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Speed and call quality testTest delay, jitter and speed, with a focus on phone calls.My IP addressYour public IPv4 and IPv6 addresses, provider and address range.WhoIs lookupWho owns a domain or IP address, when it expires, and its DNS.DNS reportEvery DNS record for a domain, with email setup checked.IP subnet calculatorWork out a network's range, mask and hosts, and split it into subnets.

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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
ff9f::/16
First address
ff9f::
Last address
ff9f: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
ff9f:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
f.9.f.f.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

ff9f::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1ff9f::/32ff9f:0:ffff:ffff:ffff:ffff:ffff:ffff
2ff9f:1::/32ff9f:1:ffff:ffff:ffff:ffff:ffff:ffff
3ff9f:2::/32ff9f:2:ffff:ffff:ffff:ffff:ffff:ffff
4ff9f:3::/32ff9f:3:ffff:ffff:ffff:ffff:ffff:ffff
5ff9f:4::/32ff9f:4:ffff:ffff:ffff:ffff:ffff:ffff
6ff9f:5::/32ff9f:5:ffff:ffff:ffff:ffff:ffff:ffff
7ff9f:6::/32ff9f:6:ffff:ffff:ffff:ffff:ffff:ffff
8ff9f:7::/32ff9f:7:ffff:ffff:ffff:ffff:ffff:ffff
9ff9f:8::/32ff9f:8:ffff:ffff:ffff:ffff:ffff:ffff
10ff9f:9::/32ff9f:9:ffff:ffff:ffff:ffff:ffff:ffff
11ff9f:a::/32ff9f:a:ffff:ffff:ffff:ffff:ffff:ffff
12ff9f:b::/32ff9f:b:ffff:ffff:ffff:ffff:ffff:ffff
13ff9f:c::/32ff9f:c:ffff:ffff:ffff:ffff:ffff:ffff
14ff9f:d::/32ff9f:d:ffff:ffff:ffff:ffff:ffff:ffff
15ff9f:e::/32ff9f:e:ffff:ffff:ffff:ffff:ffff:ffff
16ff9f:f::/32ff9f:f:ffff:ffff:ffff:ffff:ffff:ffff
17ff9f:10::/32ff9f:10:ffff:ffff:ffff:ffff:ffff:ffff
18ff9f:11::/32ff9f:11:ffff:ffff:ffff:ffff:ffff:ffff
19ff9f:12::/32ff9f:12:ffff:ffff:ffff:ffff:ffff:ffff
20ff9f:13::/32ff9f:13:ffff:ffff:ffff:ffff:ffff:ffff
21ff9f:14::/32ff9f:14:ffff:ffff:ffff:ffff:ffff:ffff
22ff9f:15::/32ff9f:15:ffff:ffff:ffff:ffff:ffff:ffff
23ff9f:16::/32ff9f:16:ffff:ffff:ffff:ffff:ffff:ffff
24ff9f:17::/32ff9f:17:ffff:ffff:ffff:ffff:ffff:ffff
