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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
fc35::/16
First address
fc35::
Last address
fc35: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
fc35:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
5.3.c.f.ip6.arpa
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

fc35::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
1fc35::/28fc35:f:ffff:ffff:ffff:ffff:ffff:ffff
2fc35:10::/28fc35:1f:ffff:ffff:ffff:ffff:ffff:ffff
3fc35:20::/28fc35:2f:ffff:ffff:ffff:ffff:ffff:ffff
4fc35:30::/28fc35:3f:ffff:ffff:ffff:ffff:ffff:ffff
5fc35:40::/28fc35:4f:ffff:ffff:ffff:ffff:ffff:ffff
6fc35:50::/28fc35:5f:ffff:ffff:ffff:ffff:ffff:ffff
7fc35:60::/28fc35:6f:ffff:ffff:ffff:ffff:ffff:ffff
8fc35:70::/28fc35:7f:ffff:ffff:ffff:ffff:ffff:ffff
9fc35:80::/28fc35:8f:ffff:ffff:ffff:ffff:ffff:ffff
10fc35:90::/28fc35:9f:ffff:ffff:ffff:ffff:ffff:ffff
11fc35:a0::/28fc35:af:ffff:ffff:ffff:ffff:ffff:ffff
12fc35:b0::/28fc35:bf:ffff:ffff:ffff:ffff:ffff:ffff
13fc35:c0::/28fc35:cf:ffff:ffff:ffff:ffff:ffff:ffff
14fc35:d0::/28fc35:df:ffff:ffff:ffff:ffff:ffff:ffff
15fc35:e0::/28fc35:ef:ffff:ffff:ffff:ffff:ffff:ffff
16fc35:f0::/28fc35:ff:ffff:ffff:ffff:ffff:ffff:ffff
17fc35:100::/28fc35:10f:ffff:ffff:ffff:ffff:ffff:ffff
18fc35:110::/28fc35:11f:ffff:ffff:ffff:ffff:ffff:ffff
19fc35:120::/28fc35:12f:ffff:ffff:ffff:ffff:ffff:ffff
20fc35:130::/28fc35:13f:ffff:ffff:ffff:ffff:ffff:ffff
21fc35:140::/28fc35:14f:ffff:ffff:ffff:ffff:ffff:ffff
22fc35:150::/28fc35:15f:ffff:ffff:ffff:ffff:ffff:ffff
23fc35:160::/28fc35:16f:ffff:ffff:ffff:ffff:ffff:ffff
24fc35:170::/28fc35:17f:ffff:ffff:ffff:ffff:ffff:ffff
25fc35:180::/28fc35:18f:ffff:ffff:ffff:ffff:ffff:ffff
26fc35:190::/28fc35:19f:ffff:ffff:ffff:ffff:ffff:ffff
27fc35:1a0::/28fc35:1af:ffff:ffff:ffff:ffff:ffff:ffff
28fc35:1b0::/28fc35:1bf:ffff:ffff:ffff:ffff:ffff:ffff
29fc35:1c0::/28fc35:1cf:ffff:ffff:ffff:ffff:ffff:ffff
30fc35:1d0::/28fc35:1df:ffff:ffff:ffff:ffff:ffff:ffff
31fc35:1e0::/28fc35:1ef:ffff:ffff:ffff:ffff:ffff:ffff
32fc35:1f0::/28fc35:1ff:ffff:ffff:ffff:ffff:ffff:ffff
33fc35:200::/28fc35:20f:ffff:ffff:ffff:ffff:ffff:ffff
34fc35:210::/28fc35:21f:ffff:ffff:ffff:ffff:ffff:ffff
35fc35:220::/28fc35:22f:ffff:ffff:ffff:ffff:ffff:ffff
36fc35:230::/28fc35:23f:ffff:ffff:ffff:ffff:ffff:ffff
37fc35:240::/28fc35:24f:ffff:ffff:ffff:ffff:ffff:ffff
38fc35:250::/28fc35:25f:ffff:ffff:ffff:ffff:ffff:ffff
