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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
ff19::/16
First address
ff19::
Last address
ff19: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
ff19:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
9.1.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)

ff19::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
1ff19::/28ff19:f:ffff:ffff:ffff:ffff:ffff:ffff
2ff19:10::/28ff19:1f:ffff:ffff:ffff:ffff:ffff:ffff
3ff19:20::/28ff19:2f:ffff:ffff:ffff:ffff:ffff:ffff
4ff19:30::/28ff19:3f:ffff:ffff:ffff:ffff:ffff:ffff
5ff19:40::/28ff19:4f:ffff:ffff:ffff:ffff:ffff:ffff
6ff19:50::/28ff19:5f:ffff:ffff:ffff:ffff:ffff:ffff
7ff19:60::/28ff19:6f:ffff:ffff:ffff:ffff:ffff:ffff
8ff19:70::/28ff19:7f:ffff:ffff:ffff:ffff:ffff:ffff
9ff19:80::/28ff19:8f:ffff:ffff:ffff:ffff:ffff:ffff
10ff19:90::/28ff19:9f:ffff:ffff:ffff:ffff:ffff:ffff
11ff19:a0::/28ff19:af:ffff:ffff:ffff:ffff:ffff:ffff
12ff19:b0::/28ff19:bf:ffff:ffff:ffff:ffff:ffff:ffff
13ff19:c0::/28ff19:cf:ffff:ffff:ffff:ffff:ffff:ffff
14ff19:d0::/28ff19:df:ffff:ffff:ffff:ffff:ffff:ffff
15ff19:e0::/28ff19:ef:ffff:ffff:ffff:ffff:ffff:ffff
16ff19:f0::/28ff19:ff:ffff:ffff:ffff:ffff:ffff:ffff
17ff19:100::/28ff19:10f:ffff:ffff:ffff:ffff:ffff:ffff
18ff19:110::/28ff19:11f:ffff:ffff:ffff:ffff:ffff:ffff
19ff19:120::/28ff19:12f:ffff:ffff:ffff:ffff:ffff:ffff
20ff19:130::/28ff19:13f:ffff:ffff:ffff:ffff:ffff:ffff
21ff19:140::/28ff19:14f:ffff:ffff:ffff:ffff:ffff:ffff
22ff19:150::/28ff19:15f:ffff:ffff:ffff:ffff:ffff:ffff
23ff19:160::/28ff19:16f:ffff:ffff:ffff:ffff:ffff:ffff
24ff19:170::/28ff19:17f:ffff:ffff:ffff:ffff:ffff:ffff
25ff19:180::/28ff19:18f:ffff:ffff:ffff:ffff:ffff:ffff
26ff19:190::/28ff19:19f:ffff:ffff:ffff:ffff:ffff:ffff
27ff19:1a0::/28ff19:1af:ffff:ffff:ffff:ffff:ffff:ffff
28ff19:1b0::/28ff19:1bf:ffff:ffff:ffff:ffff:ffff:ffff
29ff19:1c0::/28ff19:1cf:ffff:ffff:ffff:ffff:ffff:ffff
30ff19:1d0::/28ff19:1df:ffff:ffff:ffff:ffff:ffff:ffff
31ff19:1e0::/28ff19:1ef:ffff:ffff:ffff:ffff:ffff:ffff
32ff19:1f0::/28ff19:1ff:ffff:ffff:ffff:ffff:ffff:ffff
33ff19:200::/28ff19:20f:ffff:ffff:ffff:ffff:ffff:ffff
34ff19:210::/28ff19:21f:ffff:ffff:ffff:ffff:ffff:ffff
35ff19:220::/28ff19:22f:ffff:ffff:ffff:ffff:ffff:ffff
36ff19:230::/28ff19:23f:ffff:ffff:ffff:ffff:ffff:ffff
37ff19:240::/28ff19:24f:ffff:ffff:ffff:ffff:ffff:ffff
38ff19:250::/28ff19:25f:ffff:ffff:ffff:ffff:ffff:ffff
