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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
ffa4::/16
First address
ffa4::
Last address
ffa4: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
ffa4:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
4.a.f.f.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

ffa4::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1ffa4::/32ffa4:0:ffff:ffff:ffff:ffff:ffff:ffff
2ffa4:1::/32ffa4:1:ffff:ffff:ffff:ffff:ffff:ffff
3ffa4:2::/32ffa4:2:ffff:ffff:ffff:ffff:ffff:ffff
4ffa4:3::/32ffa4:3:ffff:ffff:ffff:ffff:ffff:ffff
5ffa4:4::/32ffa4:4:ffff:ffff:ffff:ffff:ffff:ffff
6ffa4:5::/32ffa4:5:ffff:ffff:ffff:ffff:ffff:ffff
7ffa4:6::/32ffa4:6:ffff:ffff:ffff:ffff:ffff:ffff
8ffa4:7::/32ffa4:7:ffff:ffff:ffff:ffff:ffff:ffff
9ffa4:8::/32ffa4:8:ffff:ffff:ffff:ffff:ffff:ffff
10ffa4:9::/32ffa4:9:ffff:ffff:ffff:ffff:ffff:ffff
11ffa4:a::/32ffa4:a:ffff:ffff:ffff:ffff:ffff:ffff
12ffa4:b::/32ffa4:b:ffff:ffff:ffff:ffff:ffff:ffff
13ffa4:c::/32ffa4:c:ffff:ffff:ffff:ffff:ffff:ffff
14ffa4:d::/32ffa4:d:ffff:ffff:ffff:ffff:ffff:ffff
15ffa4:e::/32ffa4:e:ffff:ffff:ffff:ffff:ffff:ffff
16ffa4:f::/32ffa4:f:ffff:ffff:ffff:ffff:ffff:ffff
17ffa4:10::/32ffa4:10:ffff:ffff:ffff:ffff:ffff:ffff
18ffa4:11::/32ffa4:11:ffff:ffff:ffff:ffff:ffff:ffff
19ffa4:12::/32ffa4:12:ffff:ffff:ffff:ffff:ffff:ffff
20ffa4:13::/32ffa4:13:ffff:ffff:ffff:ffff:ffff:ffff
21ffa4:14::/32ffa4:14:ffff:ffff:ffff:ffff:ffff:ffff
22ffa4:15::/32ffa4:15:ffff:ffff:ffff:ffff:ffff:ffff
23ffa4:16::/32ffa4:16:ffff:ffff:ffff:ffff:ffff:ffff
24ffa4:17::/32ffa4:17:ffff:ffff:ffff:ffff:ffff:ffff
25ffa4:18::/32ffa4:18:ffff:ffff:ffff:ffff:ffff:ffff
26ffa4:19::/32ffa4:19:ffff:ffff:ffff:ffff:ffff:ffff
27ffa4:1a::/32ffa4:1a:ffff:ffff:ffff:ffff:ffff:ffff
28ffa4:1b::/32ffa4:1b:ffff:ffff:ffff:ffff:ffff:ffff
29ffa4:1c::/32ffa4:1c:ffff:ffff:ffff:ffff:ffff:ffff
30ffa4:1d::/32ffa4:1d:ffff:ffff:ffff:ffff:ffff:ffff
31ffa4:1e::/32ffa4:1e:ffff:ffff:ffff:ffff:ffff:ffff