39fc35:260::/28fc35:26f:ffff:ffff:ffff:ffff:ffff:ffff
40fc35:270::/28fc35:27f:ffff:ffff:ffff:ffff:ffff:ffff
41fc35:280::/28fc35:28f:ffff:ffff:ffff:ffff:ffff:ffff
42fc35:290::/28fc35:29f:ffff:ffff:ffff:ffff:ffff:ffff
43fc35:2a0::/28fc35:2af:ffff:ffff:ffff:ffff:ffff:ffff
44fc35:2b0::/28fc35:2bf:ffff:ffff:ffff:ffff:ffff:ffff
45fc35:2c0::/28fc35:2cf:ffff:ffff:ffff:ffff:ffff:ffff
46fc35:2d0::/28fc35:2df:ffff:ffff:ffff:ffff:ffff:ffff
47fc35:2e0::/28fc35:2ef:ffff:ffff:ffff:ffff:ffff:ffff
48fc35:2f0::/28fc35:2ff:ffff:ffff:ffff:ffff:ffff:ffff
49fc35:300::/28fc35:30f:ffff:ffff:ffff:ffff:ffff:ffff
50fc35:310::/28fc35:31f:ffff:ffff:ffff:ffff:ffff:ffff
51fc35:320::/28fc35:32f:ffff:ffff:ffff:ffff:ffff:ffff
52fc35:330::/28fc35:33f:ffff:ffff:ffff:ffff:ffff:ffff
53fc35:340::/28fc35:34f:ffff:ffff:ffff:ffff:ffff:ffff
54fc35:350::/28fc35:35f:ffff:ffff:ffff:ffff:ffff:ffff
55fc35:360::/28fc35:36f:ffff:ffff:ffff:ffff:ffff:ffff
56fc35:370::/28fc35:37f:ffff:ffff:ffff:ffff:ffff:ffff
57fc35:380::/28fc35:38f:ffff:ffff:ffff:ffff:ffff:ffff
58fc35:390::/28fc35:39f:ffff:ffff:ffff:ffff:ffff:ffff
59fc35:3a0::/28fc35:3af:ffff:ffff:ffff:ffff:ffff:ffff
60fc35:3b0::/28fc35:3bf:ffff:ffff:ffff:ffff:ffff:ffff
61fc35:3c0::/28fc35:3cf:ffff:ffff:ffff:ffff:ffff:ffff
62fc35:3d0::/28fc35:3df:ffff:ffff:ffff:ffff:ffff:ffff
63fc35:3e0::/28fc35:3ef:ffff:ffff:ffff:ffff:ffff:ffff
64fc35:3f0::/28fc35:3ff:ffff:ffff:ffff:ffff:ffff:ffff
65fc35:400::/28fc35:40f:ffff:ffff:ffff:ffff:ffff:ffff
66fc35:410::/28fc35:41f:ffff:ffff:ffff:ffff:ffff:ffff
67fc35:420::/28fc35:42f:ffff:ffff:ffff:ffff:ffff:ffff
68fc35:430::/28fc35:43f:ffff:ffff:ffff:ffff:ffff:ffff
69fc35:440::/28fc35:44f:ffff:ffff:ffff:ffff:ffff:ffff
70fc35:450::/28fc35:45f:ffff:ffff:ffff:ffff:ffff:ffff
71fc35:460::/28fc35:46f:ffff:ffff:ffff:ffff:ffff:ffff
72fc35:470::/28fc35:47f:ffff:ffff:ffff:ffff:ffff:ffff
73fc35:480::/28fc35:48f:ffff:ffff:ffff:ffff:ffff:ffff
74fc35:490::/28fc35:49f:ffff:ffff:ffff:ffff:ffff:ffff
75fc35:4a0::/28fc35:4af:ffff:ffff:ffff:ffff:ffff:ffff
76fc35:4b0::/28fc35:4bf:ffff:ffff:ffff:ffff:ffff:ffff
77fc35:4c0::/28fc35:4cf:ffff:ffff:ffff:ffff:ffff:ffff
78fc35:4d0::/28fc35:4df:ffff:ffff:ffff:ffff:ffff:ffff
79fc35:4e0::/28fc35:4ef:ffff:ffff:ffff:ffff:ffff:ffff
80fc35:4f0::/28fc35:4ff:ffff:ffff:ffff:ffff:ffff:ffff
81fc35:500::/28fc35:50f:ffff:ffff:ffff:ffff:ffff:ffff
82fc35:510::/28fc35:51f:ffff:ffff:ffff:ffff:ffff:ffff
