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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
feb3::/16
First address
feb3::
Last address
feb3: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
feb3:0000:0000:0000:0000:0000:0000:0000
Type
Link-local fe80::/10
Every IPv6 interface has one; not routed
Reverse DNS zone
3.b.e.f.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

feb3::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1feb3::/32feb3:0:ffff:ffff:ffff:ffff:ffff:ffff
2feb3:1::/32feb3:1:ffff:ffff:ffff:ffff:ffff:ffff
3feb3:2::/32feb3:2:ffff:ffff:ffff:ffff:ffff:ffff
4feb3:3::/32feb3:3:ffff:ffff:ffff:ffff:ffff:ffff
5feb3:4::/32feb3:4:ffff:ffff:ffff:ffff:ffff:ffff
6feb3:5::/32feb3:5:ffff:ffff:ffff:ffff:ffff:ffff
7feb3:6::/32feb3:6:ffff:ffff:ffff:ffff:ffff:ffff
8feb3:7::/32feb3:7:ffff:ffff:ffff:ffff:ffff:ffff
9feb3:8::/32feb3:8:ffff:ffff:ffff:ffff:ffff:ffff
10feb3:9::/32feb3:9:ffff:ffff:ffff:ffff:ffff:ffff
11feb3:a::/32feb3:a:ffff:ffff:ffff:ffff:ffff:ffff
12feb3:b::/32feb3:b:ffff:ffff:ffff:ffff:ffff:ffff
13feb3:c::/32feb3:c:ffff:ffff:ffff:ffff:ffff:ffff
14feb3:d::/32feb3:d:ffff:ffff:ffff:ffff:ffff:ffff
15feb3:e::/32feb3:e:ffff:ffff:ffff:ffff:ffff:ffff
16feb3:f::/32feb3:f:ffff:ffff:ffff:ffff:ffff:ffff
17feb3:10::/32feb3:10:ffff:ffff:ffff:ffff:ffff:ffff
18feb3:11::/32feb3:11:ffff:ffff:ffff:ffff:ffff:ffff
19feb3:12::/32feb3:12:ffff:ffff:ffff:ffff:ffff:ffff
20feb3:13::/32feb3:13:ffff:ffff:ffff:ffff:ffff:ffff
21feb3:14::/32feb3:14:ffff:ffff:ffff:ffff:ffff:ffff
22feb3:15::/32feb3:15:ffff:ffff:ffff:ffff:ffff:ffff
23feb3:16::/32feb3:16:ffff:ffff:ffff:ffff:ffff:ffff
24feb3:17::/32feb3:17:ffff:ffff:ffff:ffff:ffff:ffff
25feb3:18::/32feb3:18:ffff:ffff:ffff:ffff:ffff:ffff
26feb3:19::/32feb3:19:ffff:ffff:ffff:ffff:ffff:ffff
27feb3:1a::/32feb3:1a:ffff:ffff:ffff:ffff:ffff:ffff
28feb3:1b::/32feb3:1b:ffff:ffff:ffff:ffff:ffff:ffff
29feb3:1c::/32feb3:1c:ffff:ffff:ffff:ffff:ffff:ffff
30feb3:1d::/32feb3:1d:ffff:ffff:ffff:ffff:ffff:ffff
31feb3:1e::/32feb3:1e:ffff:ffff:ffff:ffff:ffff:ffff
32feb3:1f::/32feb3:1f:ffff:ffff:ffff:ffff:ffff:ffff
33feb3:20::/32feb3:20:ffff:ffff:ffff:ffff:ffff:ffff
34feb3:21::/32feb3:21:ffff:ffff:ffff:ffff:ffff:ffff
35feb3:22::/32feb3:22:ffff:ffff:ffff:ffff:ffff:ffff
36feb3:23::/32feb3:23:ffff:ffff:ffff:ffff:ffff:ffff
37feb3:24::/32feb3:24:ffff:ffff:ffff:ffff:ffff:ffff
