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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
fc77::/16
First address
fc77::
Last address
fc77: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
fc77:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
7.7.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)

fc77::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
1fc77::/28fc77:f:ffff:ffff:ffff:ffff:ffff:ffff
2fc77:10::/28fc77:1f:ffff:ffff:ffff:ffff:ffff:ffff
3fc77:20::/28fc77:2f:ffff:ffff:ffff:ffff:ffff:ffff
4fc77:30::/28fc77:3f:ffff:ffff:ffff:ffff:ffff:ffff
5fc77:40::/28fc77:4f:ffff:ffff:ffff:ffff:ffff:ffff
6fc77:50::/28fc77:5f:ffff:ffff:ffff:ffff:ffff:ffff
7fc77:60::/28fc77:6f:ffff:ffff:ffff:ffff:ffff:ffff
8fc77:70::/28fc77:7f:ffff:ffff:ffff:ffff:ffff:ffff
9fc77:80::/28fc77:8f:ffff:ffff:ffff:ffff:ffff:ffff
10fc77:90::/28fc77:9f:ffff:ffff:ffff:ffff:ffff:ffff
11fc77:a0::/28fc77:af:ffff:ffff:ffff:ffff:ffff:ffff
12fc77:b0::/28fc77:bf:ffff:ffff:ffff:ffff:ffff:ffff
13fc77:c0::/28fc77:cf:ffff:ffff:ffff:ffff:ffff:ffff
14fc77:d0::/28fc77:df:ffff:ffff:ffff:ffff:ffff:ffff
15fc77:e0::/28fc77:ef:ffff:ffff:ffff:ffff:ffff:ffff
16fc77:f0::/28fc77:ff:ffff:ffff:ffff:ffff:ffff:ffff
17fc77:100::/28fc77:10f:ffff:ffff:ffff:ffff:ffff:ffff
18fc77:110::/28fc77:11f:ffff:ffff:ffff:ffff:ffff:ffff
19fc77:120::/28fc77:12f:ffff:ffff:ffff:ffff:ffff:ffff
20fc77:130::/28fc77:13f:ffff:ffff:ffff:ffff:ffff:ffff
21fc77:140::/28fc77:14f:ffff:ffff:ffff:ffff:ffff:ffff
22fc77:150::/28fc77:15f:ffff:ffff:ffff:ffff:ffff:ffff
23fc77:160::/28fc77:16f:ffff:ffff:ffff:ffff:ffff:ffff
24fc77:170::/28fc77:17f:ffff:ffff:ffff:ffff:ffff:ffff
25fc77:180::/28fc77:18f:ffff:ffff:ffff:ffff:ffff:ffff
26fc77:190::/28fc77:19f:ffff:ffff:ffff:ffff:ffff:ffff
27fc77:1a0::/28fc77:1af:ffff:ffff:ffff:ffff:ffff:ffff
28fc77:1b0::/28fc77:1bf:ffff:ffff:ffff:ffff:ffff:ffff
29fc77:1c0::/28fc77:1cf:ffff:ffff:ffff:ffff:ffff:ffff
30fc77:1d0::/28fc77:1df:ffff:ffff:ffff:ffff:ffff:ffff
31fc77:1e0::/28fc77:1ef:ffff:ffff:ffff:ffff:ffff:ffff
32fc77:1f0::/28fc77:1ff:ffff:ffff:ffff:ffff:ffff:ffff
33fc77:200::/28fc77:20f:ffff:ffff:ffff:ffff:ffff:ffff
34fc77:210::/28fc77:21f:ffff:ffff:ffff:ffff:ffff:ffff
35fc77:220::/28fc77:22f:ffff:ffff:ffff:ffff:ffff:ffff
36fc77:230::/28fc77:23f:ffff:ffff:ffff:ffff:ffff:ffff
37fc77:240::/28fc77:24f:ffff:ffff:ffff:ffff:ffff:ffff
38fc77:250::/28fc77:25f:ffff:ffff:ffff:ffff:ffff:ffff
