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Speed and call quality testTest delay, jitter and speed, with a focus on phone calls.My IP addressYour public IPv4 and IPv6 addresses, provider and address range.WhoIs lookupWho owns a domain or IP address, when it expires, and its DNS.DNS reportEvery DNS record for a domain, with email setup checked.IP subnet calculatorWork out a network's range, mask and hosts, and split it into subnets.

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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
fcc3::/16
First address
fcc3::
Last address
fcc3: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
fcc3:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
3.c.c.f.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

fcc3::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fcc3::/32fcc3:0:ffff:ffff:ffff:ffff:ffff:ffff
2fcc3:1::/32fcc3:1:ffff:ffff:ffff:ffff:ffff:ffff
3fcc3:2::/32fcc3:2:ffff:ffff:ffff:ffff:ffff:ffff
4fcc3:3::/32fcc3:3:ffff:ffff:ffff:ffff:ffff:ffff
5fcc3:4::/32fcc3:4:ffff:ffff:ffff:ffff:ffff:ffff
6fcc3:5::/32fcc3:5:ffff:ffff:ffff:ffff:ffff:ffff
7fcc3:6::/32fcc3:6:ffff:ffff:ffff:ffff:ffff:ffff
8fcc3:7::/32fcc3:7:ffff:ffff:ffff:ffff:ffff:ffff
9fcc3:8::/32fcc3:8:ffff:ffff:ffff:ffff:ffff:ffff
10fcc3:9::/32fcc3:9:ffff:ffff:ffff:ffff:ffff:ffff
11fcc3:a::/32fcc3:a:ffff:ffff:ffff:ffff:ffff:ffff
12fcc3:b::/32fcc3:b:ffff:ffff:ffff:ffff:ffff:ffff
13fcc3:c::/32fcc3:c:ffff:ffff:ffff:ffff:ffff:ffff
14fcc3:d::/32fcc3:d:ffff:ffff:ffff:ffff:ffff:ffff
15fcc3:e::/32fcc3:e:ffff:ffff:ffff:ffff:ffff:ffff
16fcc3:f::/32fcc3:f:ffff:ffff:ffff:ffff:ffff:ffff
17fcc3:10::/32fcc3:10:ffff:ffff:ffff:ffff:ffff:ffff
18fcc3:11::/32fcc3:11:ffff:ffff:ffff:ffff:ffff:ffff
19fcc3:12::/32fcc3:12:ffff:ffff:ffff:ffff:ffff:ffff
20fcc3:13::/32fcc3:13:ffff:ffff:ffff:ffff:ffff:ffff
21fcc3:14::/32fcc3:14:ffff:ffff:ffff:ffff:ffff:ffff
22fcc3:15::/32fcc3:15:ffff:ffff:ffff:ffff:ffff:ffff
23fcc3:16::/32fcc3:16:ffff:ffff:ffff:ffff:ffff:ffff
24fcc3:17::/32fcc3:17:ffff:ffff:ffff:ffff:ffff:ffff
25fcc3:18::/32fcc3:18:ffff:ffff:ffff:ffff:ffff:ffff
26fcc3:19::/32fcc3:19:ffff:ffff:ffff:ffff:ffff:ffff
27fcc3:1a::/32fcc3:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fcc3:1b::/32fcc3:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fcc3:1c::/32fcc3:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fcc3:1d::/32fcc3:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fcc3:1e::/32fcc3:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fcc3:1f::/32fcc3:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fcc3:20::/32fcc3:20:ffff:ffff:ffff:ffff:ffff:ffff
34fcc3:21::/32fcc3:21:ffff:ffff:ffff:ffff:ffff:ffff
35fcc3:22::/32fcc3:22:ffff:ffff:ffff:ffff:ffff:ffff
36fcc3:23::/32fcc3:23:ffff:ffff:ffff:ffff:ffff:ffff
37fcc3:24::/32fcc3:24:ffff:ffff:ffff:ffff:ffff:ffff
38fcc3:25::/32fcc3:25:ffff:ffff:ffff:ffff:ffff:ffff
39fcc3:26::/32fcc3:26:ffff:ffff:ffff:ffff:ffff:ffff
40fcc3:27::/32fcc3:27:ffff:ffff:ffff:ffff:ffff:ffff
41fcc3:28::/32fcc3:28:ffff:ffff:ffff:ffff:ffff:ffff
42fcc3:29::/32fcc3:29:ffff:ffff:ffff:ffff:ffff:ffff
43fcc3:2a::/32fcc3:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fcc3:2b::/32fcc3:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fcc3:2c::/32fcc3:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fcc3:2d::/32fcc3:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fcc3:2e::/32fcc3:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fcc3:2f::/32fcc3:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fcc3:30::/32fcc3:30:ffff:ffff:ffff:ffff:ffff:ffff
50fcc3:31::/32fcc3:31:ffff:ffff:ffff:ffff:ffff:ffff
51fcc3:32::/32fcc3:32:ffff:ffff:ffff:ffff:ffff:ffff
52fcc3:33::/32fcc3:33:ffff:ffff:ffff:ffff:ffff:ffff
53fcc3:34::/32fcc3:34:ffff:ffff:ffff:ffff:ffff:ffff
54fcc3:35::/32fcc3:35:ffff:ffff:ffff:ffff:ffff:ffff
55fcc3:36::/32fcc3:36:ffff:ffff:ffff:ffff:ffff:ffff
56fcc3:37::/32fcc3:37:ffff:ffff:ffff:ffff:ffff:ffff
57fcc3:38::/32fcc3:38:ffff:ffff:ffff:ffff:ffff:ffff
58fcc3:39::/32fcc3:39:ffff:ffff:ffff:ffff:ffff:ffff