38feb3:25::/32feb3:25:ffff:ffff:ffff:ffff:ffff:ffff
39feb3:26::/32feb3:26:ffff:ffff:ffff:ffff:ffff:ffff
40feb3:27::/32feb3:27:ffff:ffff:ffff:ffff:ffff:ffff
41feb3:28::/32feb3:28:ffff:ffff:ffff:ffff:ffff:ffff
42feb3:29::/32feb3:29:ffff:ffff:ffff:ffff:ffff:ffff
43feb3:2a::/32feb3:2a:ffff:ffff:ffff:ffff:ffff:ffff
44feb3:2b::/32feb3:2b:ffff:ffff:ffff:ffff:ffff:ffff
45feb3:2c::/32feb3:2c:ffff:ffff:ffff:ffff:ffff:ffff
46feb3:2d::/32feb3:2d:ffff:ffff:ffff:ffff:ffff:ffff
47feb3:2e::/32feb3:2e:ffff:ffff:ffff:ffff:ffff:ffff
48feb3:2f::/32feb3:2f:ffff:ffff:ffff:ffff:ffff:ffff
49feb3:30::/32feb3:30:ffff:ffff:ffff:ffff:ffff:ffff
50feb3:31::/32feb3:31:ffff:ffff:ffff:ffff:ffff:ffff
51feb3:32::/32feb3:32:ffff:ffff:ffff:ffff:ffff:ffff
52feb3:33::/32feb3:33:ffff:ffff:ffff:ffff:ffff:ffff
53feb3:34::/32feb3:34:ffff:ffff:ffff:ffff:ffff:ffff
54feb3:35::/32feb3:35:ffff:ffff:ffff:ffff:ffff:ffff
55feb3:36::/32feb3:36:ffff:ffff:ffff:ffff:ffff:ffff
56feb3:37::/32feb3:37:ffff:ffff:ffff:ffff:ffff:ffff
57feb3:38::/32feb3:38:ffff:ffff:ffff:ffff:ffff:ffff
58feb3:39::/32feb3:39:ffff:ffff:ffff:ffff:ffff:ffff
59feb3:3a::/32feb3:3a:ffff:ffff:ffff:ffff:ffff:ffff
60feb3:3b::/32feb3:3b:ffff:ffff:ffff:ffff:ffff:ffff
61feb3:3c::/32feb3:3c:ffff:ffff:ffff:ffff:ffff:ffff
62feb3:3d::/32feb3:3d:ffff:ffff:ffff:ffff:ffff:ffff
63feb3:3e::/32feb3:3e:ffff:ffff:ffff:ffff:ffff:ffff
64feb3:3f::/32feb3:3f:ffff:ffff:ffff:ffff:ffff:ffff
65feb3:40::/32feb3:40:ffff:ffff:ffff:ffff:ffff:ffff
66feb3:41::/32feb3:41:ffff:ffff:ffff:ffff:ffff:ffff
67feb3:42::/32feb3:42:ffff:ffff:ffff:ffff:ffff:ffff
68feb3:43::/32feb3:43:ffff:ffff:ffff:ffff:ffff:ffff
69feb3:44::/32feb3:44:ffff:ffff:ffff:ffff:ffff:ffff
70feb3:45::/32feb3:45:ffff:ffff:ffff:ffff:ffff:ffff
71feb3:46::/32feb3:46:ffff:ffff:ffff:ffff:ffff:ffff
72feb3:47::/32feb3:47:ffff:ffff:ffff:ffff:ffff:ffff
73feb3:48::/32feb3:48:ffff:ffff:ffff:ffff:ffff:ffff
74feb3:49::/32feb3:49:ffff:ffff:ffff:ffff:ffff:ffff
75feb3:4a::/32feb3:4a:ffff:ffff:ffff:ffff:ffff:ffff
76feb3:4b::/32feb3:4b:ffff:ffff:ffff:ffff:ffff:ffff
77feb3:4c::/32feb3:4c:ffff:ffff:ffff:ffff:ffff:ffff
78feb3:4d::/32feb3:4d:ffff:ffff:ffff:ffff:ffff:ffff
79feb3:4e::/32feb3:4e:ffff:ffff:ffff:ffff:ffff:ffff
80feb3:4f::/32feb3:4f:ffff:ffff:ffff:ffff:ffff:ffff
81feb3:50::/32feb3:50:ffff:ffff:ffff:ffff:ffff:ffff
