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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
feb8::/16
First address
feb8::
Last address
feb8: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
feb8:0000:0000:0000:0000:0000:0000:0000
Type
Link-local fe80::/10
Every IPv6 interface has one; not routed
Reverse DNS zone
8.b.e.f.ip6.arpa
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

feb8::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
1feb8::/28feb8:f:ffff:ffff:ffff:ffff:ffff:ffff
2feb8:10::/28feb8:1f:ffff:ffff:ffff:ffff:ffff:ffff
3feb8:20::/28feb8:2f:ffff:ffff:ffff:ffff:ffff:ffff
4feb8:30::/28feb8:3f:ffff:ffff:ffff:ffff:ffff:ffff
5feb8:40::/28feb8:4f:ffff:ffff:ffff:ffff:ffff:ffff
6feb8:50::/28feb8:5f:ffff:ffff:ffff:ffff:ffff:ffff
7feb8:60::/28feb8:6f:ffff:ffff:ffff:ffff:ffff:ffff
8feb8:70::/28feb8:7f:ffff:ffff:ffff:ffff:ffff:ffff
9feb8:80::/28feb8:8f:ffff:ffff:ffff:ffff:ffff:ffff
10feb8:90::/28feb8:9f:ffff:ffff:ffff:ffff:ffff:ffff
11feb8:a0::/28feb8:af:ffff:ffff:ffff:ffff:ffff:ffff
12feb8:b0::/28feb8:bf:ffff:ffff:ffff:ffff:ffff:ffff
13feb8:c0::/28feb8:cf:ffff:ffff:ffff:ffff:ffff:ffff
14feb8:d0::/28feb8:df:ffff:ffff:ffff:ffff:ffff:ffff
15feb8:e0::/28feb8:ef:ffff:ffff:ffff:ffff:ffff:ffff
16feb8:f0::/28feb8:ff:ffff:ffff:ffff:ffff:ffff:ffff
17feb8:100::/28feb8:10f:ffff:ffff:ffff:ffff:ffff:ffff
18feb8:110::/28feb8:11f:ffff:ffff:ffff:ffff:ffff:ffff
19feb8:120::/28feb8:12f:ffff:ffff:ffff:ffff:ffff:ffff
20feb8:130::/28feb8:13f:ffff:ffff:ffff:ffff:ffff:ffff
21feb8:140::/28feb8:14f:ffff:ffff:ffff:ffff:ffff:ffff
22feb8:150::/28feb8:15f:ffff:ffff:ffff:ffff:ffff:ffff
23feb8:160::/28feb8:16f:ffff:ffff:ffff:ffff:ffff:ffff
24feb8:170::/28feb8:17f:ffff:ffff:ffff:ffff:ffff:ffff
25feb8:180::/28feb8:18f:ffff:ffff:ffff:ffff:ffff:ffff
26feb8:190::/28feb8:19f:ffff:ffff:ffff:ffff:ffff:ffff
27feb8:1a0::/28feb8:1af:ffff:ffff:ffff:ffff:ffff:ffff
28feb8:1b0::/28feb8:1bf:ffff:ffff:ffff:ffff:ffff:ffff
29feb8:1c0::/28feb8:1cf:ffff:ffff:ffff:ffff:ffff:ffff
30feb8:1d0::/28feb8:1df:ffff:ffff:ffff:ffff:ffff:ffff
31feb8:1e0::/28feb8:1ef:ffff:ffff:ffff:ffff:ffff:ffff
32feb8:1f0::/28feb8:1ff:ffff:ffff:ffff:ffff:ffff:ffff
33feb8:200::/28feb8:20f:ffff:ffff:ffff:ffff:ffff:ffff
34feb8:210::/28feb8:21f:ffff:ffff:ffff:ffff:ffff:ffff
35feb8:220::/28feb8:22f:ffff:ffff:ffff:ffff:ffff:ffff
36feb8:230::/28feb8:23f:ffff:ffff:ffff:ffff:ffff:ffff
37feb8:240::/28feb8:24f:ffff:ffff:ffff:ffff:ffff:ffff
