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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/14
Addresses2^114
/64 networks2^50
Network
ffac::/14
First address
ffac::
Last address
ffaf:ffff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
20,769,187,434,139,310,514,121,985,316,880,384 (2^114)
/64 networks (LANs)
1,125,899,906,842,624 (2^50)
Full form
ffac:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zones
c.a.f.f.ip6.arpa
d.a.f.f.ip6.arpa
e.a.f.f.ip6.arpa
f.a.f.f.ip6.arpa
/14 is not on a 4-bit boundary, so it takes 4 /16 zones.
Split into smaller subnets/24
/15 (2)/16 (4)/17 (8)/18 (16)/20 (64)/24 (1,024)/28 (16,384)

ffac::/14 makes 1,024 subnets of /24; the first 256 are listed.

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