25ff9f:18::/32ff9f:18:ffff:ffff:ffff:ffff:ffff:ffff
26ff9f:19::/32ff9f:19:ffff:ffff:ffff:ffff:ffff:ffff
27ff9f:1a::/32ff9f:1a:ffff:ffff:ffff:ffff:ffff:ffff
28ff9f:1b::/32ff9f:1b:ffff:ffff:ffff:ffff:ffff:ffff
29ff9f:1c::/32ff9f:1c:ffff:ffff:ffff:ffff:ffff:ffff
30ff9f:1d::/32ff9f:1d:ffff:ffff:ffff:ffff:ffff:ffff
31ff9f:1e::/32ff9f:1e:ffff:ffff:ffff:ffff:ffff:ffff
32ff9f:1f::/32ff9f:1f:ffff:ffff:ffff:ffff:ffff:ffff
33ff9f:20::/32ff9f:20:ffff:ffff:ffff:ffff:ffff:ffff
34ff9f:21::/32ff9f:21:ffff:ffff:ffff:ffff:ffff:ffff
35ff9f:22::/32ff9f:22:ffff:ffff:ffff:ffff:ffff:ffff
36ff9f:23::/32ff9f:23:ffff:ffff:ffff:ffff:ffff:ffff
37ff9f:24::/32ff9f:24:ffff:ffff:ffff:ffff:ffff:ffff
38ff9f:25::/32ff9f:25:ffff:ffff:ffff:ffff:ffff:ffff
39ff9f:26::/32ff9f:26:ffff:ffff:ffff:ffff:ffff:ffff
40ff9f:27::/32ff9f:27:ffff:ffff:ffff:ffff:ffff:ffff
41ff9f:28::/32ff9f:28:ffff:ffff:ffff:ffff:ffff:ffff
42ff9f:29::/32ff9f:29:ffff:ffff:ffff:ffff:ffff:ffff
43ff9f:2a::/32ff9f:2a:ffff:ffff:ffff:ffff:ffff:ffff
44ff9f:2b::/32ff9f:2b:ffff:ffff:ffff:ffff:ffff:ffff
45ff9f:2c::/32ff9f:2c:ffff:ffff:ffff:ffff:ffff:ffff
46ff9f:2d::/32ff9f:2d:ffff:ffff:ffff:ffff:ffff:ffff
47ff9f:2e::/32ff9f:2e:ffff:ffff:ffff:ffff:ffff:ffff
48ff9f:2f::/32ff9f:2f:ffff:ffff:ffff:ffff:ffff:ffff
49ff9f:30::/32ff9f:30:ffff:ffff:ffff:ffff:ffff:ffff
50ff9f:31::/32ff9f:31:ffff:ffff:ffff:ffff:ffff:ffff
51ff9f:32::/32ff9f:32:ffff:ffff:ffff:ffff:ffff:ffff
52ff9f:33::/32ff9f:33:ffff:ffff:ffff:ffff:ffff:ffff
53ff9f:34::/32ff9f:34:ffff:ffff:ffff:ffff:ffff:ffff
54ff9f:35::/32ff9f:35:ffff:ffff:ffff:ffff:ffff:ffff
55ff9f:36::/32ff9f:36:ffff:ffff:ffff:ffff:ffff:ffff
56ff9f:37::/32ff9f:37:ffff:ffff:ffff:ffff:ffff:ffff
57ff9f:38::/32ff9f:38:ffff:ffff:ffff:ffff:ffff:ffff
58ff9f:39::/32ff9f:39:ffff:ffff:ffff:ffff:ffff:ffff
59ff9f:3a::/32ff9f:3a:ffff:ffff:ffff:ffff:ffff:ffff
60ff9f:3b::/32ff9f:3b:ffff:ffff:ffff:ffff:ffff:ffff
61ff9f:3c::/32ff9f:3c:ffff:ffff:ffff:ffff:ffff:ffff
62ff9f:3d::/32ff9f:3d:ffff:ffff:ffff:ffff:ffff:ffff
63ff9f:3e::/32ff9f:3e:ffff:ffff:ffff:ffff:ffff:ffff
