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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
ff75::/16
First address
ff75::
Last address
ff75: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
ff75:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
5.7.f.f.ip6.arpa
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

ff75::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
1ff75::/28ff75:f:ffff:ffff:ffff:ffff:ffff:ffff
2ff75:10::/28ff75:1f:ffff:ffff:ffff:ffff:ffff:ffff
3ff75:20::/28ff75:2f:ffff:ffff:ffff:ffff:ffff:ffff
4ff75:30::/28ff75:3f:ffff:ffff:ffff:ffff:ffff:ffff
5ff75:40::/28ff75:4f:ffff:ffff:ffff:ffff:ffff:ffff
6ff75:50::/28ff75:5f:ffff:ffff:ffff:ffff:ffff:ffff
7ff75:60::/28ff75:6f:ffff:ffff:ffff:ffff:ffff:ffff
8ff75:70::/28ff75:7f:ffff:ffff:ffff:ffff:ffff:ffff
9ff75:80::/28ff75:8f:ffff:ffff:ffff:ffff:ffff:ffff
10ff75:90::/28ff75:9f:ffff:ffff:ffff:ffff:ffff:ffff
11ff75:a0::/28ff75:af:ffff:ffff:ffff:ffff:ffff:ffff
12ff75:b0::/28ff75:bf:ffff:ffff:ffff:ffff:ffff:ffff
13ff75:c0::/28ff75:cf:ffff:ffff:ffff:ffff:ffff:ffff
14ff75:d0::/28ff75:df:ffff:ffff:ffff:ffff:ffff:ffff
15ff75:e0::/28ff75:ef:ffff:ffff:ffff:ffff:ffff:ffff
16ff75:f0::/28ff75:ff:ffff:ffff:ffff:ffff:ffff:ffff
17ff75:100::/28ff75:10f:ffff:ffff:ffff:ffff:ffff:ffff
18ff75:110::/28ff75:11f:ffff:ffff:ffff:ffff:ffff:ffff
19ff75:120::/28ff75:12f:ffff:ffff:ffff:ffff:ffff:ffff
20ff75:130::/28ff75:13f:ffff:ffff:ffff:ffff:ffff:ffff
21ff75:140::/28ff75:14f:ffff:ffff:ffff:ffff:ffff:ffff
22ff75:150::/28ff75:15f:ffff:ffff:ffff:ffff:ffff:ffff
23ff75:160::/28ff75:16f:ffff:ffff:ffff:ffff:ffff:ffff
24ff75:170::/28ff75:17f:ffff:ffff:ffff:ffff:ffff:ffff
25ff75:180::/28ff75:18f:ffff:ffff:ffff:ffff:ffff:ffff
26ff75:190::/28ff75:19f:ffff:ffff:ffff:ffff:ffff:ffff
27ff75:1a0::/28ff75:1af:ffff:ffff:ffff:ffff:ffff:ffff
28ff75:1b0::/28ff75:1bf:ffff:ffff:ffff:ffff:ffff:ffff
29ff75:1c0::/28ff75:1cf:ffff:ffff:ffff:ffff:ffff:ffff
30ff75:1d0::/28ff75:1df:ffff:ffff:ffff:ffff:ffff:ffff
31ff75:1e0::/28ff75:1ef:ffff:ffff:ffff:ffff:ffff:ffff
32ff75:1f0::/28ff75:1ff:ffff:ffff:ffff:ffff:ffff:ffff
33ff75:200::/28ff75:20f:ffff:ffff:ffff:ffff:ffff:ffff
34ff75:210::/28ff75:21f:ffff:ffff:ffff:ffff:ffff:ffff
35ff75:220::/28ff75:22f:ffff:ffff:ffff:ffff:ffff:ffff
36ff75:230::/28ff75:23f:ffff:ffff:ffff:ffff:ffff:ffff
37ff75:240::/28ff75:24f:ffff:ffff:ffff:ffff:ffff:ffff
38ff75:250::/28ff75:25f:ffff:ffff:ffff:ffff:ffff:ffff
