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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
ff36::/16
First address
ff36::
Last address
ff36: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
ff36:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
6.3.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)

ff36::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
1ff36::/28ff36:f:ffff:ffff:ffff:ffff:ffff:ffff
2ff36:10::/28ff36:1f:ffff:ffff:ffff:ffff:ffff:ffff
3ff36:20::/28ff36:2f:ffff:ffff:ffff:ffff:ffff:ffff
4ff36:30::/28ff36:3f:ffff:ffff:ffff:ffff:ffff:ffff
5ff36:40::/28ff36:4f:ffff:ffff:ffff:ffff:ffff:ffff
6ff36:50::/28ff36:5f:ffff:ffff:ffff:ffff:ffff:ffff
7ff36:60::/28ff36:6f:ffff:ffff:ffff:ffff:ffff:ffff
8ff36:70::/28ff36:7f:ffff:ffff:ffff:ffff:ffff:ffff
9ff36:80::/28ff36:8f:ffff:ffff:ffff:ffff:ffff:ffff
10ff36:90::/28ff36:9f:ffff:ffff:ffff:ffff:ffff:ffff
11ff36:a0::/28ff36:af:ffff:ffff:ffff:ffff:ffff:ffff
12ff36:b0::/28ff36:bf:ffff:ffff:ffff:ffff:ffff:ffff
13ff36:c0::/28ff36:cf:ffff:ffff:ffff:ffff:ffff:ffff
14ff36:d0::/28ff36:df:ffff:ffff:ffff:ffff:ffff:ffff
15ff36:e0::/28ff36:ef:ffff:ffff:ffff:ffff:ffff:ffff
16ff36:f0::/28ff36:ff:ffff:ffff:ffff:ffff:ffff:ffff
17ff36:100::/28ff36:10f:ffff:ffff:ffff:ffff:ffff:ffff
18ff36:110::/28ff36:11f:ffff:ffff:ffff:ffff:ffff:ffff
19ff36:120::/28ff36:12f:ffff:ffff:ffff:ffff:ffff:ffff
20ff36:130::/28ff36:13f:ffff:ffff:ffff:ffff:ffff:ffff
21ff36:140::/28ff36:14f:ffff:ffff:ffff:ffff:ffff:ffff
22ff36:150::/28ff36:15f:ffff:ffff:ffff:ffff:ffff:ffff
23ff36:160::/28ff36:16f:ffff:ffff:ffff:ffff:ffff:ffff
24ff36:170::/28ff36:17f:ffff:ffff:ffff:ffff:ffff:ffff
25ff36:180::/28ff36:18f:ffff:ffff:ffff:ffff:ffff:ffff
26ff36:190::/28ff36:19f:ffff:ffff:ffff:ffff:ffff:ffff
27ff36:1a0::/28ff36:1af:ffff:ffff:ffff:ffff:ffff:ffff
28ff36:1b0::/28ff36:1bf:ffff:ffff:ffff:ffff:ffff:ffff
29ff36:1c0::/28ff36:1cf:ffff:ffff:ffff:ffff:ffff:ffff
30ff36:1d0::/28ff36:1df:ffff:ffff:ffff:ffff:ffff:ffff
31ff36:1e0::/28ff36:1ef:ffff:ffff:ffff:ffff:ffff:ffff
32ff36:1f0::/28ff36:1ff:ffff:ffff:ffff:ffff:ffff:ffff
33ff36:200::/28ff36:20f:ffff:ffff:ffff:ffff:ffff:ffff
34ff36:210::/28ff36:21f:ffff:ffff:ffff:ffff:ffff:ffff
35ff36:220::/28ff36:22f:ffff:ffff:ffff:ffff:ffff:ffff
36ff36:230::/28ff36:23f:ffff:ffff:ffff:ffff:ffff:ffff
37ff36:240::/28ff36:24f:ffff:ffff:ffff:ffff:ffff:ffff
38ff36:250::/28ff36:25f:ffff:ffff:ffff:ffff:ffff:ffff