64ff9f:3f::/32ff9f:3f:ffff:ffff:ffff:ffff:ffff:ffff
65ff9f:40::/32ff9f:40:ffff:ffff:ffff:ffff:ffff:ffff
66ff9f:41::/32ff9f:41:ffff:ffff:ffff:ffff:ffff:ffff
67ff9f:42::/32ff9f:42:ffff:ffff:ffff:ffff:ffff:ffff
68ff9f:43::/32ff9f:43:ffff:ffff:ffff:ffff:ffff:ffff
69ff9f:44::/32ff9f:44:ffff:ffff:ffff:ffff:ffff:ffff
70ff9f:45::/32ff9f:45:ffff:ffff:ffff:ffff:ffff:ffff
71ff9f:46::/32ff9f:46:ffff:ffff:ffff:ffff:ffff:ffff
72ff9f:47::/32ff9f:47:ffff:ffff:ffff:ffff:ffff:ffff
73ff9f:48::/32ff9f:48:ffff:ffff:ffff:ffff:ffff:ffff
74ff9f:49::/32ff9f:49:ffff:ffff:ffff:ffff:ffff:ffff
75ff9f:4a::/32ff9f:4a:ffff:ffff:ffff:ffff:ffff:ffff
76ff9f:4b::/32ff9f:4b:ffff:ffff:ffff:ffff:ffff:ffff
77ff9f:4c::/32ff9f:4c:ffff:ffff:ffff:ffff:ffff:ffff
78ff9f:4d::/32ff9f:4d:ffff:ffff:ffff:ffff:ffff:ffff
79ff9f:4e::/32ff9f:4e:ffff:ffff:ffff:ffff:ffff:ffff
80ff9f:4f::/32ff9f:4f:ffff:ffff:ffff:ffff:ffff:ffff
81ff9f:50::/32ff9f:50:ffff:ffff:ffff:ffff:ffff:ffff
82ff9f:51::/32ff9f:51:ffff:ffff:ffff:ffff:ffff:ffff
83ff9f:52::/32ff9f:52:ffff:ffff:ffff:ffff:ffff:ffff
84ff9f:53::/32ff9f:53:ffff:ffff:ffff:ffff:ffff:ffff
85ff9f:54::/32ff9f:54:ffff:ffff:ffff:ffff:ffff:ffff
86ff9f:55::/32ff9f:55:ffff:ffff:ffff:ffff:ffff:ffff
87ff9f:56::/32ff9f:56:ffff:ffff:ffff:ffff:ffff:ffff
88ff9f:57::/32ff9f:57:ffff:ffff:ffff:ffff:ffff:ffff
89ff9f:58::/32ff9f:58:ffff:ffff:ffff:ffff:ffff:ffff
90ff9f:59::/32ff9f:59:ffff:ffff:ffff:ffff:ffff:ffff
91ff9f:5a::/32ff9f:5a:ffff:ffff:ffff:ffff:ffff:ffff
92ff9f:5b::/32ff9f:5b:ffff:ffff:ffff:ffff:ffff:ffff
93ff9f:5c::/32ff9f:5c:ffff:ffff:ffff:ffff:ffff:ffff
94ff9f:5d::/32ff9f:5d:ffff:ffff:ffff:ffff:ffff:ffff
95ff9f:5e::/32ff9f:5e:ffff:ffff:ffff:ffff:ffff:ffff
96ff9f:5f::/32ff9f:5f:ffff:ffff:ffff:ffff:ffff:ffff
97ff9f:60::/32ff9f:60:ffff:ffff:ffff:ffff:ffff:ffff
98ff9f:61::/32ff9f:61:ffff:ffff:ffff:ffff:ffff:ffff
99ff9f:62::/32ff9f:62:ffff:ffff:ffff:ffff:ffff:ffff
100ff9f:63::/32ff9f:63:ffff:ffff:ffff:ffff:ffff:ffff
101ff9f:64::/32ff9f:64:ffff:ffff:ffff:ffff:ffff:ffff
102ff9f:65::/32ff9f:65:ffff:ffff:ffff:ffff:ffff:ffff