32ffa4:1f::/32ffa4:1f:ffff:ffff:ffff:ffff:ffff:ffff
33ffa4:20::/32ffa4:20:ffff:ffff:ffff:ffff:ffff:ffff
34ffa4:21::/32ffa4:21:ffff:ffff:ffff:ffff:ffff:ffff
35ffa4:22::/32ffa4:22:ffff:ffff:ffff:ffff:ffff:ffff
36ffa4:23::/32ffa4:23:ffff:ffff:ffff:ffff:ffff:ffff
37ffa4:24::/32ffa4:24:ffff:ffff:ffff:ffff:ffff:ffff
38ffa4:25::/32ffa4:25:ffff:ffff:ffff:ffff:ffff:ffff
39ffa4:26::/32ffa4:26:ffff:ffff:ffff:ffff:ffff:ffff
40ffa4:27::/32ffa4:27:ffff:ffff:ffff:ffff:ffff:ffff
41ffa4:28::/32ffa4:28:ffff:ffff:ffff:ffff:ffff:ffff
42ffa4:29::/32ffa4:29:ffff:ffff:ffff:ffff:ffff:ffff
43ffa4:2a::/32ffa4:2a:ffff:ffff:ffff:ffff:ffff:ffff
44ffa4:2b::/32ffa4:2b:ffff:ffff:ffff:ffff:ffff:ffff
45ffa4:2c::/32ffa4:2c:ffff:ffff:ffff:ffff:ffff:ffff
46ffa4:2d::/32ffa4:2d:ffff:ffff:ffff:ffff:ffff:ffff
47ffa4:2e::/32ffa4:2e:ffff:ffff:ffff:ffff:ffff:ffff
48ffa4:2f::/32ffa4:2f:ffff:ffff:ffff:ffff:ffff:ffff
49ffa4:30::/32ffa4:30:ffff:ffff:ffff:ffff:ffff:ffff
50ffa4:31::/32ffa4:31:ffff:ffff:ffff:ffff:ffff:ffff
51ffa4:32::/32ffa4:32:ffff:ffff:ffff:ffff:ffff:ffff
52ffa4:33::/32ffa4:33:ffff:ffff:ffff:ffff:ffff:ffff
53ffa4:34::/32ffa4:34:ffff:ffff:ffff:ffff:ffff:ffff
54ffa4:35::/32ffa4:35:ffff:ffff:ffff:ffff:ffff:ffff
55ffa4:36::/32ffa4:36:ffff:ffff:ffff:ffff:ffff:ffff
56ffa4:37::/32ffa4:37:ffff:ffff:ffff:ffff:ffff:ffff
57ffa4:38::/32ffa4:38:ffff:ffff:ffff:ffff:ffff:ffff
58ffa4:39::/32ffa4:39:ffff:ffff:ffff:ffff:ffff:ffff
59ffa4:3a::/32ffa4:3a:ffff:ffff:ffff:ffff:ffff:ffff
60ffa4:3b::/32ffa4:3b:ffff:ffff:ffff:ffff:ffff:ffff
61ffa4:3c::/32ffa4:3c:ffff:ffff:ffff:ffff:ffff:ffff
62ffa4:3d::/32ffa4:3d:ffff:ffff:ffff:ffff:ffff:ffff
63ffa4:3e::/32ffa4:3e:ffff:ffff:ffff:ffff:ffff:ffff
64ffa4:3f::/32ffa4:3f:ffff:ffff:ffff:ffff:ffff:ffff
65ffa4:40::/32ffa4:40:ffff:ffff:ffff:ffff:ffff:ffff
66ffa4:41::/32ffa4:41:ffff:ffff:ffff:ffff:ffff:ffff
67ffa4:42::/32ffa4:42:ffff:ffff:ffff:ffff:ffff:ffff
68ffa4:43::/32ffa4:43:ffff:ffff:ffff:ffff:ffff:ffff
69ffa4:44::/32ffa4:44:ffff:ffff:ffff:ffff:ffff:ffff