39ff36:260::/28ff36:26f:ffff:ffff:ffff:ffff:ffff:ffff
40ff36:270::/28ff36:27f:ffff:ffff:ffff:ffff:ffff:ffff
41ff36:280::/28ff36:28f:ffff:ffff:ffff:ffff:ffff:ffff
42ff36:290::/28ff36:29f:ffff:ffff:ffff:ffff:ffff:ffff
43ff36:2a0::/28ff36:2af:ffff:ffff:ffff:ffff:ffff:ffff
44ff36:2b0::/28ff36:2bf:ffff:ffff:ffff:ffff:ffff:ffff
45ff36:2c0::/28ff36:2cf:ffff:ffff:ffff:ffff:ffff:ffff
46ff36:2d0::/28ff36:2df:ffff:ffff:ffff:ffff:ffff:ffff
47ff36:2e0::/28ff36:2ef:ffff:ffff:ffff:ffff:ffff:ffff
48ff36:2f0::/28ff36:2ff:ffff:ffff:ffff:ffff:ffff:ffff
49ff36:300::/28ff36:30f:ffff:ffff:ffff:ffff:ffff:ffff
50ff36:310::/28ff36:31f:ffff:ffff:ffff:ffff:ffff:ffff
51ff36:320::/28ff36:32f:ffff:ffff:ffff:ffff:ffff:ffff
52ff36:330::/28ff36:33f:ffff:ffff:ffff:ffff:ffff:ffff
53ff36:340::/28ff36:34f:ffff:ffff:ffff:ffff:ffff:ffff
54ff36:350::/28ff36:35f:ffff:ffff:ffff:ffff:ffff:ffff
55ff36:360::/28ff36:36f:ffff:ffff:ffff:ffff:ffff:ffff
56ff36:370::/28ff36:37f:ffff:ffff:ffff:ffff:ffff:ffff
57ff36:380::/28ff36:38f:ffff:ffff:ffff:ffff:ffff:ffff
58ff36:390::/28ff36:39f:ffff:ffff:ffff:ffff:ffff:ffff
59ff36:3a0::/28ff36:3af:ffff:ffff:ffff:ffff:ffff:ffff
60ff36:3b0::/28ff36:3bf:ffff:ffff:ffff:ffff:ffff:ffff
61ff36:3c0::/28ff36:3cf:ffff:ffff:ffff:ffff:ffff:ffff
62ff36:3d0::/28ff36:3df:ffff:ffff:ffff:ffff:ffff:ffff
63ff36:3e0::/28ff36:3ef:ffff:ffff:ffff:ffff:ffff:ffff
64ff36:3f0::/28ff36:3ff:ffff:ffff:ffff:ffff:ffff:ffff
65ff36:400::/28ff36:40f:ffff:ffff:ffff:ffff:ffff:ffff
66ff36:410::/28ff36:41f:ffff:ffff:ffff:ffff:ffff:ffff
67ff36:420::/28ff36:42f:ffff:ffff:ffff:ffff:ffff:ffff
68ff36:430::/28ff36:43f:ffff:ffff:ffff:ffff:ffff:ffff
69ff36:440::/28ff36:44f:ffff:ffff:ffff:ffff:ffff:ffff
70ff36:450::/28ff36:45f:ffff:ffff:ffff:ffff:ffff:ffff
71ff36:460::/28ff36:46f:ffff:ffff:ffff:ffff:ffff:ffff
72ff36:470::/28ff36:47f:ffff:ffff:ffff:ffff:ffff:ffff
73ff36:480::/28ff36:48f:ffff:ffff:ffff:ffff:ffff:ffff
74ff36:490::/28ff36:49f:ffff:ffff:ffff:ffff:ffff:ffff
75ff36:4a0::/28ff36:4af:ffff:ffff:ffff:ffff:ffff:ffff
76ff36:4b0::/28ff36:4bf:ffff:ffff:ffff:ffff:ffff:ffff
77ff36:4c0::/28ff36:4cf:ffff:ffff:ffff:ffff:ffff:ffff
78ff36:4d0::/28ff36:4df:ffff:ffff:ffff:ffff:ffff:ffff
79ff36:4e0::/28ff36:4ef:ffff:ffff:ffff:ffff:ffff:ffff
80ff36:4f0::/28ff36:4ff:ffff:ffff:ffff:ffff:ffff:ffff
81ff36:500::/28ff36:50f:ffff:ffff:ffff:ffff:ffff:ffff
82ff36:510::/28ff36:51f:ffff:ffff:ffff:ffff:ffff:ffff
