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

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

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