39fc77:260::/28fc77:26f:ffff:ffff:ffff:ffff:ffff:ffff
40fc77:270::/28fc77:27f:ffff:ffff:ffff:ffff:ffff:ffff
41fc77:280::/28fc77:28f:ffff:ffff:ffff:ffff:ffff:ffff
42fc77:290::/28fc77:29f:ffff:ffff:ffff:ffff:ffff:ffff
43fc77:2a0::/28fc77:2af:ffff:ffff:ffff:ffff:ffff:ffff
44fc77:2b0::/28fc77:2bf:ffff:ffff:ffff:ffff:ffff:ffff
45fc77:2c0::/28fc77:2cf:ffff:ffff:ffff:ffff:ffff:ffff
46fc77:2d0::/28fc77:2df:ffff:ffff:ffff:ffff:ffff:ffff
47fc77:2e0::/28fc77:2ef:ffff:ffff:ffff:ffff:ffff:ffff
48fc77:2f0::/28fc77:2ff:ffff:ffff:ffff:ffff:ffff:ffff
49fc77:300::/28fc77:30f:ffff:ffff:ffff:ffff:ffff:ffff
50fc77:310::/28fc77:31f:ffff:ffff:ffff:ffff:ffff:ffff
51fc77:320::/28fc77:32f:ffff:ffff:ffff:ffff:ffff:ffff
52fc77:330::/28fc77:33f:ffff:ffff:ffff:ffff:ffff:ffff
53fc77:340::/28fc77:34f:ffff:ffff:ffff:ffff:ffff:ffff
54fc77:350::/28fc77:35f:ffff:ffff:ffff:ffff:ffff:ffff
55fc77:360::/28fc77:36f:ffff:ffff:ffff:ffff:ffff:ffff
56fc77:370::/28fc77:37f:ffff:ffff:ffff:ffff:ffff:ffff
57fc77:380::/28fc77:38f:ffff:ffff:ffff:ffff:ffff:ffff
58fc77:390::/28fc77:39f:ffff:ffff:ffff:ffff:ffff:ffff
59fc77:3a0::/28fc77:3af:ffff:ffff:ffff:ffff:ffff:ffff
60fc77:3b0::/28fc77:3bf:ffff:ffff:ffff:ffff:ffff:ffff
61fc77:3c0::/28fc77:3cf:ffff:ffff:ffff:ffff:ffff:ffff
62fc77:3d0::/28fc77:3df:ffff:ffff:ffff:ffff:ffff:ffff
63fc77:3e0::/28fc77:3ef:ffff:ffff:ffff:ffff:ffff:ffff
64fc77:3f0::/28fc77:3ff:ffff:ffff:ffff:ffff:ffff:ffff
65fc77:400::/28fc77:40f:ffff:ffff:ffff:ffff:ffff:ffff
66fc77:410::/28fc77:41f:ffff:ffff:ffff:ffff:ffff:ffff
67fc77:420::/28fc77:42f:ffff:ffff:ffff:ffff:ffff:ffff
68fc77:430::/28fc77:43f:ffff:ffff:ffff:ffff:ffff:ffff
69fc77:440::/28fc77:44f:ffff:ffff:ffff:ffff:ffff:ffff
70fc77:450::/28fc77:45f:ffff:ffff:ffff:ffff:ffff:ffff
71fc77:460::/28fc77:46f:ffff:ffff:ffff:ffff:ffff:ffff
72fc77:470::/28fc77:47f:ffff:ffff:ffff:ffff:ffff:ffff
73fc77:480::/28fc77:48f:ffff:ffff:ffff:ffff:ffff:ffff
74fc77:490::/28fc77:49f:ffff:ffff:ffff:ffff:ffff:ffff
75fc77:4a0::/28fc77:4af:ffff:ffff:ffff:ffff:ffff:ffff
76fc77:4b0::/28fc77:4bf:ffff:ffff:ffff:ffff:ffff:ffff
77fc77:4c0::/28fc77:4cf:ffff:ffff:ffff:ffff:ffff:ffff
78fc77:4d0::/28fc77:4df:ffff:ffff:ffff:ffff:ffff:ffff
79fc77:4e0::/28fc77:4ef:ffff:ffff:ffff:ffff:ffff:ffff
80fc77:4f0::/28fc77:4ff:ffff:ffff:ffff:ffff:ffff:ffff
81fc77:500::/28fc77:50f:ffff:ffff:ffff:ffff:ffff:ffff
82fc77:510::/28fc77:51f:ffff:ffff:ffff:ffff:ffff:ffff