83fc35:520::/28fc35:52f:ffff:ffff:ffff:ffff:ffff:ffff
84fc35:530::/28fc35:53f:ffff:ffff:ffff:ffff:ffff:ffff
85fc35:540::/28fc35:54f:ffff:ffff:ffff:ffff:ffff:ffff
86fc35:550::/28fc35:55f:ffff:ffff:ffff:ffff:ffff:ffff
87fc35:560::/28fc35:56f:ffff:ffff:ffff:ffff:ffff:ffff
88fc35:570::/28fc35:57f:ffff:ffff:ffff:ffff:ffff:ffff
89fc35:580::/28fc35:58f:ffff:ffff:ffff:ffff:ffff:ffff
90fc35:590::/28fc35:59f:ffff:ffff:ffff:ffff:ffff:ffff
91fc35:5a0::/28fc35:5af:ffff:ffff:ffff:ffff:ffff:ffff
92fc35:5b0::/28fc35:5bf:ffff:ffff:ffff:ffff:ffff:ffff
93fc35:5c0::/28fc35:5cf:ffff:ffff:ffff:ffff:ffff:ffff
94fc35:5d0::/28fc35:5df:ffff:ffff:ffff:ffff:ffff:ffff
95fc35:5e0::/28fc35:5ef:ffff:ffff:ffff:ffff:ffff:ffff
96fc35:5f0::/28fc35:5ff:ffff:ffff:ffff:ffff:ffff:ffff
97fc35:600::/28fc35:60f:ffff:ffff:ffff:ffff:ffff:ffff
98fc35:610::/28fc35:61f:ffff:ffff:ffff:ffff:ffff:ffff
99fc35:620::/28fc35:62f:ffff:ffff:ffff:ffff:ffff:ffff
100fc35:630::/28fc35:63f:ffff:ffff:ffff:ffff:ffff:ffff
101fc35:640::/28fc35:64f:ffff:ffff:ffff:ffff:ffff:ffff
102fc35:650::/28fc35:65f:ffff:ffff:ffff:ffff:ffff:ffff
103fc35:660::/28fc35:66f:ffff:ffff:ffff:ffff:ffff:ffff
104fc35:670::/28fc35:67f:ffff:ffff:ffff:ffff:ffff:ffff
105fc35:680::/28fc35:68f:ffff:ffff:ffff:ffff:ffff:ffff
106fc35:690::/28fc35:69f:ffff:ffff:ffff:ffff:ffff:ffff
107fc35:6a0::/28fc35:6af:ffff:ffff:ffff:ffff:ffff:ffff
108fc35:6b0::/28fc35:6bf:ffff:ffff:ffff:ffff:ffff:ffff
109fc35:6c0::/28fc35:6cf:ffff:ffff:ffff:ffff:ffff:ffff
110fc35:6d0::/28fc35:6df:ffff:ffff:ffff:ffff:ffff:ffff
111fc35:6e0::/28fc35:6ef:ffff:ffff:ffff:ffff:ffff:ffff
112fc35:6f0::/28fc35:6ff:ffff:ffff:ffff:ffff:ffff:ffff
113fc35:700::/28fc35:70f:ffff:ffff:ffff:ffff:ffff:ffff
114fc35:710::/28fc35:71f:ffff:ffff:ffff:ffff:ffff:ffff
115fc35:720::/28fc35:72f:ffff:ffff:ffff:ffff:ffff:ffff
116fc35:730::/28fc35:73f:ffff:ffff:ffff:ffff:ffff:ffff
117fc35:740::/28fc35:74f:ffff:ffff:ffff:ffff:ffff:ffff
118fc35:750::/28fc35:75f:ffff:ffff:ffff:ffff:ffff:ffff
119fc35:760::/28fc35:76f:ffff:ffff:ffff:ffff:ffff:ffff
120fc35:770::/28fc35:77f:ffff:ffff:ffff:ffff:ffff:ffff
121fc35:780::/28fc35:78f:ffff:ffff:ffff:ffff:ffff:ffff
122fc35:790::/28fc35:79f:ffff:ffff:ffff:ffff:ffff:ffff
123fc35:7a0::/28fc35:7af:ffff:ffff:ffff:ffff:ffff:ffff
124fc35:7b0::/28fc35:7bf:ffff:ffff:ffff:ffff:ffff:ffff
125fc35:7c0::/28fc35:7cf:ffff:ffff:ffff:ffff:ffff:ffff
126fc35:7d0::/28fc35:7df:ffff:ffff:ffff:ffff:ffff:ffff