70ffa4:45::/32ffa4:45:ffff:ffff:ffff:ffff:ffff:ffff
71ffa4:46::/32ffa4:46:ffff:ffff:ffff:ffff:ffff:ffff
72ffa4:47::/32ffa4:47:ffff:ffff:ffff:ffff:ffff:ffff
73ffa4:48::/32ffa4:48:ffff:ffff:ffff:ffff:ffff:ffff
74ffa4:49::/32ffa4:49:ffff:ffff:ffff:ffff:ffff:ffff
75ffa4:4a::/32ffa4:4a:ffff:ffff:ffff:ffff:ffff:ffff
76ffa4:4b::/32ffa4:4b:ffff:ffff:ffff:ffff:ffff:ffff
77ffa4:4c::/32ffa4:4c:ffff:ffff:ffff:ffff:ffff:ffff
78ffa4:4d::/32ffa4:4d:ffff:ffff:ffff:ffff:ffff:ffff
79ffa4:4e::/32ffa4:4e:ffff:ffff:ffff:ffff:ffff:ffff
80ffa4:4f::/32ffa4:4f:ffff:ffff:ffff:ffff:ffff:ffff
81ffa4:50::/32ffa4:50:ffff:ffff:ffff:ffff:ffff:ffff
82ffa4:51::/32ffa4:51:ffff:ffff:ffff:ffff:ffff:ffff
83ffa4:52::/32ffa4:52:ffff:ffff:ffff:ffff:ffff:ffff
84ffa4:53::/32ffa4:53:ffff:ffff:ffff:ffff:ffff:ffff
85ffa4:54::/32ffa4:54:ffff:ffff:ffff:ffff:ffff:ffff
86ffa4:55::/32ffa4:55:ffff:ffff:ffff:ffff:ffff:ffff
87ffa4:56::/32ffa4:56:ffff:ffff:ffff:ffff:ffff:ffff
88ffa4:57::/32ffa4:57:ffff:ffff:ffff:ffff:ffff:ffff
89ffa4:58::/32ffa4:58:ffff:ffff:ffff:ffff:ffff:ffff
90ffa4:59::/32ffa4:59:ffff:ffff:ffff:ffff:ffff:ffff
91ffa4:5a::/32ffa4:5a:ffff:ffff:ffff:ffff:ffff:ffff
92ffa4:5b::/32ffa4:5b:ffff:ffff:ffff:ffff:ffff:ffff
93ffa4:5c::/32ffa4:5c:ffff:ffff:ffff:ffff:ffff:ffff
94ffa4:5d::/32ffa4:5d:ffff:ffff:ffff:ffff:ffff:ffff
95ffa4:5e::/32ffa4:5e:ffff:ffff:ffff:ffff:ffff:ffff
96ffa4:5f::/32ffa4:5f:ffff:ffff:ffff:ffff:ffff:ffff
97ffa4:60::/32ffa4:60:ffff:ffff:ffff:ffff:ffff:ffff
98ffa4:61::/32ffa4:61:ffff:ffff:ffff:ffff:ffff:ffff
99ffa4:62::/32ffa4:62:ffff:ffff:ffff:ffff:ffff:ffff
100ffa4:63::/32ffa4:63:ffff:ffff:ffff:ffff:ffff:ffff
101ffa4:64::/32ffa4:64:ffff:ffff:ffff:ffff:ffff:ffff
102ffa4:65::/32ffa4:65:ffff:ffff:ffff:ffff:ffff:ffff
103ffa4:66::/32ffa4:66:ffff:ffff:ffff:ffff:ffff:ffff
104ffa4:67::/32ffa4:67:ffff:ffff:ffff:ffff:ffff:ffff
105ffa4:68::/32ffa4:68:ffff:ffff:ffff:ffff:ffff:ffff
106ffa4:69::/32ffa4:69:ffff:ffff:ffff:ffff:ffff:ffff
107ffa4:6a::/32ffa4:6a:ffff:ffff:ffff:ffff:ffff:ffff
