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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
fc89::/16
First address
fc89::
Last address
fc89: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
fc89:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
9.8.c.f.ip6.arpa
Split into smaller subnets/32
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

fc89::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fc89::/32fc89:0:ffff:ffff:ffff:ffff:ffff:ffff
2fc89:1::/32fc89:1:ffff:ffff:ffff:ffff:ffff:ffff
3fc89:2::/32fc89:2:ffff:ffff:ffff:ffff:ffff:ffff
4fc89:3::/32fc89:3:ffff:ffff:ffff:ffff:ffff:ffff
5fc89:4::/32fc89:4:ffff:ffff:ffff:ffff:ffff:ffff
6fc89:5::/32fc89:5:ffff:ffff:ffff:ffff:ffff:ffff
7fc89:6::/32fc89:6:ffff:ffff:ffff:ffff:ffff:ffff
8fc89:7::/32fc89:7:ffff:ffff:ffff:ffff:ffff:ffff
9fc89:8::/32fc89:8:ffff:ffff:ffff:ffff:ffff:ffff
10fc89:9::/32fc89:9:ffff:ffff:ffff:ffff:ffff:ffff
11fc89:a::/32fc89:a:ffff:ffff:ffff:ffff:ffff:ffff
12fc89:b::/32fc89:b:ffff:ffff:ffff:ffff:ffff:ffff
13fc89:c::/32fc89:c:ffff:ffff:ffff:ffff:ffff:ffff
14fc89:d::/32fc89:d:ffff:ffff:ffff:ffff:ffff:ffff
15fc89:e::/32fc89:e:ffff:ffff:ffff:ffff:ffff:ffff
16fc89:f::/32fc89:f:ffff:ffff:ffff:ffff:ffff:ffff
17fc89:10::/32fc89:10:ffff:ffff:ffff:ffff:ffff:ffff
18fc89:11::/32fc89:11:ffff:ffff:ffff:ffff:ffff:ffff
19fc89:12::/32fc89:12:ffff:ffff:ffff:ffff:ffff:ffff
20fc89:13::/32fc89:13:ffff:ffff:ffff:ffff:ffff:ffff
21fc89:14::/32fc89:14:ffff:ffff:ffff:ffff:ffff:ffff
22fc89:15::/32fc89:15:ffff:ffff:ffff:ffff:ffff:ffff
23fc89:16::/32fc89:16:ffff:ffff:ffff:ffff:ffff:ffff
24fc89:17::/32fc89:17:ffff:ffff:ffff:ffff:ffff:ffff
25fc89:18::/32fc89:18:ffff:ffff:ffff:ffff:ffff:ffff
26fc89:19::/32fc89:19:ffff:ffff:ffff:ffff:ffff:ffff
27fc89:1a::/32fc89:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fc89:1b::/32fc89:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fc89:1c::/32fc89:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fc89:1d::/32fc89:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fc89:1e::/32fc89:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fc89:1f::/32fc89:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fc89:20::/32fc89:20:ffff:ffff:ffff:ffff:ffff:ffff
34fc89:21::/32fc89:21:ffff:ffff:ffff:ffff:ffff:ffff
35fc89:22::/32fc89:22:ffff:ffff:ffff:ffff:ffff:ffff
36fc89:23::/32fc89:23:ffff:ffff:ffff:ffff:ffff:ffff
37fc89:24::/32fc89:24:ffff:ffff:ffff:ffff:ffff:ffff
38fc89:25::/32fc89:25:ffff:ffff:ffff:ffff:ffff:ffff
39fc89:26::/32fc89:26:ffff:ffff:ffff:ffff:ffff:ffff
40fc89:27::/32fc89:27:ffff:ffff:ffff:ffff:ffff:ffff
41fc89:28::/32fc89:28:ffff:ffff:ffff:ffff:ffff:ffff
42fc89:29::/32fc89:29:ffff:ffff:ffff:ffff:ffff:ffff
43fc89:2a::/32fc89:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fc89:2b::/32fc89:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fc89:2c::/32fc89:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fc89:2d::/32fc89:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fc89:2e::/32fc89:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fc89:2f::/32fc89:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fc89:30::/32fc89:30:ffff:ffff:ffff:ffff:ffff:ffff
50fc89:31::/32fc89:31:ffff:ffff:ffff:ffff:ffff:ffff
51fc89:32::/32fc89:32:ffff:ffff:ffff:ffff:ffff:ffff
52fc89:33::/32fc89:33:ffff:ffff:ffff:ffff:ffff:ffff
53fc89:34::/32fc89:34:ffff:ffff:ffff:ffff:ffff:ffff
54fc89:35::/32fc89:35:ffff:ffff:ffff:ffff:ffff:ffff
55fc89:36::/32fc89:36:ffff:ffff:ffff:ffff:ffff:ffff
56fc89:37::/32fc89:37:ffff:ffff:ffff:ffff:ffff:ffff
57fc89:38::/32fc89:38:ffff:ffff:ffff:ffff:ffff:ffff
58fc89:39::/32fc89:39:ffff:ffff:ffff:ffff:ffff:ffff
59fc89:3a::/32fc89:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fc89:3b::/32fc89:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fc89:3c::/32fc89:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fc89:3d::/32fc89:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fc89:3e::/32fc89:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fc89:3f::/32fc89:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fc89:40::/32fc89:40:ffff:ffff:ffff:ffff:ffff:ffff
