14ffa0:d00::/24ffa0:dff:ffff:ffff:ffff:ffff:ffff:ffff
15ffa0:e00::/24ffa0:eff:ffff:ffff:ffff:ffff:ffff:ffff
16ffa0:f00::/24ffa0:fff:ffff:ffff:ffff:ffff:ffff:ffff
17ffa0:1000::/24ffa0:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18ffa0:1100::/24ffa0:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19ffa0:1200::/24ffa0:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20ffa0:1300::/24ffa0:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21ffa0:1400::/24ffa0:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22ffa0:1500::/24ffa0:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23ffa0:1600::/24ffa0:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24ffa0:1700::/24ffa0:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25ffa0:1800::/24ffa0:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26ffa0:1900::/24ffa0:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27ffa0:1a00::/24ffa0:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28ffa0:1b00::/24ffa0:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29ffa0:1c00::/24ffa0:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30ffa0:1d00::/24ffa0:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31ffa0:1e00::/24ffa0:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32ffa0:1f00::/24ffa0:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33ffa0:2000::/24ffa0:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34ffa0:2100::/24ffa0:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35ffa0:2200::/24ffa0:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36ffa0:2300::/24ffa0:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37ffa0:2400::/24ffa0:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38ffa0:2500::/24ffa0:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39ffa0:2600::/24ffa0:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40ffa0:2700::/24ffa0:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41ffa0:2800::/24ffa0:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42ffa0:2900::/24ffa0:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43ffa0:2a00::/24ffa0:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44ffa0:2b00::/24ffa0:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45ffa0:2c00::/24ffa0:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46ffa0:2d00::/24ffa0:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47ffa0:2e00::/24ffa0:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48ffa0:2f00::/24ffa0:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49ffa0:3000::/24ffa0:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50ffa0:3100::/24ffa0:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51ffa0:3200::/24ffa0:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52ffa0:3300::/24ffa0:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53ffa0:3400::/24ffa0:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54ffa0:3500::/24ffa0:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55ffa0:3600::/24ffa0:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56ffa0:3700::/24ffa0:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57ffa0:3800::/24ffa0:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58ffa0:3900::/24ffa0:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59ffa0:3a00::/24ffa0:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60ffa0:3b00::/24ffa0:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61ffa0:3c00::/24ffa0:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62ffa0:3d00::/24ffa0:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63ffa0:3e00::/24ffa0:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64ffa0:3f00::/24ffa0:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65ffa0:4000::/24ffa0:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66ffa0:4100::/24ffa0:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67ffa0:4200::/24ffa0:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68ffa0:4300::/24ffa0:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69ffa0:4400::/24ffa0:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70ffa0:4500::/24ffa0:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71ffa0:4600::/24ffa0:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72ffa0:4700::/24ffa0:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73ffa0:4800::/24ffa0:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74ffa0:4900::/24ffa0:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75ffa0:4a00::/24ffa0:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76ffa0:4b00::/24ffa0:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77ffa0:4c00::/24ffa0:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78ffa0:4d00::/24ffa0:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79ffa0:4e00::/24ffa0:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80ffa0:4f00::/24ffa0:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81ffa0:5000::/24ffa0:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82ffa0:5100::/24ffa0:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83ffa0:5200::/24ffa0:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84ffa0:5300::/24ffa0:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85ffa0:5400::/24ffa0:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86ffa0:5500::/24ffa0:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87ffa0:5600::/24ffa0:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88ffa0:5700::/24ffa0:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89ffa0:5800::/24ffa0:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90ffa0:5900::/24ffa0:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91ffa0:5a00::/24ffa0:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92ffa0:5b00::/24ffa0:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93ffa0:5c00::/24ffa0:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94ffa0:5d00::/24ffa0:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95ffa0:5e00::/24