103ff9f:66::/32ff9f:66:ffff:ffff:ffff:ffff:ffff:ffff
104ff9f:67::/32ff9f:67:ffff:ffff:ffff:ffff:ffff:ffff
105ff9f:68::/32ff9f:68:ffff:ffff:ffff:ffff:ffff:ffff
106ff9f:69::/32ff9f:69:ffff:ffff:ffff:ffff:ffff:ffff
107ff9f:6a::/32ff9f:6a:ffff:ffff:ffff:ffff:ffff:ffff
108ff9f:6b::/32ff9f:6b:ffff:ffff:ffff:ffff:ffff:ffff
109ff9f:6c::/32ff9f:6c:ffff:ffff:ffff:ffff:ffff:ffff
110ff9f:6d::/32ff9f:6d:ffff:ffff:ffff:ffff:ffff:ffff
111ff9f:6e::/32ff9f:6e:ffff:ffff:ffff:ffff:ffff:ffff
112ff9f:6f::/32ff9f:6f:ffff:ffff:ffff:ffff:ffff:ffff
113ff9f:70::/32ff9f:70:ffff:ffff:ffff:ffff:ffff:ffff
114ff9f:71::/32ff9f:71:ffff:ffff:ffff:ffff:ffff:ffff
115ff9f:72::/32ff9f:72:ffff:ffff:ffff:ffff:ffff:ffff
116ff9f:73::/32ff9f:73:ffff:ffff:ffff:ffff:ffff:ffff
117ff9f:74::/32ff9f:74:ffff:ffff:ffff:ffff:ffff:ffff
118ff9f:75::/32ff9f:75:ffff:ffff:ffff:ffff:ffff:ffff
119ff9f:76::/32ff9f:76:ffff:ffff:ffff:ffff:ffff:ffff
120ff9f:77::/32ff9f:77:ffff:ffff:ffff:ffff:ffff:ffff
121ff9f:78::/32ff9f:78:ffff:ffff:ffff:ffff:ffff:ffff
122ff9f:79::/32ff9f:79:ffff:ffff:ffff:ffff:ffff:ffff
123ff9f:7a::/32ff9f:7a:ffff:ffff:ffff:ffff:ffff:ffff
124ff9f:7b::/32ff9f:7b:ffff:ffff:ffff:ffff:ffff:ffff
125ff9f:7c::/32ff9f:7c:ffff:ffff:ffff:ffff:ffff:ffff
126ff9f:7d::/32ff9f:7d:ffff:ffff:ffff:ffff:ffff:ffff
127ff9f:7e::/32ff9f:7e:ffff:ffff:ffff:ffff:ffff:ffff
128ff9f:7f::/32ff9f:7f:ffff:ffff:ffff:ffff:ffff:ffff
129ff9f:80::/32ff9f:80:ffff:ffff:ffff:ffff:ffff:ffff
130ff9f:81::/32ff9f:81:ffff:ffff:ffff:ffff:ffff:ffff
131ff9f:82::/32ff9f:82:ffff:ffff:ffff:ffff:ffff:ffff
132ff9f:83::/32ff9f:83:ffff:ffff:ffff:ffff:ffff:ffff
133ff9f:84::/32ff9f:84:ffff:ffff:ffff:ffff:ffff:ffff
134ff9f:85::/32ff9f:85:ffff:ffff:ffff:ffff:ffff:ffff
135ff9f:86::/32ff9f:86:ffff:ffff:ffff:ffff:ffff:ffff
136ff9f:87::/32ff9f:87:ffff:ffff:ffff:ffff:ffff:ffff
137ff9f:88::/32ff9f:88:ffff:ffff:ffff:ffff:ffff:ffff
138ff9f:89::/32ff9f:89:ffff:ffff:ffff:ffff:ffff:ffff
139ff9f:8a::/32ff9f:8a:ffff:ffff:ffff:ffff:ffff:ffff
140ff9f:8b::/32ff9f:8b:ffff:ffff:ffff:ffff:ffff:ffff
141ff9f:8c::/32ff9f:8c:ffff:ffff:ffff:ffff:ffff:ffff
