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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
ff5e::/16
First address
ff5e::
Last address
ff5e: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
ff5e:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
e.5.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)

ff5e::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1ff5e::/32ff5e:0:ffff:ffff:ffff:ffff:ffff:ffff
2ff5e:1::/32ff5e:1:ffff:ffff:ffff:ffff:ffff:ffff
3ff5e:2::/32ff5e:2:ffff:ffff:ffff:ffff:ffff:ffff
4ff5e:3::/32ff5e:3:ffff:ffff:ffff:ffff:ffff:ffff
5ff5e:4::/32ff5e:4:ffff:ffff:ffff:ffff:ffff:ffff
6ff5e:5::/32ff5e:5:ffff:ffff:ffff:ffff:ffff:ffff
7ff5e:6::/32ff5e:6:ffff:ffff:ffff:ffff:ffff:ffff
8ff5e:7::/32ff5e:7:ffff:ffff:ffff:ffff:ffff:ffff
9ff5e:8::/32ff5e:8:ffff:ffff:ffff:ffff:ffff:ffff
10ff5e:9::/32ff5e:9:ffff:ffff:ffff:ffff:ffff:ffff
11ff5e:a::/32ff5e:a:ffff:ffff:ffff:ffff:ffff:ffff
12ff5e:b::/32ff5e:b:ffff:ffff:ffff:ffff:ffff:ffff
13ff5e:c::/32ff5e:c:ffff:ffff:ffff:ffff:ffff:ffff
14ff5e:d::/32ff5e:d:ffff:ffff:ffff:ffff:ffff:ffff
15ff5e:e::/32ff5e:e:ffff:ffff:ffff:ffff:ffff:ffff
16ff5e:f::/32ff5e:f:ffff:ffff:ffff:ffff:ffff:ffff
17ff5e:10::/32ff5e:10:ffff:ffff:ffff:ffff:ffff:ffff
18ff5e:11::/32ff5e:11:ffff:ffff:ffff:ffff:ffff:ffff
19ff5e:12::/32ff5e:12:ffff:ffff:ffff:ffff:ffff:ffff
20ff5e:13::/32ff5e:13:ffff:ffff:ffff:ffff:ffff:ffff
21ff5e:14::/32ff5e:14:ffff:ffff:ffff:ffff:ffff:ffff
22ff5e:15::/32ff5e:15:ffff:ffff:ffff:ffff:ffff:ffff
23ff5e:16::/32ff5e:16:ffff:ffff:ffff:ffff:ffff:ffff
24ff5e:17::/32ff5e:17:ffff:ffff:ffff:ffff:ffff:ffff
25ff5e:18::/32ff5e:18:ffff:ffff:ffff:ffff:ffff:ffff
26ff5e:19::/32ff5e:19:ffff:ffff:ffff:ffff:ffff:ffff
27ff5e:1a::/32ff5e:1a:ffff:ffff:ffff:ffff:ffff:ffff
28ff5e:1b::/32ff5e:1b:ffff:ffff:ffff:ffff:ffff:ffff
29ff5e:1c::/32ff5e:1c:ffff:ffff:ffff:ffff:ffff:ffff
30ff5e:1d::/32ff5e:1d:ffff:ffff:ffff:ffff:ffff:ffff
31ff5e:1e::/32ff5e:1e:ffff:ffff:ffff:ffff:ffff:ffff