83fc77:520::/28fc77:52f:ffff:ffff:ffff:ffff:ffff:ffff
84fc77:530::/28fc77:53f:ffff:ffff:ffff:ffff:ffff:ffff
85fc77:540::/28fc77:54f:ffff:ffff:ffff:ffff:ffff:ffff
86fc77:550::/28fc77:55f:ffff:ffff:ffff:ffff:ffff:ffff
87fc77:560::/28fc77:56f:ffff:ffff:ffff:ffff:ffff:ffff
88fc77:570::/28fc77:57f:ffff:ffff:ffff:ffff:ffff:ffff
89fc77:580::/28fc77:58f:ffff:ffff:ffff:ffff:ffff:ffff
90fc77:590::/28fc77:59f:ffff:ffff:ffff:ffff:ffff:ffff
91fc77:5a0::/28fc77:5af:ffff:ffff:ffff:ffff:ffff:ffff
92fc77:5b0::/28fc77:5bf:ffff:ffff:ffff:ffff:ffff:ffff
93fc77:5c0::/28fc77:5cf:ffff:ffff:ffff:ffff:ffff:ffff
94fc77:5d0::/28fc77:5df:ffff:ffff:ffff:ffff:ffff:ffff
95fc77:5e0::/28fc77:5ef:ffff:ffff:ffff:ffff:ffff:ffff
96fc77:5f0::/28fc77:5ff:ffff:ffff:ffff:ffff:ffff:ffff
97fc77:600::/28fc77:60f:ffff:ffff:ffff:ffff:ffff:ffff
98fc77:610::/28fc77:61f:ffff:ffff:ffff:ffff:ffff:ffff
99fc77:620::/28fc77:62f:ffff:ffff:ffff:ffff:ffff:ffff
100fc77:630::/28fc77:63f:ffff:ffff:ffff:ffff:ffff:ffff
101fc77:640::/28fc77:64f:ffff:ffff:ffff:ffff:ffff:ffff
102fc77:650::/28fc77:65f:ffff:ffff:ffff:ffff:ffff:ffff
103fc77:660::/28fc77:66f:ffff:ffff:ffff:ffff:ffff:ffff
104fc77:670::/28fc77:67f:ffff:ffff:ffff:ffff:ffff:ffff
105fc77:680::/28fc77:68f:ffff:ffff:ffff:ffff:ffff:ffff
106fc77:690::/28fc77:69f:ffff:ffff:ffff:ffff:ffff:ffff
107fc77:6a0::/28fc77:6af:ffff:ffff:ffff:ffff:ffff:ffff
108fc77:6b0::/28fc77:6bf:ffff:ffff:ffff:ffff:ffff:ffff
109fc77:6c0::/28fc77:6cf:ffff:ffff:ffff:ffff:ffff:ffff
110fc77:6d0::/28fc77:6df:ffff:ffff:ffff:ffff:ffff:ffff
111fc77:6e0::/28fc77:6ef:ffff:ffff:ffff:ffff:ffff:ffff
112fc77:6f0::/28fc77:6ff:ffff:ffff:ffff:ffff:ffff:ffff
113fc77:700::/28fc77:70f:ffff:ffff:ffff:ffff:ffff:ffff
114fc77:710::/28fc77:71f:ffff:ffff:ffff:ffff:ffff:ffff
115fc77:720::/28fc77:72f:ffff:ffff:ffff:ffff:ffff:ffff
116fc77:730::/28fc77:73f:ffff:ffff:ffff:ffff:ffff:ffff
117fc77:740::/28fc77:74f:ffff:ffff:ffff:ffff:ffff:ffff
118fc77:750::/28fc77:75f:ffff:ffff:ffff:ffff:ffff:ffff
119fc77:760::/28fc77:76f:ffff:ffff:ffff:ffff:ffff:ffff
120fc77:770::/28fc77:77f:ffff:ffff:ffff:ffff:ffff:ffff
121fc77:780::/28fc77:78f:ffff:ffff:ffff:ffff:ffff:ffff
122fc77:790::/28fc77:79f:ffff:ffff:ffff:ffff:ffff:ffff
123fc77:7a0::/28fc77:7af:ffff:ffff:ffff:ffff:ffff:ffff
124fc77:7b0::/28fc77:7bf:ffff:ffff:ffff:ffff:ffff:ffff
125fc77:7c0::/28fc77:7cf:ffff:ffff:ffff:ffff:ffff:ffff
126fc77:7d0::/28fc77:7df:ffff:ffff:ffff:ffff:ffff:ffff