82feb3:51::/32feb3:51:ffff:ffff:ffff:ffff:ffff:ffff
83feb3:52::/32feb3:52:ffff:ffff:ffff:ffff:ffff:ffff
84feb3:53::/32feb3:53:ffff:ffff:ffff:ffff:ffff:ffff
85feb3:54::/32feb3:54:ffff:ffff:ffff:ffff:ffff:ffff
86feb3:55::/32feb3:55:ffff:ffff:ffff:ffff:ffff:ffff
87feb3:56::/32feb3:56:ffff:ffff:ffff:ffff:ffff:ffff
88feb3:57::/32feb3:57:ffff:ffff:ffff:ffff:ffff:ffff
89feb3:58::/32feb3:58:ffff:ffff:ffff:ffff:ffff:ffff
90feb3:59::/32feb3:59:ffff:ffff:ffff:ffff:ffff:ffff
91feb3:5a::/32feb3:5a:ffff:ffff:ffff:ffff:ffff:ffff
92feb3:5b::/32feb3:5b:ffff:ffff:ffff:ffff:ffff:ffff
93feb3:5c::/32feb3:5c:ffff:ffff:ffff:ffff:ffff:ffff
94feb3:5d::/32feb3:5d:ffff:ffff:ffff:ffff:ffff:ffff
95feb3:5e::/32feb3:5e:ffff:ffff:ffff:ffff:ffff:ffff
96feb3:5f::/32feb3:5f:ffff:ffff:ffff:ffff:ffff:ffff
97feb3:60::/32feb3:60:ffff:ffff:ffff:ffff:ffff:ffff
98feb3:61::/32feb3:61:ffff:ffff:ffff:ffff:ffff:ffff
99feb3:62::/32feb3:62:ffff:ffff:ffff:ffff:ffff:ffff
100feb3:63::/32feb3:63:ffff:ffff:ffff:ffff:ffff:ffff
101feb3:64::/32feb3:64:ffff:ffff:ffff:ffff:ffff:ffff
102feb3:65::/32feb3:65:ffff:ffff:ffff:ffff:ffff:ffff
103feb3:66::/32feb3:66:ffff:ffff:ffff:ffff:ffff:ffff
104feb3:67::/32feb3:67:ffff:ffff:ffff:ffff:ffff:ffff
105feb3:68::/32feb3:68:ffff:ffff:ffff:ffff:ffff:ffff
106feb3:69::/32feb3:69:ffff:ffff:ffff:ffff:ffff:ffff
107feb3:6a::/32feb3:6a:ffff:ffff:ffff:ffff:ffff:ffff
108feb3:6b::/32feb3:6b:ffff:ffff:ffff:ffff:ffff:ffff
109feb3:6c::/32feb3:6c:ffff:ffff:ffff:ffff:ffff:ffff
110feb3:6d::/32feb3:6d:ffff:ffff:ffff:ffff:ffff:ffff
111feb3:6e::/32feb3:6e:ffff:ffff:ffff:ffff:ffff:ffff
112feb3:6f::/32feb3:6f:ffff:ffff:ffff:ffff:ffff:ffff
113feb3:70::/32feb3:70:ffff:ffff:ffff:ffff:ffff:ffff
114feb3:71::/32feb3:71:ffff:ffff:ffff:ffff:ffff:ffff
115feb3:72::/32feb3:72:ffff:ffff:ffff:ffff:ffff:ffff
116feb3:73::/32feb3:73:ffff:ffff:ffff:ffff:ffff:ffff
117feb3:74::/32feb3:74:ffff:ffff:ffff:ffff:ffff:ffff
118feb3:75::/32feb3:75:ffff:ffff:ffff:ffff:ffff:ffff
119feb3:76::/32feb3:76:ffff:ffff:ffff:ffff:ffff:ffff
120feb3:77::/32feb3:77:ffff:ffff:ffff:ffff:ffff:ffff
121feb3:78::/32feb3:78:ffff:ffff:ffff:ffff:ffff:ffff
122feb3:79::/32feb3:79:ffff:ffff:ffff:ffff:ffff:ffff
123feb3:7a::/32feb3:7a:ffff:ffff:ffff:ffff:ffff:ffff
124feb3:7b::/32feb3:7b:ffff:ffff:ffff:ffff:ffff:ffff
125feb3:7c::/32feb3:7c:ffff:ffff:ffff:ffff:ffff:ffff