83ff36:520::/28ff36:52f:ffff:ffff:ffff:ffff:ffff:ffff
84ff36:530::/28ff36:53f:ffff:ffff:ffff:ffff:ffff:ffff
85ff36:540::/28ff36:54f:ffff:ffff:ffff:ffff:ffff:ffff
86ff36:550::/28ff36:55f:ffff:ffff:ffff:ffff:ffff:ffff
87ff36:560::/28ff36:56f:ffff:ffff:ffff:ffff:ffff:ffff
88ff36:570::/28ff36:57f:ffff:ffff:ffff:ffff:ffff:ffff
89ff36:580::/28ff36:58f:ffff:ffff:ffff:ffff:ffff:ffff
90ff36:590::/28ff36:59f:ffff:ffff:ffff:ffff:ffff:ffff
91ff36:5a0::/28ff36:5af:ffff:ffff:ffff:ffff:ffff:ffff
92ff36:5b0::/28ff36:5bf:ffff:ffff:ffff:ffff:ffff:ffff
93ff36:5c0::/28ff36:5cf:ffff:ffff:ffff:ffff:ffff:ffff
94ff36:5d0::/28ff36:5df:ffff:ffff:ffff:ffff:ffff:ffff
95ff36:5e0::/28ff36:5ef:ffff:ffff:ffff:ffff:ffff:ffff
96ff36:5f0::/28ff36:5ff:ffff:ffff:ffff:ffff:ffff:ffff
97ff36:600::/28ff36:60f:ffff:ffff:ffff:ffff:ffff:ffff
98ff36:610::/28ff36:61f:ffff:ffff:ffff:ffff:ffff:ffff
99ff36:620::/28ff36:62f:ffff:ffff:ffff:ffff:ffff:ffff
100ff36:630::/28ff36:63f:ffff:ffff:ffff:ffff:ffff:ffff
101ff36:640::/28ff36:64f:ffff:ffff:ffff:ffff:ffff:ffff
102ff36:650::/28ff36:65f:ffff:ffff:ffff:ffff:ffff:ffff
103ff36:660::/28ff36:66f:ffff:ffff:ffff:ffff:ffff:ffff
104ff36:670::/28ff36:67f:ffff:ffff:ffff:ffff:ffff:ffff
105ff36:680::/28ff36:68f:ffff:ffff:ffff:ffff:ffff:ffff
106ff36:690::/28ff36:69f:ffff:ffff:ffff:ffff:ffff:ffff
107ff36:6a0::/28ff36:6af:ffff:ffff:ffff:ffff:ffff:ffff
108ff36:6b0::/28ff36:6bf:ffff:ffff:ffff:ffff:ffff:ffff
109ff36:6c0::/28ff36:6cf:ffff:ffff:ffff:ffff:ffff:ffff
110ff36:6d0::/28ff36:6df:ffff:ffff:ffff:ffff:ffff:ffff
111ff36:6e0::/28ff36:6ef:ffff:ffff:ffff:ffff:ffff:ffff
112ff36:6f0::/28ff36:6ff:ffff:ffff:ffff:ffff:ffff:ffff
113ff36:700::/28ff36:70f:ffff:ffff:ffff:ffff:ffff:ffff
114ff36:710::/28ff36:71f:ffff:ffff:ffff:ffff:ffff:ffff
115ff36:720::/28ff36:72f:ffff:ffff:ffff:ffff:ffff:ffff
116ff36:730::/28ff36:73f:ffff:ffff:ffff:ffff:ffff:ffff
117ff36:740::/28ff36:74f:ffff:ffff:ffff:ffff:ffff:ffff
118ff36:750::/28ff36:75f:ffff:ffff:ffff:ffff:ffff:ffff
119ff36:760::/28ff36:76f:ffff:ffff:ffff:ffff:ffff:ffff
120ff36:770::/28ff36:77f:ffff:ffff:ffff:ffff:ffff:ffff
121ff36:780::/28ff36:78f:ffff:ffff:ffff:ffff:ffff:ffff
122ff36:790::/28ff36:79f:ffff:ffff:ffff:ffff:ffff:ffff
123ff36:7a0::/28ff36:7af:ffff:ffff:ffff:ffff:ffff:ffff
124ff36:7b0::/28ff36:7bf:ffff:ffff:ffff:ffff:ffff:ffff
125ff36:7c0::/28ff36:7cf:ffff:ffff:ffff:ffff:ffff:ffff
126ff36:7d0::/28ff36:7df:ffff:ffff:ffff:ffff:ffff:ffff
