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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
ffa2::/16
First address
ffa2::
Last address
ffa2: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
ffa2:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
2.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)

ffa2::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
1ffa2::/24ffa2:ff:ffff:ffff:ffff:ffff:ffff:ffff
2ffa2:100::/24ffa2:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3ffa2:200::/24ffa2:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4ffa2:300::/24ffa2:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5ffa2:400::/24ffa2:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6ffa2:500::/24ffa2:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7ffa2:600::/24ffa2:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8ffa2:700::/24ffa2:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9ffa2:800::/24ffa2:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10ffa2:900::/24ffa2:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11ffa2:a00::/24ffa2:aff:ffff:ffff:ffff:ffff:ffff:ffff
12ffa2:b00::/24ffa2:bff:ffff:ffff:ffff:ffff:ffff:ffff
13ffa2:c00::/24ffa2:cff:ffff:ffff:ffff:ffff:ffff:ffff
14ffa2:d00::/24ffa2:dff:ffff:ffff:ffff:ffff:ffff:ffff
15ffa2:e00::/24ffa2:eff:ffff:ffff:ffff:ffff:ffff:ffff
16ffa2:f00::/24ffa2:fff:ffff:ffff:ffff:ffff:ffff:ffff
17ffa2:1000::/24ffa2:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18ffa2:1100::/24ffa2:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19ffa2:1200::/24ffa2:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20ffa2:1300::/24ffa2:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21ffa2:1400::/24ffa2:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22ffa2:1500::/24ffa2:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23ffa2:1600::/24ffa2:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24ffa2:1700::/24ffa2:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25ffa2:1800::/24ffa2:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26ffa2:1900::/24ffa2:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27ffa2:1a00::/24ffa2:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28ffa2:1b00::/24ffa2:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29ffa2:1c00::/24ffa2:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30ffa2:1d00::/24ffa2:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31ffa2:1e00::/24ffa2:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32ffa2:1f00::/24ffa2:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33ffa2:2000::/24ffa2:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34ffa2:2100::/24ffa2:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35ffa2:2200::/24ffa2:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36ffa2:2300::/24ffa2:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37ffa2:2400::/24ffa2:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38ffa2:2500::/24ffa2:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39ffa2:2600::/24ffa2:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40ffa2:2700::/24ffa2:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41ffa2:2800::/24ffa2:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42ffa2:2900::/24ffa2:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43ffa2:2a00::/24ffa2:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44ffa2:2b00::/24ffa2:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45ffa2:2c00::/24ffa2:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46ffa2:2d00::/24ffa2:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47ffa2:2e00::/24ffa2:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48ffa2:2f00::/24ffa2:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49ffa2:3000::/24ffa2:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50ffa2:3100::/24ffa2:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51ffa2:3200::/24ffa2:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52ffa2:3300::/24ffa2:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53ffa2:3400::/24ffa2:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54ffa2:3500::/24ffa2:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55ffa2:3600::/24ffa2:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56ffa2:3700::/24ffa2:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57ffa2:3800::/24ffa2:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58ffa2:3900::/24ffa2:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59ffa2:3a00::/24ffa2:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60ffa2:3b00::/24ffa2:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61ffa2:3c00::/24ffa2:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62ffa2:3d00::/24ffa2:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63ffa2:3e00::/24ffa2:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64ffa2:3f00::/24ffa2:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65ffa2:4000::/24ffa2:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66ffa2:4100::/24ffa2:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67ffa2:4200::/24ffa2:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68ffa2:4300::/24ffa2:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69ffa2:4400::/24ffa2:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70ffa2:4500::/24ffa2:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71ffa2:4600::/24ffa2:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72ffa2:4700::/24ffa2:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73ffa2:4800::/24ffa2:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74ffa2:4900::/24ffa2:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75ffa2:4a00::/24ffa2:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76ffa2:4b00::/24ffa2:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77ffa2:4c00::/24ffa2:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78ffa2:4d00::/24ffa2:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79ffa2:4e00::/24ffa2:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80ffa2:4f00::/24ffa2:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81ffa2:5000::/24ffa2:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82ffa2:5100::/24ffa2:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83ffa2:5200::/24ffa2:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