127fc35:7e0::/28fc35:7ef:ffff:ffff:ffff:ffff:ffff:ffff
128fc35:7f0::/28fc35:7ff:ffff:ffff:ffff:ffff:ffff:ffff
129fc35:800::/28fc35:80f:ffff:ffff:ffff:ffff:ffff:ffff
130fc35:810::/28fc35:81f:ffff:ffff:ffff:ffff:ffff:ffff
131fc35:820::/28fc35:82f:ffff:ffff:ffff:ffff:ffff:ffff
132fc35:830::/28fc35:83f:ffff:ffff:ffff:ffff:ffff:ffff
133fc35:840::/28fc35:84f:ffff:ffff:ffff:ffff:ffff:ffff
134fc35:850::/28fc35:85f:ffff:ffff:ffff:ffff:ffff:ffff
135fc35:860::/28fc35:86f:ffff:ffff:ffff:ffff:ffff:ffff
136fc35:870::/28fc35:87f:ffff:ffff:ffff:ffff:ffff:ffff
137fc35:880::/28fc35:88f:ffff:ffff:ffff:ffff:ffff:ffff
138fc35:890::/28fc35:89f:ffff:ffff:ffff:ffff:ffff:ffff
139fc35:8a0::/28fc35:8af:ffff:ffff:ffff:ffff:ffff:ffff
140fc35:8b0::/28fc35:8bf:ffff:ffff:ffff:ffff:ffff:ffff
141fc35:8c0::/28fc35:8cf:ffff:ffff:ffff:ffff:ffff:ffff
142fc35:8d0::/28fc35:8df:ffff:ffff:ffff:ffff:ffff:ffff
143fc35:8e0::/28fc35:8ef:ffff:ffff:ffff:ffff:ffff:ffff
144fc35:8f0::/28fc35:8ff:ffff:ffff:ffff:ffff:ffff:ffff
145fc35:900::/28fc35:90f:ffff:ffff:ffff:ffff:ffff:ffff
146fc35:910::/28fc35:91f:ffff:ffff:ffff:ffff:ffff:ffff
147fc35:920::/28fc35:92f:ffff:ffff:ffff:ffff:ffff:ffff
148fc35:930::/28fc35:93f:ffff:ffff:ffff:ffff:ffff:ffff
149fc35:940::/28fc35:94f:ffff:ffff:ffff:ffff:ffff:ffff
150fc35:950::/28fc35:95f:ffff:ffff:ffff:ffff:ffff:ffff
151fc35:960::/28fc35:96f:ffff:ffff:ffff:ffff:ffff:ffff
152fc35:970::/28fc35:97f:ffff:ffff:ffff:ffff:ffff:ffff
153fc35:980::/28fc35:98f:ffff:ffff:ffff:ffff:ffff:ffff
154fc35:990::/28fc35:99f:ffff:ffff:ffff:ffff:ffff:ffff
155fc35:9a0::/28fc35:9af:ffff:ffff:ffff:ffff:ffff:ffff
156fc35:9b0::/28fc35:9bf:ffff:ffff:ffff:ffff:ffff:ffff
157fc35:9c0::/28fc35:9cf:ffff:ffff:ffff:ffff:ffff:ffff
158fc35:9d0::/28fc35:9df:ffff:ffff:ffff:ffff:ffff:ffff
159fc35:9e0::/28fc35:9ef:ffff:ffff:ffff:ffff:ffff:ffff
160fc35:9f0::/28fc35:9ff:ffff:ffff:ffff:ffff:ffff:ffff
161fc35:a00::/28fc35:a0f:ffff:ffff:ffff:ffff:ffff:ffff
162fc35:a10::/28fc35:a1f:ffff:ffff:ffff:ffff:ffff:ffff
163fc35:a20::/28fc35:a2f:ffff:ffff:ffff:ffff:ffff:ffff
164fc35:a30::/28fc35:a3f:ffff:ffff:ffff:ffff:ffff:ffff
165fc35:a40::/28fc35:a4f:ffff:ffff:ffff:ffff:ffff:ffff
166fc35:a50::/28fc35:a5f:ffff:ffff:ffff:ffff:ffff:ffff
167fc35:a60::/28fc35:a6f:ffff:ffff:ffff:ffff:ffff:ffff
168fc35:a70::/28fc35:a7f:ffff:ffff:ffff:ffff:ffff:ffff
169fc35:a80::/28fc35:a8f:ffff:ffff:ffff:ffff:ffff:ffff