59fcc3:3a::/32fcc3:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fcc3:3b::/32fcc3:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fcc3:3c::/32fcc3:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fcc3:3d::/32fcc3:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fcc3:3e::/32fcc3:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fcc3:3f::/32fcc3:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fcc3:40::/32fcc3:40:ffff:ffff:ffff:ffff:ffff:ffff
66fcc3:41::/32fcc3:41:ffff:ffff:ffff:ffff:ffff:ffff
67fcc3:42::/32fcc3:42:ffff:ffff:ffff:ffff:ffff:ffff
68fcc3:43::/32fcc3:43:ffff:ffff:ffff:ffff:ffff:ffff
69fcc3:44::/32fcc3:44:ffff:ffff:ffff:ffff:ffff:ffff
70fcc3:45::/32fcc3:45:ffff:ffff:ffff:ffff:ffff:ffff
71fcc3:46::/32fcc3:46:ffff:ffff:ffff:ffff:ffff:ffff
72fcc3:47::/32fcc3:47:ffff:ffff:ffff:ffff:ffff:ffff
73fcc3:48::/32fcc3:48:ffff:ffff:ffff:ffff:ffff:ffff
74fcc3:49::/32fcc3:49:ffff:ffff:ffff:ffff:ffff:ffff
75fcc3:4a::/32fcc3:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fcc3:4b::/32fcc3:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fcc3:4c::/32fcc3:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fcc3:4d::/32fcc3:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fcc3:4e::/32fcc3:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fcc3:4f::/32fcc3:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fcc3:50::/32fcc3:50:ffff:ffff:ffff:ffff:ffff:ffff
82fcc3:51::/32fcc3:51:ffff:ffff:ffff:ffff:ffff:ffff
83fcc3:52::/32fcc3:52:ffff:ffff:ffff:ffff:ffff:ffff
84fcc3:53::/32fcc3:53:ffff:ffff:ffff:ffff:ffff:ffff
85fcc3:54::/32fcc3:54:ffff:ffff:ffff:ffff:ffff:ffff
86fcc3:55::/32fcc3:55:ffff:ffff:ffff:ffff:ffff:ffff
87fcc3:56::/32fcc3:56:ffff:ffff:ffff:ffff:ffff:ffff
88fcc3:57::/32fcc3:57:ffff:ffff:ffff:ffff:ffff:ffff
89fcc3:58::/32fcc3:58:ffff:ffff:ffff:ffff:ffff:ffff
90fcc3:59::/32fcc3:59:ffff:ffff:ffff:ffff:ffff:ffff
91fcc3:5a::/32fcc3:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fcc3:5b::/32fcc3:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fcc3:5c::/32fcc3:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fcc3:5d::/32fcc3:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fcc3:5e::/32fcc3:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fcc3:5f::/32fcc3:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fcc3:60::/32fcc3:60:ffff:ffff:ffff:ffff:ffff:ffff
98fcc3:61::/32fcc3:61:ffff:ffff:ffff:ffff:ffff:ffff
99fcc3:62::/32fcc3:62:ffff:ffff:ffff:ffff:ffff:ffff
100fcc3:63::/32fcc3:63:ffff:ffff:ffff:ffff:ffff:ffff
101fcc3:64::/32fcc3:64:ffff:ffff:ffff:ffff:ffff:ffff
102fcc3:65::/32fcc3:65:ffff:ffff:ffff:ffff:ffff:ffff
103fcc3:66::/32fcc3:66:ffff:ffff:ffff:ffff:ffff:ffff
104fcc3:67::/32fcc3:67:ffff:ffff:ffff:ffff:ffff:ffff
105fcc3:68::/32fcc3:68:ffff:ffff:ffff:ffff:ffff:ffff
106fcc3:69::/32fcc3:69:ffff:ffff:ffff:ffff:ffff:ffff
107fcc3:6a::/32fcc3:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fcc3:6b::/32fcc3:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fcc3:6c::/32fcc3:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fcc3:6d::/32fcc3:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fcc3:6e::/32fcc3:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fcc3:6f::/32fcc3:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fcc3:70::/32fcc3:70:ffff:ffff:ffff:ffff:ffff:ffff
114fcc3:71::/32fcc3:71:ffff:ffff:ffff:ffff:ffff:ffff
115fcc3:72::/32fcc3:72:ffff:ffff:ffff:ffff:ffff:ffff
116fcc3:73::/32fcc3:73:ffff:ffff:ffff:ffff:ffff:ffff
117fcc3:74::/32fcc3:74:ffff:ffff:ffff:ffff:ffff:ffff
118fcc3:75::/32fcc3:75:ffff:ffff:ffff:ffff:ffff:ffff
119fcc3:76::/32fcc3:76:ffff:ffff:ffff:ffff:ffff:ffff
120fcc3:77::/32fcc3:77:ffff:ffff:ffff:ffff:ffff:ffff
121fcc3:78::/32fcc3:78:ffff:ffff:ffff:ffff:ffff:ffff
122fcc3:79::/32fcc3:79:ffff:ffff:ffff:ffff:ffff:ffff
123fcc3:7a::/32fcc3:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fcc3:7b::/32fcc3:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fcc3:7c::/32fcc3:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fcc3:7d::/32fcc3:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fcc3:7e::/32fcc3:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fcc3:7f::/32fcc3:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fcc3:80::/32fcc3:80:ffff:ffff:ffff:ffff:ffff:ffff
130fcc3:81::/32fcc3:81:ffff:ffff:ffff:ffff:ffff:ffff
131fcc3:82::/32fcc3:82:ffff:ffff:ffff:ffff:ffff:ffff