39ff75:260::/28ff75:26f:ffff:ffff:ffff:ffff:ffff:ffff
40ff75:270::/28ff75:27f:ffff:ffff:ffff:ffff:ffff:ffff
41ff75:280::/28ff75:28f:ffff:ffff:ffff:ffff:ffff:ffff
42ff75:290::/28ff75:29f:ffff:ffff:ffff:ffff:ffff:ffff
43ff75:2a0::/28ff75:2af:ffff:ffff:ffff:ffff:ffff:ffff
44ff75:2b0::/28ff75:2bf:ffff:ffff:ffff:ffff:ffff:ffff
45ff75:2c0::/28ff75:2cf:ffff:ffff:ffff:ffff:ffff:ffff
46ff75:2d0::/28ff75:2df:ffff:ffff:ffff:ffff:ffff:ffff
47ff75:2e0::/28ff75:2ef:ffff:ffff:ffff:ffff:ffff:ffff
48ff75:2f0::/28ff75:2ff:ffff:ffff:ffff:ffff:ffff:ffff
49ff75:300::/28ff75:30f:ffff:ffff:ffff:ffff:ffff:ffff
50ff75:310::/28ff75:31f:ffff:ffff:ffff:ffff:ffff:ffff
51ff75:320::/28ff75:32f:ffff:ffff:ffff:ffff:ffff:ffff
52ff75:330::/28ff75:33f:ffff:ffff:ffff:ffff:ffff:ffff
53ff75:340::/28ff75:34f:ffff:ffff:ffff:ffff:ffff:ffff
54ff75:350::/28ff75:35f:ffff:ffff:ffff:ffff:ffff:ffff
55ff75:360::/28ff75:36f:ffff:ffff:ffff:ffff:ffff:ffff
56ff75:370::/28ff75:37f:ffff:ffff:ffff:ffff:ffff:ffff
57ff75:380::/28ff75:38f:ffff:ffff:ffff:ffff:ffff:ffff
58ff75:390::/28ff75:39f:ffff:ffff:ffff:ffff:ffff:ffff
59ff75:3a0::/28ff75:3af:ffff:ffff:ffff:ffff:ffff:ffff
60ff75:3b0::/28ff75:3bf:ffff:ffff:ffff:ffff:ffff:ffff
61ff75:3c0::/28ff75:3cf:ffff:ffff:ffff:ffff:ffff:ffff
62ff75:3d0::/28ff75:3df:ffff:ffff:ffff:ffff:ffff:ffff
63ff75:3e0::/28ff75:3ef:ffff:ffff:ffff:ffff:ffff:ffff
64ff75:3f0::/28ff75:3ff:ffff:ffff:ffff:ffff:ffff:ffff
65ff75:400::/28ff75:40f:ffff:ffff:ffff:ffff:ffff:ffff
66ff75:410::/28ff75:41f:ffff:ffff:ffff:ffff:ffff:ffff
67ff75:420::/28ff75:42f:ffff:ffff:ffff:ffff:ffff:ffff
68ff75:430::/28ff75:43f:ffff:ffff:ffff:ffff:ffff:ffff
69ff75:440::/28ff75:44f:ffff:ffff:ffff:ffff:ffff:ffff
70ff75:450::/28ff75:45f:ffff:ffff:ffff:ffff:ffff:ffff
71ff75:460::/28ff75:46f:ffff:ffff:ffff:ffff:ffff:ffff
72ff75:470::/28ff75:47f:ffff:ffff:ffff:ffff:ffff:ffff
73ff75:480::/28ff75:48f:ffff:ffff:ffff:ffff:ffff:ffff
74ff75:490::/28ff75:49f:ffff:ffff:ffff:ffff:ffff:ffff
75ff75:4a0::/28ff75:4af:ffff:ffff:ffff:ffff:ffff:ffff
76ff75:4b0::/28ff75:4bf:ffff:ffff:ffff:ffff:ffff:ffff
77ff75:4c0::/28ff75:4cf:ffff:ffff:ffff:ffff:ffff:ffff
78ff75:4d0::/28ff75:4df:ffff:ffff:ffff:ffff:ffff:ffff
79ff75:4e0::/28ff75:4ef:ffff:ffff:ffff:ffff:ffff:ffff
80ff75:4f0::/28ff75:4ff:ffff:ffff:ffff:ffff:ffff:ffff
81ff75:500::/28ff75:50f:ffff:ffff:ffff:ffff:ffff:ffff
82ff75:510::/28ff75:51f:ffff:ffff:ffff:ffff:ffff:ffff