32ff5e:1f::/32ff5e:1f:ffff:ffff:ffff:ffff:ffff:ffff
33ff5e:20::/32ff5e:20:ffff:ffff:ffff:ffff:ffff:ffff
34ff5e:21::/32ff5e:21:ffff:ffff:ffff:ffff:ffff:ffff
35ff5e:22::/32ff5e:22:ffff:ffff:ffff:ffff:ffff:ffff
36ff5e:23::/32ff5e:23:ffff:ffff:ffff:ffff:ffff:ffff
37ff5e:24::/32ff5e:24:ffff:ffff:ffff:ffff:ffff:ffff
38ff5e:25::/32ff5e:25:ffff:ffff:ffff:ffff:ffff:ffff
39ff5e:26::/32ff5e:26:ffff:ffff:ffff:ffff:ffff:ffff
40ff5e:27::/32ff5e:27:ffff:ffff:ffff:ffff:ffff:ffff
41ff5e:28::/32ff5e:28:ffff:ffff:ffff:ffff:ffff:ffff
42ff5e:29::/32ff5e:29:ffff:ffff:ffff:ffff:ffff:ffff
43ff5e:2a::/32ff5e:2a:ffff:ffff:ffff:ffff:ffff:ffff
44ff5e:2b::/32ff5e:2b:ffff:ffff:ffff:ffff:ffff:ffff
45ff5e:2c::/32ff5e:2c:ffff:ffff:ffff:ffff:ffff:ffff
46ff5e:2d::/32ff5e:2d:ffff:ffff:ffff:ffff:ffff:ffff
47ff5e:2e::/32ff5e:2e:ffff:ffff:ffff:ffff:ffff:ffff
48ff5e:2f::/32ff5e:2f:ffff:ffff:ffff:ffff:ffff:ffff
49ff5e:30::/32ff5e:30:ffff:ffff:ffff:ffff:ffff:ffff
50ff5e:31::/32ff5e:31:ffff:ffff:ffff:ffff:ffff:ffff
51ff5e:32::/32ff5e:32:ffff:ffff:ffff:ffff:ffff:ffff
52ff5e:33::/32ff5e:33:ffff:ffff:ffff:ffff:ffff:ffff
53ff5e:34::/32ff5e:34:ffff:ffff:ffff:ffff:ffff:ffff
54ff5e:35::/32ff5e:35:ffff:ffff:ffff:ffff:ffff:ffff
55ff5e:36::/32ff5e:36:ffff:ffff:ffff:ffff:ffff:ffff
56ff5e:37::/32ff5e:37:ffff:ffff:ffff:ffff:ffff:ffff
57ff5e:38::/32ff5e:38:ffff:ffff:ffff:ffff:ffff:ffff
58ff5e:39::/32ff5e:39:ffff:ffff:ffff:ffff:ffff:ffff
59ff5e:3a::/32ff5e:3a:ffff:ffff:ffff:ffff:ffff:ffff
60ff5e:3b::/32ff5e:3b:ffff:ffff:ffff:ffff:ffff:ffff
61ff5e:3c::/32ff5e:3c:ffff:ffff:ffff:ffff:ffff:ffff
62ff5e:3d::/32ff5e:3d:ffff:ffff:ffff:ffff:ffff:ffff
63ff5e:3e::/32ff5e:3e:ffff:ffff:ffff:ffff:ffff:ffff
64ff5e:3f::/32ff5e:3f:ffff:ffff:ffff:ffff:ffff:ffff
65ff5e:40::/32ff5e:40:ffff:ffff:ffff:ffff:ffff:ffff
66ff5e:41::/32ff5e:41:ffff:ffff:ffff:ffff:ffff:ffff
67ff5e:42::/32ff5e:42:ffff:ffff:ffff:ffff:ffff:ffff
68ff5e:43::/32ff5e:43:ffff:ffff:ffff:ffff:ffff:ffff
69ff5e:44::/32ff5e:44:ffff:ffff:ffff:ffff:ffff:ffff