39ff19:260::/28ff19:26f:ffff:ffff:ffff:ffff:ffff:ffff
40ff19:270::/28ff19:27f:ffff:ffff:ffff:ffff:ffff:ffff
41ff19:280::/28ff19:28f:ffff:ffff:ffff:ffff:ffff:ffff
42ff19:290::/28ff19:29f:ffff:ffff:ffff:ffff:ffff:ffff
43ff19:2a0::/28ff19:2af:ffff:ffff:ffff:ffff:ffff:ffff
44ff19:2b0::/28ff19:2bf:ffff:ffff:ffff:ffff:ffff:ffff
45ff19:2c0::/28ff19:2cf:ffff:ffff:ffff:ffff:ffff:ffff
46ff19:2d0::/28ff19:2df:ffff:ffff:ffff:ffff:ffff:ffff
47ff19:2e0::/28ff19:2ef:ffff:ffff:ffff:ffff:ffff:ffff
48ff19:2f0::/28ff19:2ff:ffff:ffff:ffff:ffff:ffff:ffff
49ff19:300::/28ff19:30f:ffff:ffff:ffff:ffff:ffff:ffff
50ff19:310::/28ff19:31f:ffff:ffff:ffff:ffff:ffff:ffff
51ff19:320::/28ff19:32f:ffff:ffff:ffff:ffff:ffff:ffff
52ff19:330::/28ff19:33f:ffff:ffff:ffff:ffff:ffff:ffff
53ff19:340::/28ff19:34f:ffff:ffff:ffff:ffff:ffff:ffff
54ff19:350::/28ff19:35f:ffff:ffff:ffff:ffff:ffff:ffff
55ff19:360::/28ff19:36f:ffff:ffff:ffff:ffff:ffff:ffff
56ff19:370::/28ff19:37f:ffff:ffff:ffff:ffff:ffff:ffff
57ff19:380::/28ff19:38f:ffff:ffff:ffff:ffff:ffff:ffff
58ff19:390::/28ff19:39f:ffff:ffff:ffff:ffff:ffff:ffff
59ff19:3a0::/28ff19:3af:ffff:ffff:ffff:ffff:ffff:ffff
60ff19:3b0::/28ff19:3bf:ffff:ffff:ffff:ffff:ffff:ffff
61ff19:3c0::/28ff19:3cf:ffff:ffff:ffff:ffff:ffff:ffff
62ff19:3d0::/28ff19:3df:ffff:ffff:ffff:ffff:ffff:ffff
63ff19:3e0::/28ff19:3ef:ffff:ffff:ffff:ffff:ffff:ffff
64ff19:3f0::/28ff19:3ff:ffff:ffff:ffff:ffff:ffff:ffff
65ff19:400::/28ff19:40f:ffff:ffff:ffff:ffff:ffff:ffff
66ff19:410::/28ff19:41f:ffff:ffff:ffff:ffff:ffff:ffff
67ff19:420::/28ff19:42f:ffff:ffff:ffff:ffff:ffff:ffff
68ff19:430::/28ff19:43f:ffff:ffff:ffff:ffff:ffff:ffff
69ff19:440::/28ff19:44f:ffff:ffff:ffff:ffff:ffff:ffff
70ff19:450::/28ff19:45f:ffff:ffff:ffff:ffff:ffff:ffff
71ff19:460::/28ff19:46f:ffff:ffff:ffff:ffff:ffff:ffff
72ff19:470::/28ff19:47f:ffff:ffff:ffff:ffff:ffff:ffff
73ff19:480::/28ff19:48f:ffff:ffff:ffff:ffff:ffff:ffff
74ff19:490::/28ff19:49f:ffff:ffff:ffff:ffff:ffff:ffff
75ff19:4a0::/28ff19:4af:ffff:ffff:ffff:ffff:ffff:ffff
76ff19:4b0::/28ff19:4bf:ffff:ffff:ffff:ffff:ffff:ffff
77ff19:4c0::/28ff19:4cf:ffff:ffff:ffff:ffff:ffff:ffff
78ff19:4d0::/28ff19:4df:ffff:ffff:ffff:ffff:ffff:ffff
79ff19:4e0::/28ff19:4ef:ffff:ffff:ffff:ffff:ffff:ffff
80ff19:4f0::/28ff19:4ff:ffff:ffff:ffff:ffff:ffff:ffff
81ff19:500::/28ff19:50f:ffff:ffff:ffff:ffff:ffff:ffff
82ff19:510::/28ff19:51f:ffff:ffff:ffff:ffff:ffff:ffff