84ffa2:5300::/24ffa2:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85ffa2:5400::/24ffa2:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86ffa2:5500::/24ffa2:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87ffa2:5600::/24ffa2:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88ffa2:5700::/24ffa2:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89ffa2:5800::/24ffa2:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90ffa2:5900::/24ffa2:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91ffa2:5a00::/24ffa2:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92ffa2:5b00::/24ffa2:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93ffa2:5c00::/24ffa2:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94ffa2:5d00::/24ffa2:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95ffa2:5e00::/24ffa2:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96ffa2:5f00::/24ffa2:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97ffa2:6000::/24ffa2:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98ffa2:6100::/24ffa2:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99ffa2:6200::/24ffa2:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100ffa2:6300::/24ffa2:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101ffa2:6400::/24ffa2:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102ffa2:6500::/24ffa2:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103ffa2:6600::/24ffa2:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104ffa2:6700::/24ffa2:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105ffa2:6800::/24ffa2:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106ffa2:6900::/24ffa2:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107ffa2:6a00::/24ffa2:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108ffa2:6b00::/24ffa2:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109ffa2:6c00::/24ffa2:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110ffa2:6d00::/24ffa2:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111ffa2:6e00::/24ffa2:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112ffa2:6f00::/24ffa2:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113ffa2:7000::/24ffa2:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114ffa2:7100::/24ffa2:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115ffa2:7200::/24ffa2:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116ffa2:7300::/24ffa2:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117ffa2:7400::/24ffa2:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118ffa2:7500::/24ffa2:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119ffa2:7600::/24ffa2:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120ffa2:7700::/24ffa2:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121ffa2:7800::/24ffa2:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122ffa2:7900::/24ffa2:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123ffa2:7a00::/24ffa2:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124ffa2:7b00::/24ffa2:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125ffa2:7c00::/24ffa2:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126ffa2:7d00::/24ffa2:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127ffa2:7e00::/24ffa2:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128ffa2:7f00::/24ffa2:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129ffa2:8000::/24ffa2:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130ffa2:8100::/24ffa2:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131ffa2:8200::/24ffa2:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132ffa2:8300::/24ffa2:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133ffa2:8400::/24ffa2:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134ffa2:8500::/24ffa2:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135ffa2:8600::/24ffa2:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136ffa2:8700::/24ffa2:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137ffa2:8800::/24ffa2:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138ffa2:8900::/24ffa2:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139ffa2:8a00::/24ffa2:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140ffa2:8b00::/24ffa2:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141ffa2:8c00::/24ffa2:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142ffa2:8d00::/24ffa2:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143ffa2:8e00::/24ffa2:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144ffa2:8f00::/24ffa2:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145ffa2:9000::/24ffa2:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146ffa2:9100::/24ffa2:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147ffa2:9200::/24ffa2:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148ffa2:9300::/24ffa2:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149ffa2:9400::/24ffa2:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150ffa2:9500::/24ffa2:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151ffa2:9600::/24ffa2:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152ffa2:9700::/24ffa2:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153ffa2:9800::/24ffa2:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154ffa2:9900::/24ffa2:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155ffa2:9a00::/24ffa2:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156ffa2:9b00::/24ffa2:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157ffa2:9c00::/24ffa2:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158ffa2:9d00::/24ffa2:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159ffa2:9e00::/24ffa2:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160ffa2:9f00::/24ffa2:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161ffa2:a000::/24ffa2:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162ffa2:a100::/24ffa2:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163ffa2:a200::/24ffa2:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164ffa2:a300::/24ffa2:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165ffa2:a400::/24ffa2:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166ffa2:a500::/24ffa2:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167ffa2:a600::/24ffa2:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168ffa2:a700::/24ffa2:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169ffa2:a800::/24ffa2:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170ffa2:a900::/24ffa2:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171ffa2:aa00::/24ffa2:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172ffa2:ab00::/24ffa2:abff:ffff:ffff:ffff:ffff:ffff:ffff