38feb8:250::/28feb8:25f:ffff:ffff:ffff:ffff:ffff:ffff
39feb8:260::/28feb8:26f:ffff:ffff:ffff:ffff:ffff:ffff
40feb8:270::/28feb8:27f:ffff:ffff:ffff:ffff:ffff:ffff
41feb8:280::/28feb8:28f:ffff:ffff:ffff:ffff:ffff:ffff
42feb8:290::/28feb8:29f:ffff:ffff:ffff:ffff:ffff:ffff
43feb8:2a0::/28feb8:2af:ffff:ffff:ffff:ffff:ffff:ffff
44feb8:2b0::/28feb8:2bf:ffff:ffff:ffff:ffff:ffff:ffff
45feb8:2c0::/28feb8:2cf:ffff:ffff:ffff:ffff:ffff:ffff
46feb8:2d0::/28feb8:2df:ffff:ffff:ffff:ffff:ffff:ffff
47feb8:2e0::/28feb8:2ef:ffff:ffff:ffff:ffff:ffff:ffff
48feb8:2f0::/28feb8:2ff:ffff:ffff:ffff:ffff:ffff:ffff
49feb8:300::/28feb8:30f:ffff:ffff:ffff:ffff:ffff:ffff
50feb8:310::/28feb8:31f:ffff:ffff:ffff:ffff:ffff:ffff
51feb8:320::/28feb8:32f:ffff:ffff:ffff:ffff:ffff:ffff
52feb8:330::/28feb8:33f:ffff:ffff:ffff:ffff:ffff:ffff
53feb8:340::/28feb8:34f:ffff:ffff:ffff:ffff:ffff:ffff
54feb8:350::/28feb8:35f:ffff:ffff:ffff:ffff:ffff:ffff
55feb8:360::/28feb8:36f:ffff:ffff:ffff:ffff:ffff:ffff
56feb8:370::/28feb8:37f:ffff:ffff:ffff:ffff:ffff:ffff
57feb8:380::/28feb8:38f:ffff:ffff:ffff:ffff:ffff:ffff
58feb8:390::/28feb8:39f:ffff:ffff:ffff:ffff:ffff:ffff
59feb8:3a0::/28feb8:3af:ffff:ffff:ffff:ffff:ffff:ffff
60feb8:3b0::/28feb8:3bf:ffff:ffff:ffff:ffff:ffff:ffff
61feb8:3c0::/28feb8:3cf:ffff:ffff:ffff:ffff:ffff:ffff
62feb8:3d0::/28feb8:3df:ffff:ffff:ffff:ffff:ffff:ffff
63feb8:3e0::/28feb8:3ef:ffff:ffff:ffff:ffff:ffff:ffff
64feb8:3f0::/28feb8:3ff:ffff:ffff:ffff:ffff:ffff:ffff
65feb8:400::/28feb8:40f:ffff:ffff:ffff:ffff:ffff:ffff
66feb8:410::/28feb8:41f:ffff:ffff:ffff:ffff:ffff:ffff
67feb8:420::/28feb8:42f:ffff:ffff:ffff:ffff:ffff:ffff
68feb8:430::/28feb8:43f:ffff:ffff:ffff:ffff:ffff:ffff
69feb8:440::/28feb8:44f:ffff:ffff:ffff:ffff:ffff:ffff
70feb8:450::/28feb8:45f:ffff:ffff:ffff:ffff:ffff:ffff
71feb8:460::/28feb8:46f:ffff:ffff:ffff:ffff:ffff:ffff
72feb8:470::/28feb8:47f:ffff:ffff:ffff:ffff:ffff:ffff
73feb8:480::/28feb8:48f:ffff:ffff:ffff:ffff:ffff:ffff
74feb8:490::/28feb8:49f:ffff:ffff:ffff:ffff:ffff:ffff
75feb8:4a0::/28feb8:4af:ffff:ffff:ffff:ffff:ffff:ffff
76feb8:4b0::/28feb8:4bf:ffff:ffff:ffff:ffff:ffff:ffff
77feb8:4c0::/28feb8:4cf:ffff:ffff:ffff:ffff:ffff:ffff
78feb8:4d0::/28feb8:4df:ffff:ffff:ffff:ffff:ffff:ffff
79feb8:4e0::/28feb8:4ef:ffff:ffff:ffff:ffff:ffff:ffff
80feb8:4f0::/28feb8:4ff:ffff:ffff:ffff:ffff:ffff:ffff
81feb8:500::/28feb8:50f:ffff:ffff:ffff:ffff:ffff:ffff
