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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
fc68::/14
First address
fc68::
Last address
fc6b: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
fc68:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zones
8.6.c.f.ip6.arpa
9.6.c.f.ip6.arpa
a.6.c.f.ip6.arpa
b.6.c.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)

fc68::/14 makes 1,024 subnets of /24; the first 256 are listed.

Subnets
#SubnetLast address
1fc68::/24fc68:ff:ffff:ffff:ffff:ffff:ffff:ffff
2fc68:100::/24fc68:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3fc68:200::/24fc68:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4fc68:300::/24fc68:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5fc68:400::/24fc68:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6fc68:500::/24fc68:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7fc68:600::/24fc68:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8fc68:700::/24fc68:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9fc68:800::/24fc68:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10fc68:900::/24fc68:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11fc68:a00::/24fc68:aff:ffff:ffff:ffff:ffff:ffff:ffff
12fc68:b00::/24fc68:bff:ffff:ffff:ffff:ffff:ffff:ffff
13fc68:c00::/24fc68:cff:ffff:ffff:ffff:ffff:ffff:ffff
14fc68:d00::/24fc68:dff:ffff:ffff:ffff:ffff:ffff:ffff
15fc68:e00::/24fc68:eff:ffff:ffff:ffff:ffff:ffff:ffff
16fc68:f00::/24fc68:fff:ffff:ffff:ffff:ffff:ffff:ffff
17fc68:1000::/24fc68:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18fc68:1100::/24fc68:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19fc68:1200::/24fc68:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20fc68:1300::/24fc68:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21fc68:1400::/24fc68:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22fc68:1500::/24fc68:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23fc68:1600::/24fc68:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24fc68:1700::/24fc68:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25fc68:1800::/24fc68:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26fc68:1900::/24fc68:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27fc68:1a00::/24fc68:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28fc68:1b00::/24fc68:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29fc68:1c00::/24fc68:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30fc68:1d00::/24fc68:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31fc68:1e00::/24fc68:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32fc68:1f00::/24fc68:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33fc68:2000::/24fc68:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34fc68:2100::/24fc68:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35fc68:2200::/24fc68:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36fc68:2300::/24fc68:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37fc68:2400::/24fc68:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38fc68:2500::/24fc68:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39fc68:2600::/24fc68:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40fc68:2700::/24fc68:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41fc68:2800::/24fc68:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42fc68:2900::/24fc68:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43fc68:2a00::/24fc68:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44fc68:2b00::/24fc68:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45fc68:2c00::/24fc68:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46fc68:2d00::/24fc68:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47fc68:2e00::/24fc68:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48fc68:2f00::/24fc68:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49fc68:3000::/24fc68:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50fc68:3100::/24fc68:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51fc68:3200::/24fc68:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52fc68:3300::/24fc68:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53fc68:3400::/24fc68:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54fc68:3500::/24fc68:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55fc68:3600::/24fc68:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56fc68:3700::/24fc68:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57fc68:3800::/24fc68:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58fc68:3900::/24fc68:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59fc68:3a00::/24fc68:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60fc68:3b00::/24fc68:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61fc68:3c00::/24fc68:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62fc68:3d00::/24fc68:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63fc68:3e00::/24fc68:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64fc68:3f00::/24fc68:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65fc68:4000::/24fc68:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66fc68:4100::/24fc68:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67fc68:4200::/24fc68:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68fc68:4300::/24fc68:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69fc68:4400::/24fc68:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70fc68:4500::/24fc68:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71fc68:4600::/24fc68:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72fc68:4700::/24fc68:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73fc68:4800::/24fc68:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74fc68:4900::/24fc68:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75fc68:4a00::/24fc68:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76fc68:4b00::/24fc68:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77fc68:4c00::/24fc68:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78fc68:4d00::/24fc68:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79fc68:4e00::/24fc68:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80fc68:4f00::/24fc68:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81fc68:5000::/24fc68:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82fc68:5100::/24fc68:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83fc68:5200::/24fc68:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84fc68:5300::/24fc68:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85fc68:5400::/24fc68:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86fc68:5500::/24fc68:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87fc68:5600::/24fc68:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88fc68:5700::/24fc68:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89fc68:5800::/24fc68:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90fc68:5900::/24fc68:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91fc68:5a00::/24fc68:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92fc68:5b00::/24fc68:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93fc68:5c00::/24fc68:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94fc68:5d00::/24fc68:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95fc68:5e00::/24fc68:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96fc68:5f00::/24fc68:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97fc68:6000::/24fc68:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98fc68:6100::/24fc68:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99fc68:6200::/24fc68:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100fc68:6300::/24fc68:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101fc68:6400::/24fc68:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102fc68:6500::/24fc68:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103fc68:6600::/24fc68:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104fc68:6700::/24fc68:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105fc68:6800::/24fc68:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106fc68:6900::/24fc68:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107fc68:6a00::/24fc68:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108fc68:6b00::/24fc68:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109fc68:6c00::/24fc68:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110fc68:6d00::/24fc68:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111fc68:6e00::/24fc68:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112fc68:6f00::/24fc68:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113fc68:7000::/24fc68:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114fc68:7100::/24fc68:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115fc68:7200::/24fc68:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116fc68:7300::/24fc68:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117fc68:7400::/24fc68:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118fc68:7500::/24fc68:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119fc68:7600::/24fc68:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120fc68:7700::/24fc68:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121fc68:7800::/24fc68:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122fc68:7900::/24fc68:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123fc68:7a00::/24fc68:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124fc68:7b00::/24fc68:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125fc68:7c00::/24fc68:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