142ff9f:8d::/32ff9f:8d:ffff:ffff:ffff:ffff:ffff:ffff
143ff9f:8e::/32ff9f:8e:ffff:ffff:ffff:ffff:ffff:ffff
144ff9f:8f::/32ff9f:8f:ffff:ffff:ffff:ffff:ffff:ffff
145ff9f:90::/32ff9f:90:ffff:ffff:ffff:ffff:ffff:ffff
146ff9f:91::/32ff9f:91:ffff:ffff:ffff:ffff:ffff:ffff
147ff9f:92::/32ff9f:92:ffff:ffff:ffff:ffff:ffff:ffff
148ff9f:93::/32ff9f:93:ffff:ffff:ffff:ffff:ffff:ffff
149ff9f:94::/32ff9f:94:ffff:ffff:ffff:ffff:ffff:ffff
150ff9f:95::/32ff9f:95:ffff:ffff:ffff:ffff:ffff:ffff
151ff9f:96::/32ff9f:96:ffff:ffff:ffff:ffff:ffff:ffff
152ff9f:97::/32ff9f:97:ffff:ffff:ffff:ffff:ffff:ffff
153ff9f:98::/32ff9f:98:ffff:ffff:ffff:ffff:ffff:ffff
154ff9f:99::/32ff9f:99:ffff:ffff:ffff:ffff:ffff:ffff
155ff9f:9a::/32ff9f:9a:ffff:ffff:ffff:ffff:ffff:ffff
156ff9f:9b::/32ff9f:9b:ffff:ffff:ffff:ffff:ffff:ffff
157ff9f:9c::/32ff9f:9c:ffff:ffff:ffff:ffff:ffff:ffff
158ff9f:9d::/32ff9f:9d:ffff:ffff:ffff:ffff:ffff:ffff
159ff9f:9e::/32ff9f:9e:ffff:ffff:ffff:ffff:ffff:ffff
160ff9f:9f::/32ff9f:9f:ffff:ffff:ffff:ffff:ffff:ffff
161ff9f:a0::/32ff9f:a0:ffff:ffff:ffff:ffff:ffff:ffff
162ff9f:a1::/32ff9f:a1:ffff:ffff:ffff:ffff:ffff:ffff
163ff9f:a2::/32ff9f:a2:ffff:ffff:ffff:ffff:ffff:ffff
164ff9f:a3::/32ff9f:a3:ffff:ffff:ffff:ffff:ffff:ffff
165ff9f:a4::/32ff9f:a4:ffff:ffff:ffff:ffff:ffff:ffff
166ff9f:a5::/32ff9f:a5:ffff:ffff:ffff:ffff:ffff:ffff
167ff9f:a6::/32ff9f:a6:ffff:ffff:ffff:ffff:ffff:ffff
168ff9f:a7::/32ff9f:a7:ffff:ffff:ffff:ffff:ffff:ffff
169ff9f:a8::/32ff9f:a8:ffff:ffff:ffff:ffff:ffff:ffff
170ff9f:a9::/32ff9f:a9:ffff:ffff:ffff:ffff:ffff:ffff
171ff9f:aa::/32ff9f:aa:ffff:ffff:ffff:ffff:ffff:ffff
172ff9f:ab::/32ff9f:ab:ffff:ffff:ffff:ffff:ffff:ffff
173ff9f:ac::/32ff9f:ac:ffff:ffff:ffff:ffff:ffff:ffff
174ff9f:ad::/32ff9f:ad:ffff:ffff:ffff:ffff:ffff:ffff
175ff9f:ae::/32ff9f:ae:ffff:ffff:ffff:ffff:ffff:ffff
176ff9f:af::/32ff9f:af:ffff:ffff:ffff:ffff:ffff:ffff
177ff9f:b0::/32ff9f:b0:ffff:ffff:ffff:ffff:ffff:ffff
178ff9f:b1::/32ff9f:b1:ffff:ffff:ffff:ffff:ffff:ffff
179ff9f:b2::/32ff9f:b2:ffff:ffff:ffff:ffff:ffff:ffff