82feb8:510::/28feb8:51f:ffff:ffff:ffff:ffff:ffff:ffff
83feb8:520::/28feb8:52f:ffff:ffff:ffff:ffff:ffff:ffff
84feb8:530::/28feb8:53f:ffff:ffff:ffff:ffff:ffff:ffff
85feb8:540::/28feb8:54f:ffff:ffff:ffff:ffff:ffff:ffff
86feb8:550::/28feb8:55f:ffff:ffff:ffff:ffff:ffff:ffff
87feb8:560::/28feb8:56f:ffff:ffff:ffff:ffff:ffff:ffff
88feb8:570::/28feb8:57f:ffff:ffff:ffff:ffff:ffff:ffff
89feb8:580::/28feb8:58f:ffff:ffff:ffff:ffff:ffff:ffff
90feb8:590::/28feb8:59f:ffff:ffff:ffff:ffff:ffff:ffff
91feb8:5a0::/28feb8:5af:ffff:ffff:ffff:ffff:ffff:ffff
92feb8:5b0::/28feb8:5bf:ffff:ffff:ffff:ffff:ffff:ffff
93feb8:5c0::/28feb8:5cf:ffff:ffff:ffff:ffff:ffff:ffff
94feb8:5d0::/28feb8:5df:ffff:ffff:ffff:ffff:ffff:ffff
95feb8:5e0::/28feb8:5ef:ffff:ffff:ffff:ffff:ffff:ffff
96feb8:5f0::/28feb8:5ff:ffff:ffff:ffff:ffff:ffff:ffff
97feb8:600::/28feb8:60f:ffff:ffff:ffff:ffff:ffff:ffff
98feb8:610::/28feb8:61f:ffff:ffff:ffff:ffff:ffff:ffff
99feb8:620::/28feb8:62f:ffff:ffff:ffff:ffff:ffff:ffff
100feb8:630::/28feb8:63f:ffff:ffff:ffff:ffff:ffff:ffff
101feb8:640::/28feb8:64f:ffff:ffff:ffff:ffff:ffff:ffff
102feb8:650::/28feb8:65f:ffff:ffff:ffff:ffff:ffff:ffff
103feb8:660::/28feb8:66f:ffff:ffff:ffff:ffff:ffff:ffff
104feb8:670::/28feb8:67f:ffff:ffff:ffff:ffff:ffff:ffff
105feb8:680::/28feb8:68f:ffff:ffff:ffff:ffff:ffff:ffff
106feb8:690::/28feb8:69f:ffff:ffff:ffff:ffff:ffff:ffff
107feb8:6a0::/28feb8:6af:ffff:ffff:ffff:ffff:ffff:ffff
108feb8:6b0::/28feb8:6bf:ffff:ffff:ffff:ffff:ffff:ffff
109feb8:6c0::/28feb8:6cf:ffff:ffff:ffff:ffff:ffff:ffff
110feb8:6d0::/28feb8:6df:ffff:ffff:ffff:ffff:ffff:ffff
111feb8:6e0::/28feb8:6ef:ffff:ffff:ffff:ffff:ffff:ffff
112feb8:6f0::/28feb8:6ff:ffff:ffff:ffff:ffff:ffff:ffff
113feb8:700::/28feb8:70f:ffff:ffff:ffff:ffff:ffff:ffff
114feb8:710::/28feb8:71f:ffff:ffff:ffff:ffff:ffff:ffff
115feb8:720::/28feb8:72f:ffff:ffff:ffff:ffff:ffff:ffff
116feb8:730::/28feb8:73f:ffff:ffff:ffff:ffff:ffff:ffff
117feb8:740::/28feb8:74f:ffff:ffff:ffff:ffff:ffff:ffff
118feb8:750::/28feb8:75f:ffff:ffff:ffff:ffff:ffff:ffff
119feb8:760::/28feb8:76f:ffff:ffff:ffff:ffff:ffff:ffff
120feb8:770::/28feb8:77f:ffff:ffff:ffff:ffff:ffff:ffff
121feb8:780::/28feb8:78f:ffff:ffff:ffff:ffff:ffff:ffff
122feb8:790::/28feb8:79f:ffff:ffff:ffff:ffff:ffff:ffff
123feb8:7a0::/28feb8:7af:ffff:ffff:ffff:ffff:ffff:ffff
124feb8:7b0::/28feb8:7bf:ffff:ffff:ffff:ffff:ffff:ffff
125feb8:7c0::/28feb8:7cf:ffff:ffff:ffff:ffff:ffff:ffff
