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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
fc99::/16
First address
fc99::
Last address
fc99: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
fc99:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
9.9.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)

fc99::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
1fc99::/24fc99:ff:ffff:ffff:ffff:ffff:ffff:ffff
2fc99:100::/24fc99:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3fc99:200::/24fc99:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4fc99:300::/24fc99:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5fc99:400::/24fc99:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6fc99:500::/24fc99:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7fc99:600::/24fc99:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8fc99:700::/24fc99:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9fc99:800::/24fc99:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10fc99:900::/24fc99:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11fc99:a00::/24fc99:aff:ffff:ffff:ffff:ffff:ffff:ffff
12fc99:b00::/24fc99:bff:ffff:ffff:ffff:ffff:ffff:ffff
13fc99:c00::/24fc99:cff:ffff:ffff:ffff:ffff:ffff:ffff
14fc99:d00::/24fc99:dff:ffff:ffff:ffff:ffff:ffff:ffff
15fc99:e00::/24fc99:eff:ffff:ffff:ffff:ffff:ffff:ffff
16fc99:f00::/24fc99:fff:ffff:ffff:ffff:ffff:ffff:ffff
17fc99:1000::/24fc99:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18fc99:1100::/24fc99:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19fc99:1200::/24fc99:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20fc99:1300::/24fc99:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21fc99:1400::/24fc99:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22fc99:1500::/24fc99:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23fc99:1600::/24fc99:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24fc99:1700::/24fc99:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25fc99:1800::/24fc99:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26fc99:1900::/24fc99:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27fc99:1a00::/24fc99:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28fc99:1b00::/24fc99:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29fc99:1c00::/24fc99:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30fc99:1d00::/24fc99:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31fc99:1e00::/24fc99:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32fc99:1f00::/24fc99:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33fc99:2000::/24fc99:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34fc99:2100::/24fc99:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35fc99:2200::/24fc99:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36fc99:2300::/24fc99:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37fc99:2400::/24fc99:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38fc99:2500::/24fc99:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39fc99:2600::/24fc99:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40fc99:2700::/24fc99:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41fc99:2800::/24fc99:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42fc99:2900::/24fc99:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43fc99:2a00::/24fc99:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44fc99:2b00::/24fc99:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45fc99:2c00::/24fc99:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46fc99:2d00::/24fc99:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47fc99:2e00::/24fc99:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48fc99:2f00::/24fc99:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49fc99:3000::/24fc99:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50fc99:3100::/24fc99:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51fc99:3200::/24fc99:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52fc99:3300::/24fc99:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53fc99:3400::/24fc99:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54fc99:3500::/24fc99:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55fc99:3600::/24fc99:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56fc99:3700::/24fc99:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57fc99:3800::/24fc99:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58fc99:3900::/24fc99:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59fc99:3a00::/24fc99:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60fc99:3b00::/24fc99:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61fc99:3c00::/24fc99:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62fc99:3d00::/24fc99:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63fc99:3e00::/24fc99:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64fc99:3f00::/24fc99:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65fc99:4000::/24fc99:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66fc99:4100::/24fc99:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67fc99:4200::/24fc99:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68fc99:4300::/24fc99:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69fc99:4400::/24fc99:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70fc99:4500::/24fc99:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71fc99:4600::/24fc99:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72fc99:4700::/24fc99:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73fc99:4800::/24fc99:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74fc99:4900::/24fc99:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75fc99:4a00::/24fc99:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76fc99:4b00::/24fc99:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77fc99:4c00::/24fc99:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78fc99:4d00::/24fc99:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79fc99:4e00::/24fc99:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80fc99:4f00::/24fc99:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81fc99:5000::/24fc99:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82fc99:5100::/24fc99:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83fc99:5200::/24fc99:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84fc99:5300::/24fc99:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85fc99:5400::/24fc99:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86fc99:5500::/24fc99:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87fc99:5600::/24fc99:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88fc99:5700::/24fc99:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89fc99:5800::/24fc99:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90fc99:5900::/24fc99:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91fc99:5a00::/24fc99:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92fc99:5b00::/24fc99:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93fc99:5c00::/24fc99:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94fc99:5d00::/24fc99:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95fc99:5e00::/24fc99:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96fc99:5f00::/24fc99:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97fc99:6000::/24fc99:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98fc99:6100::/24fc99:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99fc99:6200::/24fc99:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100fc99:6300::/24fc99:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101fc99:6400::/24fc99:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102fc99:6500::/24fc99:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103fc99:6600::/24fc99:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104fc99:6700::/24fc99:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105fc99:6800::/24fc99:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106fc99:6900::/24fc99:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107fc99:6a00::/24fc99:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108fc99:6b00::/24fc99:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109fc99:6c00::/24fc99:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110fc99:6d00::/24fc99:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111fc99:6e00::/24fc99:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112fc99:6f00::/24fc99:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113fc99:7000::/24fc99:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114fc99:7100::/24fc99:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115fc99:7200::/24fc99:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116fc99:7300::/24fc99:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117fc99:7400::/24fc99:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118fc99:7500::/24fc99:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119fc99:7600::/24fc99:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120fc99:7700::/24fc99:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121fc99:7800::/24fc99:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122fc99:7900::/24fc99:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123fc99:7a00::/24fc99:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124fc99:7b00::/24fc99:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125fc99:7c00::/24fc99:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126fc99:7d00::/24fc99:