132fcc3:83::/32fcc3:83:ffff:ffff:ffff:ffff:ffff:ffff
133fcc3:84::/32fcc3:84:ffff:ffff:ffff:ffff:ffff:ffff
134fcc3:85::/32fcc3:85:ffff:ffff:ffff:ffff:ffff:ffff
135fcc3:86::/32fcc3:86:ffff:ffff:ffff:ffff:ffff:ffff
136fcc3:87::/32fcc3:87:ffff:ffff:ffff:ffff:ffff:ffff
137fcc3:88::/32fcc3:88:ffff:ffff:ffff:ffff:ffff:ffff
138fcc3:89::/32fcc3:89:ffff:ffff:ffff:ffff:ffff:ffff
139fcc3:8a::/32fcc3:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fcc3:8b::/32fcc3:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fcc3:8c::/32fcc3:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fcc3:8d::/32fcc3:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fcc3:8e::/32fcc3:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fcc3:8f::/32fcc3:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fcc3:90::/32fcc3:90:ffff:ffff:ffff:ffff:ffff:ffff
146fcc3:91::/32fcc3:91:ffff:ffff:ffff:ffff:ffff:ffff
147fcc3:92::/32fcc3:92:ffff:ffff:ffff:ffff:ffff:ffff
148fcc3:93::/32fcc3:93:ffff:ffff:ffff:ffff:ffff:ffff
149fcc3:94::/32fcc3:94:ffff:ffff:ffff:ffff:ffff:ffff
150fcc3:95::/32fcc3:95:ffff:ffff:ffff:ffff:ffff:ffff
151fcc3:96::/32fcc3:96:ffff:ffff:ffff:ffff:ffff:ffff
152fcc3:97::/32fcc3:97:ffff:ffff:ffff:ffff:ffff:ffff
153fcc3:98::/32fcc3:98:ffff:ffff:ffff:ffff:ffff:ffff
154fcc3:99::/32fcc3:99:ffff:ffff:ffff:ffff:ffff:ffff
155fcc3:9a::/32fcc3:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fcc3:9b::/32fcc3:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fcc3:9c::/32fcc3:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fcc3:9d::/32fcc3:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fcc3:9e::/32fcc3:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fcc3:9f::/32fcc3:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fcc3:a0::/32fcc3:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fcc3:a1::/32fcc3:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fcc3:a2::/32fcc3:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fcc3:a3::/32fcc3:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fcc3:a4::/32fcc3:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fcc3:a5::/32fcc3:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fcc3:a6::/32fcc3:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fcc3:a7::/32fcc3:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fcc3:a8::/32fcc3:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fcc3:a9::/32fcc3:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fcc3:aa::/32fcc3:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fcc3:ab::/32fcc3:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fcc3:ac::/32fcc3:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fcc3:ad::/32fcc3:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fcc3:ae::/32fcc3:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fcc3:af::/32fcc3:af:ffff:ffff:ffff:ffff:ffff:ffff
177fcc3:b0::/32fcc3:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fcc3:b1::/32fcc3:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fcc3:b2::/32fcc3:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fcc3:b3::/32fcc3:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fcc3:b4::/32fcc3:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fcc3:b5::/32fcc3:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fcc3:b6::/32fcc3:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fcc3:b7::/32fcc3:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fcc3:b8::/32fcc3:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fcc3:b9::/32fcc3:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fcc3:ba::/32fcc3:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fcc3:bb::/32fcc3:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fcc3:bc::/32fcc3:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fcc3:bd::/32fcc3:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fcc3:be::/32fcc3:be:ffff:ffff:ffff:ffff:ffff:ffff