83ff19:520::/28ff19:52f:ffff:ffff:ffff:ffff:ffff:ffff
84ff19:530::/28ff19:53f:ffff:ffff:ffff:ffff:ffff:ffff
85ff19:540::/28ff19:54f:ffff:ffff:ffff:ffff:ffff:ffff
86ff19:550::/28ff19:55f:ffff:ffff:ffff:ffff:ffff:ffff
87ff19:560::/28ff19:56f:ffff:ffff:ffff:ffff:ffff:ffff
88ff19:570::/28ff19:57f:ffff:ffff:ffff:ffff:ffff:ffff
89ff19:580::/28ff19:58f:ffff:ffff:ffff:ffff:ffff:ffff
90ff19:590::/28ff19:59f:ffff:ffff:ffff:ffff:ffff:ffff
91ff19:5a0::/28ff19:5af:ffff:ffff:ffff:ffff:ffff:ffff
92ff19:5b0::/28ff19:5bf:ffff:ffff:ffff:ffff:ffff:ffff
93ff19:5c0::/28ff19:5cf:ffff:ffff:ffff:ffff:ffff:ffff
94ff19:5d0::/28ff19:5df:ffff:ffff:ffff:ffff:ffff:ffff
95ff19:5e0::/28ff19:5ef:ffff:ffff:ffff:ffff:ffff:ffff
96ff19:5f0::/28ff19:5ff:ffff:ffff:ffff:ffff:ffff:ffff
97ff19:600::/28ff19:60f:ffff:ffff:ffff:ffff:ffff:ffff
98ff19:610::/28ff19:61f:ffff:ffff:ffff:ffff:ffff:ffff
99ff19:620::/28ff19:62f:ffff:ffff:ffff:ffff:ffff:ffff
100ff19:630::/28ff19:63f:ffff:ffff:ffff:ffff:ffff:ffff
101ff19:640::/28ff19:64f:ffff:ffff:ffff:ffff:ffff:ffff
102ff19:650::/28ff19:65f:ffff:ffff:ffff:ffff:ffff:ffff
103ff19:660::/28ff19:66f:ffff:ffff:ffff:ffff:ffff:ffff
104ff19:670::/28ff19:67f:ffff:ffff:ffff:ffff:ffff:ffff
105ff19:680::/28ff19:68f:ffff:ffff:ffff:ffff:ffff:ffff
106ff19:690::/28ff19:69f:ffff:ffff:ffff:ffff:ffff:ffff
107ff19:6a0::/28ff19:6af:ffff:ffff:ffff:ffff:ffff:ffff
108ff19:6b0::/28ff19:6bf:ffff:ffff:ffff:ffff:ffff:ffff
109ff19:6c0::/28ff19:6cf:ffff:ffff:ffff:ffff:ffff:ffff
110ff19:6d0::/28ff19:6df:ffff:ffff:ffff:ffff:ffff:ffff
111ff19:6e0::/28ff19:6ef:ffff:ffff:ffff:ffff:ffff:ffff
112ff19:6f0::/28ff19:6ff:ffff:ffff:ffff:ffff:ffff:ffff
113ff19:700::/28ff19:70f:ffff:ffff:ffff:ffff:ffff:ffff
114ff19:710::/28ff19:71f:ffff:ffff:ffff:ffff:ffff:ffff
115ff19:720::/28ff19:72f:ffff:ffff:ffff:ffff:ffff:ffff
116ff19:730::/28ff19:73f:ffff:ffff:ffff:ffff:ffff:ffff
117ff19:740::/28ff19:74f:ffff:ffff:ffff:ffff:ffff:ffff
118ff19:750::/28ff19:75f:ffff:ffff:ffff:ffff:ffff:ffff
119ff19:760::/28ff19:76f:ffff:ffff:ffff:ffff:ffff:ffff
120ff19:770::/28ff19:77f:ffff:ffff:ffff:ffff:ffff:ffff
121ff19:780::/28ff19:78f:ffff:ffff:ffff:ffff:ffff:ffff
122ff19:790::/28ff19:79f:ffff:ffff:ffff:ffff:ffff:ffff
123ff19:7a0::/28ff19:7af:ffff:ffff:ffff:ffff:ffff:ffff
124ff19:7b0::/28ff19:7bf:ffff:ffff:ffff:ffff:ffff:ffff
125ff19:7c0::/28ff19:7cf:ffff:ffff:ffff:ffff:ffff:ffff
126ff19:7d0::/28ff19:7df:ffff:ffff:ffff:ffff:ffff:ffff