108ffa4:6b::/32ffa4:6b:ffff:ffff:ffff:ffff:ffff:ffff
109ffa4:6c::/32ffa4:6c:ffff:ffff:ffff:ffff:ffff:ffff
110ffa4:6d::/32ffa4:6d:ffff:ffff:ffff:ffff:ffff:ffff
111ffa4:6e::/32ffa4:6e:ffff:ffff:ffff:ffff:ffff:ffff
112ffa4:6f::/32ffa4:6f:ffff:ffff:ffff:ffff:ffff:ffff
113ffa4:70::/32ffa4:70:ffff:ffff:ffff:ffff:ffff:ffff
114ffa4:71::/32ffa4:71:ffff:ffff:ffff:ffff:ffff:ffff
115ffa4:72::/32ffa4:72:ffff:ffff:ffff:ffff:ffff:ffff
116ffa4:73::/32ffa4:73:ffff:ffff:ffff:ffff:ffff:ffff
117ffa4:74::/32ffa4:74:ffff:ffff:ffff:ffff:ffff:ffff
118ffa4:75::/32ffa4:75:ffff:ffff:ffff:ffff:ffff:ffff
119ffa4:76::/32ffa4:76:ffff:ffff:ffff:ffff:ffff:ffff
120ffa4:77::/32ffa4:77:ffff:ffff:ffff:ffff:ffff:ffff
121ffa4:78::/32ffa4:78:ffff:ffff:ffff:ffff:ffff:ffff
122ffa4:79::/32ffa4:79:ffff:ffff:ffff:ffff:ffff:ffff
123ffa4:7a::/32ffa4:7a:ffff:ffff:ffff:ffff:ffff:ffff
124ffa4:7b::/32ffa4:7b:ffff:ffff:ffff:ffff:ffff:ffff
125ffa4:7c::/32ffa4:7c:ffff:ffff:ffff:ffff:ffff:ffff
126ffa4:7d::/32ffa4:7d:ffff:ffff:ffff:ffff:ffff:ffff
127ffa4:7e::/32ffa4:7e:ffff:ffff:ffff:ffff:ffff:ffff
128ffa4:7f::/32ffa4:7f:ffff:ffff:ffff:ffff:ffff:ffff
129ffa4:80::/32ffa4:80:ffff:ffff:ffff:ffff:ffff:ffff
130ffa4:81::/32ffa4:81:ffff:ffff:ffff:ffff:ffff:ffff
131ffa4:82::/32ffa4:82:ffff:ffff:ffff:ffff:ffff:ffff
132ffa4:83::/32ffa4:83:ffff:ffff:ffff:ffff:ffff:ffff
133ffa4:84::/32ffa4:84:ffff:ffff:ffff:ffff:ffff:ffff
134ffa4:85::/32ffa4:85:ffff:ffff:ffff:ffff:ffff:ffff
135ffa4:86::/32ffa4:86:ffff:ffff:ffff:ffff:ffff:ffff
136ffa4:87::/32ffa4:87:ffff:ffff:ffff:ffff:ffff:ffff
137ffa4:88::/32ffa4:88:ffff:ffff:ffff:ffff:ffff:ffff
138ffa4:89::/32ffa4:89:ffff:ffff:ffff:ffff:ffff:ffff
139ffa4:8a::/32ffa4:8a:ffff:ffff:ffff:ffff:ffff:ffff
140ffa4:8b::/32ffa4:8b:ffff:ffff:ffff:ffff:ffff:ffff
141ffa4:8c::/32ffa4:8c:ffff:ffff:ffff:ffff:ffff:ffff
142ffa4:8d::/32ffa4:8d:ffff:ffff:ffff:ffff:ffff:ffff
143ffa4:8e::/32ffa4:8e:ffff:ffff:ffff:ffff:ffff:ffff
144ffa4:8f::/32ffa4:8f:ffff:ffff:ffff:ffff:ffff:ffff