126feb8:7d0::/28feb8:7df:ffff:ffff:ffff:ffff:ffff:ffff
127feb8:7e0::/28feb8:7ef:ffff:ffff:ffff:ffff:ffff:ffff
128feb8:7f0::/28feb8:7ff:ffff:ffff:ffff:ffff:ffff:ffff
129feb8:800::/28feb8:80f:ffff:ffff:ffff:ffff:ffff:ffff
130feb8:810::/28feb8:81f:ffff:ffff:ffff:ffff:ffff:ffff
131feb8:820::/28feb8:82f:ffff:ffff:ffff:ffff:ffff:ffff
132feb8:830::/28feb8:83f:ffff:ffff:ffff:ffff:ffff:ffff
133feb8:840::/28feb8:84f:ffff:ffff:ffff:ffff:ffff:ffff
134feb8:850::/28feb8:85f:ffff:ffff:ffff:ffff:ffff:ffff
135feb8:860::/28feb8:86f:ffff:ffff:ffff:ffff:ffff:ffff
136feb8:870::/28feb8:87f:ffff:ffff:ffff:ffff:ffff:ffff
137feb8:880::/28feb8:88f:ffff:ffff:ffff:ffff:ffff:ffff
138feb8:890::/28feb8:89f:ffff:ffff:ffff:ffff:ffff:ffff
139feb8:8a0::/28feb8:8af:ffff:ffff:ffff:ffff:ffff:ffff
140feb8:8b0::/28feb8:8bf:ffff:ffff:ffff:ffff:ffff:ffff
141feb8:8c0::/28feb8:8cf:ffff:ffff:ffff:ffff:ffff:ffff
142feb8:8d0::/28feb8:8df:ffff:ffff:ffff:ffff:ffff:ffff
143feb8:8e0::/28feb8:8ef:ffff:ffff:ffff:ffff:ffff:ffff
144feb8:8f0::/28feb8:8ff:ffff:ffff:ffff:ffff:ffff:ffff
145feb8:900::/28feb8:90f:ffff:ffff:ffff:ffff:ffff:ffff
146feb8:910::/28feb8:91f:ffff:ffff:ffff:ffff:ffff:ffff
147feb8:920::/28feb8:92f:ffff:ffff:ffff:ffff:ffff:ffff
148feb8:930::/28feb8:93f:ffff:ffff:ffff:ffff:ffff:ffff
149feb8:940::/28feb8:94f:ffff:ffff:ffff:ffff:ffff:ffff
150feb8:950::/28feb8:95f:ffff:ffff:ffff:ffff:ffff:ffff
151feb8:960::/28feb8:96f:ffff:ffff:ffff:ffff:ffff:ffff
152feb8:970::/28feb8:97f:ffff:ffff:ffff:ffff:ffff:ffff
153feb8:980::/28feb8:98f:ffff:ffff:ffff:ffff:ffff:ffff
154feb8:990::/28feb8:99f:ffff:ffff:ffff:ffff:ffff:ffff
155feb8:9a0::/28feb8:9af:ffff:ffff:ffff:ffff:ffff:ffff
156feb8:9b0::/28feb8:9bf:ffff:ffff:ffff:ffff:ffff:ffff
157feb8:9c0::/28feb8:9cf:ffff:ffff:ffff:ffff:ffff:ffff
158feb8:9d0::/28feb8:9df:ffff:ffff:ffff:ffff:ffff:ffff
159feb8:9e0::/28feb8:9ef:ffff:ffff:ffff:ffff:ffff:ffff
160feb8:9f0::/28feb8:9ff:ffff:ffff:ffff:ffff:ffff:ffff
161feb8:a00::/28feb8:a0f:ffff:ffff:ffff:ffff:ffff:ffff
162feb8:a10::/28feb8:a1f:ffff:ffff:ffff:ffff:ffff:ffff
163feb8:a20::/28feb8:a2f:ffff:ffff:ffff:ffff:ffff:ffff
164feb8:a30::/28feb8:a3f:ffff:ffff:ffff:ffff:ffff:ffff
165feb8:a40::/28feb8:a4f:ffff:ffff:ffff:ffff:ffff:ffff
166feb8:a50::/28feb8:a5f:ffff:ffff:ffff:ffff:ffff:ffff
167feb8:a60::/28feb8:a6f:ffff:ffff:ffff:ffff:ffff:ffff
168feb8:a70::/28feb8:a7f:ffff:ffff:ffff:ffff:ffff:ffff
169feb8:a80::/28feb8:a8f:ffff:ffff:ffff:ffff:ffff:ffff