127ff19:7e0::/28ff19:7ef:ffff:ffff:ffff:ffff:ffff:ffff
128ff19:7f0::/28ff19:7ff:ffff:ffff:ffff:ffff:ffff:ffff
129ff19:800::/28ff19:80f:ffff:ffff:ffff:ffff:ffff:ffff
130ff19:810::/28ff19:81f:ffff:ffff:ffff:ffff:ffff:ffff
131ff19:820::/28ff19:82f:ffff:ffff:ffff:ffff:ffff:ffff
132ff19:830::/28ff19:83f:ffff:ffff:ffff:ffff:ffff:ffff
133ff19:840::/28ff19:84f:ffff:ffff:ffff:ffff:ffff:ffff
134ff19:850::/28ff19:85f:ffff:ffff:ffff:ffff:ffff:ffff
135ff19:860::/28ff19:86f:ffff:ffff:ffff:ffff:ffff:ffff
136ff19:870::/28ff19:87f:ffff:ffff:ffff:ffff:ffff:ffff
137ff19:880::/28ff19:88f:ffff:ffff:ffff:ffff:ffff:ffff
138ff19:890::/28ff19:89f:ffff:ffff:ffff:ffff:ffff:ffff
139ff19:8a0::/28ff19:8af:ffff:ffff:ffff:ffff:ffff:ffff
140ff19:8b0::/28ff19:8bf:ffff:ffff:ffff:ffff:ffff:ffff
141ff19:8c0::/28ff19:8cf:ffff:ffff:ffff:ffff:ffff:ffff
142ff19:8d0::/28ff19:8df:ffff:ffff:ffff:ffff:ffff:ffff
143ff19:8e0::/28ff19:8ef:ffff:ffff:ffff:ffff:ffff:ffff
144ff19:8f0::/28ff19:8ff:ffff:ffff:ffff:ffff:ffff:ffff
145ff19:900::/28ff19:90f:ffff:ffff:ffff:ffff:ffff:ffff
146ff19:910::/28ff19:91f:ffff:ffff:ffff:ffff:ffff:ffff
147ff19:920::/28ff19:92f:ffff:ffff:ffff:ffff:ffff:ffff
148ff19:930::/28ff19:93f:ffff:ffff:ffff:ffff:ffff:ffff
149ff19:940::/28ff19:94f:ffff:ffff:ffff:ffff:ffff:ffff
150ff19:950::/28ff19:95f:ffff:ffff:ffff:ffff:ffff:ffff
151ff19:960::/28ff19:96f:ffff:ffff:ffff:ffff:ffff:ffff
152ff19:970::/28ff19:97f:ffff:ffff:ffff:ffff:ffff:ffff
153ff19:980::/28ff19:98f:ffff:ffff:ffff:ffff:ffff:ffff
154ff19:990::/28ff19:99f:ffff:ffff:ffff:ffff:ffff:ffff
155ff19:9a0::/28ff19:9af:ffff:ffff:ffff:ffff:ffff:ffff
156ff19:9b0::/28ff19:9bf:ffff:ffff:ffff:ffff:ffff:ffff
157ff19:9c0::/28ff19:9cf:ffff:ffff:ffff:ffff:ffff:ffff
158ff19:9d0::/28ff19:9df:ffff:ffff:ffff:ffff:ffff:ffff
159ff19:9e0::/28ff19:9ef:ffff:ffff:ffff:ffff:ffff:ffff
160ff19:9f0::/28ff19:9ff:ffff:ffff:ffff:ffff:ffff:ffff
161ff19:a00::/28ff19:a0f:ffff:ffff:ffff:ffff:ffff:ffff
162ff19:a10::/28ff19:a1f:ffff:ffff:ffff:ffff:ffff:ffff
163ff19:a20::/28ff19:a2f:ffff:ffff:ffff:ffff:ffff:ffff
164ff19:a30::/28ff19:a3f:ffff:ffff:ffff:ffff:ffff:ffff
165ff19:a40::/28ff19:a4f:ffff:ffff:ffff:ffff:ffff:ffff
166ff19:a50::/28ff19:a5f:ffff:ffff:ffff:ffff:ffff:ffff
167ff19:a60::/28ff19:a6f:ffff:ffff:ffff:ffff:ffff:ffff
168ff19:a70::/28ff19:a7f:ffff:ffff:ffff:ffff:ffff:ffff
169ff19:a80::/28ff19:a8f:ffff:ffff:ffff:ffff:ffff:ffff