70ff5e:45::/32ff5e:45:ffff:ffff:ffff:ffff:ffff:ffff
71ff5e:46::/32ff5e:46:ffff:ffff:ffff:ffff:ffff:ffff
72ff5e:47::/32ff5e:47:ffff:ffff:ffff:ffff:ffff:ffff
73ff5e:48::/32ff5e:48:ffff:ffff:ffff:ffff:ffff:ffff
74ff5e:49::/32ff5e:49:ffff:ffff:ffff:ffff:ffff:ffff
75ff5e:4a::/32ff5e:4a:ffff:ffff:ffff:ffff:ffff:ffff
76ff5e:4b::/32ff5e:4b:ffff:ffff:ffff:ffff:ffff:ffff
77ff5e:4c::/32ff5e:4c:ffff:ffff:ffff:ffff:ffff:ffff
78ff5e:4d::/32ff5e:4d:ffff:ffff:ffff:ffff:ffff:ffff
79ff5e:4e::/32ff5e:4e:ffff:ffff:ffff:ffff:ffff:ffff
80ff5e:4f::/32ff5e:4f:ffff:ffff:ffff:ffff:ffff:ffff
81ff5e:50::/32ff5e:50:ffff:ffff:ffff:ffff:ffff:ffff
82ff5e:51::/32ff5e:51:ffff:ffff:ffff:ffff:ffff:ffff
83ff5e:52::/32ff5e:52:ffff:ffff:ffff:ffff:ffff:ffff
84ff5e:53::/32ff5e:53:ffff:ffff:ffff:ffff:ffff:ffff
85ff5e:54::/32ff5e:54:ffff:ffff:ffff:ffff:ffff:ffff
86ff5e:55::/32ff5e:55:ffff:ffff:ffff:ffff:ffff:ffff
87ff5e:56::/32ff5e:56:ffff:ffff:ffff:ffff:ffff:ffff
88ff5e:57::/32ff5e:57:ffff:ffff:ffff:ffff:ffff:ffff
89ff5e:58::/32ff5e:58:ffff:ffff:ffff:ffff:ffff:ffff
90ff5e:59::/32ff5e:59:ffff:ffff:ffff:ffff:ffff:ffff
91ff5e:5a::/32ff5e:5a:ffff:ffff:ffff:ffff:ffff:ffff
92ff5e:5b::/32ff5e:5b:ffff:ffff:ffff:ffff:ffff:ffff
93ff5e:5c::/32ff5e:5c:ffff:ffff:ffff:ffff:ffff:ffff
94ff5e:5d::/32ff5e:5d:ffff:ffff:ffff:ffff:ffff:ffff
95ff5e:5e::/32ff5e:5e:ffff:ffff:ffff:ffff:ffff:ffff
96ff5e:5f::/32ff5e:5f:ffff:ffff:ffff:ffff:ffff:ffff
97ff5e:60::/32ff5e:60:ffff:ffff:ffff:ffff:ffff:ffff
98ff5e:61::/32ff5e:61:ffff:ffff:ffff:ffff:ffff:ffff
99ff5e:62::/32ff5e:62:ffff:ffff:ffff:ffff:ffff:ffff
100ff5e:63::/32ff5e:63:ffff:ffff:ffff:ffff:ffff:ffff
101ff5e:64::/32ff5e:64:ffff:ffff:ffff:ffff:ffff:ffff
102ff5e:65::/32ff5e:65:ffff:ffff:ffff:ffff:ffff:ffff
103ff5e:66::/32ff5e:66:ffff:ffff:ffff:ffff:ffff:ffff
104ff5e:67::/32ff5e:67:ffff:ffff:ffff:ffff:ffff:ffff
105ff5e:68::/32ff5e:68:ffff:ffff:ffff:ffff:ffff:ffff
106ff5e:69::/32ff5e:69:ffff:ffff:ffff:ffff:ffff:ffff
107ff5e:6a::/32ff5e:6a:ffff:ffff:ffff:ffff:ffff:ffff