ffa0:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96ffa0:5f00::/24ffa0:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97ffa0:6000::/24ffa0:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98ffa0:6100::/24ffa0:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99ffa0:6200::/24ffa0:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100ffa0:6300::/24ffa0:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101ffa0:6400::/24ffa0:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102ffa0:6500::/24ffa0:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103ffa0:6600::/24ffa0:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104ffa0:6700::/24ffa0:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105ffa0:6800::/24ffa0:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106ffa0:6900::/24ffa0:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107ffa0:6a00::/24ffa0:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108ffa0:6b00::/24ffa0:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109ffa0:6c00::/24ffa0:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110ffa0:6d00::/24ffa0:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111ffa0:6e00::/24ffa0:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112ffa0:6f00::/24ffa0:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113ffa0:7000::/24ffa0:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114ffa0:7100::/24ffa0:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115ffa0:7200::/24ffa0:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116ffa0:7300::/24ffa0:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117ffa0:7400::/24ffa0:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118ffa0:7500::/24ffa0:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119ffa0:7600::/24ffa0:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120ffa0:7700::/24ffa0:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121ffa0:7800::/24ffa0:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122ffa0:7900::/24ffa0:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123ffa0:7a00::/24ffa0:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124ffa0:7b00::/24ffa0:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125ffa0:7c00::/24ffa0:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126ffa0:7d00::/24ffa0:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127ffa0:7e00::/24ffa0:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128ffa0:7f00::/24ffa0:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129ffa0:8000::/24ffa0:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130ffa0:8100::/24ffa0:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131ffa0:8200::/24ffa0:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132ffa0:8300::/24ffa0:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133ffa0:8400::/24ffa0:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134ffa0:8500::/24ffa0:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135ffa0:8600::/24ffa0:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136ffa0:8700::/24ffa0:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137ffa0:8800::/24ffa0:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138ffa0:8900::/24ffa0:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139ffa0:8a00::/24ffa0:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140ffa0:8b00::/24ffa0:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141ffa0:8c00::/24ffa0:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142ffa0:8d00::/24ffa0:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143ffa0:8e00::/24ffa0:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144ffa0:8f00::/24ffa0:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145ffa0:9000::/24ffa0:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146ffa0:9100::/24ffa0:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147ffa0:9200::/24ffa0:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148ffa0:9300::/24ffa0:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149ffa0:9400::/24ffa0:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150ffa0:9500::/24ffa0:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151ffa0:9600::/24ffa0:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152ffa0:9700::/24ffa0:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153ffa0:9800::/24ffa0:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154ffa0:9900::/24ffa0:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155ffa0:9a00::/24ffa0:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156ffa0:9b00::/24ffa0:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157ffa0:9c00::/24ffa0:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158ffa0:9d00::/24ffa0:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159ffa0:9e00::/24ffa0:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160ffa0:9f00::/24ffa0:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161ffa0:a000::/24ffa0:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162ffa0:a100::/24ffa0:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163ffa0:a200::/24ffa0:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164ffa0:a300::/24ffa0:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165ffa0:a400::/24ffa0:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166ffa0:a500::/24ffa0:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167ffa0:a600::/24ffa0:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168ffa0:a700::/24ffa0:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169ffa0:a800::/24ffa0:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170ffa0:a900::/24ffa0:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171ffa0:aa00::/24ffa0:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172ffa0:ab00::/24ffa0:abff:ffff:ffff:ffff:ffff:ffff:ffff
173ffa0:ac00::/24ffa0:acff:ffff:ffff:ffff:ffff:ffff:ffff
174ffa0:ad00::/24ffa0:adff:ffff:ffff:ffff:ffff:ffff:ffff