170ff19:a90::/28ff19:a9f:ffff:ffff:ffff:ffff:ffff:ffff
171ff19:aa0::/28ff19:aaf:ffff:ffff:ffff:ffff:ffff:ffff
172ff19:ab0::/28ff19:abf:ffff:ffff:ffff:ffff:ffff:ffff
173ff19:ac0::/28ff19:acf:ffff:ffff:ffff:ffff:ffff:ffff
174ff19:ad0::/28ff19:adf:ffff:ffff:ffff:ffff:ffff:ffff
175ff19:ae0::/28ff19:aef:ffff:ffff:ffff:ffff:ffff:ffff
176ff19:af0::/28ff19:aff:ffff:ffff:ffff:ffff:ffff:ffff
177ff19:b00::/28ff19:b0f:ffff:ffff:ffff:ffff:ffff:ffff
178ff19:b10::/28ff19:b1f:ffff:ffff:ffff:ffff:ffff:ffff
179ff19:b20::/28ff19:b2f:ffff:ffff:ffff:ffff:ffff:ffff
180ff19:b30::/28ff19:b3f:ffff:ffff:ffff:ffff:ffff:ffff
181ff19:b40::/28ff19:b4f:ffff:ffff:ffff:ffff:ffff:ffff
182ff19:b50::/28ff19:b5f:ffff:ffff:ffff:ffff:ffff:ffff
183ff19:b60::/28ff19:b6f:ffff:ffff:ffff:ffff:ffff:ffff
184ff19:b70::/28ff19:b7f:ffff:ffff:ffff:ffff:ffff:ffff
185ff19:b80::/28ff19:b8f:ffff:ffff:ffff:ffff:ffff:ffff
186ff19:b90::/28ff19:b9f:ffff:ffff:ffff:ffff:ffff:ffff
187ff19:ba0::/28ff19:baf:ffff:ffff:ffff:ffff:ffff:ffff
188ff19:bb0::/28ff19:bbf:ffff:ffff:ffff:ffff:ffff:ffff
189ff19:bc0::/28ff19:bcf:ffff:ffff:ffff:ffff:ffff:ffff
190ff19:bd0::/28ff19:bdf:ffff:ffff:ffff:ffff:ffff:ffff
191ff19:be0::/28ff19:bef:ffff:ffff:ffff:ffff:ffff:ffff
192ff19:bf0::/28ff19:bff:ffff:ffff:ffff:ffff:ffff:ffff
193ff19:c00::/28ff19:c0f:ffff:ffff:ffff:ffff:ffff:ffff
194ff19:c10::/28ff19:c1f:ffff:ffff:ffff:ffff:ffff:ffff
195ff19:c20::/28ff19:c2f:ffff:ffff:ffff:ffff:ffff:ffff
196ff19:c30::/28ff19:c3f:ffff:ffff:ffff:ffff:ffff:ffff
197ff19:c40::/28ff19:c4f:ffff:ffff:ffff:ffff:ffff:ffff
198ff19:c50::/28ff19:c5f:ffff:ffff:ffff:ffff:ffff:ffff
199ff19:c60::/28ff19:c6f:ffff:ffff:ffff:ffff:ffff:ffff
200ff19:c70::/28ff19:c7f:ffff:ffff:ffff:ffff:ffff:ffff
201ff19:c80::/28ff19:c8f:ffff:ffff:ffff:ffff:ffff:ffff
202ff19:c90::/28ff19:c9f:ffff:ffff:ffff:ffff:ffff:ffff
203ff19:ca0::/28ff19:caf:ffff:ffff:ffff:ffff:ffff:ffff
204ff19:cb0::/28ff19:cbf:ffff:ffff:ffff:ffff:ffff:ffff
205ff19:cc0::/28ff19:ccf:ffff:ffff:ffff:ffff:ffff:ffff
206ff19:cd0::/28ff19:cdf:ffff:ffff:ffff:ffff:ffff:ffff
207ff19:ce0::/28ff19:cef:ffff:ffff:ffff:ffff:ffff:ffff
208ff19:cf0::/28ff19:cff:ffff:ffff:ffff:ffff:ffff:ffff
209ff19:d00::/28ff19:d0f:ffff:ffff:ffff:ffff:ffff:ffff
210ff19:d10::/28ff19:d1f:ffff:ffff:ffff:ffff:ffff:ffff
211ff19:d20::/28ff19:d2f:ffff:ffff:ffff:ffff:ffff:ffff
212ff19:d30::/28ff19:d3f:ffff:ffff:ffff:ffff:ffff:ffff
213ff19:d40::/28ff19:d4f:ffff:ffff:ffff:ffff:ffff:ffff