127ff36:7e0::/28ff36:7ef:ffff:ffff:ffff:ffff:ffff:ffff
128ff36:7f0::/28ff36:7ff:ffff:ffff:ffff:ffff:ffff:ffff
129ff36:800::/28ff36:80f:ffff:ffff:ffff:ffff:ffff:ffff
130ff36:810::/28ff36:81f:ffff:ffff:ffff:ffff:ffff:ffff
131ff36:820::/28ff36:82f:ffff:ffff:ffff:ffff:ffff:ffff
132ff36:830::/28ff36:83f:ffff:ffff:ffff:ffff:ffff:ffff
133ff36:840::/28ff36:84f:ffff:ffff:ffff:ffff:ffff:ffff
134ff36:850::/28ff36:85f:ffff:ffff:ffff:ffff:ffff:ffff
135ff36:860::/28ff36:86f:ffff:ffff:ffff:ffff:ffff:ffff
136ff36:870::/28ff36:87f:ffff:ffff:ffff:ffff:ffff:ffff
137ff36:880::/28ff36:88f:ffff:ffff:ffff:ffff:ffff:ffff
138ff36:890::/28ff36:89f:ffff:ffff:ffff:ffff:ffff:ffff
139ff36:8a0::/28ff36:8af:ffff:ffff:ffff:ffff:ffff:ffff
140ff36:8b0::/28ff36:8bf:ffff:ffff:ffff:ffff:ffff:ffff
141ff36:8c0::/28ff36:8cf:ffff:ffff:ffff:ffff:ffff:ffff
142ff36:8d0::/28ff36:8df:ffff:ffff:ffff:ffff:ffff:ffff
143ff36:8e0::/28ff36:8ef:ffff:ffff:ffff:ffff:ffff:ffff
144ff36:8f0::/28ff36:8ff:ffff:ffff:ffff:ffff:ffff:ffff
145ff36:900::/28ff36:90f:ffff:ffff:ffff:ffff:ffff:ffff
146ff36:910::/28ff36:91f:ffff:ffff:ffff:ffff:ffff:ffff
147ff36:920::/28ff36:92f:ffff:ffff:ffff:ffff:ffff:ffff
148ff36:930::/28ff36:93f:ffff:ffff:ffff:ffff:ffff:ffff
149ff36:940::/28ff36:94f:ffff:ffff:ffff:ffff:ffff:ffff
150ff36:950::/28ff36:95f:ffff:ffff:ffff:ffff:ffff:ffff
151ff36:960::/28ff36:96f:ffff:ffff:ffff:ffff:ffff:ffff
152ff36:970::/28ff36:97f:ffff:ffff:ffff:ffff:ffff:ffff
153ff36:980::/28ff36:98f:ffff:ffff:ffff:ffff:ffff:ffff
154ff36:990::/28ff36:99f:ffff:ffff:ffff:ffff:ffff:ffff
155ff36:9a0::/28ff36:9af:ffff:ffff:ffff:ffff:ffff:ffff
156ff36:9b0::/28ff36:9bf:ffff:ffff:ffff:ffff:ffff:ffff
157ff36:9c0::/28ff36:9cf:ffff:ffff:ffff:ffff:ffff:ffff
158ff36:9d0::/28ff36:9df:ffff:ffff:ffff:ffff:ffff:ffff
159ff36:9e0::/28ff36:9ef:ffff:ffff:ffff:ffff:ffff:ffff
160ff36:9f0::/28ff36:9ff:ffff:ffff:ffff:ffff:ffff:ffff
161ff36:a00::/28ff36:a0f:ffff:ffff:ffff:ffff:ffff:ffff
162ff36:a10::/28ff36:a1f:ffff:ffff:ffff:ffff:ffff:ffff
163ff36:a20::/28ff36:a2f:ffff:ffff:ffff:ffff:ffff:ffff
164ff36:a30::/28ff36:a3f:ffff:ffff:ffff:ffff:ffff:ffff
165ff36:a40::/28ff36:a4f:ffff:ffff:ffff:ffff:ffff:ffff
166ff36:a50::/28ff36:a5f:ffff:ffff:ffff:ffff:ffff:ffff
167ff36:a60::/28ff36:a6f:ffff:ffff:ffff:ffff:ffff:ffff
168ff36:a70::/28ff36:a7f:ffff:ffff:ffff:ffff:ffff:ffff
169ff36:a80::/28ff36:a8f:ffff:ffff:ffff:ffff:ffff:ffff
