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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
ff44::/16
First address
ff44::
Last address
ff44: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
ff44:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
4.4.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)

ff44::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
1ff44::/24ff44:ff:ffff:ffff:ffff:ffff:ffff:ffff
2ff44:100::/24ff44:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3ff44:200::/24ff44:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4ff44:300::/24ff44:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5ff44:400::/24ff44:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6ff44:500::/24ff44:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7ff44:600::/24ff44:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8ff44:700::/24ff44:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9ff44:800::/24ff44:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10ff44:900::/24ff44:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11ff44:a00::/24ff44:aff:ffff:ffff:ffff:ffff:ffff:ffff
12ff44:b00::/24ff44:bff:ffff:ffff:ffff:ffff:ffff:ffff
13ff44:c00::/24ff44:cff:ffff:ffff:ffff:ffff:ffff:ffff
14ff44:d00::/24ff44:dff:ffff:ffff:ffff:ffff:ffff:ffff
15ff44:e00::/24ff44:eff:ffff:ffff:ffff:ffff:ffff:ffff
16ff44:f00::/24ff44:fff:ffff:ffff:ffff:ffff:ffff:ffff
17ff44:1000::/24ff44:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18ff44:1100::/24ff44:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19ff44:1200::/24ff44:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20ff44:1300::/24ff44:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21ff44:1400::/24ff44:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22ff44:1500::/24ff44:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23ff44:1600::/24ff44:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24ff44:1700::/24ff44:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25ff44:1800::/24ff44:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26ff44:1900::/24ff44:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27ff44:1a00::/24ff44:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28ff44:1b00::/24ff44:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29ff44:1c00::/24ff44:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30ff44:1d00::/24ff44:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31ff44:1e00::/24ff44:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32ff44:1f00::/24ff44:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33ff44:2000::/24ff44:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34ff44:2100::/24ff44:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35ff44:2200::/24ff44:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36ff44:2300::/24ff44:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37ff44:2400::/24ff44:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38ff44:2500::/24ff44:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39ff44:2600::/24ff44:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40ff44:2700::/24ff44:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41ff44:2800::/24ff44:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42ff44:2900::/24ff44:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43ff44:2a00::/24ff44:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44ff44:2b00::/24ff44:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45ff44:2c00::/24ff44:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46ff44:2d00::/24ff44:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47ff44:2e00::/24ff44:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48ff44:2f00::/24ff44:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49ff44:3000::/24ff44:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50ff44:3100::/24ff44:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51ff44:3200::/24ff44:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52ff44:3300::/24ff44:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53ff44:3400::/24ff44:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54ff44:3500::/24ff44:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55ff44:3600::/24ff44:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56ff44:3700::/24ff44:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57ff44:3800::/24ff44:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58ff44:3900::/24ff44:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59ff44:3a00::/24ff44:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60ff44:3b00::/24ff44:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61ff44:3c00::/24ff44:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62ff44:3d00::/24ff44:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63ff44:3e00::/24ff44:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64ff44:3f00::/24ff44:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65ff44:4000::/24ff44:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66ff44:4100::/24ff44:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67ff44:4200::/24ff44:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68ff44:4300::/24ff44:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69ff44:4400::/24ff44:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70ff44:4500::/24ff44:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71ff44:4600::/24ff44:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72ff44:4700::/24ff44:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73ff44:4800::/24ff44:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74ff44:4900::/24ff44:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75ff44:4a00::/24ff44:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76ff44:4b00::/24ff44:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77ff44:4c00::/24ff44:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78ff44:4d00::/24ff44:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79ff44:4e00::/24ff44:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80ff44:4f00::/24ff44:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81ff44:5000::/24ff44:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82ff44:5100::/24ff44:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83ff44:5200::/24ff44:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84ff44:5300::/24ff44:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85ff44:5400::/24ff44:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86ff44:5500::/24ff44:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87ff44:5600::/24ff44:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88ff44:5700::/24ff44:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89ff44:5800::/24ff44:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90ff44:5900::/24ff44:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91ff44:5a00::/24ff44:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92ff44:5b00::/24ff44:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93ff44:5c00::/24ff44:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94ff44:5d00::/24ff44:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95ff44:5e00::/24ff44:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96ff44:5f00::/24ff44:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97ff44:6000::/24ff44:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98ff44:6100::/24ff44:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99ff44:6200::/24ff44:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100ff44:6300::/24ff44:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101ff44:6400::/24ff44:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102ff44:6500::/24ff44:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103ff44:6600::/24ff44:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104ff44:6700::/24ff44:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105ff44:6800::/24ff44:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106ff44:6900::/24ff44:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107ff44:6a00::/24ff44:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108ff44:6b00::/24ff44:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109ff44:6c00::/24ff44:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110ff44:6d00::/24ff44:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111ff44:6e00::/24ff44:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112ff44:6f00::/24ff44:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113ff44:7000::/24ff44:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114ff44:7100::/24ff44:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115ff44:7200::/24ff44:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116ff44:7300::/24ff44:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117ff44:7400::/24ff44:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118ff44:7500::/24ff44:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119ff44:7600::/24ff44:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120ff44:7700::/24ff44:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121ff44:7800::/24ff44:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122ff44:7900::/24ff44:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123ff44:7a00::/24ff44:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124ff44:7b00::/24ff44:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125ff44:7c00::/24ff44:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126ff44:7d00::/24ff44:