214ff19:d50::/28ff19:d5f:ffff:ffff:ffff:ffff:ffff:ffff
215ff19:d60::/28ff19:d6f:ffff:ffff:ffff:ffff:ffff:ffff
216ff19:d70::/28ff19:d7f:ffff:ffff:ffff:ffff:ffff:ffff
217ff19:d80::/28ff19:d8f:ffff:ffff:ffff:ffff:ffff:ffff
218ff19:d90::/28ff19:d9f:ffff:ffff:ffff:ffff:ffff:ffff
219ff19:da0::/28ff19:daf:ffff:ffff:ffff:ffff:ffff:ffff
220ff19:db0::/28ff19:dbf:ffff:ffff:ffff:ffff:ffff:ffff
221ff19:dc0::/28ff19:dcf:ffff:ffff:ffff:ffff:ffff:ffff
222ff19:dd0::/28ff19:ddf:ffff:ffff:ffff:ffff:ffff:ffff
223ff19:de0::/28ff19:def:ffff:ffff:ffff:ffff:ffff:ffff
224ff19:df0::/28ff19:dff:ffff:ffff:ffff:ffff:ffff:ffff
225ff19:e00::/28ff19:e0f:ffff:ffff:ffff:ffff:ffff:ffff
226ff19:e10::/28ff19:e1f:ffff:ffff:ffff:ffff:ffff:ffff
227ff19:e20::/28ff19:e2f:ffff:ffff:ffff:ffff:ffff:ffff
228ff19:e30::/28ff19:e3f:ffff:ffff:ffff:ffff:ffff:ffff
229ff19:e40::/28ff19:e4f:ffff:ffff:ffff:ffff:ffff:ffff
230ff19:e50::/28ff19:e5f:ffff:ffff:ffff:ffff:ffff:ffff
231ff19:e60::/28ff19:e6f:ffff:ffff:ffff:ffff:ffff:ffff
232ff19:e70::/28ff19:e7f:ffff:ffff:ffff:ffff:ffff:ffff
233ff19:e80::/28ff19:e8f:ffff:ffff:ffff:ffff:ffff:ffff
234ff19:e90::/28ff19:e9f:ffff:ffff:ffff:ffff:ffff:ffff
235ff19:ea0::/28ff19:eaf:ffff:ffff:ffff:ffff:ffff:ffff
236ff19:eb0::/28ff19:ebf:ffff:ffff:ffff:ffff:ffff:ffff
237ff19:ec0::/28ff19:ecf:ffff:ffff:ffff:ffff:ffff:ffff
238ff19:ed0::/28ff19:edf:ffff:ffff:ffff:ffff:ffff:ffff
239ff19:ee0::/28ff19:eef:ffff:ffff:ffff:ffff:ffff:ffff
240ff19:ef0::/28ff19:eff:ffff:ffff:ffff:ffff:ffff:ffff
241ff19:f00::/28ff19:f0f:ffff:ffff:ffff:ffff:ffff:ffff
242ff19:f10::/28ff19:f1f:ffff:ffff:ffff:ffff:ffff:ffff
243ff19:f20::/28ff19:f2f:ffff:ffff:ffff:ffff:ffff:ffff
244ff19:f30::/28ff19:f3f:ffff:ffff:ffff:ffff:ffff:ffff
245ff19:f40::/28ff19:f4f:ffff:ffff:ffff:ffff:ffff:ffff
246ff19:f50::/28ff19:f5f:ffff:ffff:ffff:ffff:ffff:ffff
247ff19:f60::/28ff19:f6f:ffff:ffff:ffff:ffff:ffff:ffff
248ff19:f70::/28ff19:f7f:ffff:ffff:ffff:ffff:ffff:ffff
249ff19:f80::/28ff19:f8f:ffff:ffff:ffff:ffff:ffff:ffff
250ff19:f90::/28ff19:f9f:ffff:ffff:ffff:ffff:ffff:ffff
251ff19:fa0::/28ff19:faf:ffff:ffff:ffff:ffff:ffff:ffff
252ff19:fb0::/28ff19:fbf:ffff:ffff:ffff:ffff:ffff:ffff
253ff19:fc0::/28ff19:fcf:ffff:ffff:ffff:ffff:ffff:ffff
254ff19:fd0::/28ff19:fdf:ffff:ffff:ffff:ffff:ffff:ffff
255ff19:fe0::/28ff19:fef:ffff:ffff:ffff:ffff:ffff:ffff
256ff19:ff0::/28ff19: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.