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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
ff63::/16
First address
ff63::
Last address
ff63: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
ff63:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
3.6.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)

ff63::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
1ff63::/24ff63:ff:ffff:ffff:ffff:ffff:ffff:ffff
2ff63:100::/24ff63:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3ff63:200::/24ff63:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4ff63:300::/24ff63:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5ff63:400::/24ff63:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6ff63:500::/24ff63:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7ff63:600::/24ff63:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8ff63:700::/24ff63:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9ff63:800::/24ff63:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10ff63:900::/24ff63:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11ff63:a00::/24ff63:aff:ffff:ffff:ffff:ffff:ffff:ffff
12ff63:b00::/24ff63:bff:ffff:ffff:ffff:ffff:ffff:ffff
13ff63:c00::/24ff63:cff:ffff:ffff:ffff:ffff:ffff:ffff
14ff63:d00::/24ff63:dff:ffff:ffff:ffff:ffff:ffff:ffff
15ff63:e00::/24ff63:eff:ffff:ffff:ffff:ffff:ffff:ffff
16ff63:f00::/24ff63:fff:ffff:ffff:ffff:ffff:ffff:ffff
17ff63:1000::/24ff63:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18ff63:1100::/24ff63:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19ff63:1200::/24ff63:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20ff63:1300::/24ff63:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21ff63:1400::/24ff63:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22ff63:1500::/24ff63:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23ff63:1600::/24ff63:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24ff63:1700::/24ff63:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25ff63:1800::/24ff63:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26ff63:1900::/24ff63:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27ff63:1a00::/24ff63:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28ff63:1b00::/24ff63:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29ff63:1c00::/24ff63:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30ff63:1d00::/24ff63:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31ff63:1e00::/24ff63:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32ff63:1f00::/24ff63:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33ff63:2000::/24ff63:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34ff63:2100::/24ff63:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35ff63:2200::/24ff63:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36ff63:2300::/24ff63:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37ff63:2400::/24ff63:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38ff63:2500::/24ff63:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39ff63:2600::/24ff63:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40ff63:2700::/24ff63:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41ff63:2800::/24ff63:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42ff63:2900::/24ff63:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43ff63:2a00::/24ff63:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44ff63:2b00::/24ff63:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45ff63:2c00::/24ff63:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46ff63:2d00::/24ff63:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47ff63:2e00::/24ff63:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48ff63:2f00::/24ff63:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49ff63:3000::/24ff63:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50ff63:3100::/24ff63:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51ff63:3200::/24ff63:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52ff63:3300::/24ff63:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53ff63:3400::/24ff63:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54ff63:3500::/24ff63:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55ff63:3600::/24ff63:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56ff63:3700::/24ff63:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57ff63:3800::/24ff63:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58ff63:3900::/24ff63:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59ff63:3a00::/24ff63:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60ff63:3b00::/24ff63:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61ff63:3c00::/24ff63:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62ff63:3d00::/24ff63:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63ff63:3e00::/24ff63:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64ff63:3f00::/24ff63:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65ff63:4000::/24ff63:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66ff63:4100::/24ff63:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67ff63:4200::/24ff63:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68ff63:4300::/24ff63:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69ff63:4400::/24ff63:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70ff63:4500::/24ff63:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71ff63:4600::/24ff63:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72ff63:4700::/24ff63:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73ff63:4800::/24ff63:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74ff63:4900::/24ff63:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75ff63:4a00::/24ff63:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76ff63:4b00::/24ff63:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77ff63:4c00::/24ff63:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78ff63:4d00::/24ff63:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79ff63:4e00::/24ff63:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80ff63:4f00::/24ff63:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81ff63:5000::/24ff63:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82ff63:5100::/24ff63:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83ff63:5200::/24ff63:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84ff63:5300::/24ff63:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85ff63:5400::/24ff63:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86ff63:5500::/24ff63:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87ff63:5600::/24ff63:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88ff63:5700::/24ff63:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89ff63:5800::/24ff63:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90ff63:5900::/24ff63:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91ff63:5a00::/24ff63:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92ff63:5b00::/24ff63:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93ff63:5c00::/24ff63:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94ff63:5d00::/24ff63:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95ff63:5e00::/24ff63:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96ff63:5f00::/24ff63:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97ff63:6000::/24ff63:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98ff63:6100::/24ff63:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99ff63:6200::/24ff63:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100ff63:6300::/24ff63:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101ff63:6400::/24ff63:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102ff63:6500::/24ff63:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103ff63:6600::/24ff63:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104ff63:6700::/24ff63:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105ff63:6800::/24ff63:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106ff63:6900::/24ff63:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107ff63:6a00::/24ff63:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108ff63:6b00::/24ff63:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109ff63:6c00::/24ff63:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110ff63:6d00::/24ff63:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111ff63:6e00::/24ff63:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112ff63:6f00::/24ff63:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113ff63:7000::/24ff63:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114ff63:7100::/24ff63:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115ff63:7200::/24ff63:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116ff63:7300::/24ff63:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117ff63:7400::/24ff63:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118ff63:7500::/24ff63:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119ff63:7600::/24ff63:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120ff63:7700::/24ff63:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121ff63:7800::/24ff63:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122ff63:7900::/24ff63:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123ff63:7a00::/24ff63:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124ff63:7b00::/24ff63:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125ff63:7c00::/24ff63:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126ff63:7d00::/24ff63:