192fcc3:bf::/32fcc3:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fcc3:c0::/32fcc3:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fcc3:c1::/32fcc3:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fcc3:c2::/32fcc3:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fcc3:c3::/32fcc3:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fcc3:c4::/32fcc3:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fcc3:c5::/32fcc3:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fcc3:c6::/32fcc3:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fcc3:c7::/32fcc3:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fcc3:c8::/32fcc3:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fcc3:c9::/32fcc3:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fcc3:ca::/32fcc3:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fcc3:cb::/32fcc3:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fcc3:cc::/32fcc3:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fcc3:cd::/32fcc3:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fcc3:ce::/32fcc3:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fcc3:cf::/32fcc3:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fcc3:d0::/32fcc3:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fcc3:d1::/32fcc3:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fcc3:d2::/32fcc3:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fcc3:d3::/32fcc3:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fcc3:d4::/32fcc3:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fcc3:d5::/32fcc3:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fcc3:d6::/32fcc3:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fcc3:d7::/32fcc3:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fcc3:d8::/32fcc3:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fcc3:d9::/32fcc3:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fcc3:da::/32fcc3:da:ffff:ffff:ffff:ffff:ffff:ffff
220fcc3:db::/32fcc3:db:ffff:ffff:ffff:ffff:ffff:ffff
221fcc3:dc::/32fcc3:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fcc3:dd::/32fcc3:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fcc3:de::/32fcc3:de:ffff:ffff:ffff:ffff:ffff:ffff
224fcc3:df::/32fcc3:df:ffff:ffff:ffff:ffff:ffff:ffff
225fcc3:e0::/32fcc3:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fcc3:e1::/32fcc3:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fcc3:e2::/32fcc3:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fcc3:e3::/32fcc3:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fcc3:e4::/32fcc3:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fcc3:e5::/32fcc3:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fcc3:e6::/32fcc3:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fcc3:e7::/32fcc3:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fcc3:e8::/32fcc3:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fcc3:e9::/32fcc3:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fcc3:ea::/32fcc3:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fcc3:eb::/32fcc3:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fcc3:ec::/32fcc3:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fcc3:ed::/32fcc3:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fcc3:ee::/32fcc3:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fcc3:ef::/32fcc3:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fcc3:f0::/32fcc3:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fcc3:f1::/32fcc3:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fcc3:f2::/32fcc3:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fcc3:f3::/32fcc3:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fcc3:f4::/32fcc3:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fcc3:f5::/32fcc3:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fcc3:f6::/32fcc3:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fcc3:f7::/32fcc3:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fcc3:f8::/32fcc3:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fcc3:f9::/32fcc3:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fcc3:fa::/32fcc3:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fcc3:fb::/32fcc3:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fcc3:fc::/32fcc3:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fcc3:fd::/32fcc3:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fcc3:fe::/32fcc3:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fcc3:ff::/32fcc3:ff: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.