170fc35:a90::/28fc35:a9f:ffff:ffff:ffff:ffff:ffff:ffff
171fc35:aa0::/28fc35:aaf:ffff:ffff:ffff:ffff:ffff:ffff
172fc35:ab0::/28fc35:abf:ffff:ffff:ffff:ffff:ffff:ffff
173fc35:ac0::/28fc35:acf:ffff:ffff:ffff:ffff:ffff:ffff
174fc35:ad0::/28fc35:adf:ffff:ffff:ffff:ffff:ffff:ffff
175fc35:ae0::/28fc35:aef:ffff:ffff:ffff:ffff:ffff:ffff
176fc35:af0::/28fc35:aff:ffff:ffff:ffff:ffff:ffff:ffff
177fc35:b00::/28fc35:b0f:ffff:ffff:ffff:ffff:ffff:ffff
178fc35:b10::/28fc35:b1f:ffff:ffff:ffff:ffff:ffff:ffff
179fc35:b20::/28fc35:b2f:ffff:ffff:ffff:ffff:ffff:ffff
180fc35:b30::/28fc35:b3f:ffff:ffff:ffff:ffff:ffff:ffff
181fc35:b40::/28fc35:b4f:ffff:ffff:ffff:ffff:ffff:ffff
182fc35:b50::/28fc35:b5f:ffff:ffff:ffff:ffff:ffff:ffff
183fc35:b60::/28fc35:b6f:ffff:ffff:ffff:ffff:ffff:ffff
184fc35:b70::/28fc35:b7f:ffff:ffff:ffff:ffff:ffff:ffff
185fc35:b80::/28fc35:b8f:ffff:ffff:ffff:ffff:ffff:ffff
186fc35:b90::/28fc35:b9f:ffff:ffff:ffff:ffff:ffff:ffff
187fc35:ba0::/28fc35:baf:ffff:ffff:ffff:ffff:ffff:ffff
188fc35:bb0::/28fc35:bbf:ffff:ffff:ffff:ffff:ffff:ffff
189fc35:bc0::/28fc35:bcf:ffff:ffff:ffff:ffff:ffff:ffff
190fc35:bd0::/28fc35:bdf:ffff:ffff:ffff:ffff:ffff:ffff
191fc35:be0::/28fc35:bef:ffff:ffff:ffff:ffff:ffff:ffff
192fc35:bf0::/28fc35:bff:ffff:ffff:ffff:ffff:ffff:ffff
193fc35:c00::/28fc35:c0f:ffff:ffff:ffff:ffff:ffff:ffff
194fc35:c10::/28fc35:c1f:ffff:ffff:ffff:ffff:ffff:ffff
195fc35:c20::/28fc35:c2f:ffff:ffff:ffff:ffff:ffff:ffff
196fc35:c30::/28fc35:c3f:ffff:ffff:ffff:ffff:ffff:ffff
197fc35:c40::/28fc35:c4f:ffff:ffff:ffff:ffff:ffff:ffff
198fc35:c50::/28fc35:c5f:ffff:ffff:ffff:ffff:ffff:ffff
199fc35:c60::/28fc35:c6f:ffff:ffff:ffff:ffff:ffff:ffff
200fc35:c70::/28fc35:c7f:ffff:ffff:ffff:ffff:ffff:ffff
201fc35:c80::/28fc35:c8f:ffff:ffff:ffff:ffff:ffff:ffff
202fc35:c90::/28fc35:c9f:ffff:ffff:ffff:ffff:ffff:ffff
203fc35:ca0::/28fc35:caf:ffff:ffff:ffff:ffff:ffff:ffff
204fc35:cb0::/28fc35:cbf:ffff:ffff:ffff:ffff:ffff:ffff
205fc35:cc0::/28fc35:ccf:ffff:ffff:ffff:ffff:ffff:ffff
206fc35:cd0::/28fc35:cdf:ffff:ffff:ffff:ffff:ffff:ffff
207fc35:ce0::/28fc35:cef:ffff:ffff:ffff:ffff:ffff:ffff
208fc35:cf0::/28fc35:cff:ffff:ffff:ffff:ffff:ffff:ffff
209fc35:d00::/28fc35:d0f:ffff:ffff:ffff:ffff:ffff:ffff
210fc35:d10::/28fc35:d1f:ffff:ffff:ffff:ffff:ffff:ffff
211fc35:d20::/28fc35:d2f:ffff:ffff:ffff:ffff:ffff:ffff
212fc35:d30::/28fc35:d3f:ffff:ffff:ffff:ffff:ffff:ffff
213fc35:d40::/28fc35:d4f:ffff:ffff:ffff:ffff:ffff:ffff
