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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
febc::/16
First address
febc::
Last address
febc: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
febc:0000:0000:0000:0000:0000:0000:0000
Type
Link-local fe80::/10
Every IPv6 interface has one; not routed
Reverse DNS zone
c.b.e.f.ip6.arpa
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

febc::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
1febc::/24febc:ff:ffff:ffff:ffff:ffff:ffff:ffff
2febc:100::/24febc:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3febc:200::/24febc:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4febc:300::/24febc:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5febc:400::/24febc:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6febc:500::/24febc:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7febc:600::/24febc:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8febc:700::/24febc:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9febc:800::/24febc:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10febc:900::/24febc:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11febc:a00::/24febc:aff:ffff:ffff:ffff:ffff:ffff:ffff
12febc:b00::/24febc:bff:ffff:ffff:ffff:ffff:ffff:ffff
13febc:c00::/24febc:cff:ffff:ffff:ffff:ffff:ffff:ffff
14febc:d00::/24febc:dff:ffff:ffff:ffff:ffff:ffff:ffff
15febc:e00::/24febc:eff:ffff:ffff:ffff:ffff:ffff:ffff
16febc:f00::/24febc:fff:ffff:ffff:ffff:ffff:ffff:ffff
17febc:1000::/24febc:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18febc:1100::/24febc:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19febc:1200::/24febc:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20febc:1300::/24febc:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21febc:1400::/24febc:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22febc:1500::/24febc:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23febc:1600::/24febc:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24febc:1700::/24febc:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25febc:1800::/24febc:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26febc:1900::/24febc:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27febc:1a00::/24febc:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28febc:1b00::/24febc:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29febc:1c00::/24febc:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30febc:1d00::/24febc:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31febc:1e00::/24febc:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32febc:1f00::/24febc:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33febc:2000::/24febc:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34febc:2100::/24febc:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35febc:2200::/24febc:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36febc:2300::/24febc:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37febc:2400::/24febc:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38febc:2500::/24febc:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39febc:2600::/24febc:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40febc:2700::/24febc:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41febc:2800::/24febc:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42febc:2900::/24febc:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43febc:2a00::/24febc:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44febc:2b00::/24febc:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45febc:2c00::/24febc:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46febc:2d00::/24febc:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47febc:2e00::/24febc:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48febc:2f00::/24febc:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49febc:3000::/24febc:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50febc:3100::/24febc:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51febc:3200::/24febc:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52febc:3300::/24febc:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53febc:3400::/24febc:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54febc:3500::/24febc:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55febc:3600::/24febc:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56febc:3700::/24febc:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57febc:3800::/24febc:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58febc:3900::/24febc:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59febc:3a00::/24febc:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60febc:3b00::/24febc:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61febc:3c00::/24febc:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62febc:3d00::/24febc:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63febc:3e00::/24febc:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64febc:3f00::/24febc:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65febc:4000::/24febc:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66febc:4100::/24febc:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67febc:4200::/24febc:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68febc:4300::/24febc:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69febc:4400::/24febc:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70febc:4500::/24febc:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71febc:4600::/24febc:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72febc:4700::/24febc:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73febc:4800::/24febc:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74febc:4900::/24febc:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75febc:4a00::/24febc:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76febc:4b00::/24febc:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77febc:4c00::/24febc:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78febc:4d00::/24febc:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79febc:4e00::/24febc:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80febc:4f00::/24febc:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81febc:5000::/24febc:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82febc:5100::/24febc:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83febc:5200::/24febc:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84febc:5300::/24febc:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85febc:5400::/24febc:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86febc:5500::/24febc:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87febc:5600::/24febc:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88febc:5700::/24febc:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89febc:5800::/24febc:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90febc:5900::/24febc:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91febc:5a00::/24febc:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92febc:5b00::/24febc:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93febc:5c00::/24febc:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94febc:5d00::/24febc:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95febc:5e00::/24febc:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96febc:5f00::/24febc:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97febc:6000::/24febc:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98febc:6100::/24febc:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99febc:6200::/24febc:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100febc:6300::/24febc:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101febc:6400::/24febc:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102febc:6500::/24febc:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103febc:6600::/24febc:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104febc:6700::/24febc:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105febc:6800::/24febc:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106febc:6900::/24febc:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107febc:6a00::/24febc:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108febc:6b00::/24febc:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109febc:6c00::/24febc:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110febc:6d00::/24febc:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111febc:6e00::/24febc:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112febc:6f00::/24febc:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113febc:7000::/24febc:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114febc:7100::/24febc:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115febc:7200::/24febc:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116febc:7300::/24febc:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117febc:7400::/24febc:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118febc:7500::/24febc:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119febc:7600::/24febc:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120febc:7700::/24febc:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121febc:7800::/24febc:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122febc:7900::/24febc:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123febc:7a00::/24febc:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124febc:7b00::/24febc:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125febc:7c00::/24febc:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126febc:7