126feb3:7d::/32feb3:7d:ffff:ffff:ffff:ffff:ffff:ffff
127feb3:7e::/32feb3:7e:ffff:ffff:ffff:ffff:ffff:ffff
128feb3:7f::/32feb3:7f:ffff:ffff:ffff:ffff:ffff:ffff
129feb3:80::/32feb3:80:ffff:ffff:ffff:ffff:ffff:ffff
130feb3:81::/32feb3:81:ffff:ffff:ffff:ffff:ffff:ffff
131feb3:82::/32feb3:82:ffff:ffff:ffff:ffff:ffff:ffff
132feb3:83::/32feb3:83:ffff:ffff:ffff:ffff:ffff:ffff
133feb3:84::/32feb3:84:ffff:ffff:ffff:ffff:ffff:ffff
134feb3:85::/32feb3:85:ffff:ffff:ffff:ffff:ffff:ffff
135feb3:86::/32feb3:86:ffff:ffff:ffff:ffff:ffff:ffff
136feb3:87::/32feb3:87:ffff:ffff:ffff:ffff:ffff:ffff
137feb3:88::/32feb3:88:ffff:ffff:ffff:ffff:ffff:ffff
138feb3:89::/32feb3:89:ffff:ffff:ffff:ffff:ffff:ffff
139feb3:8a::/32feb3:8a:ffff:ffff:ffff:ffff:ffff:ffff
140feb3:8b::/32feb3:8b:ffff:ffff:ffff:ffff:ffff:ffff
141feb3:8c::/32feb3:8c:ffff:ffff:ffff:ffff:ffff:ffff
142feb3:8d::/32feb3:8d:ffff:ffff:ffff:ffff:ffff:ffff
143feb3:8e::/32feb3:8e:ffff:ffff:ffff:ffff:ffff:ffff
144feb3:8f::/32feb3:8f:ffff:ffff:ffff:ffff:ffff:ffff
145feb3:90::/32feb3:90:ffff:ffff:ffff:ffff:ffff:ffff
146feb3:91::/32feb3:91:ffff:ffff:ffff:ffff:ffff:ffff
147feb3:92::/32feb3:92:ffff:ffff:ffff:ffff:ffff:ffff
148feb3:93::/32feb3:93:ffff:ffff:ffff:ffff:ffff:ffff
149feb3:94::/32feb3:94:ffff:ffff:ffff:ffff:ffff:ffff
150feb3:95::/32feb3:95:ffff:ffff:ffff:ffff:ffff:ffff
151feb3:96::/32feb3:96:ffff:ffff:ffff:ffff:ffff:ffff
152feb3:97::/32feb3:97:ffff:ffff:ffff:ffff:ffff:ffff
153feb3:98::/32feb3:98:ffff:ffff:ffff:ffff:ffff:ffff
154feb3:99::/32feb3:99:ffff:ffff:ffff:ffff:ffff:ffff
155feb3:9a::/32feb3:9a:ffff:ffff:ffff:ffff:ffff:ffff
156feb3:9b::/32feb3:9b:ffff:ffff:ffff:ffff:ffff:ffff
157feb3:9c::/32feb3:9c:ffff:ffff:ffff:ffff:ffff:ffff
158feb3:9d::/32feb3:9d:ffff:ffff:ffff:ffff:ffff:ffff
159feb3:9e::/32feb3:9e:ffff:ffff:ffff:ffff:ffff:ffff
160feb3:9f::/32feb3:9f:ffff:ffff:ffff:ffff:ffff:ffff
161feb3:a0::/32feb3:a0:ffff:ffff:ffff:ffff:ffff:ffff
162feb3:a1::/32feb3:a1:ffff:ffff:ffff:ffff:ffff:ffff
163feb3:a2::/32feb3:a2:ffff:ffff:ffff:ffff:ffff:ffff
164feb3:a3::/32feb3:a3:ffff:ffff:ffff:ffff:ffff:ffff
165feb3:a4::/32feb3:a4:ffff:ffff:ffff:ffff:ffff:ffff
166feb3:a5::/32feb3:a5:ffff:ffff:ffff:ffff:ffff:ffff
167feb3:a6::/32feb3:a6:ffff:ffff:ffff:ffff:ffff:ffff
168feb3:a7::/32feb3:a7:ffff:ffff:ffff:ffff:ffff:ffff
169feb3:a8::/32feb3:a8:ffff:ffff:ffff:ffff:ffff:ffff