83ff75:520::/28ff75:52f:ffff:ffff:ffff:ffff:ffff:ffff
84ff75:530::/28ff75:53f:ffff:ffff:ffff:ffff:ffff:ffff
85ff75:540::/28ff75:54f:ffff:ffff:ffff:ffff:ffff:ffff
86ff75:550::/28ff75:55f:ffff:ffff:ffff:ffff:ffff:ffff
87ff75:560::/28ff75:56f:ffff:ffff:ffff:ffff:ffff:ffff
88ff75:570::/28ff75:57f:ffff:ffff:ffff:ffff:ffff:ffff
89ff75:580::/28ff75:58f:ffff:ffff:ffff:ffff:ffff:ffff
90ff75:590::/28ff75:59f:ffff:ffff:ffff:ffff:ffff:ffff
91ff75:5a0::/28ff75:5af:ffff:ffff:ffff:ffff:ffff:ffff
92ff75:5b0::/28ff75:5bf:ffff:ffff:ffff:ffff:ffff:ffff
93ff75:5c0::/28ff75:5cf:ffff:ffff:ffff:ffff:ffff:ffff
94ff75:5d0::/28ff75:5df:ffff:ffff:ffff:ffff:ffff:ffff
95ff75:5e0::/28ff75:5ef:ffff:ffff:ffff:ffff:ffff:ffff
96ff75:5f0::/28ff75:5ff:ffff:ffff:ffff:ffff:ffff:ffff
97ff75:600::/28ff75:60f:ffff:ffff:ffff:ffff:ffff:ffff
98ff75:610::/28ff75:61f:ffff:ffff:ffff:ffff:ffff:ffff
99ff75:620::/28ff75:62f:ffff:ffff:ffff:ffff:ffff:ffff
100ff75:630::/28ff75:63f:ffff:ffff:ffff:ffff:ffff:ffff
101ff75:640::/28ff75:64f:ffff:ffff:ffff:ffff:ffff:ffff
102ff75:650::/28ff75:65f:ffff:ffff:ffff:ffff:ffff:ffff
103ff75:660::/28ff75:66f:ffff:ffff:ffff:ffff:ffff:ffff
104ff75:670::/28ff75:67f:ffff:ffff:ffff:ffff:ffff:ffff
105ff75:680::/28ff75:68f:ffff:ffff:ffff:ffff:ffff:ffff
106ff75:690::/28ff75:69f:ffff:ffff:ffff:ffff:ffff:ffff
107ff75:6a0::/28ff75:6af:ffff:ffff:ffff:ffff:ffff:ffff
108ff75:6b0::/28ff75:6bf:ffff:ffff:ffff:ffff:ffff:ffff
109ff75:6c0::/28ff75:6cf:ffff:ffff:ffff:ffff:ffff:ffff
110ff75:6d0::/28ff75:6df:ffff:ffff:ffff:ffff:ffff:ffff
111ff75:6e0::/28ff75:6ef:ffff:ffff:ffff:ffff:ffff:ffff
112ff75:6f0::/28ff75:6ff:ffff:ffff:ffff:ffff:ffff:ffff
113ff75:700::/28ff75:70f:ffff:ffff:ffff:ffff:ffff:ffff
114ff75:710::/28ff75:71f:ffff:ffff:ffff:ffff:ffff:ffff
115ff75:720::/28ff75:72f:ffff:ffff:ffff:ffff:ffff:ffff
116ff75:730::/28ff75:73f:ffff:ffff:ffff:ffff:ffff:ffff
117ff75:740::/28ff75:74f:ffff:ffff:ffff:ffff:ffff:ffff
118ff75:750::/28ff75:75f:ffff:ffff:ffff:ffff:ffff:ffff
119ff75:760::/28ff75:76f:ffff:ffff:ffff:ffff:ffff:ffff
120ff75:770::/28ff75:77f:ffff:ffff:ffff:ffff:ffff:ffff
121ff75:780::/28ff75:78f:ffff:ffff:ffff:ffff:ffff:ffff
122ff75:790::/28ff75:79f:ffff:ffff:ffff:ffff:ffff:ffff
123ff75:7a0::/28ff75:7af:ffff:ffff:ffff:ffff:ffff:ffff
124ff75:7b0::/28ff75:7bf:ffff:ffff:ffff:ffff:ffff:ffff
125ff75:7c0::/28ff75:7cf:ffff:ffff:ffff:ffff:ffff:ffff
126ff75:7d0::/28ff75:7df:ffff:ffff:ffff:ffff:ffff:ffff