d00::/24febc:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127febc:7e00::/24febc:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128febc:7f00::/24febc:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129febc:8000::/24febc:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130febc:8100::/24febc:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131febc:8200::/24febc:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132febc:8300::/24febc:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133febc:8400::/24febc:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134febc:8500::/24febc:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135febc:8600::/24febc:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136febc:8700::/24febc:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137febc:8800::/24febc:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138febc:8900::/24febc:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139febc:8a00::/24febc:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140febc:8b00::/24febc:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141febc:8c00::/24febc:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142febc:8d00::/24febc:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143febc:8e00::/24febc:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144febc:8f00::/24febc:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145febc:9000::/24febc:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146febc:9100::/24febc:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147febc:9200::/24febc:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148febc:9300::/24febc:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149febc:9400::/24febc:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150febc:9500::/24febc:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151febc:9600::/24febc:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152febc:9700::/24febc:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153febc:9800::/24febc:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154febc:9900::/24febc:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155febc:9a00::/24febc:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156febc:9b00::/24febc:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157febc:9c00::/24febc:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158febc:9d00::/24febc:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159febc:9e00::/24febc:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160febc:9f00::/24febc:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161febc:a000::/24febc:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162febc:a100::/24febc:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163febc:a200::/24febc:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164febc:a300::/24febc:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165febc:a400::/24febc:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166febc:a500::/24febc:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167febc:a600::/24febc:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168febc:a700::/24febc:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169febc:a800::/24febc:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170febc:a900::/24febc:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171febc:aa00::/24febc:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172febc:ab00::/24febc:abff:ffff:ffff:ffff:ffff:ffff:ffff
173febc:ac00::/24febc:acff:ffff:ffff:ffff:ffff:ffff:ffff
174febc:ad00::/24febc:adff:ffff:ffff:ffff:ffff:ffff:ffff
175febc:ae00::/24febc:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176febc:af00::/24febc:afff:ffff:ffff:ffff:ffff:ffff:ffff
177febc:b000::/24febc:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178febc:b100::/24febc:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179febc:b200::/24febc:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180febc:b300::/24febc:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181febc:b400::/24febc:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182febc:b500::/24febc:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183febc:b600::/24febc:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184febc:b700::/24febc:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185febc:b800::/24febc:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186febc:b900::/24febc:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187febc:ba00::/24febc:baff:ffff:ffff:ffff:ffff:ffff:ffff
188febc:bb00::/24febc:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189febc:bc00::/24febc:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190febc:bd00::/24febc:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191febc:be00::/24febc:beff:ffff:ffff:ffff:ffff:ffff:ffff
192febc:bf00::/24febc:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193febc:c000::/24febc:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194febc:c100::/24febc:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195febc:c200::/24febc:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196febc:c300::/24febc:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197febc:c400::/24febc:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198febc:c500::/24febc:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199febc:c600::/24febc:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200febc:c700::/24febc:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201febc:c800::/24febc:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202febc:c900::/24febc:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203febc:ca00::/24febc:caff:ffff:ffff:ffff:ffff:ffff:ffff
204febc:cb00::/24febc:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205febc:cc00::/24febc:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206febc:cd00::/24febc:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207febc:ce00::/24febc:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208febc:cf00::/24febc:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209febc:d000::/24febc:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210febc:d100::/24febc:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211febc:d200::/24febc:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212febc:d300::/24febc:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213febc:d400::/24febc:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214febc:d500::/24febc:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215febc:d600::/24febc:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216febc:d700::/24febc:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217febc:d800::/24febc:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218febc:d900::/24febc:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219febc:da00::/24febc:daff:ffff:ffff:ffff:ffff:ffff:ffff
220febc:db00::/24febc:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221febc:dc00::/24febc:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222febc:dd00::/24febc:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223febc:de00::/24febc:deff:ffff:ffff:ffff:ffff:ffff:ffff
224febc:df00::/24febc:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225febc:e000::/24febc:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226febc:e100::/24febc:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227febc:e200::/24febc:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228febc:e300::/24febc:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229febc:e400::/24febc:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230febc:e500::/24febc:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231febc:e600::/24febc:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232febc:e700::/24febc:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233febc:e800::/24febc:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234febc:e900::/24febc:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235febc:ea00::/24febc:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236febc:eb00::/24febc:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237febc:ec00::/24febc:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238febc:ed00::/24febc:edff:ffff:ffff:ffff:ffff:ffff:ffff
239febc:ee00::/24febc:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240febc:ef00::/24febc:efff:ffff:ffff:ffff:ffff:ffff:ffff
241febc:f000::/24febc:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242febc:f100::/24febc:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243febc:f200::/24febc:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244febc:f300::/24febc:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245febc:f400::/24febc:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246febc:f500::/24febc:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247febc:f600::/24febc:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248febc:f700::/24febc:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249febc:f800::/24febc:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250febc:f900::/24febc:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251febc:fa00::/24febc:faff:ffff:ffff:ffff:ffff:ffff:ffff
252febc:fb00::/24febc:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253febc:fc00::/24febc:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254febc:fd00::/24febc:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255febc:fe00::/24febc:feff:ffff:ffff:ffff:ffff:ffff:ffff
256febc:ff00::/24febc:ffff: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.