180ff9f:b3::/32ff9f:b3:ffff:ffff:ffff:ffff:ffff:ffff
181ff9f:b4::/32ff9f:b4:ffff:ffff:ffff:ffff:ffff:ffff
182ff9f:b5::/32ff9f:b5:ffff:ffff:ffff:ffff:ffff:ffff
183ff9f:b6::/32ff9f:b6:ffff:ffff:ffff:ffff:ffff:ffff
184ff9f:b7::/32ff9f:b7:ffff:ffff:ffff:ffff:ffff:ffff
185ff9f:b8::/32ff9f:b8:ffff:ffff:ffff:ffff:ffff:ffff
186ff9f:b9::/32ff9f:b9:ffff:ffff:ffff:ffff:ffff:ffff
187ff9f:ba::/32ff9f:ba:ffff:ffff:ffff:ffff:ffff:ffff
188ff9f:bb::/32ff9f:bb:ffff:ffff:ffff:ffff:ffff:ffff
189ff9f:bc::/32ff9f:bc:ffff:ffff:ffff:ffff:ffff:ffff
190ff9f:bd::/32ff9f:bd:ffff:ffff:ffff:ffff:ffff:ffff
191ff9f:be::/32ff9f:be:ffff:ffff:ffff:ffff:ffff:ffff
192ff9f:bf::/32ff9f:bf:ffff:ffff:ffff:ffff:ffff:ffff
193ff9f:c0::/32ff9f:c0:ffff:ffff:ffff:ffff:ffff:ffff
194ff9f:c1::/32ff9f:c1:ffff:ffff:ffff:ffff:ffff:ffff
195ff9f:c2::/32ff9f:c2:ffff:ffff:ffff:ffff:ffff:ffff
196ff9f:c3::/32ff9f:c3:ffff:ffff:ffff:ffff:ffff:ffff
197ff9f:c4::/32ff9f:c4:ffff:ffff:ffff:ffff:ffff:ffff
198ff9f:c5::/32ff9f:c5:ffff:ffff:ffff:ffff:ffff:ffff
199ff9f:c6::/32ff9f:c6:ffff:ffff:ffff:ffff:ffff:ffff
200ff9f:c7::/32ff9f:c7:ffff:ffff:ffff:ffff:ffff:ffff
201ff9f:c8::/32ff9f:c8:ffff:ffff:ffff:ffff:ffff:ffff
202ff9f:c9::/32ff9f:c9:ffff:ffff:ffff:ffff:ffff:ffff
203ff9f:ca::/32ff9f:ca:ffff:ffff:ffff:ffff:ffff:ffff
204ff9f:cb::/32ff9f:cb:ffff:ffff:ffff:ffff:ffff:ffff
205ff9f:cc::/32ff9f:cc:ffff:ffff:ffff:ffff:ffff:ffff
206ff9f:cd::/32ff9f:cd:ffff:ffff:ffff:ffff:ffff:ffff
207ff9f:ce::/32ff9f:ce:ffff:ffff:ffff:ffff:ffff:ffff
208ff9f:cf::/32ff9f:cf:ffff:ffff:ffff:ffff:ffff:ffff
209ff9f:d0::/32ff9f:d0:ffff:ffff:ffff:ffff:ffff:ffff
210ff9f:d1::/32ff9f:d1:ffff:ffff:ffff:ffff:ffff:ffff
211ff9f:d2::/32ff9f:d2:ffff:ffff:ffff:ffff:ffff:ffff
212ff9f:d3::/32ff9f:d3:ffff:ffff:ffff:ffff:ffff:ffff
213ff9f:d4::/32ff9f:d4:ffff:ffff:ffff:ffff:ffff:ffff
214ff9f:d5::/32ff9f:d5:ffff:ffff:ffff:ffff:ffff:ffff
215ff9f:d6::/32ff9f:d6:ffff:ffff:ffff:ffff:ffff:ffff
216ff9f:d7::/32ff9f:d7:ffff:ffff:ffff:ffff:ffff:ffff
217ff9f:d8::/32ff9f:d8:ffff:ffff:ffff:ffff:ffff:ffff
218ff9f:d9::/32ff9f:d9:ffff:ffff:ffff:ffff:ffff:ffff