127ff75:7e0::/28ff75:7ef:ffff:ffff:ffff:ffff:ffff:ffff
128ff75:7f0::/28ff75:7ff:ffff:ffff:ffff:ffff:ffff:ffff
129ff75:800::/28ff75:80f:ffff:ffff:ffff:ffff:ffff:ffff
130ff75:810::/28ff75:81f:ffff:ffff:ffff:ffff:ffff:ffff
131ff75:820::/28ff75:82f:ffff:ffff:ffff:ffff:ffff:ffff
132ff75:830::/28ff75:83f:ffff:ffff:ffff:ffff:ffff:ffff
133ff75:840::/28ff75:84f:ffff:ffff:ffff:ffff:ffff:ffff
134ff75:850::/28ff75:85f:ffff:ffff:ffff:ffff:ffff:ffff
135ff75:860::/28ff75:86f:ffff:ffff:ffff:ffff:ffff:ffff
136ff75:870::/28ff75:87f:ffff:ffff:ffff:ffff:ffff:ffff
137ff75:880::/28ff75:88f:ffff:ffff:ffff:ffff:ffff:ffff
138ff75:890::/28ff75:89f:ffff:ffff:ffff:ffff:ffff:ffff
139ff75:8a0::/28ff75:8af:ffff:ffff:ffff:ffff:ffff:ffff
140ff75:8b0::/28ff75:8bf:ffff:ffff:ffff:ffff:ffff:ffff
141ff75:8c0::/28ff75:8cf:ffff:ffff:ffff:ffff:ffff:ffff
142ff75:8d0::/28ff75:8df:ffff:ffff:ffff:ffff:ffff:ffff
143ff75:8e0::/28ff75:8ef:ffff:ffff:ffff:ffff:ffff:ffff
144ff75:8f0::/28ff75:8ff:ffff:ffff:ffff:ffff:ffff:ffff
145ff75:900::/28ff75:90f:ffff:ffff:ffff:ffff:ffff:ffff
146ff75:910::/28ff75:91f:ffff:ffff:ffff:ffff:ffff:ffff
147ff75:920::/28ff75:92f:ffff:ffff:ffff:ffff:ffff:ffff
148ff75:930::/28ff75:93f:ffff:ffff:ffff:ffff:ffff:ffff
149ff75:940::/28ff75:94f:ffff:ffff:ffff:ffff:ffff:ffff
150ff75:950::/28ff75:95f:ffff:ffff:ffff:ffff:ffff:ffff
151ff75:960::/28ff75:96f:ffff:ffff:ffff:ffff:ffff:ffff
152ff75:970::/28ff75:97f:ffff:ffff:ffff:ffff:ffff:ffff
153ff75:980::/28ff75:98f:ffff:ffff:ffff:ffff:ffff:ffff
154ff75:990::/28ff75:99f:ffff:ffff:ffff:ffff:ffff:ffff
155ff75:9a0::/28ff75:9af:ffff:ffff:ffff:ffff:ffff:ffff
156ff75:9b0::/28ff75:9bf:ffff:ffff:ffff:ffff:ffff:ffff
157ff75:9c0::/28ff75:9cf:ffff:ffff:ffff:ffff:ffff:ffff
158ff75:9d0::/28ff75:9df:ffff:ffff:ffff:ffff:ffff:ffff
159ff75:9e0::/28ff75:9ef:ffff:ffff:ffff:ffff:ffff:ffff
160ff75:9f0::/28ff75:9ff:ffff:ffff:ffff:ffff:ffff:ffff
161ff75:a00::/28ff75:a0f:ffff:ffff:ffff:ffff:ffff:ffff
162ff75:a10::/28ff75:a1f:ffff:ffff:ffff:ffff:ffff:ffff
163ff75:a20::/28ff75:a2f:ffff:ffff:ffff:ffff:ffff:ffff
164ff75:a30::/28ff75:a3f:ffff:ffff:ffff:ffff:ffff:ffff
165ff75:a40::/28ff75:a4f:ffff:ffff:ffff:ffff:ffff:ffff
166ff75:a50::/28ff75:a5f:ffff:ffff:ffff:ffff:ffff:ffff
167ff75:a60::/28ff75:a6f:ffff:ffff:ffff:ffff:ffff:ffff
168ff75:a70::/28ff75:a7f:ffff:ffff:ffff:ffff:ffff:ffff
169ff75:a80::/28ff75:a8f:ffff:ffff:ffff:ffff:ffff:ffff