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127ff44:7e00::/24ff44:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128ff44:7f00::/24ff44:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129ff44:8000::/24ff44:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130ff44:8100::/24ff44:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131ff44:8200::/24ff44:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132ff44:8300::/24ff44:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133ff44:8400::/24ff44:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134ff44:8500::/24ff44:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135ff44:8600::/24ff44:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136ff44:8700::/24ff44:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137ff44:8800::/24ff44:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138ff44:8900::/24ff44:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139ff44:8a00::/24ff44:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140ff44:8b00::/24ff44:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141ff44:8c00::/24ff44:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142ff44:8d00::/24ff44:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143ff44:8e00::/24ff44:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144ff44:8f00::/24ff44:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145ff44:9000::/24ff44:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146ff44:9100::/24ff44:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147ff44:9200::/24ff44:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148ff44:9300::/24ff44:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149ff44:9400::/24ff44:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150ff44:9500::/24ff44:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151ff44:9600::/24ff44:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152ff44:9700::/24ff44:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153ff44:9800::/24ff44:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154ff44:9900::/24ff44:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155ff44:9a00::/24ff44:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156ff44:9b00::/24ff44:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157ff44:9c00::/24ff44:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158ff44:9d00::/24ff44:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159ff44:9e00::/24ff44:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160ff44:9f00::/24ff44:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161ff44:a000::/24ff44:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162ff44:a100::/24ff44:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163ff44:a200::/24ff44:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164ff44:a300::/24ff44:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165ff44:a400::/24ff44:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166ff44:a500::/24ff44:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167ff44:a600::/24ff44:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168ff44:a700::/24ff44:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169ff44:a800::/24ff44:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170ff44:a900::/24ff44:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171ff44:aa00::/24ff44:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172ff44:ab00::/24ff44:abff:ffff:ffff:ffff:ffff:ffff:ffff
173ff44:ac00::/24ff44:acff:ffff:ffff:ffff:ffff:ffff:ffff
174ff44:ad00::/24ff44:adff:ffff:ffff:ffff:ffff:ffff:ffff
175ff44:ae00::/24ff44:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176ff44:af00::/24ff44:afff:ffff:ffff:ffff:ffff:ffff:ffff
177ff44:b000::/24ff44:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178ff44:b100::/24ff44:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179ff44:b200::/24ff44:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180ff44:b300::/24ff44:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181ff44:b400::/24ff44:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182ff44:b500::/24ff44:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183ff44:b600::/24ff44:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184ff44:b700::/24ff44:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185ff44:b800::/24ff44:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186ff44:b900::/24ff44:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187ff44:ba00::/24ff44:baff:ffff:ffff:ffff:ffff:ffff:ffff
188ff44:bb00::/24ff44:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189ff44:bc00::/24ff44:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190ff44:bd00::/24ff44:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191ff44:be00::/24ff44:beff:ffff:ffff:ffff:ffff:ffff:ffff
192ff44:bf00::/24ff44:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193ff44:c000::/24ff44:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194ff44:c100::/24ff44:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195ff44:c200::/24ff44:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196ff44:c300::/24ff44:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197ff44:c400::/24ff44:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198ff44:c500::/24ff44:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199ff44:c600::/24ff44:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200ff44:c700::/24ff44:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201ff44:c800::/24ff44:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202ff44:c900::/24ff44:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203ff44:ca00::/24ff44:caff:ffff:ffff:ffff:ffff:ffff:ffff
204ff44:cb00::/24ff44:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205ff44:cc00::/24ff44:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206ff44:cd00::/24ff44:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207ff44:ce00::/24ff44:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208ff44:cf00::/24ff44:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209ff44:d000::/24ff44:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210ff44:d100::/24ff44:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211ff44:d200::/24ff44:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212ff44:d300::/24ff44:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213ff44:d400::/24ff44:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214ff44:d500::/24ff44:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215ff44:d600::/24ff44:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216ff44:d700::/24ff44:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217ff44:d800::/24ff44:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218ff44:d900::/24ff44:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219ff44:da00::/24ff44:daff:ffff:ffff:ffff:ffff:ffff:ffff
220ff44:db00::/24ff44:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221ff44:dc00::/24ff44:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222ff44:dd00::/24ff44:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223ff44:de00::/24ff44:deff:ffff:ffff:ffff:ffff:ffff:ffff
224ff44:df00::/24ff44:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225ff44:e000::/24ff44:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226ff44:e100::/24ff44:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227ff44:e200::/24ff44:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228ff44:e300::/24ff44:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229ff44:e400::/24ff44:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230ff44:e500::/24ff44:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231ff44:e600::/24ff44:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232ff44:e700::/24ff44:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233ff44:e800::/24ff44:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234ff44:e900::/24ff44:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235ff44:ea00::/24ff44:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236ff44:eb00::/24ff44:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237ff44:ec00::/24ff44:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238ff44:ed00::/24ff44:edff:ffff:ffff:ffff:ffff:ffff:ffff
239ff44:ee00::/24ff44:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240ff44:ef00::/24ff44:efff:ffff:ffff:ffff:ffff:ffff:ffff
241ff44:f000::/24ff44:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242ff44:f100::/24ff44:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243ff44:f200::/24ff44:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244ff44:f300::/24ff44:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245ff44:f400::/24ff44:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246ff44:f500::/24ff44:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247ff44:f600::/24ff44:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248ff44:f700::/24ff44:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249ff44:f800::/24ff44:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250ff44:f900::/24ff44:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251ff44:fa00::/24ff44:faff:ffff:ffff:ffff:ffff:ffff:ffff
252ff44:fb00::/24ff44:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253ff44:fc00::/24ff44:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254ff44:fd00::/24ff44:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255ff44:fe00::/24ff44:feff:ffff:ffff:ffff:ffff:ffff:ffff
256ff44:ff00::/24ff44: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.