145ffa4:90::/32ffa4:90:ffff:ffff:ffff:ffff:ffff:ffff
146ffa4:91::/32ffa4:91:ffff:ffff:ffff:ffff:ffff:ffff
147ffa4:92::/32ffa4:92:ffff:ffff:ffff:ffff:ffff:ffff
148ffa4:93::/32ffa4:93:ffff:ffff:ffff:ffff:ffff:ffff
149ffa4:94::/32ffa4:94:ffff:ffff:ffff:ffff:ffff:ffff
150ffa4:95::/32ffa4:95:ffff:ffff:ffff:ffff:ffff:ffff
151ffa4:96::/32ffa4:96:ffff:ffff:ffff:ffff:ffff:ffff
152ffa4:97::/32ffa4:97:ffff:ffff:ffff:ffff:ffff:ffff
153ffa4:98::/32ffa4:98:ffff:ffff:ffff:ffff:ffff:ffff
154ffa4:99::/32ffa4:99:ffff:ffff:ffff:ffff:ffff:ffff
155ffa4:9a::/32ffa4:9a:ffff:ffff:ffff:ffff:ffff:ffff
156ffa4:9b::/32ffa4:9b:ffff:ffff:ffff:ffff:ffff:ffff
157ffa4:9c::/32ffa4:9c:ffff:ffff:ffff:ffff:ffff:ffff
158ffa4:9d::/32ffa4:9d:ffff:ffff:ffff:ffff:ffff:ffff
159ffa4:9e::/32ffa4:9e:ffff:ffff:ffff:ffff:ffff:ffff
160ffa4:9f::/32ffa4:9f:ffff:ffff:ffff:ffff:ffff:ffff
161ffa4:a0::/32ffa4:a0:ffff:ffff:ffff:ffff:ffff:ffff
162ffa4:a1::/32ffa4:a1:ffff:ffff:ffff:ffff:ffff:ffff
163ffa4:a2::/32ffa4:a2:ffff:ffff:ffff:ffff:ffff:ffff
164ffa4:a3::/32ffa4:a3:ffff:ffff:ffff:ffff:ffff:ffff
165ffa4:a4::/32ffa4:a4:ffff:ffff:ffff:ffff:ffff:ffff
166ffa4:a5::/32ffa4:a5:ffff:ffff:ffff:ffff:ffff:ffff
167ffa4:a6::/32ffa4:a6:ffff:ffff:ffff:ffff:ffff:ffff
168ffa4:a7::/32ffa4:a7:ffff:ffff:ffff:ffff:ffff:ffff
169ffa4:a8::/32ffa4:a8:ffff:ffff:ffff:ffff:ffff:ffff
170ffa4:a9::/32ffa4:a9:ffff:ffff:ffff:ffff:ffff:ffff
171ffa4:aa::/32ffa4:aa:ffff:ffff:ffff:ffff:ffff:ffff
172ffa4:ab::/32ffa4:ab:ffff:ffff:ffff:ffff:ffff:ffff
173ffa4:ac::/32ffa4:ac:ffff:ffff:ffff:ffff:ffff:ffff
174ffa4:ad::/32ffa4:ad:ffff:ffff:ffff:ffff:ffff:ffff
175ffa4:ae::/32ffa4:ae:ffff:ffff:ffff:ffff:ffff:ffff
176ffa4:af::/32ffa4:af:ffff:ffff:ffff:ffff:ffff:ffff
177ffa4:b0::/32ffa4:b0:ffff:ffff:ffff:ffff:ffff:ffff
178ffa4:b1::/32ffa4:b1:ffff:ffff:ffff:ffff:ffff:ffff
179ffa4:b2::/32ffa4:b2:ffff:ffff:ffff:ffff:ffff:ffff
180ffa4:b3::/32ffa4:b3:ffff:ffff:ffff:ffff:ffff:ffff
181ffa4:b4::/32ffa4:b4:ffff:ffff:ffff:ffff:ffff:ffff
182ffa4:b5::/32ffa4:b5:ffff:ffff:ffff:ffff:ffff:ffff