108ff5e:6b::/32ff5e:6b:ffff:ffff:ffff:ffff:ffff:ffff
109ff5e:6c::/32ff5e:6c:ffff:ffff:ffff:ffff:ffff:ffff
110ff5e:6d::/32ff5e:6d:ffff:ffff:ffff:ffff:ffff:ffff
111ff5e:6e::/32ff5e:6e:ffff:ffff:ffff:ffff:ffff:ffff
112ff5e:6f::/32ff5e:6f:ffff:ffff:ffff:ffff:ffff:ffff
113ff5e:70::/32ff5e:70:ffff:ffff:ffff:ffff:ffff:ffff
114ff5e:71::/32ff5e:71:ffff:ffff:ffff:ffff:ffff:ffff
115ff5e:72::/32ff5e:72:ffff:ffff:ffff:ffff:ffff:ffff
116ff5e:73::/32ff5e:73:ffff:ffff:ffff:ffff:ffff:ffff
117ff5e:74::/32ff5e:74:ffff:ffff:ffff:ffff:ffff:ffff
118ff5e:75::/32ff5e:75:ffff:ffff:ffff:ffff:ffff:ffff
119ff5e:76::/32ff5e:76:ffff:ffff:ffff:ffff:ffff:ffff
120ff5e:77::/32ff5e:77:ffff:ffff:ffff:ffff:ffff:ffff
121ff5e:78::/32ff5e:78:ffff:ffff:ffff:ffff:ffff:ffff
122ff5e:79::/32ff5e:79:ffff:ffff:ffff:ffff:ffff:ffff
123ff5e:7a::/32ff5e:7a:ffff:ffff:ffff:ffff:ffff:ffff
124ff5e:7b::/32ff5e:7b:ffff:ffff:ffff:ffff:ffff:ffff
125ff5e:7c::/32ff5e:7c:ffff:ffff:ffff:ffff:ffff:ffff
126ff5e:7d::/32ff5e:7d:ffff:ffff:ffff:ffff:ffff:ffff
127ff5e:7e::/32ff5e:7e:ffff:ffff:ffff:ffff:ffff:ffff
128ff5e:7f::/32ff5e:7f:ffff:ffff:ffff:ffff:ffff:ffff
129ff5e:80::/32ff5e:80:ffff:ffff:ffff:ffff:ffff:ffff
130ff5e:81::/32ff5e:81:ffff:ffff:ffff:ffff:ffff:ffff
131ff5e:82::/32ff5e:82:ffff:ffff:ffff:ffff:ffff:ffff
132ff5e:83::/32ff5e:83:ffff:ffff:ffff:ffff:ffff:ffff
133ff5e:84::/32ff5e:84:ffff:ffff:ffff:ffff:ffff:ffff
134ff5e:85::/32ff5e:85:ffff:ffff:ffff:ffff:ffff:ffff
135ff5e:86::/32ff5e:86:ffff:ffff:ffff:ffff:ffff:ffff
136ff5e:87::/32ff5e:87:ffff:ffff:ffff:ffff:ffff:ffff
137ff5e:88::/32ff5e:88:ffff:ffff:ffff:ffff:ffff:ffff
138ff5e:89::/32ff5e:89:ffff:ffff:ffff:ffff:ffff:ffff
139ff5e:8a::/32ff5e:8a:ffff:ffff:ffff:ffff:ffff:ffff
140ff5e:8b::/32ff5e:8b:ffff:ffff:ffff:ffff:ffff:ffff
141ff5e:8c::/32ff5e:8c:ffff:ffff:ffff:ffff:ffff:ffff
142ff5e:8d::/32ff5e:8d:ffff:ffff:ffff:ffff:ffff:ffff
143ff5e:8e::/32ff5e:8e:ffff:ffff:ffff:ffff:ffff:ffff
144ff5e:8f::/32ff5e:8f:ffff:ffff:ffff:ffff:ffff:ffff
145ff5e:90::/32ff5e:90:ffff:ffff:ffff:ffff:ffff:ffff