127fc77:7e0::/28fc77:7ef:ffff:ffff:ffff:ffff:ffff:ffff
128fc77:7f0::/28fc77:7ff:ffff:ffff:ffff:ffff:ffff:ffff
129fc77:800::/28fc77:80f:ffff:ffff:ffff:ffff:ffff:ffff
130fc77:810::/28fc77:81f:ffff:ffff:ffff:ffff:ffff:ffff
131fc77:820::/28fc77:82f:ffff:ffff:ffff:ffff:ffff:ffff
132fc77:830::/28fc77:83f:ffff:ffff:ffff:ffff:ffff:ffff
133fc77:840::/28fc77:84f:ffff:ffff:ffff:ffff:ffff:ffff
134fc77:850::/28fc77:85f:ffff:ffff:ffff:ffff:ffff:ffff
135fc77:860::/28fc77:86f:ffff:ffff:ffff:ffff:ffff:ffff
136fc77:870::/28fc77:87f:ffff:ffff:ffff:ffff:ffff:ffff
137fc77:880::/28fc77:88f:ffff:ffff:ffff:ffff:ffff:ffff
138fc77:890::/28fc77:89f:ffff:ffff:ffff:ffff:ffff:ffff
139fc77:8a0::/28fc77:8af:ffff:ffff:ffff:ffff:ffff:ffff
140fc77:8b0::/28fc77:8bf:ffff:ffff:ffff:ffff:ffff:ffff
141fc77:8c0::/28fc77:8cf:ffff:ffff:ffff:ffff:ffff:ffff
142fc77:8d0::/28fc77:8df:ffff:ffff:ffff:ffff:ffff:ffff
143fc77:8e0::/28fc77:8ef:ffff:ffff:ffff:ffff:ffff:ffff
144fc77:8f0::/28fc77:8ff:ffff:ffff:ffff:ffff:ffff:ffff
145fc77:900::/28fc77:90f:ffff:ffff:ffff:ffff:ffff:ffff
146fc77:910::/28fc77:91f:ffff:ffff:ffff:ffff:ffff:ffff
147fc77:920::/28fc77:92f:ffff:ffff:ffff:ffff:ffff:ffff
148fc77:930::/28fc77:93f:ffff:ffff:ffff:ffff:ffff:ffff
149fc77:940::/28fc77:94f:ffff:ffff:ffff:ffff:ffff:ffff
150fc77:950::/28fc77:95f:ffff:ffff:ffff:ffff:ffff:ffff
151fc77:960::/28fc77:96f:ffff:ffff:ffff:ffff:ffff:ffff
152fc77:970::/28fc77:97f:ffff:ffff:ffff:ffff:ffff:ffff
153fc77:980::/28fc77:98f:ffff:ffff:ffff:ffff:ffff:ffff
154fc77:990::/28fc77:99f:ffff:ffff:ffff:ffff:ffff:ffff
155fc77:9a0::/28fc77:9af:ffff:ffff:ffff:ffff:ffff:ffff
156fc77:9b0::/28fc77:9bf:ffff:ffff:ffff:ffff:ffff:ffff
157fc77:9c0::/28fc77:9cf:ffff:ffff:ffff:ffff:ffff:ffff
158fc77:9d0::/28fc77:9df:ffff:ffff:ffff:ffff:ffff:ffff
159fc77:9e0::/28fc77:9ef:ffff:ffff:ffff:ffff:ffff:ffff
160fc77:9f0::/28fc77:9ff:ffff:ffff:ffff:ffff:ffff:ffff
161fc77:a00::/28fc77:a0f:ffff:ffff:ffff:ffff:ffff:ffff
162fc77:a10::/28fc77:a1f:ffff:ffff:ffff:ffff:ffff:ffff
163fc77:a20::/28fc77:a2f:ffff:ffff:ffff:ffff:ffff:ffff
164fc77:a30::/28fc77:a3f:ffff:ffff:ffff:ffff:ffff:ffff
165fc77:a40::/28fc77:a4f:ffff:ffff:ffff:ffff:ffff:ffff
166fc77:a50::/28fc77:a5f:ffff:ffff:ffff:ffff:ffff:ffff
167fc77:a60::/28fc77:a6f:ffff:ffff:ffff:ffff:ffff:ffff
168fc77:a70::/28fc77:a7f:ffff:ffff:ffff:ffff:ffff:ffff
169fc77:a80::/28fc77:a8f:ffff:ffff:ffff:ffff:ffff:ffff