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127ff63:7e00::/24ff63:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128ff63:7f00::/24ff63:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129ff63:8000::/24ff63:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130ff63:8100::/24ff63:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131ff63:8200::/24ff63:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132ff63:8300::/24ff63:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133ff63:8400::/24ff63:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134ff63:8500::/24ff63:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135ff63:8600::/24ff63:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136ff63:8700::/24ff63:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137ff63:8800::/24ff63:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138ff63:8900::/24ff63:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139ff63:8a00::/24ff63:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140ff63:8b00::/24ff63:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141ff63:8c00::/24ff63:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142ff63:8d00::/24ff63:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143ff63:8e00::/24ff63:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144ff63:8f00::/24ff63:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145ff63:9000::/24ff63:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146ff63:9100::/24ff63:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147ff63:9200::/24ff63:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148ff63:9300::/24ff63:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149ff63:9400::/24ff63:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150ff63:9500::/24ff63:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151ff63:9600::/24ff63:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152ff63:9700::/24ff63:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153ff63:9800::/24ff63:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154ff63:9900::/24ff63:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155ff63:9a00::/24ff63:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156ff63:9b00::/24ff63:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157ff63:9c00::/24ff63:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158ff63:9d00::/24ff63:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159ff63:9e00::/24ff63:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160ff63:9f00::/24ff63:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161ff63:a000::/24ff63:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162ff63:a100::/24ff63:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163ff63:a200::/24ff63:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164ff63:a300::/24ff63:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165ff63:a400::/24ff63:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166ff63:a500::/24ff63:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167ff63:a600::/24ff63:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168ff63:a700::/24ff63:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169ff63:a800::/24ff63:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170ff63:a900::/24ff63:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171ff63:aa00::/24ff63:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172ff63:ab00::/24ff63:abff:ffff:ffff:ffff:ffff:ffff:ffff
173ff63:ac00::/24ff63:acff:ffff:ffff:ffff:ffff:ffff:ffff
174ff63:ad00::/24ff63:adff:ffff:ffff:ffff:ffff:ffff:ffff
175ff63:ae00::/24ff63:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176ff63:af00::/24ff63:afff:ffff:ffff:ffff:ffff:ffff:ffff
177ff63:b000::/24ff63:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178ff63:b100::/24ff63:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179ff63:b200::/24ff63:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180ff63:b300::/24ff63:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181ff63:b400::/24ff63:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182ff63:b500::/24ff63:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183ff63:b600::/24ff63:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184ff63:b700::/24ff63:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185ff63:b800::/24ff63:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186ff63:b900::/24ff63:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187ff63:ba00::/24ff63:baff:ffff:ffff:ffff:ffff:ffff:ffff
188ff63:bb00::/24ff63:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189ff63:bc00::/24ff63:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190ff63:bd00::/24ff63:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191ff63:be00::/24ff63:beff:ffff:ffff:ffff:ffff:ffff:ffff
192ff63:bf00::/24ff63:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193ff63:c000::/24ff63:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194ff63:c100::/24ff63:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195ff63:c200::/24ff63:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196ff63:c300::/24ff63:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197ff63:c400::/24ff63:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198ff63:c500::/24ff63:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199ff63:c600::/24ff63:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200ff63:c700::/24ff63:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201ff63:c800::/24ff63:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202ff63:c900::/24ff63:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203ff63:ca00::/24ff63:caff:ffff:ffff:ffff:ffff:ffff:ffff
204ff63:cb00::/24ff63:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205ff63:cc00::/24ff63:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206ff63:cd00::/24ff63:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207ff63:ce00::/24ff63:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208ff63:cf00::/24ff63:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209ff63:d000::/24ff63:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210ff63:d100::/24ff63:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211ff63:d200::/24ff63:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212ff63:d300::/24ff63:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213ff63:d400::/24ff63:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214ff63:d500::/24ff63:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215ff63:d600::/24ff63:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216ff63:d700::/24ff63:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217ff63:d800::/24ff63:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218ff63:d900::/24ff63:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219ff63:da00::/24ff63:daff:ffff:ffff:ffff:ffff:ffff:ffff
220ff63:db00::/24ff63:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221ff63:dc00::/24ff63:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222ff63:dd00::/24ff63:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223ff63:de00::/24ff63:deff:ffff:ffff:ffff:ffff:ffff:ffff
224ff63:df00::/24ff63:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225ff63:e000::/24ff63:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226ff63:e100::/24ff63:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227ff63:e200::/24ff63:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228ff63:e300::/24ff63:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229ff63:e400::/24ff63:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230ff63:e500::/24ff63:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231ff63:e600::/24ff63:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232ff63:e700::/24ff63:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233ff63:e800::/24ff63:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234ff63:e900::/24ff63:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235ff63:ea00::/24ff63:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236ff63:eb00::/24ff63:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237ff63:ec00::/24ff63:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238ff63:ed00::/24ff63:edff:ffff:ffff:ffff:ffff:ffff:ffff
239ff63:ee00::/24ff63:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240ff63:ef00::/24ff63:efff:ffff:ffff:ffff:ffff:ffff:ffff
241ff63:f000::/24ff63:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242ff63:f100::/24ff63:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243ff63:f200::/24ff63:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244ff63:f300::/24ff63:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245ff63:f400::/24ff63:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246ff63:f500::/24ff63:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247ff63:f600::/24ff63:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248ff63:f700::/24ff63:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249ff63:f800::/24ff63:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250ff63:f900::/24ff63:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251ff63:fa00::/24ff63:faff:ffff:ffff:ffff:ffff:ffff:ffff
252ff63:fb00::/24ff63:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253ff63:fc00::/24ff63:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254ff63:fd00::/24ff63:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255ff63:fe00::/24ff63:feff:ffff:ffff:ffff:ffff:ffff:ffff
256ff63:ff00::/24ff63: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.