146ff5e:91::/32ff5e:91:ffff:ffff:ffff:ffff:ffff:ffff
147ff5e:92::/32ff5e:92:ffff:ffff:ffff:ffff:ffff:ffff
148ff5e:93::/32ff5e:93:ffff:ffff:ffff:ffff:ffff:ffff
149ff5e:94::/32ff5e:94:ffff:ffff:ffff:ffff:ffff:ffff
150ff5e:95::/32ff5e:95:ffff:ffff:ffff:ffff:ffff:ffff
151ff5e:96::/32ff5e:96:ffff:ffff:ffff:ffff:ffff:ffff
152ff5e:97::/32ff5e:97:ffff:ffff:ffff:ffff:ffff:ffff
153ff5e:98::/32ff5e:98:ffff:ffff:ffff:ffff:ffff:ffff
154ff5e:99::/32ff5e:99:ffff:ffff:ffff:ffff:ffff:ffff
155ff5e:9a::/32ff5e:9a:ffff:ffff:ffff:ffff:ffff:ffff
156ff5e:9b::/32ff5e:9b:ffff:ffff:ffff:ffff:ffff:ffff
157ff5e:9c::/32ff5e:9c:ffff:ffff:ffff:ffff:ffff:ffff
158ff5e:9d::/32ff5e:9d:ffff:ffff:ffff:ffff:ffff:ffff
159ff5e:9e::/32ff5e:9e:ffff:ffff:ffff:ffff:ffff:ffff
160ff5e:9f::/32ff5e:9f:ffff:ffff:ffff:ffff:ffff:ffff
161ff5e:a0::/32ff5e:a0:ffff:ffff:ffff:ffff:ffff:ffff
162ff5e:a1::/32ff5e:a1:ffff:ffff:ffff:ffff:ffff:ffff
163ff5e:a2::/32ff5e:a2:ffff:ffff:ffff:ffff:ffff:ffff
164ff5e:a3::/32ff5e:a3:ffff:ffff:ffff:ffff:ffff:ffff
165ff5e:a4::/32ff5e:a4:ffff:ffff:ffff:ffff:ffff:ffff
166ff5e:a5::/32ff5e:a5:ffff:ffff:ffff:ffff:ffff:ffff
167ff5e:a6::/32ff5e:a6:ffff:ffff:ffff:ffff:ffff:ffff
168ff5e:a7::/32ff5e:a7:ffff:ffff:ffff:ffff:ffff:ffff
169ff5e:a8::/32ff5e:a8:ffff:ffff:ffff:ffff:ffff:ffff
170ff5e:a9::/32ff5e:a9:ffff:ffff:ffff:ffff:ffff:ffff
171ff5e:aa::/32ff5e:aa:ffff:ffff:ffff:ffff:ffff:ffff
172ff5e:ab::/32ff5e:ab:ffff:ffff:ffff:ffff:ffff:ffff
173ff5e:ac::/32ff5e:ac:ffff:ffff:ffff:ffff:ffff:ffff
174ff5e:ad::/32ff5e:ad:ffff:ffff:ffff:ffff:ffff:ffff
175ff5e:ae::/32ff5e:ae:ffff:ffff:ffff:ffff:ffff:ffff
176ff5e:af::/32ff5e:af:ffff:ffff:ffff:ffff:ffff:ffff
177ff5e:b0::/32ff5e:b0:ffff:ffff:ffff:ffff:ffff:ffff
178ff5e:b1::/32ff5e:b1:ffff:ffff:ffff:ffff:ffff:ffff
179ff5e:b2::/32ff5e:b2:ffff:ffff:ffff:ffff:ffff:ffff
180ff5e:b3::/32ff5e:b3:ffff:ffff:ffff:ffff:ffff:ffff
181ff5e:b4::/32ff5e:b4:ffff:ffff:ffff:ffff:ffff:ffff
182ff5e:b5::/32ff5e:b5:ffff:ffff:ffff:ffff:ffff:ffff