170feb8:a90::/28feb8:a9f:ffff:ffff:ffff:ffff:ffff:ffff
171feb8:aa0::/28feb8:aaf:ffff:ffff:ffff:ffff:ffff:ffff
172feb8:ab0::/28feb8:abf:ffff:ffff:ffff:ffff:ffff:ffff
173feb8:ac0::/28feb8:acf:ffff:ffff:ffff:ffff:ffff:ffff
174feb8:ad0::/28feb8:adf:ffff:ffff:ffff:ffff:ffff:ffff
175feb8:ae0::/28feb8:aef:ffff:ffff:ffff:ffff:ffff:ffff
176feb8:af0::/28feb8:aff:ffff:ffff:ffff:ffff:ffff:ffff
177feb8:b00::/28feb8:b0f:ffff:ffff:ffff:ffff:ffff:ffff
178feb8:b10::/28feb8:b1f:ffff:ffff:ffff:ffff:ffff:ffff
179feb8:b20::/28feb8:b2f:ffff:ffff:ffff:ffff:ffff:ffff
180feb8:b30::/28feb8:b3f:ffff:ffff:ffff:ffff:ffff:ffff
181feb8:b40::/28feb8:b4f:ffff:ffff:ffff:ffff:ffff:ffff
182feb8:b50::/28feb8:b5f:ffff:ffff:ffff:ffff:ffff:ffff
183feb8:b60::/28feb8:b6f:ffff:ffff:ffff:ffff:ffff:ffff
184feb8:b70::/28feb8:b7f:ffff:ffff:ffff:ffff:ffff:ffff
185feb8:b80::/28feb8:b8f:ffff:ffff:ffff:ffff:ffff:ffff
186feb8:b90::/28feb8:b9f:ffff:ffff:ffff:ffff:ffff:ffff
187feb8:ba0::/28feb8:baf:ffff:ffff:ffff:ffff:ffff:ffff
188feb8:bb0::/28feb8:bbf:ffff:ffff:ffff:ffff:ffff:ffff
189feb8:bc0::/28feb8:bcf:ffff:ffff:ffff:ffff:ffff:ffff
190feb8:bd0::/28feb8:bdf:ffff:ffff:ffff:ffff:ffff:ffff
191feb8:be0::/28feb8:bef:ffff:ffff:ffff:ffff:ffff:ffff
192feb8:bf0::/28feb8:bff:ffff:ffff:ffff:ffff:ffff:ffff
193feb8:c00::/28feb8:c0f:ffff:ffff:ffff:ffff:ffff:ffff
194feb8:c10::/28feb8:c1f:ffff:ffff:ffff:ffff:ffff:ffff
195feb8:c20::/28feb8:c2f:ffff:ffff:ffff:ffff:ffff:ffff
196feb8:c30::/28feb8:c3f:ffff:ffff:ffff:ffff:ffff:ffff
197feb8:c40::/28feb8:c4f:ffff:ffff:ffff:ffff:ffff:ffff
198feb8:c50::/28feb8:c5f:ffff:ffff:ffff:ffff:ffff:ffff
199feb8:c60::/28feb8:c6f:ffff:ffff:ffff:ffff:ffff:ffff
200feb8:c70::/28feb8:c7f:ffff:ffff:ffff:ffff:ffff:ffff
201feb8:c80::/28feb8:c8f:ffff:ffff:ffff:ffff:ffff:ffff
202feb8:c90::/28feb8:c9f:ffff:ffff:ffff:ffff:ffff:ffff
203feb8:ca0::/28feb8:caf:ffff:ffff:ffff:ffff:ffff:ffff
204feb8:cb0::/28feb8:cbf:ffff:ffff:ffff:ffff:ffff:ffff
205feb8:cc0::/28feb8:ccf:ffff:ffff:ffff:ffff:ffff:ffff
206feb8:cd0::/28feb8:cdf:ffff:ffff:ffff:ffff:ffff:ffff
207feb8:ce0::/28feb8:cef:ffff:ffff:ffff:ffff:ffff:ffff
208feb8:cf0::/28feb8:cff:ffff:ffff:ffff:ffff:ffff:ffff
209feb8:d00::/28feb8:d0f:ffff:ffff:ffff:ffff:ffff:ffff
210feb8:d10::/28feb8:d1f:ffff:ffff:ffff:ffff:ffff:ffff
211feb8:d20::/28feb8:d2f:ffff:ffff:ffff:ffff:ffff:ffff
212feb8:d30::/28feb8:d3f:ffff:ffff:ffff:ffff:ffff:ffff
213feb8:d40::/28feb8:d4f:ffff:ffff:ffff:ffff:ffff:ffff