170fc77:a90::/28fc77:a9f:ffff:ffff:ffff:ffff:ffff:ffff
171fc77:aa0::/28fc77:aaf:ffff:ffff:ffff:ffff:ffff:ffff
172fc77:ab0::/28fc77:abf:ffff:ffff:ffff:ffff:ffff:ffff
173fc77:ac0::/28fc77:acf:ffff:ffff:ffff:ffff:ffff:ffff
174fc77:ad0::/28fc77:adf:ffff:ffff:ffff:ffff:ffff:ffff
175fc77:ae0::/28fc77:aef:ffff:ffff:ffff:ffff:ffff:ffff
176fc77:af0::/28fc77:aff:ffff:ffff:ffff:ffff:ffff:ffff
177fc77:b00::/28fc77:b0f:ffff:ffff:ffff:ffff:ffff:ffff
178fc77:b10::/28fc77:b1f:ffff:ffff:ffff:ffff:ffff:ffff
179fc77:b20::/28fc77:b2f:ffff:ffff:ffff:ffff:ffff:ffff
180fc77:b30::/28fc77:b3f:ffff:ffff:ffff:ffff:ffff:ffff
181fc77:b40::/28fc77:b4f:ffff:ffff:ffff:ffff:ffff:ffff
182fc77:b50::/28fc77:b5f:ffff:ffff:ffff:ffff:ffff:ffff
183fc77:b60::/28fc77:b6f:ffff:ffff:ffff:ffff:ffff:ffff
184fc77:b70::/28fc77:b7f:ffff:ffff:ffff:ffff:ffff:ffff
185fc77:b80::/28fc77:b8f:ffff:ffff:ffff:ffff:ffff:ffff
186fc77:b90::/28fc77:b9f:ffff:ffff:ffff:ffff:ffff:ffff
187fc77:ba0::/28fc77:baf:ffff:ffff:ffff:ffff:ffff:ffff
188fc77:bb0::/28fc77:bbf:ffff:ffff:ffff:ffff:ffff:ffff
189fc77:bc0::/28fc77:bcf:ffff:ffff:ffff:ffff:ffff:ffff
190fc77:bd0::/28fc77:bdf:ffff:ffff:ffff:ffff:ffff:ffff
191fc77:be0::/28fc77:bef:ffff:ffff:ffff:ffff:ffff:ffff
192fc77:bf0::/28fc77:bff:ffff:ffff:ffff:ffff:ffff:ffff
193fc77:c00::/28fc77:c0f:ffff:ffff:ffff:ffff:ffff:ffff
194fc77:c10::/28fc77:c1f:ffff:ffff:ffff:ffff:ffff:ffff
195fc77:c20::/28fc77:c2f:ffff:ffff:ffff:ffff:ffff:ffff
196fc77:c30::/28fc77:c3f:ffff:ffff:ffff:ffff:ffff:ffff
197fc77:c40::/28fc77:c4f:ffff:ffff:ffff:ffff:ffff:ffff
198fc77:c50::/28fc77:c5f:ffff:ffff:ffff:ffff:ffff:ffff
199fc77:c60::/28fc77:c6f:ffff:ffff:ffff:ffff:ffff:ffff
200fc77:c70::/28fc77:c7f:ffff:ffff:ffff:ffff:ffff:ffff
201fc77:c80::/28fc77:c8f:ffff:ffff:ffff:ffff:ffff:ffff
202fc77:c90::/28fc77:c9f:ffff:ffff:ffff:ffff:ffff:ffff
203fc77:ca0::/28fc77:caf:ffff:ffff:ffff:ffff:ffff:ffff
204fc77:cb0::/28fc77:cbf:ffff:ffff:ffff:ffff:ffff:ffff
205fc77:cc0::/28fc77:ccf:ffff:ffff:ffff:ffff:ffff:ffff
206fc77:cd0::/28fc77:cdf:ffff:ffff:ffff:ffff:ffff:ffff
207fc77:ce0::/28fc77:cef:ffff:ffff:ffff:ffff:ffff:ffff
208fc77:cf0::/28fc77:cff:ffff:ffff:ffff:ffff:ffff:ffff
209fc77:d00::/28fc77:d0f:ffff:ffff:ffff:ffff:ffff:ffff
210fc77:d10::/28fc77:d1f:ffff:ffff:ffff:ffff:ffff:ffff
211fc77:d20::/28fc77:d2f:ffff:ffff:ffff:ffff:ffff:ffff
212fc77:d30::/28fc77:d3f:ffff:ffff:ffff:ffff:ffff:ffff
213fc77:d40::/28fc77:d4f:ffff:ffff:ffff:ffff:ffff:ffff