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127fc99:7e00::/24fc99:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128fc99:7f00::/24fc99:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129fc99:8000::/24fc99:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130fc99:8100::/24fc99:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131fc99:8200::/24fc99:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132fc99:8300::/24fc99:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133fc99:8400::/24fc99:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134fc99:8500::/24fc99:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135fc99:8600::/24fc99:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136fc99:8700::/24fc99:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137fc99:8800::/24fc99:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138fc99:8900::/24fc99:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139fc99:8a00::/24fc99:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140fc99:8b00::/24fc99:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141fc99:8c00::/24fc99:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142fc99:8d00::/24fc99:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143fc99:8e00::/24fc99:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144fc99:8f00::/24fc99:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145fc99:9000::/24fc99:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146fc99:9100::/24fc99:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147fc99:9200::/24fc99:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148fc99:9300::/24fc99:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149fc99:9400::/24fc99:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150fc99:9500::/24fc99:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151fc99:9600::/24fc99:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152fc99:9700::/24fc99:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153fc99:9800::/24fc99:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154fc99:9900::/24fc99:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155fc99:9a00::/24fc99:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156fc99:9b00::/24fc99:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157fc99:9c00::/24fc99:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158fc99:9d00::/24fc99:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159fc99:9e00::/24fc99:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160fc99:9f00::/24fc99:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161fc99:a000::/24fc99:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162fc99:a100::/24fc99:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163fc99:a200::/24fc99:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164fc99:a300::/24fc99:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165fc99:a400::/24fc99:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166fc99:a500::/24fc99:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167fc99:a600::/24fc99:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168fc99:a700::/24fc99:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169fc99:a800::/24fc99:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170fc99:a900::/24fc99:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171fc99:aa00::/24fc99:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172fc99:ab00::/24fc99:abff:ffff:ffff:ffff:ffff:ffff:ffff
173fc99:ac00::/24fc99:acff:ffff:ffff:ffff:ffff:ffff:ffff
174fc99:ad00::/24fc99:adff:ffff:ffff:ffff:ffff:ffff:ffff
175fc99:ae00::/24fc99:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176fc99:af00::/24fc99:afff:ffff:ffff:ffff:ffff:ffff:ffff
177fc99:b000::/24fc99:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178fc99:b100::/24fc99:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179fc99:b200::/24fc99:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180fc99:b300::/24fc99:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181fc99:b400::/24fc99:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182fc99:b500::/24fc99:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183fc99:b600::/24fc99:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184fc99:b700::/24fc99:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185fc99:b800::/24fc99:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186fc99:b900::/24fc99:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187fc99:ba00::/24fc99:baff:ffff:ffff:ffff:ffff:ffff:ffff
188fc99:bb00::/24fc99:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189fc99:bc00::/24fc99:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190fc99:bd00::/24fc99:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191fc99:be00::/24fc99:beff:ffff:ffff:ffff:ffff:ffff:ffff
192fc99:bf00::/24fc99:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193fc99:c000::/24fc99:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194fc99:c100::/24fc99:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195fc99:c200::/24fc99:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196fc99:c300::/24fc99:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197fc99:c400::/24fc99:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198fc99:c500::/24fc99:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199fc99:c600::/24fc99:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200fc99:c700::/24fc99:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201fc99:c800::/24fc99:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202fc99:c900::/24fc99:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203fc99:ca00::/24fc99:caff:ffff:ffff:ffff:ffff:ffff:ffff
204fc99:cb00::/24fc99:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205fc99:cc00::/24fc99:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206fc99:cd00::/24fc99:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207fc99:ce00::/24fc99:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208fc99:cf00::/24fc99:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209fc99:d000::/24fc99:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210fc99:d100::/24fc99:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211fc99:d200::/24fc99:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212fc99:d300::/24fc99:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213fc99:d400::/24fc99:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214fc99:d500::/24fc99:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215fc99:d600::/24fc99:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216fc99:d700::/24fc99:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217fc99:d800::/24fc99:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218fc99:d900::/24fc99:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219fc99:da00::/24fc99:daff:ffff:ffff:ffff:ffff:ffff:ffff
220fc99:db00::/24fc99:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221fc99:dc00::/24fc99:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222fc99:dd00::/24fc99:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223fc99:de00::/24fc99:deff:ffff:ffff:ffff:ffff:ffff:ffff
224fc99:df00::/24fc99:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225fc99:e000::/24fc99:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226fc99:e100::/24fc99:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227fc99:e200::/24fc99:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228fc99:e300::/24fc99:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229fc99:e400::/24fc99:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230fc99:e500::/24fc99:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231fc99:e600::/24fc99:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232fc99:e700::/24fc99:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233fc99:e800::/24fc99:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234fc99:e900::/24fc99:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235fc99:ea00::/24fc99:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236fc99:eb00::/24fc99:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237fc99:ec00::/24fc99:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238fc99:ed00::/24fc99:edff:ffff:ffff:ffff:ffff:ffff:ffff
239fc99:ee00::/24fc99:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240fc99:ef00::/24fc99:efff:ffff:ffff:ffff:ffff:ffff:ffff
241fc99:f000::/24fc99:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242fc99:f100::/24fc99:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243fc99:f200::/24fc99:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244fc99:f300::/24fc99:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245fc99:f400::/24fc99:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246fc99:f500::/24fc99:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247fc99:f600::/24fc99:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248fc99:f700::/24fc99:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249fc99:f800::/24fc99:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250fc99:f900::/24fc99:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251fc99:fa00::/24fc99:faff:ffff:ffff:ffff:ffff:ffff:ffff
252fc99:fb00::/24fc99:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253fc99:fc00::/24fc99:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254fc99:fd00::/24fc99:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255fc99:fe00::/24fc99:feff:ffff:ffff:ffff:ffff:ffff:ffff
256fc99:ff00::/24fc99: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.