170feb3:a9::/32feb3:a9:ffff:ffff:ffff:ffff:ffff:ffff
171feb3:aa::/32feb3:aa:ffff:ffff:ffff:ffff:ffff:ffff
172feb3:ab::/32feb3:ab:ffff:ffff:ffff:ffff:ffff:ffff
173feb3:ac::/32feb3:ac:ffff:ffff:ffff:ffff:ffff:ffff
174feb3:ad::/32feb3:ad:ffff:ffff:ffff:ffff:ffff:ffff
175feb3:ae::/32feb3:ae:ffff:ffff:ffff:ffff:ffff:ffff
176feb3:af::/32feb3:af:ffff:ffff:ffff:ffff:ffff:ffff
177feb3:b0::/32feb3:b0:ffff:ffff:ffff:ffff:ffff:ffff
178feb3:b1::/32feb3:b1:ffff:ffff:ffff:ffff:ffff:ffff
179feb3:b2::/32feb3:b2:ffff:ffff:ffff:ffff:ffff:ffff
180feb3:b3::/32feb3:b3:ffff:ffff:ffff:ffff:ffff:ffff
181feb3:b4::/32feb3:b4:ffff:ffff:ffff:ffff:ffff:ffff
182feb3:b5::/32feb3:b5:ffff:ffff:ffff:ffff:ffff:ffff
183feb3:b6::/32feb3:b6:ffff:ffff:ffff:ffff:ffff:ffff
184feb3:b7::/32feb3:b7:ffff:ffff:ffff:ffff:ffff:ffff
185feb3:b8::/32feb3:b8:ffff:ffff:ffff:ffff:ffff:ffff
186feb3:b9::/32feb3:b9:ffff:ffff:ffff:ffff:ffff:ffff
187feb3:ba::/32feb3:ba:ffff:ffff:ffff:ffff:ffff:ffff
188feb3:bb::/32feb3:bb:ffff:ffff:ffff:ffff:ffff:ffff
189feb3:bc::/32feb3:bc:ffff:ffff:ffff:ffff:ffff:ffff
190feb3:bd::/32feb3:bd:ffff:ffff:ffff:ffff:ffff:ffff
191feb3:be::/32feb3:be:ffff:ffff:ffff:ffff:ffff:ffff
192feb3:bf::/32feb3:bf:ffff:ffff:ffff:ffff:ffff:ffff
193feb3:c0::/32feb3:c0:ffff:ffff:ffff:ffff:ffff:ffff
194feb3:c1::/32feb3:c1:ffff:ffff:ffff:ffff:ffff:ffff
195feb3:c2::/32feb3:c2:ffff:ffff:ffff:ffff:ffff:ffff
196feb3:c3::/32feb3:c3:ffff:ffff:ffff:ffff:ffff:ffff
197feb3:c4::/32feb3:c4:ffff:ffff:ffff:ffff:ffff:ffff
198feb3:c5::/32feb3:c5:ffff:ffff:ffff:ffff:ffff:ffff
199feb3:c6::/32feb3:c6:ffff:ffff:ffff:ffff:ffff:ffff
200feb3:c7::/32feb3:c7:ffff:ffff:ffff:ffff:ffff:ffff
201feb3:c8::/32feb3:c8:ffff:ffff:ffff:ffff:ffff:ffff
202feb3:c9::/32feb3:c9:ffff:ffff:ffff:ffff:ffff:ffff
203feb3:ca::/32feb3:ca:ffff:ffff:ffff:ffff:ffff:ffff
204feb3:cb::/32feb3:cb:ffff:ffff:ffff:ffff:ffff:ffff
205feb3:cc::/32feb3:cc:ffff:ffff:ffff:ffff:ffff:ffff
206feb3:cd::/32feb3:cd:ffff:ffff:ffff:ffff:ffff:ffff
207feb3:ce::/32feb3:ce:ffff:ffff:ffff:ffff:ffff:ffff
208feb3:cf::/32feb3:cf:ffff:ffff:ffff:ffff:ffff:ffff
209feb3:d0::/32feb3:d0:ffff:ffff:ffff:ffff:ffff:ffff
210feb3:d1::/32feb3:d1:ffff:ffff:ffff:ffff:ffff:ffff
211feb3:d2::/32feb3:d2:ffff:ffff:ffff:ffff:ffff:ffff
212feb3:d3::/32feb3:d3:ffff:ffff:ffff:ffff:ffff:ffff
213feb3:d4::/32feb3:d4:ffff:ffff:ffff:ffff:ffff:ffff