183ff5e:b6::/32ff5e:b6:ffff:ffff:ffff:ffff:ffff:ffff
184ff5e:b7::/32ff5e:b7:ffff:ffff:ffff:ffff:ffff:ffff
185ff5e:b8::/32ff5e:b8:ffff:ffff:ffff:ffff:ffff:ffff
186ff5e:b9::/32ff5e:b9:ffff:ffff:ffff:ffff:ffff:ffff
187ff5e:ba::/32ff5e:ba:ffff:ffff:ffff:ffff:ffff:ffff
188ff5e:bb::/32ff5e:bb:ffff:ffff:ffff:ffff:ffff:ffff
189ff5e:bc::/32ff5e:bc:ffff:ffff:ffff:ffff:ffff:ffff
190ff5e:bd::/32ff5e:bd:ffff:ffff:ffff:ffff:ffff:ffff
191ff5e:be::/32ff5e:be:ffff:ffff:ffff:ffff:ffff:ffff
192ff5e:bf::/32ff5e:bf:ffff:ffff:ffff:ffff:ffff:ffff
193ff5e:c0::/32ff5e:c0:ffff:ffff:ffff:ffff:ffff:ffff
194ff5e:c1::/32ff5e:c1:ffff:ffff:ffff:ffff:ffff:ffff
195ff5e:c2::/32ff5e:c2:ffff:ffff:ffff:ffff:ffff:ffff
196ff5e:c3::/32ff5e:c3:ffff:ffff:ffff:ffff:ffff:ffff
197ff5e:c4::/32ff5e:c4:ffff:ffff:ffff:ffff:ffff:ffff
198ff5e:c5::/32ff5e:c5:ffff:ffff:ffff:ffff:ffff:ffff
199ff5e:c6::/32ff5e:c6:ffff:ffff:ffff:ffff:ffff:ffff
200ff5e:c7::/32ff5e:c7:ffff:ffff:ffff:ffff:ffff:ffff
201ff5e:c8::/32ff5e:c8:ffff:ffff:ffff:ffff:ffff:ffff
202ff5e:c9::/32ff5e:c9:ffff:ffff:ffff:ffff:ffff:ffff
203ff5e:ca::/32ff5e:ca:ffff:ffff:ffff:ffff:ffff:ffff
204ff5e:cb::/32ff5e:cb:ffff:ffff:ffff:ffff:ffff:ffff
205ff5e:cc::/32ff5e:cc:ffff:ffff:ffff:ffff:ffff:ffff
206ff5e:cd::/32ff5e:cd:ffff:ffff:ffff:ffff:ffff:ffff
207ff5e:ce::/32ff5e:ce:ffff:ffff:ffff:ffff:ffff:ffff
208ff5e:cf::/32ff5e:cf:ffff:ffff:ffff:ffff:ffff:ffff
209ff5e:d0::/32ff5e:d0:ffff:ffff:ffff:ffff:ffff:ffff
210ff5e:d1::/32ff5e:d1:ffff:ffff:ffff:ffff:ffff:ffff
211ff5e:d2::/32ff5e:d2:ffff:ffff:ffff:ffff:ffff:ffff
212ff5e:d3::/32ff5e:d3:ffff:ffff:ffff:ffff:ffff:ffff
213ff5e:d4::/32ff5e:d4:ffff:ffff:ffff:ffff:ffff:ffff
214ff5e:d5::/32ff5e:d5:ffff:ffff:ffff:ffff:ffff:ffff
215ff5e:d6::/32ff5e:d6:ffff:ffff:ffff:ffff:ffff:ffff
216ff5e:d7::/32ff5e:d7:ffff:ffff:ffff:ffff:ffff:ffff
217ff5e:d8::/32ff5e:d8:ffff:ffff:ffff:ffff:ffff:ffff
218ff5e:d9::/32ff5e:d9:ffff:ffff:ffff:ffff:ffff:ffff
219ff5e:da::/32ff5e:da:ffff:ffff:ffff:ffff:ffff:ffff