183ffa4:b6::/32ffa4:b6:ffff:ffff:ffff:ffff:ffff:ffff
184ffa4:b7::/32ffa4:b7:ffff:ffff:ffff:ffff:ffff:ffff
185ffa4:b8::/32ffa4:b8:ffff:ffff:ffff:ffff:ffff:ffff
186ffa4:b9::/32ffa4:b9:ffff:ffff:ffff:ffff:ffff:ffff
187ffa4:ba::/32ffa4:ba:ffff:ffff:ffff:ffff:ffff:ffff
188ffa4:bb::/32ffa4:bb:ffff:ffff:ffff:ffff:ffff:ffff
189ffa4:bc::/32ffa4:bc:ffff:ffff:ffff:ffff:ffff:ffff
190ffa4:bd::/32ffa4:bd:ffff:ffff:ffff:ffff:ffff:ffff
191ffa4:be::/32ffa4:be:ffff:ffff:ffff:ffff:ffff:ffff
192ffa4:bf::/32ffa4:bf:ffff:ffff:ffff:ffff:ffff:ffff
193ffa4:c0::/32ffa4:c0:ffff:ffff:ffff:ffff:ffff:ffff
194ffa4:c1::/32ffa4:c1:ffff:ffff:ffff:ffff:ffff:ffff
195ffa4:c2::/32ffa4:c2:ffff:ffff:ffff:ffff:ffff:ffff
196ffa4:c3::/32ffa4:c3:ffff:ffff:ffff:ffff:ffff:ffff
197ffa4:c4::/32ffa4:c4:ffff:ffff:ffff:ffff:ffff:ffff
198ffa4:c5::/32ffa4:c5:ffff:ffff:ffff:ffff:ffff:ffff
199ffa4:c6::/32ffa4:c6:ffff:ffff:ffff:ffff:ffff:ffff
200ffa4:c7::/32ffa4:c7:ffff:ffff:ffff:ffff:ffff:ffff
201ffa4:c8::/32ffa4:c8:ffff:ffff:ffff:ffff:ffff:ffff
202ffa4:c9::/32ffa4:c9:ffff:ffff:ffff:ffff:ffff:ffff
203ffa4:ca::/32ffa4:ca:ffff:ffff:ffff:ffff:ffff:ffff
204ffa4:cb::/32ffa4:cb:ffff:ffff:ffff:ffff:ffff:ffff
205ffa4:cc::/32ffa4:cc:ffff:ffff:ffff:ffff:ffff:ffff
206ffa4:cd::/32ffa4:cd:ffff:ffff:ffff:ffff:ffff:ffff
207ffa4:ce::/32ffa4:ce:ffff:ffff:ffff:ffff:ffff:ffff
208ffa4:cf::/32ffa4:cf:ffff:ffff:ffff:ffff:ffff:ffff
209ffa4:d0::/32ffa4:d0:ffff:ffff:ffff:ffff:ffff:ffff
210ffa4:d1::/32ffa4:d1:ffff:ffff:ffff:ffff:ffff:ffff
211ffa4:d2::/32ffa4:d2:ffff:ffff:ffff:ffff:ffff:ffff
212ffa4:d3::/32ffa4:d3:ffff:ffff:ffff:ffff:ffff:ffff
213ffa4:d4::/32ffa4:d4:ffff:ffff:ffff:ffff:ffff:ffff
214ffa4:d5::/32ffa4:d5:ffff:ffff:ffff:ffff:ffff:ffff
215ffa4:d6::/32ffa4:d6:ffff:ffff:ffff:ffff:ffff:ffff
216ffa4:d7::/32ffa4:d7:ffff:ffff:ffff:ffff:ffff:ffff
217ffa4:d8::/32ffa4:d8:ffff:ffff:ffff:ffff:ffff:ffff
218ffa4:d9::/32ffa4:d9:ffff:ffff:ffff:ffff:ffff:ffff
219ffa4:da::/32ffa4:da:ffff:ffff:ffff:ffff:ffff:ffff