214feb3:d5::/32feb3:d5:ffff:ffff:ffff:ffff:ffff:ffff
215feb3:d6::/32feb3:d6:ffff:ffff:ffff:ffff:ffff:ffff
216feb3:d7::/32feb3:d7:ffff:ffff:ffff:ffff:ffff:ffff
217feb3:d8::/32feb3:d8:ffff:ffff:ffff:ffff:ffff:ffff
218feb3:d9::/32feb3:d9:ffff:ffff:ffff:ffff:ffff:ffff
219feb3:da::/32feb3:da:ffff:ffff:ffff:ffff:ffff:ffff
220feb3:db::/32feb3:db:ffff:ffff:ffff:ffff:ffff:ffff
221feb3:dc::/32feb3:dc:ffff:ffff:ffff:ffff:ffff:ffff
222feb3:dd::/32feb3:dd:ffff:ffff:ffff:ffff:ffff:ffff
223feb3:de::/32feb3:de:ffff:ffff:ffff:ffff:ffff:ffff
224feb3:df::/32feb3:df:ffff:ffff:ffff:ffff:ffff:ffff
225feb3:e0::/32feb3:e0:ffff:ffff:ffff:ffff:ffff:ffff
226feb3:e1::/32feb3:e1:ffff:ffff:ffff:ffff:ffff:ffff
227feb3:e2::/32feb3:e2:ffff:ffff:ffff:ffff:ffff:ffff
228feb3:e3::/32feb3:e3:ffff:ffff:ffff:ffff:ffff:ffff
229feb3:e4::/32feb3:e4:ffff:ffff:ffff:ffff:ffff:ffff
230feb3:e5::/32feb3:e5:ffff:ffff:ffff:ffff:ffff:ffff
231feb3:e6::/32feb3:e6:ffff:ffff:ffff:ffff:ffff:ffff
232feb3:e7::/32feb3:e7:ffff:ffff:ffff:ffff:ffff:ffff
233feb3:e8::/32feb3:e8:ffff:ffff:ffff:ffff:ffff:ffff
234feb3:e9::/32feb3:e9:ffff:ffff:ffff:ffff:ffff:ffff
235feb3:ea::/32feb3:ea:ffff:ffff:ffff:ffff:ffff:ffff
236feb3:eb::/32feb3:eb:ffff:ffff:ffff:ffff:ffff:ffff
237feb3:ec::/32feb3:ec:ffff:ffff:ffff:ffff:ffff:ffff
238feb3:ed::/32feb3:ed:ffff:ffff:ffff:ffff:ffff:ffff
239feb3:ee::/32feb3:ee:ffff:ffff:ffff:ffff:ffff:ffff
240feb3:ef::/32feb3:ef:ffff:ffff:ffff:ffff:ffff:ffff
241feb3:f0::/32feb3:f0:ffff:ffff:ffff:ffff:ffff:ffff
242feb3:f1::/32feb3:f1:ffff:ffff:ffff:ffff:ffff:ffff
243feb3:f2::/32feb3:f2:ffff:ffff:ffff:ffff:ffff:ffff
244feb3:f3::/32feb3:f3:ffff:ffff:ffff:ffff:ffff:ffff
245feb3:f4::/32feb3:f4:ffff:ffff:ffff:ffff:ffff:ffff
246feb3:f5::/32feb3:f5:ffff:ffff:ffff:ffff:ffff:ffff
247feb3:f6::/32feb3:f6:ffff:ffff:ffff:ffff:ffff:ffff
248feb3:f7::/32feb3:f7:ffff:ffff:ffff:ffff:ffff:ffff
249feb3:f8::/32feb3:f8:ffff:ffff:ffff:ffff:ffff:ffff
250feb3:f9::/32feb3:f9:ffff:ffff:ffff:ffff:ffff:ffff
251feb3:fa::/32feb3:fa:ffff:ffff:ffff:ffff:ffff:ffff
252feb3:fb::/32feb3:fb:ffff:ffff:ffff:ffff:ffff:ffff
253feb3:fc::/32feb3:fc:ffff:ffff:ffff:ffff:ffff:ffff
254feb3:fd::/32feb3:fd:ffff:ffff:ffff:ffff:ffff:ffff
255feb3:fe::/32feb3:fe:ffff:ffff:ffff:ffff:ffff:ffff
256feb3:ff::/32feb3: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.