220ff5e:db::/32ff5e:db:ffff:ffff:ffff:ffff:ffff:ffff
221ff5e:dc::/32ff5e:dc:ffff:ffff:ffff:ffff:ffff:ffff
222ff5e:dd::/32ff5e:dd:ffff:ffff:ffff:ffff:ffff:ffff
223ff5e:de::/32ff5e:de:ffff:ffff:ffff:ffff:ffff:ffff
224ff5e:df::/32ff5e:df:ffff:ffff:ffff:ffff:ffff:ffff
225ff5e:e0::/32ff5e:e0:ffff:ffff:ffff:ffff:ffff:ffff
226ff5e:e1::/32ff5e:e1:ffff:ffff:ffff:ffff:ffff:ffff
227ff5e:e2::/32ff5e:e2:ffff:ffff:ffff:ffff:ffff:ffff
228ff5e:e3::/32ff5e:e3:ffff:ffff:ffff:ffff:ffff:ffff
229ff5e:e4::/32ff5e:e4:ffff:ffff:ffff:ffff:ffff:ffff
230ff5e:e5::/32ff5e:e5:ffff:ffff:ffff:ffff:ffff:ffff
231ff5e:e6::/32ff5e:e6:ffff:ffff:ffff:ffff:ffff:ffff
232ff5e:e7::/32ff5e:e7:ffff:ffff:ffff:ffff:ffff:ffff
233ff5e:e8::/32ff5e:e8:ffff:ffff:ffff:ffff:ffff:ffff
234ff5e:e9::/32ff5e:e9:ffff:ffff:ffff:ffff:ffff:ffff
235ff5e:ea::/32ff5e:ea:ffff:ffff:ffff:ffff:ffff:ffff
236ff5e:eb::/32ff5e:eb:ffff:ffff:ffff:ffff:ffff:ffff
237ff5e:ec::/32ff5e:ec:ffff:ffff:ffff:ffff:ffff:ffff
238ff5e:ed::/32ff5e:ed:ffff:ffff:ffff:ffff:ffff:ffff
239ff5e:ee::/32ff5e:ee:ffff:ffff:ffff:ffff:ffff:ffff
240ff5e:ef::/32ff5e:ef:ffff:ffff:ffff:ffff:ffff:ffff
241ff5e:f0::/32ff5e:f0:ffff:ffff:ffff:ffff:ffff:ffff
242ff5e:f1::/32ff5e:f1:ffff:ffff:ffff:ffff:ffff:ffff
243ff5e:f2::/32ff5e:f2:ffff:ffff:ffff:ffff:ffff:ffff
244ff5e:f3::/32ff5e:f3:ffff:ffff:ffff:ffff:ffff:ffff
245ff5e:f4::/32ff5e:f4:ffff:ffff:ffff:ffff:ffff:ffff
246ff5e:f5::/32ff5e:f5:ffff:ffff:ffff:ffff:ffff:ffff
247ff5e:f6::/32ff5e:f6:ffff:ffff:ffff:ffff:ffff:ffff
248ff5e:f7::/32ff5e:f7:ffff:ffff:ffff:ffff:ffff:ffff
249ff5e:f8::/32ff5e:f8:ffff:ffff:ffff:ffff:ffff:ffff
250ff5e:f9::/32ff5e:f9:ffff:ffff:ffff:ffff:ffff:ffff
251ff5e:fa::/32ff5e:fa:ffff:ffff:ffff:ffff:ffff:ffff
252ff5e:fb::/32ff5e:fb:ffff:ffff:ffff:ffff:ffff:ffff
253ff5e:fc::/32ff5e:fc:ffff:ffff:ffff:ffff:ffff:ffff
254ff5e:fd::/32ff5e:fd:ffff:ffff:ffff:ffff:ffff:ffff
255ff5e:fe::/32ff5e:fe:ffff:ffff:ffff:ffff:ffff:ffff
256ff5e:ff::/32ff5e: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.