220ffa4:db::/32ffa4:db:ffff:ffff:ffff:ffff:ffff:ffff
221ffa4:dc::/32ffa4:dc:ffff:ffff:ffff:ffff:ffff:ffff
222ffa4:dd::/32ffa4:dd:ffff:ffff:ffff:ffff:ffff:ffff
223ffa4:de::/32ffa4:de:ffff:ffff:ffff:ffff:ffff:ffff
224ffa4:df::/32ffa4:df:ffff:ffff:ffff:ffff:ffff:ffff
225ffa4:e0::/32ffa4:e0:ffff:ffff:ffff:ffff:ffff:ffff
226ffa4:e1::/32ffa4:e1:ffff:ffff:ffff:ffff:ffff:ffff
227ffa4:e2::/32ffa4:e2:ffff:ffff:ffff:ffff:ffff:ffff
228ffa4:e3::/32ffa4:e3:ffff:ffff:ffff:ffff:ffff:ffff
229ffa4:e4::/32ffa4:e4:ffff:ffff:ffff:ffff:ffff:ffff
230ffa4:e5::/32ffa4:e5:ffff:ffff:ffff:ffff:ffff:ffff
231ffa4:e6::/32ffa4:e6:ffff:ffff:ffff:ffff:ffff:ffff
232ffa4:e7::/32ffa4:e7:ffff:ffff:ffff:ffff:ffff:ffff
233ffa4:e8::/32ffa4:e8:ffff:ffff:ffff:ffff:ffff:ffff
234ffa4:e9::/32ffa4:e9:ffff:ffff:ffff:ffff:ffff:ffff
235ffa4:ea::/32ffa4:ea:ffff:ffff:ffff:ffff:ffff:ffff
236ffa4:eb::/32ffa4:eb:ffff:ffff:ffff:ffff:ffff:ffff
237ffa4:ec::/32ffa4:ec:ffff:ffff:ffff:ffff:ffff:ffff
238ffa4:ed::/32ffa4:ed:ffff:ffff:ffff:ffff:ffff:ffff
239ffa4:ee::/32ffa4:ee:ffff:ffff:ffff:ffff:ffff:ffff
240ffa4:ef::/32ffa4:ef:ffff:ffff:ffff:ffff:ffff:ffff
241ffa4:f0::/32ffa4:f0:ffff:ffff:ffff:ffff:ffff:ffff
242ffa4:f1::/32ffa4:f1:ffff:ffff:ffff:ffff:ffff:ffff
243ffa4:f2::/32ffa4:f2:ffff:ffff:ffff:ffff:ffff:ffff
244ffa4:f3::/32ffa4:f3:ffff:ffff:ffff:ffff:ffff:ffff
245ffa4:f4::/32ffa4:f4:ffff:ffff:ffff:ffff:ffff:ffff
246ffa4:f5::/32ffa4:f5:ffff:ffff:ffff:ffff:ffff:ffff
247ffa4:f6::/32ffa4:f6:ffff:ffff:ffff:ffff:ffff:ffff
248ffa4:f7::/32ffa4:f7:ffff:ffff:ffff:ffff:ffff:ffff
249ffa4:f8::/32ffa4:f8:ffff:ffff:ffff:ffff:ffff:ffff
250ffa4:f9::/32ffa4:f9:ffff:ffff:ffff:ffff:ffff:ffff
251ffa4:fa::/32ffa4:fa:ffff:ffff:ffff:ffff:ffff:ffff
252ffa4:fb::/32ffa4:fb:ffff:ffff:ffff:ffff:ffff:ffff
253ffa4:fc::/32ffa4:fc:ffff:ffff:ffff:ffff:ffff:ffff
254ffa4:fd::/32ffa4:fd:ffff:ffff:ffff:ffff:ffff:ffff
255ffa4:fe::/32ffa4:fe:ffff:ffff:ffff:ffff:ffff:ffff
256ffa4:ff::/32ffa4: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.