214fc35:d50::/28fc35:d5f:ffff:ffff:ffff:ffff:ffff:ffff
215fc35:d60::/28fc35:d6f:ffff:ffff:ffff:ffff:ffff:ffff
216fc35:d70::/28fc35:d7f:ffff:ffff:ffff:ffff:ffff:ffff
217fc35:d80::/28fc35:d8f:ffff:ffff:ffff:ffff:ffff:ffff
218fc35:d90::/28fc35:d9f:ffff:ffff:ffff:ffff:ffff:ffff
219fc35:da0::/28fc35:daf:ffff:ffff:ffff:ffff:ffff:ffff
220fc35:db0::/28fc35:dbf:ffff:ffff:ffff:ffff:ffff:ffff
221fc35:dc0::/28fc35:dcf:ffff:ffff:ffff:ffff:ffff:ffff
222fc35:dd0::/28fc35:ddf:ffff:ffff:ffff:ffff:ffff:ffff
223fc35:de0::/28fc35:def:ffff:ffff:ffff:ffff:ffff:ffff
224fc35:df0::/28fc35:dff:ffff:ffff:ffff:ffff:ffff:ffff
225fc35:e00::/28fc35:e0f:ffff:ffff:ffff:ffff:ffff:ffff
226fc35:e10::/28fc35:e1f:ffff:ffff:ffff:ffff:ffff:ffff
227fc35:e20::/28fc35:e2f:ffff:ffff:ffff:ffff:ffff:ffff
228fc35:e30::/28fc35:e3f:ffff:ffff:ffff:ffff:ffff:ffff
229fc35:e40::/28fc35:e4f:ffff:ffff:ffff:ffff:ffff:ffff
230fc35:e50::/28fc35:e5f:ffff:ffff:ffff:ffff:ffff:ffff
231fc35:e60::/28fc35:e6f:ffff:ffff:ffff:ffff:ffff:ffff
232fc35:e70::/28fc35:e7f:ffff:ffff:ffff:ffff:ffff:ffff
233fc35:e80::/28fc35:e8f:ffff:ffff:ffff:ffff:ffff:ffff
234fc35:e90::/28fc35:e9f:ffff:ffff:ffff:ffff:ffff:ffff
235fc35:ea0::/28fc35:eaf:ffff:ffff:ffff:ffff:ffff:ffff
236fc35:eb0::/28fc35:ebf:ffff:ffff:ffff:ffff:ffff:ffff
237fc35:ec0::/28fc35:ecf:ffff:ffff:ffff:ffff:ffff:ffff
238fc35:ed0::/28fc35:edf:ffff:ffff:ffff:ffff:ffff:ffff
239fc35:ee0::/28fc35:eef:ffff:ffff:ffff:ffff:ffff:ffff
240fc35:ef0::/28fc35:eff:ffff:ffff:ffff:ffff:ffff:ffff
241fc35:f00::/28fc35:f0f:ffff:ffff:ffff:ffff:ffff:ffff
242fc35:f10::/28fc35:f1f:ffff:ffff:ffff:ffff:ffff:ffff
243fc35:f20::/28fc35:f2f:ffff:ffff:ffff:ffff:ffff:ffff
244fc35:f30::/28fc35:f3f:ffff:ffff:ffff:ffff:ffff:ffff
245fc35:f40::/28fc35:f4f:ffff:ffff:ffff:ffff:ffff:ffff
246fc35:f50::/28fc35:f5f:ffff:ffff:ffff:ffff:ffff:ffff
247fc35:f60::/28fc35:f6f:ffff:ffff:ffff:ffff:ffff:ffff
248fc35:f70::/28fc35:f7f:ffff:ffff:ffff:ffff:ffff:ffff
249fc35:f80::/28fc35:f8f:ffff:ffff:ffff:ffff:ffff:ffff
250fc35:f90::/28fc35:f9f:ffff:ffff:ffff:ffff:ffff:ffff
251fc35:fa0::/28fc35:faf:ffff:ffff:ffff:ffff:ffff:ffff
252fc35:fb0::/28fc35:fbf:ffff:ffff:ffff:ffff:ffff:ffff
253fc35:fc0::/28fc35:fcf:ffff:ffff:ffff:ffff:ffff:ffff
254fc35:fd0::/28fc35:fdf:ffff:ffff:ffff:ffff:ffff:ffff
255fc35:fe0::/28fc35:fef:ffff:ffff:ffff:ffff:ffff:ffff
256fc35:ff0::/28fc35: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.