170ff36:a90::/28ff36:a9f:ffff:ffff:ffff:ffff:ffff:ffff
171ff36:aa0::/28ff36:aaf:ffff:ffff:ffff:ffff:ffff:ffff
172ff36:ab0::/28ff36:abf:ffff:ffff:ffff:ffff:ffff:ffff
173ff36:ac0::/28ff36:acf:ffff:ffff:ffff:ffff:ffff:ffff
174ff36:ad0::/28ff36:adf:ffff:ffff:ffff:ffff:ffff:ffff
175ff36:ae0::/28ff36:aef:ffff:ffff:ffff:ffff:ffff:ffff
176ff36:af0::/28ff36:aff:ffff:ffff:ffff:ffff:ffff:ffff
177ff36:b00::/28ff36:b0f:ffff:ffff:ffff:ffff:ffff:ffff
178ff36:b10::/28ff36:b1f:ffff:ffff:ffff:ffff:ffff:ffff
179ff36:b20::/28ff36:b2f:ffff:ffff:ffff:ffff:ffff:ffff
180ff36:b30::/28ff36:b3f:ffff:ffff:ffff:ffff:ffff:ffff
181ff36:b40::/28ff36:b4f:ffff:ffff:ffff:ffff:ffff:ffff
182ff36:b50::/28ff36:b5f:ffff:ffff:ffff:ffff:ffff:ffff
183ff36:b60::/28ff36:b6f:ffff:ffff:ffff:ffff:ffff:ffff
184ff36:b70::/28ff36:b7f:ffff:ffff:ffff:ffff:ffff:ffff
185ff36:b80::/28ff36:b8f:ffff:ffff:ffff:ffff:ffff:ffff
186ff36:b90::/28ff36:b9f:ffff:ffff:ffff:ffff:ffff:ffff
187ff36:ba0::/28ff36:baf:ffff:ffff:ffff:ffff:ffff:ffff
188ff36:bb0::/28ff36:bbf:ffff:ffff:ffff:ffff:ffff:ffff
189ff36:bc0::/28ff36:bcf:ffff:ffff:ffff:ffff:ffff:ffff
190ff36:bd0::/28ff36:bdf:ffff:ffff:ffff:ffff:ffff:ffff
191ff36:be0::/28ff36:bef:ffff:ffff:ffff:ffff:ffff:ffff
192ff36:bf0::/28ff36:bff:ffff:ffff:ffff:ffff:ffff:ffff
193ff36:c00::/28ff36:c0f:ffff:ffff:ffff:ffff:ffff:ffff
194ff36:c10::/28ff36:c1f:ffff:ffff:ffff:ffff:ffff:ffff
195ff36:c20::/28ff36:c2f:ffff:ffff:ffff:ffff:ffff:ffff
196ff36:c30::/28ff36:c3f:ffff:ffff:ffff:ffff:ffff:ffff
197ff36:c40::/28ff36:c4f:ffff:ffff:ffff:ffff:ffff:ffff
198ff36:c50::/28ff36:c5f:ffff:ffff:ffff:ffff:ffff:ffff
199ff36:c60::/28ff36:c6f:ffff:ffff:ffff:ffff:ffff:ffff
200ff36:c70::/28ff36:c7f:ffff:ffff:ffff:ffff:ffff:ffff
201ff36:c80::/28ff36:c8f:ffff:ffff:ffff:ffff:ffff:ffff
202ff36:c90::/28ff36:c9f:ffff:ffff:ffff:ffff:ffff:ffff
203ff36:ca0::/28ff36:caf:ffff:ffff:ffff:ffff:ffff:ffff
204ff36:cb0::/28ff36:cbf:ffff:ffff:ffff:ffff:ffff:ffff
205ff36:cc0::/28ff36:ccf:ffff:ffff:ffff:ffff:ffff:ffff
206ff36:cd0::/28ff36:cdf:ffff:ffff:ffff:ffff:ffff:ffff
207ff36:ce0::/28ff36:cef:ffff:ffff:ffff:ffff:ffff:ffff
208ff36:cf0::/28ff36:cff:ffff:ffff:ffff:ffff:ffff:ffff
209ff36:d00::/28ff36:d0f:ffff:ffff:ffff:ffff:ffff:ffff
210ff36:d10::/28ff36:d1f:ffff:ffff:ffff:ffff:ffff:ffff
211ff36:d20::/28ff36:d2f:ffff:ffff:ffff:ffff:ffff:ffff
212ff36:d30::/28ff36:d3f:ffff:ffff:ffff:ffff:ffff:ffff
213ff36:d40::/28ff36:d4f:ffff:ffff:ffff:ffff:ffff:ffff