170ff75:a90::/28ff75:a9f:ffff:ffff:ffff:ffff:ffff:ffff
171ff75:aa0::/28ff75:aaf:ffff:ffff:ffff:ffff:ffff:ffff
172ff75:ab0::/28ff75:abf:ffff:ffff:ffff:ffff:ffff:ffff
173ff75:ac0::/28ff75:acf:ffff:ffff:ffff:ffff:ffff:ffff
174ff75:ad0::/28ff75:adf:ffff:ffff:ffff:ffff:ffff:ffff
175ff75:ae0::/28ff75:aef:ffff:ffff:ffff:ffff:ffff:ffff
176ff75:af0::/28ff75:aff:ffff:ffff:ffff:ffff:ffff:ffff
177ff75:b00::/28ff75:b0f:ffff:ffff:ffff:ffff:ffff:ffff
178ff75:b10::/28ff75:b1f:ffff:ffff:ffff:ffff:ffff:ffff
179ff75:b20::/28ff75:b2f:ffff:ffff:ffff:ffff:ffff:ffff
180ff75:b30::/28ff75:b3f:ffff:ffff:ffff:ffff:ffff:ffff
181ff75:b40::/28ff75:b4f:ffff:ffff:ffff:ffff:ffff:ffff
182ff75:b50::/28ff75:b5f:ffff:ffff:ffff:ffff:ffff:ffff
183ff75:b60::/28ff75:b6f:ffff:ffff:ffff:ffff:ffff:ffff
184ff75:b70::/28ff75:b7f:ffff:ffff:ffff:ffff:ffff:ffff
185ff75:b80::/28ff75:b8f:ffff:ffff:ffff:ffff:ffff:ffff
186ff75:b90::/28ff75:b9f:ffff:ffff:ffff:ffff:ffff:ffff
187ff75:ba0::/28ff75:baf:ffff:ffff:ffff:ffff:ffff:ffff
188ff75:bb0::/28ff75:bbf:ffff:ffff:ffff:ffff:ffff:ffff
189ff75:bc0::/28ff75:bcf:ffff:ffff:ffff:ffff:ffff:ffff
190ff75:bd0::/28ff75:bdf:ffff:ffff:ffff:ffff:ffff:ffff
191ff75:be0::/28ff75:bef:ffff:ffff:ffff:ffff:ffff:ffff
192ff75:bf0::/28ff75:bff:ffff:ffff:ffff:ffff:ffff:ffff
193ff75:c00::/28ff75:c0f:ffff:ffff:ffff:ffff:ffff:ffff
194ff75:c10::/28ff75:c1f:ffff:ffff:ffff:ffff:ffff:ffff
195ff75:c20::/28ff75:c2f:ffff:ffff:ffff:ffff:ffff:ffff
196ff75:c30::/28ff75:c3f:ffff:ffff:ffff:ffff:ffff:ffff
197ff75:c40::/28ff75:c4f:ffff:ffff:ffff:ffff:ffff:ffff
198ff75:c50::/28ff75:c5f:ffff:ffff:ffff:ffff:ffff:ffff
199ff75:c60::/28ff75:c6f:ffff:ffff:ffff:ffff:ffff:ffff
200ff75:c70::/28ff75:c7f:ffff:ffff:ffff:ffff:ffff:ffff
201ff75:c80::/28ff75:c8f:ffff:ffff:ffff:ffff:ffff:ffff
202ff75:c90::/28ff75:c9f:ffff:ffff:ffff:ffff:ffff:ffff
203ff75:ca0::/28ff75:caf:ffff:ffff:ffff:ffff:ffff:ffff
204ff75:cb0::/28ff75:cbf:ffff:ffff:ffff:ffff:ffff:ffff
205ff75:cc0::/28ff75:ccf:ffff:ffff:ffff:ffff:ffff:ffff
206ff75:cd0::/28ff75:cdf:ffff:ffff:ffff:ffff:ffff:ffff
207ff75:ce0::/28ff75:cef:ffff:ffff:ffff:ffff:ffff:ffff
208ff75:cf0::/28ff75:cff:ffff:ffff:ffff:ffff:ffff:ffff
209ff75:d00::/28ff75:d0f:ffff:ffff:ffff:ffff:ffff:ffff
210ff75:d10::/28ff75:d1f:ffff:ffff:ffff:ffff:ffff:ffff
211ff75:d20::/28ff75:d2f:ffff:ffff:ffff:ffff:ffff:ffff
212ff75:d30::/28ff75:d3f:ffff:ffff:ffff:ffff:ffff:ffff
213ff75:d40::/28ff75:d4f:ffff:ffff:ffff:ffff:ffff:ffff