219ff9f:da::/32ff9f:da:ffff:ffff:ffff:ffff:ffff:ffff
220ff9f:db::/32ff9f:db:ffff:ffff:ffff:ffff:ffff:ffff
221ff9f:dc::/32ff9f:dc:ffff:ffff:ffff:ffff:ffff:ffff
222ff9f:dd::/32ff9f:dd:ffff:ffff:ffff:ffff:ffff:ffff
223ff9f:de::/32ff9f:de:ffff:ffff:ffff:ffff:ffff:ffff
224ff9f:df::/32ff9f:df:ffff:ffff:ffff:ffff:ffff:ffff
225ff9f:e0::/32ff9f:e0:ffff:ffff:ffff:ffff:ffff:ffff
226ff9f:e1::/32ff9f:e1:ffff:ffff:ffff:ffff:ffff:ffff
227ff9f:e2::/32ff9f:e2:ffff:ffff:ffff:ffff:ffff:ffff
228ff9f:e3::/32ff9f:e3:ffff:ffff:ffff:ffff:ffff:ffff
229ff9f:e4::/32ff9f:e4:ffff:ffff:ffff:ffff:ffff:ffff
230ff9f:e5::/32ff9f:e5:ffff:ffff:ffff:ffff:ffff:ffff
231ff9f:e6::/32ff9f:e6:ffff:ffff:ffff:ffff:ffff:ffff
232ff9f:e7::/32ff9f:e7:ffff:ffff:ffff:ffff:ffff:ffff
233ff9f:e8::/32ff9f:e8:ffff:ffff:ffff:ffff:ffff:ffff
234ff9f:e9::/32ff9f:e9:ffff:ffff:ffff:ffff:ffff:ffff
235ff9f:ea::/32ff9f:ea:ffff:ffff:ffff:ffff:ffff:ffff
236ff9f:eb::/32ff9f:eb:ffff:ffff:ffff:ffff:ffff:ffff
237ff9f:ec::/32ff9f:ec:ffff:ffff:ffff:ffff:ffff:ffff
238ff9f:ed::/32ff9f:ed:ffff:ffff:ffff:ffff:ffff:ffff
239ff9f:ee::/32ff9f:ee:ffff:ffff:ffff:ffff:ffff:ffff
240ff9f:ef::/32ff9f:ef:ffff:ffff:ffff:ffff:ffff:ffff
241ff9f:f0::/32ff9f:f0:ffff:ffff:ffff:ffff:ffff:ffff
242ff9f:f1::/32ff9f:f1:ffff:ffff:ffff:ffff:ffff:ffff
243ff9f:f2::/32ff9f:f2:ffff:ffff:ffff:ffff:ffff:ffff
244ff9f:f3::/32ff9f:f3:ffff:ffff:ffff:ffff:ffff:ffff
245ff9f:f4::/32ff9f:f4:ffff:ffff:ffff:ffff:ffff:ffff
246ff9f:f5::/32ff9f:f5:ffff:ffff:ffff:ffff:ffff:ffff
247ff9f:f6::/32ff9f:f6:ffff:ffff:ffff:ffff:ffff:ffff
248ff9f:f7::/32ff9f:f7:ffff:ffff:ffff:ffff:ffff:ffff
249ff9f:f8::/32ff9f:f8:ffff:ffff:ffff:ffff:ffff:ffff
250ff9f:f9::/32ff9f:f9:ffff:ffff:ffff:ffff:ffff:ffff
251ff9f:fa::/32ff9f:fa:ffff:ffff:ffff:ffff:ffff:ffff
252ff9f:fb::/32ff9f:fb:ffff:ffff:ffff:ffff:ffff:ffff
253ff9f:fc::/32ff9f:fc:ffff:ffff:ffff:ffff:ffff:ffff
254ff9f:fd::/32ff9f:fd:ffff:ffff:ffff:ffff:ffff:ffff
255ff9f:fe::/32ff9f:fe:ffff:ffff:ffff:ffff:ffff:ffff
256ff9f:ff::/32ff9f:ff: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.