214ff36:d50::/28ff36:d5f:ffff:ffff:ffff:ffff:ffff:ffff
215ff36:d60::/28ff36:d6f:ffff:ffff:ffff:ffff:ffff:ffff
216ff36:d70::/28ff36:d7f:ffff:ffff:ffff:ffff:ffff:ffff
217ff36:d80::/28ff36:d8f:ffff:ffff:ffff:ffff:ffff:ffff
218ff36:d90::/28ff36:d9f:ffff:ffff:ffff:ffff:ffff:ffff
219ff36:da0::/28ff36:daf:ffff:ffff:ffff:ffff:ffff:ffff
220ff36:db0::/28ff36:dbf:ffff:ffff:ffff:ffff:ffff:ffff
221ff36:dc0::/28ff36:dcf:ffff:ffff:ffff:ffff:ffff:ffff
222ff36:dd0::/28ff36:ddf:ffff:ffff:ffff:ffff:ffff:ffff
223ff36:de0::/28ff36:def:ffff:ffff:ffff:ffff:ffff:ffff
224ff36:df0::/28ff36:dff:ffff:ffff:ffff:ffff:ffff:ffff
225ff36:e00::/28ff36:e0f:ffff:ffff:ffff:ffff:ffff:ffff
226ff36:e10::/28ff36:e1f:ffff:ffff:ffff:ffff:ffff:ffff
227ff36:e20::/28ff36:e2f:ffff:ffff:ffff:ffff:ffff:ffff
228ff36:e30::/28ff36:e3f:ffff:ffff:ffff:ffff:ffff:ffff
229ff36:e40::/28ff36:e4f:ffff:ffff:ffff:ffff:ffff:ffff
230ff36:e50::/28ff36:e5f:ffff:ffff:ffff:ffff:ffff:ffff
231ff36:e60::/28ff36:e6f:ffff:ffff:ffff:ffff:ffff:ffff
232ff36:e70::/28ff36:e7f:ffff:ffff:ffff:ffff:ffff:ffff
233ff36:e80::/28ff36:e8f:ffff:ffff:ffff:ffff:ffff:ffff
234ff36:e90::/28ff36:e9f:ffff:ffff:ffff:ffff:ffff:ffff
235ff36:ea0::/28ff36:eaf:ffff:ffff:ffff:ffff:ffff:ffff
236ff36:eb0::/28ff36:ebf:ffff:ffff:ffff:ffff:ffff:ffff
237ff36:ec0::/28ff36:ecf:ffff:ffff:ffff:ffff:ffff:ffff
238ff36:ed0::/28ff36:edf:ffff:ffff:ffff:ffff:ffff:ffff
239ff36:ee0::/28ff36:eef:ffff:ffff:ffff:ffff:ffff:ffff
240ff36:ef0::/28ff36:eff:ffff:ffff:ffff:ffff:ffff:ffff
241ff36:f00::/28ff36:f0f:ffff:ffff:ffff:ffff:ffff:ffff
242ff36:f10::/28ff36:f1f:ffff:ffff:ffff:ffff:ffff:ffff
243ff36:f20::/28ff36:f2f:ffff:ffff:ffff:ffff:ffff:ffff
244ff36:f30::/28ff36:f3f:ffff:ffff:ffff:ffff:ffff:ffff
245ff36:f40::/28ff36:f4f:ffff:ffff:ffff:ffff:ffff:ffff
246ff36:f50::/28ff36:f5f:ffff:ffff:ffff:ffff:ffff:ffff
247ff36:f60::/28ff36:f6f:ffff:ffff:ffff:ffff:ffff:ffff
248ff36:f70::/28ff36:f7f:ffff:ffff:ffff:ffff:ffff:ffff
249ff36:f80::/28ff36:f8f:ffff:ffff:ffff:ffff:ffff:ffff
250ff36:f90::/28ff36:f9f:ffff:ffff:ffff:ffff:ffff:ffff
251ff36:fa0::/28ff36:faf:ffff:ffff:ffff:ffff:ffff:ffff
252ff36:fb0::/28ff36:fbf:ffff:ffff:ffff:ffff:ffff:ffff
253ff36:fc0::/28ff36:fcf:ffff:ffff:ffff:ffff:ffff:ffff
254ff36:fd0::/28ff36:fdf:ffff:ffff:ffff:ffff:ffff:ffff
255ff36:fe0::/28ff36:fef:ffff:ffff:ffff:ffff:ffff:ffff
256ff36:ff0::/28ff36: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.