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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
fcae::/16
First address
fcae::
Last address
fcae: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
fcae:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
e.a.c.f.ip6.arpa
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

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

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