175ffa0:ae00::/24ffa0:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176ffa0:af00::/24ffa0:afff:ffff:ffff:ffff:ffff:ffff:ffff
177ffa0:b000::/24ffa0:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178ffa0:b100::/24ffa0:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179ffa0:b200::/24ffa0:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180ffa0:b300::/24ffa0:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181ffa0:b400::/24ffa0:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182ffa0:b500::/24ffa0:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183ffa0:b600::/24ffa0:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184ffa0:b700::/24ffa0:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185ffa0:b800::/24ffa0:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186ffa0:b900::/24ffa0:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187ffa0:ba00::/24ffa0:baff:ffff:ffff:ffff:ffff:ffff:ffff
188ffa0:bb00::/24ffa0:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189ffa0:bc00::/24ffa0:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190ffa0:bd00::/24ffa0:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191ffa0:be00::/24ffa0:beff:ffff:ffff:ffff:ffff:ffff:ffff
192ffa0:bf00::/24ffa0:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193ffa0:c000::/24ffa0:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194ffa0:c100::/24ffa0:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195ffa0:c200::/24ffa0:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196ffa0:c300::/24ffa0:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197ffa0:c400::/24ffa0:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198ffa0:c500::/24ffa0:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199ffa0:c600::/24ffa0:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200ffa0:c700::/24ffa0:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201ffa0:c800::/24ffa0:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202ffa0:c900::/24ffa0:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203ffa0:ca00::/24ffa0:caff:ffff:ffff:ffff:ffff:ffff:ffff
204ffa0:cb00::/24ffa0:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205ffa0:cc00::/24ffa0:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206ffa0:cd00::/24ffa0:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207ffa0:ce00::/24ffa0:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208ffa0:cf00::/24ffa0:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209ffa0:d000::/24ffa0:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210ffa0:d100::/24ffa0:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211ffa0:d200::/24ffa0:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212ffa0:d300::/24ffa0:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213ffa0:d400::/24ffa0:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214ffa0:d500::/24ffa0:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215ffa0:d600::/24ffa0:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216ffa0:d700::/24ffa0:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217ffa0:d800::/24ffa0:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218ffa0:d900::/24ffa0:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219ffa0:da00::/24ffa0:daff:ffff:ffff:ffff:ffff:ffff:ffff
220ffa0:db00::/24ffa0:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221ffa0:dc00::/24ffa0:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222ffa0:dd00::/24ffa0:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223ffa0:de00::/24ffa0:deff:ffff:ffff:ffff:ffff:ffff:ffff
224ffa0:df00::/24ffa0:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225ffa0:e000::/24ffa0:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226ffa0:e100::/24ffa0:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227ffa0:e200::/24ffa0:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228ffa0:e300::/24ffa0:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229ffa0:e400::/24ffa0:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230ffa0:e500::/24ffa0:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231ffa0:e600::/24ffa0:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232ffa0:e700::/24ffa0:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233ffa0:e800::/24ffa0:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234ffa0:e900::/24ffa0:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235ffa0:ea00::/24ffa0:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236ffa0:eb00::/24ffa0:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237ffa0:ec00::/24ffa0:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238ffa0:ed00::/24ffa0:edff:ffff:ffff:ffff:ffff:ffff:ffff
239ffa0:ee00::/24ffa0:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240ffa0:ef00::/24ffa0:efff:ffff:ffff:ffff:ffff:ffff:ffff
241ffa0:f000::/24ffa0:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242ffa0:f100::/24ffa0:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243ffa0:f200::/24ffa0:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244ffa0:f300::/24ffa0:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245ffa0:f400::/24ffa0:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246ffa0:f500::/24ffa0:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247ffa0:f600::/24ffa0:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248ffa0:f700::/24ffa0:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249ffa0:f800::/24ffa0:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250ffa0:f900::/24ffa0:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251ffa0:fa00::/24ffa0:faff:ffff:ffff:ffff:ffff:ffff:ffff
252ffa0:fb00::/24ffa0:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253ffa0:fc00::/24ffa0:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254ffa0:fd00::/24ffa0:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255ffa0:fe00::/24ffa0:feff:ffff:ffff:ffff:ffff:ffff:ffff
256ffa0:ff00::/24ffa0: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.