126fc68:7d00::/24fc68:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127fc68:7e00::/24fc68:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128fc68:7f00::/24fc68:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129fc68:8000::/24fc68:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130fc68:8100::/24fc68:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131fc68:8200::/24fc68:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132fc68:8300::/24fc68:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133fc68:8400::/24fc68:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134fc68:8500::/24fc68:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135fc68:8600::/24fc68:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136fc68:8700::/24fc68:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137fc68:8800::/24fc68:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138fc68:8900::/24fc68:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139fc68:8a00::/24fc68:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140fc68:8b00::/24fc68:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141fc68:8c00::/24fc68:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142fc68:8d00::/24fc68:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143fc68:8e00::/24fc68:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144fc68:8f00::/24fc68:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145fc68:9000::/24fc68:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146fc68:9100::/24fc68:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147fc68:9200::/24fc68:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148fc68:9300::/24fc68:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149fc68:9400::/24fc68:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150fc68:9500::/24fc68:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151fc68:9600::/24fc68:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152fc68:9700::/24fc68:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153fc68:9800::/24fc68:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154fc68:9900::/24fc68:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155fc68:9a00::/24fc68:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156fc68:9b00::/24fc68:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157fc68:9c00::/24fc68:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158fc68:9d00::/24fc68:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159fc68:9e00::/24fc68:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160fc68:9f00::/24fc68:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161fc68:a000::/24fc68:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162fc68:a100::/24fc68:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163fc68:a200::/24fc68:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164fc68:a300::/24fc68:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165fc68:a400::/24fc68:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166fc68:a500::/24fc68:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167fc68:a600::/24fc68:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168fc68:a700::/24fc68:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169fc68:a800::/24fc68:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170fc68:a900::/24fc68:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171fc68:aa00::/24fc68:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172fc68:ab00::/24fc68:abff:ffff:ffff:ffff:ffff:ffff:ffff
173fc68:ac00::/24fc68:acff:ffff:ffff:ffff:ffff:ffff:ffff
174fc68:ad00::/24fc68:adff:ffff:ffff:ffff:ffff:ffff:ffff
175fc68:ae00::/24fc68:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176fc68:af00::/24fc68:afff:ffff:ffff:ffff:ffff:ffff:ffff
177fc68:b000::/24fc68:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178fc68:b100::/24fc68:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179fc68:b200::/24fc68:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180fc68:b300::/24fc68:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181fc68:b400::/24fc68:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182fc68:b500::/24fc68:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183fc68:b600::/24fc68:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184fc68:b700::/24fc68:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185fc68:b800::/24fc68:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186fc68:b900::/24fc68:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187fc68:ba00::/24fc68:baff:ffff:ffff:ffff:ffff:ffff:ffff
188fc68:bb00::/24fc68:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189fc68:bc00::/24fc68:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190fc68:bd00::/24fc68:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191fc68:be00::/24fc68:beff:ffff:ffff:ffff:ffff:ffff:ffff
192fc68:bf00::/24fc68:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193fc68:c000::/24fc68:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194fc68:c100::/24fc68:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195fc68:c200::/24fc68:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196fc68:c300::/24fc68:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197fc68:c400::/24fc68:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198fc68:c500::/24fc68:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199fc68:c600::/24fc68:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200fc68:c700::/24fc68:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201fc68:c800::/24fc68:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202fc68:c900::/24fc68:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203fc68:ca00::/24fc68:caff:ffff:ffff:ffff:ffff:ffff:ffff
204fc68:cb00::/24fc68:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205fc68:cc00::/24fc68:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206fc68:cd00::/24fc68:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207fc68:ce00::/24fc68:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208fc68:cf00::/24fc68:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209fc68:d000::/24fc68:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210fc68:d100::/24fc68:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211fc68:d200::/24fc68:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212fc68:d300::/24fc68:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213fc68:d400::/24fc68:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214fc68:d500::/24fc68:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215fc68:d600::/24fc68:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216fc68:d700::/24fc68:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217fc68:d800::/24fc68:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218fc68:d900::/24fc68:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219fc68:da00::/24fc68:daff:ffff:ffff:ffff:ffff:ffff:ffff
220fc68:db00::/24fc68:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221fc68:dc00::/24fc68:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222fc68:dd00::/24fc68:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223fc68:de00::/24fc68:deff:ffff:ffff:ffff:ffff:ffff:ffff
224fc68:df00::/24fc68:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225fc68:e000::/24fc68:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226fc68:e100::/24fc68:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227fc68:e200::/24fc68:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228fc68:e300::/24fc68:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229fc68:e400::/24fc68:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230fc68:e500::/24fc68:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231fc68:e600::/24fc68:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232fc68:e700::/24fc68:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233fc68:e800::/24fc68:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234fc68:e900::/24fc68:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235fc68:ea00::/24fc68:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236fc68:eb00::/24fc68:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237fc68:ec00::/24fc68:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238fc68:ed00::/24fc68:edff:ffff:ffff:ffff:ffff:ffff:ffff
239fc68:ee00::/24fc68:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240fc68:ef00::/24fc68:efff:ffff:ffff:ffff:ffff:ffff:ffff
241fc68:f000::/24fc68:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242fc68:f100::/24fc68:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243fc68:f200::/24fc68:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244fc68:f300::/24fc68:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245fc68:f400::/24fc68:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246fc68:f500::/24fc68:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247fc68:f600::/24fc68:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248fc68:f700::/24fc68:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249fc68:f800::/24fc68:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250fc68:f900::/24fc68:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251fc68:fa00::/24fc68:faff:ffff:ffff:ffff:ffff:ffff:ffff
252fc68:fb00::/24fc68:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253fc68:fc00::/24fc68:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254fc68:fd00::/24fc68:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255fc68:fe00::/24fc68:feff:ffff:ffff:ffff:ffff:ffff:ffff
256fc68:ff00::/24fc68: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.