214ff75:d50::/28ff75:d5f:ffff:ffff:ffff:ffff:ffff:ffff
215ff75:d60::/28ff75:d6f:ffff:ffff:ffff:ffff:ffff:ffff
216ff75:d70::/28ff75:d7f:ffff:ffff:ffff:ffff:ffff:ffff
217ff75:d80::/28ff75:d8f:ffff:ffff:ffff:ffff:ffff:ffff
218ff75:d90::/28ff75:d9f:ffff:ffff:ffff:ffff:ffff:ffff
219ff75:da0::/28ff75:daf:ffff:ffff:ffff:ffff:ffff:ffff
220ff75:db0::/28ff75:dbf:ffff:ffff:ffff:ffff:ffff:ffff
221ff75:dc0::/28ff75:dcf:ffff:ffff:ffff:ffff:ffff:ffff
222ff75:dd0::/28ff75:ddf:ffff:ffff:ffff:ffff:ffff:ffff
223ff75:de0::/28ff75:def:ffff:ffff:ffff:ffff:ffff:ffff
224ff75:df0::/28ff75:dff:ffff:ffff:ffff:ffff:ffff:ffff
225ff75:e00::/28ff75:e0f:ffff:ffff:ffff:ffff:ffff:ffff
226ff75:e10::/28ff75:e1f:ffff:ffff:ffff:ffff:ffff:ffff
227ff75:e20::/28ff75:e2f:ffff:ffff:ffff:ffff:ffff:ffff
228ff75:e30::/28ff75:e3f:ffff:ffff:ffff:ffff:ffff:ffff
229ff75:e40::/28ff75:e4f:ffff:ffff:ffff:ffff:ffff:ffff
230ff75:e50::/28ff75:e5f:ffff:ffff:ffff:ffff:ffff:ffff
231ff75:e60::/28ff75:e6f:ffff:ffff:ffff:ffff:ffff:ffff
232ff75:e70::/28ff75:e7f:ffff:ffff:ffff:ffff:ffff:ffff
233ff75:e80::/28ff75:e8f:ffff:ffff:ffff:ffff:ffff:ffff
234ff75:e90::/28ff75:e9f:ffff:ffff:ffff:ffff:ffff:ffff
235ff75:ea0::/28ff75:eaf:ffff:ffff:ffff:ffff:ffff:ffff
236ff75:eb0::/28ff75:ebf:ffff:ffff:ffff:ffff:ffff:ffff
237ff75:ec0::/28ff75:ecf:ffff:ffff:ffff:ffff:ffff:ffff
238ff75:ed0::/28ff75:edf:ffff:ffff:ffff:ffff:ffff:ffff
239ff75:ee0::/28ff75:eef:ffff:ffff:ffff:ffff:ffff:ffff
240ff75:ef0::/28ff75:eff:ffff:ffff:ffff:ffff:ffff:ffff
241ff75:f00::/28ff75:f0f:ffff:ffff:ffff:ffff:ffff:ffff
242ff75:f10::/28ff75:f1f:ffff:ffff:ffff:ffff:ffff:ffff
243ff75:f20::/28ff75:f2f:ffff:ffff:ffff:ffff:ffff:ffff
244ff75:f30::/28ff75:f3f:ffff:ffff:ffff:ffff:ffff:ffff
245ff75:f40::/28ff75:f4f:ffff:ffff:ffff:ffff:ffff:ffff
246ff75:f50::/28ff75:f5f:ffff:ffff:ffff:ffff:ffff:ffff
247ff75:f60::/28ff75:f6f:ffff:ffff:ffff:ffff:ffff:ffff
248ff75:f70::/28ff75:f7f:ffff:ffff:ffff:ffff:ffff:ffff
249ff75:f80::/28ff75:f8f:ffff:ffff:ffff:ffff:ffff:ffff
250ff75:f90::/28ff75:f9f:ffff:ffff:ffff:ffff:ffff:ffff
251ff75:fa0::/28ff75:faf:ffff:ffff:ffff:ffff:ffff:ffff
252ff75:fb0::/28ff75:fbf:ffff:ffff:ffff:ffff:ffff:ffff
253ff75:fc0::/28ff75:fcf:ffff:ffff:ffff:ffff:ffff:ffff
254ff75:fd0::/28ff75:fdf:ffff:ffff:ffff:ffff:ffff:ffff
255ff75:fe0::/28ff75:fef:ffff:ffff:ffff:ffff:ffff:ffff
256ff75:ff0::/28ff75:fff: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.