214feb8:d50::/28feb8:d5f:ffff:ffff:ffff:ffff:ffff:ffff
215feb8:d60::/28feb8:d6f:ffff:ffff:ffff:ffff:ffff:ffff
216feb8:d70::/28feb8:d7f:ffff:ffff:ffff:ffff:ffff:ffff
217feb8:d80::/28feb8:d8f:ffff:ffff:ffff:ffff:ffff:ffff
218feb8:d90::/28feb8:d9f:ffff:ffff:ffff:ffff:ffff:ffff
219feb8:da0::/28feb8:daf:ffff:ffff:ffff:ffff:ffff:ffff
220feb8:db0::/28feb8:dbf:ffff:ffff:ffff:ffff:ffff:ffff
221feb8:dc0::/28feb8:dcf:ffff:ffff:ffff:ffff:ffff:ffff
222feb8:dd0::/28feb8:ddf:ffff:ffff:ffff:ffff:ffff:ffff
223feb8:de0::/28feb8:def:ffff:ffff:ffff:ffff:ffff:ffff
224feb8:df0::/28feb8:dff:ffff:ffff:ffff:ffff:ffff:ffff
225feb8:e00::/28feb8:e0f:ffff:ffff:ffff:ffff:ffff:ffff
226feb8:e10::/28feb8:e1f:ffff:ffff:ffff:ffff:ffff:ffff
227feb8:e20::/28feb8:e2f:ffff:ffff:ffff:ffff:ffff:ffff
228feb8:e30::/28feb8:e3f:ffff:ffff:ffff:ffff:ffff:ffff
229feb8:e40::/28feb8:e4f:ffff:ffff:ffff:ffff:ffff:ffff
230feb8:e50::/28feb8:e5f:ffff:ffff:ffff:ffff:ffff:ffff
231feb8:e60::/28feb8:e6f:ffff:ffff:ffff:ffff:ffff:ffff
232feb8:e70::/28feb8:e7f:ffff:ffff:ffff:ffff:ffff:ffff
233feb8:e80::/28feb8:e8f:ffff:ffff:ffff:ffff:ffff:ffff
234feb8:e90::/28feb8:e9f:ffff:ffff:ffff:ffff:ffff:ffff
235feb8:ea0::/28feb8:eaf:ffff:ffff:ffff:ffff:ffff:ffff
236feb8:eb0::/28feb8:ebf:ffff:ffff:ffff:ffff:ffff:ffff
237feb8:ec0::/28feb8:ecf:ffff:ffff:ffff:ffff:ffff:ffff
238feb8:ed0::/28feb8:edf:ffff:ffff:ffff:ffff:ffff:ffff
239feb8:ee0::/28feb8:eef:ffff:ffff:ffff:ffff:ffff:ffff
240feb8:ef0::/28feb8:eff:ffff:ffff:ffff:ffff:ffff:ffff
241feb8:f00::/28feb8:f0f:ffff:ffff:ffff:ffff:ffff:ffff
242feb8:f10::/28feb8:f1f:ffff:ffff:ffff:ffff:ffff:ffff
243feb8:f20::/28feb8:f2f:ffff:ffff:ffff:ffff:ffff:ffff
244feb8:f30::/28feb8:f3f:ffff:ffff:ffff:ffff:ffff:ffff
245feb8:f40::/28feb8:f4f:ffff:ffff:ffff:ffff:ffff:ffff
246feb8:f50::/28feb8:f5f:ffff:ffff:ffff:ffff:ffff:ffff
247feb8:f60::/28feb8:f6f:ffff:ffff:ffff:ffff:ffff:ffff
248feb8:f70::/28feb8:f7f:ffff:ffff:ffff:ffff:ffff:ffff
249feb8:f80::/28feb8:f8f:ffff:ffff:ffff:ffff:ffff:ffff
250feb8:f90::/28feb8:f9f:ffff:ffff:ffff:ffff:ffff:ffff
251feb8:fa0::/28feb8:faf:ffff:ffff:ffff:ffff:ffff:ffff
252feb8:fb0::/28feb8:fbf:ffff:ffff:ffff:ffff:ffff:ffff
253feb8:fc0::/28feb8:fcf:ffff:ffff:ffff:ffff:ffff:ffff
254feb8:fd0::/28feb8:fdf:ffff:ffff:ffff:ffff:ffff:ffff
255feb8:fe0::/28feb8:fef:ffff:ffff:ffff:ffff:ffff:ffff
256feb8:ff0::/28feb8:fff: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.