173ffa2:ac00::/24ffa2:acff:ffff:ffff:ffff:ffff:ffff:ffff
174ffa2:ad00::/24ffa2:adff:ffff:ffff:ffff:ffff:ffff:ffff
175ffa2:ae00::/24ffa2:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176ffa2:af00::/24ffa2:afff:ffff:ffff:ffff:ffff:ffff:ffff
177ffa2:b000::/24ffa2:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178ffa2:b100::/24ffa2:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179ffa2:b200::/24ffa2:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180ffa2:b300::/24ffa2:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181ffa2:b400::/24ffa2:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182ffa2:b500::/24ffa2:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183ffa2:b600::/24ffa2:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184ffa2:b700::/24ffa2:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185ffa2:b800::/24ffa2:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186ffa2:b900::/24ffa2:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187ffa2:ba00::/24ffa2:baff:ffff:ffff:ffff:ffff:ffff:ffff
188ffa2:bb00::/24ffa2:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189ffa2:bc00::/24ffa2:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190ffa2:bd00::/24ffa2:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191ffa2:be00::/24ffa2:beff:ffff:ffff:ffff:ffff:ffff:ffff
192ffa2:bf00::/24ffa2:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193ffa2:c000::/24ffa2:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194ffa2:c100::/24ffa2:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195ffa2:c200::/24ffa2:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196ffa2:c300::/24ffa2:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197ffa2:c400::/24ffa2:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198ffa2:c500::/24ffa2:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199ffa2:c600::/24ffa2:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200ffa2:c700::/24ffa2:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201ffa2:c800::/24ffa2:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202ffa2:c900::/24ffa2:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203ffa2:ca00::/24ffa2:caff:ffff:ffff:ffff:ffff:ffff:ffff
204ffa2:cb00::/24ffa2:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205ffa2:cc00::/24ffa2:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206ffa2:cd00::/24ffa2:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207ffa2:ce00::/24ffa2:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208ffa2:cf00::/24ffa2:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209ffa2:d000::/24ffa2:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210ffa2:d100::/24ffa2:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211ffa2:d200::/24ffa2:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212ffa2:d300::/24ffa2:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213ffa2:d400::/24ffa2:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214ffa2:d500::/24ffa2:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215ffa2:d600::/24ffa2:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216ffa2:d700::/24ffa2:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217ffa2:d800::/24ffa2:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218ffa2:d900::/24ffa2:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219ffa2:da00::/24ffa2:daff:ffff:ffff:ffff:ffff:ffff:ffff
220ffa2:db00::/24ffa2:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221ffa2:dc00::/24ffa2:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222ffa2:dd00::/24ffa2:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223ffa2:de00::/24ffa2:deff:ffff:ffff:ffff:ffff:ffff:ffff
224ffa2:df00::/24ffa2:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225ffa2:e000::/24ffa2:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226ffa2:e100::/24ffa2:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227ffa2:e200::/24ffa2:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228ffa2:e300::/24ffa2:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229ffa2:e400::/24ffa2:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230ffa2:e500::/24ffa2:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231ffa2:e600::/24ffa2:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232ffa2:e700::/24ffa2:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233ffa2:e800::/24ffa2:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234ffa2:e900::/24ffa2:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235ffa2:ea00::/24ffa2:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236ffa2:eb00::/24ffa2:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237ffa2:ec00::/24ffa2:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238ffa2:ed00::/24ffa2:edff:ffff:ffff:ffff:ffff:ffff:ffff
239ffa2:ee00::/24ffa2:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240ffa2:ef00::/24ffa2:efff:ffff:ffff:ffff:ffff:ffff:ffff
241ffa2:f000::/24ffa2:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242ffa2:f100::/24ffa2:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243ffa2:f200::/24ffa2:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244ffa2:f300::/24ffa2:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245ffa2:f400::/24ffa2:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246ffa2:f500::/24ffa2:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247ffa2:f600::/24ffa2:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248ffa2:f700::/24ffa2:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249ffa2:f800::/24ffa2:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250ffa2:f900::/24ffa2:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251ffa2:fa00::/24ffa2:faff:ffff:ffff:ffff:ffff:ffff:ffff
252ffa2:fb00::/24ffa2:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253ffa2:fc00::/24ffa2:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254ffa2:fd00::/24ffa2:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255ffa2:fe00::/24ffa2:feff:ffff:ffff:ffff:ffff:ffff:ffff
256ffa2:ff00::/24ffa2: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.