214fc77:d50::/28fc77:d5f:ffff:ffff:ffff:ffff:ffff:ffff
215fc77:d60::/28fc77:d6f:ffff:ffff:ffff:ffff:ffff:ffff
216fc77:d70::/28fc77:d7f:ffff:ffff:ffff:ffff:ffff:ffff
217fc77:d80::/28fc77:d8f:ffff:ffff:ffff:ffff:ffff:ffff
218fc77:d90::/28fc77:d9f:ffff:ffff:ffff:ffff:ffff:ffff
219fc77:da0::/28fc77:daf:ffff:ffff:ffff:ffff:ffff:ffff
220fc77:db0::/28fc77:dbf:ffff:ffff:ffff:ffff:ffff:ffff
221fc77:dc0::/28fc77:dcf:ffff:ffff:ffff:ffff:ffff:ffff
222fc77:dd0::/28fc77:ddf:ffff:ffff:ffff:ffff:ffff:ffff
223fc77:de0::/28fc77:def:ffff:ffff:ffff:ffff:ffff:ffff
224fc77:df0::/28fc77:dff:ffff:ffff:ffff:ffff:ffff:ffff
225fc77:e00::/28fc77:e0f:ffff:ffff:ffff:ffff:ffff:ffff
226fc77:e10::/28fc77:e1f:ffff:ffff:ffff:ffff:ffff:ffff
227fc77:e20::/28fc77:e2f:ffff:ffff:ffff:ffff:ffff:ffff
228fc77:e30::/28fc77:e3f:ffff:ffff:ffff:ffff:ffff:ffff
229fc77:e40::/28fc77:e4f:ffff:ffff:ffff:ffff:ffff:ffff
230fc77:e50::/28fc77:e5f:ffff:ffff:ffff:ffff:ffff:ffff
231fc77:e60::/28fc77:e6f:ffff:ffff:ffff:ffff:ffff:ffff
232fc77:e70::/28fc77:e7f:ffff:ffff:ffff:ffff:ffff:ffff
233fc77:e80::/28fc77:e8f:ffff:ffff:ffff:ffff:ffff:ffff
234fc77:e90::/28fc77:e9f:ffff:ffff:ffff:ffff:ffff:ffff
235fc77:ea0::/28fc77:eaf:ffff:ffff:ffff:ffff:ffff:ffff
236fc77:eb0::/28fc77:ebf:ffff:ffff:ffff:ffff:ffff:ffff
237fc77:ec0::/28fc77:ecf:ffff:ffff:ffff:ffff:ffff:ffff
238fc77:ed0::/28fc77:edf:ffff:ffff:ffff:ffff:ffff:ffff
239fc77:ee0::/28fc77:eef:ffff:ffff:ffff:ffff:ffff:ffff
240fc77:ef0::/28fc77:eff:ffff:ffff:ffff:ffff:ffff:ffff
241fc77:f00::/28fc77:f0f:ffff:ffff:ffff:ffff:ffff:ffff
242fc77:f10::/28fc77:f1f:ffff:ffff:ffff:ffff:ffff:ffff
243fc77:f20::/28fc77:f2f:ffff:ffff:ffff:ffff:ffff:ffff
244fc77:f30::/28fc77:f3f:ffff:ffff:ffff:ffff:ffff:ffff
245fc77:f40::/28fc77:f4f:ffff:ffff:ffff:ffff:ffff:ffff
246fc77:f50::/28fc77:f5f:ffff:ffff:ffff:ffff:ffff:ffff
247fc77:f60::/28fc77:f6f:ffff:ffff:ffff:ffff:ffff:ffff
248fc77:f70::/28fc77:f7f:ffff:ffff:ffff:ffff:ffff:ffff
249fc77:f80::/28fc77:f8f:ffff:ffff:ffff:ffff:ffff:ffff
250fc77:f90::/28fc77:f9f:ffff:ffff:ffff:ffff:ffff:ffff
251fc77:fa0::/28fc77:faf:ffff:ffff:ffff:ffff:ffff:ffff
252fc77:fb0::/28fc77:fbf:ffff:ffff:ffff:ffff:ffff:ffff
253fc77:fc0::/28fc77:fcf:ffff:ffff:ffff:ffff:ffff:ffff
254fc77:fd0::/28fc77:fdf:ffff:ffff:ffff:ffff:ffff:ffff
255fc77:fe0::/28fc77:fef:ffff:ffff:ffff:ffff:ffff:ffff
256fc77:ff0::/28fc77: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.