66fc89:41::/32fc89:41:ffff:ffff:ffff:ffff:ffff:ffff
67fc89:42::/32fc89:42:ffff:ffff:ffff:ffff:ffff:ffff
68fc89:43::/32fc89:43:ffff:ffff:ffff:ffff:ffff:ffff
69fc89:44::/32fc89:44:ffff:ffff:ffff:ffff:ffff:ffff
70fc89:45::/32fc89:45:ffff:ffff:ffff:ffff:ffff:ffff
71fc89:46::/32fc89:46:ffff:ffff:ffff:ffff:ffff:ffff
72fc89:47::/32fc89:47:ffff:ffff:ffff:ffff:ffff:ffff
73fc89:48::/32fc89:48:ffff:ffff:ffff:ffff:ffff:ffff
74fc89:49::/32fc89:49:ffff:ffff:ffff:ffff:ffff:ffff
75fc89:4a::/32fc89:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fc89:4b::/32fc89:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fc89:4c::/32fc89:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fc89:4d::/32fc89:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fc89:4e::/32fc89:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fc89:4f::/32fc89:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fc89:50::/32fc89:50:ffff:ffff:ffff:ffff:ffff:ffff
82fc89:51::/32fc89:51:ffff:ffff:ffff:ffff:ffff:ffff
83fc89:52::/32fc89:52:ffff:ffff:ffff:ffff:ffff:ffff
84fc89:53::/32fc89:53:ffff:ffff:ffff:ffff:ffff:ffff
85fc89:54::/32fc89:54:ffff:ffff:ffff:ffff:ffff:ffff
86fc89:55::/32fc89:55:ffff:ffff:ffff:ffff:ffff:ffff
87fc89:56::/32fc89:56:ffff:ffff:ffff:ffff:ffff:ffff
88fc89:57::/32fc89:57:ffff:ffff:ffff:ffff:ffff:ffff
89fc89:58::/32fc89:58:ffff:ffff:ffff:ffff:ffff:ffff
90fc89:59::/32fc89:59:ffff:ffff:ffff:ffff:ffff:ffff
91fc89:5a::/32fc89:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fc89:5b::/32fc89:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fc89:5c::/32fc89:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fc89:5d::/32fc89:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fc89:5e::/32fc89:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fc89:5f::/32fc89:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fc89:60::/32fc89:60:ffff:ffff:ffff:ffff:ffff:ffff
98fc89:61::/32fc89:61:ffff:ffff:ffff:ffff:ffff:ffff
99fc89:62::/32fc89:62:ffff:ffff:ffff:ffff:ffff:ffff
100fc89:63::/32fc89:63:ffff:ffff:ffff:ffff:ffff:ffff
101fc89:64::/32fc89:64:ffff:ffff:ffff:ffff:ffff:ffff
102fc89:65::/32fc89:65:ffff:ffff:ffff:ffff:ffff:ffff
103fc89:66::/32fc89:66:ffff:ffff:ffff:ffff:ffff:ffff
104fc89:67::/32fc89:67:ffff:ffff:ffff:ffff:ffff:ffff
105fc89:68::/32fc89:68:ffff:ffff:ffff:ffff:ffff:ffff
106fc89:69::/32fc89:69:ffff:ffff:ffff:ffff:ffff:ffff
107fc89:6a::/32fc89:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fc89:6b::/32fc89:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fc89:6c::/32fc89:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fc89:6d::/32fc89:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fc89:6e::/32fc89:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fc89:6f::/32fc89:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fc89:70::/32fc89:70:ffff:ffff:ffff:ffff:ffff:ffff
114fc89:71::/32fc89:71:ffff:ffff:ffff:ffff:ffff:ffff
115fc89:72::/32fc89:72:ffff:ffff:ffff:ffff:ffff:ffff
116fc89:73::/32fc89:73:ffff:ffff:ffff:ffff:ffff:ffff
117fc89:74::/32fc89:74:ffff:ffff:ffff:ffff:ffff:ffff
118fc89:75::/32fc89:75:ffff:ffff:ffff:ffff:ffff:ffff
119fc89:76::/32fc89:76:ffff:ffff:ffff:ffff:ffff:ffff
120fc89:77::/32fc89:77:ffff:ffff:ffff:ffff:ffff:ffff
121fc89:78::/32fc89:78:ffff:ffff:ffff:ffff:ffff:ffff
122fc89:79::/32fc89:79:ffff:ffff:ffff:ffff:ffff:ffff
123fc89:7a::/32fc89:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fc89:7b::/32fc89:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fc89:7c::/32fc89:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fc89:7d::/32fc89:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fc89:7e::/32fc89:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fc89:7f::/32fc89:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fc89:80::/32fc89:80:ffff:ffff:ffff:ffff:ffff:ffff
130fc89:81::/32fc89:81:ffff:ffff:ffff:ffff:ffff:ffff
131fc89:82::/32fc89:82:ffff:ffff:ffff:ffff:ffff:ffff
132fc89:83::/32fc89:83:ffff:ffff:ffff:ffff:ffff:ffff
133fc89:84::/32fc89:84:ffff:ffff:ffff:ffff:ffff:ffff
134fc89:85::/32fc89:85:ffff:ffff:ffff:ffff:ffff:ffff
135fc89:86::/32fc89:86:ffff:ffff:ffff:ffff:ffff:ffff
136fc89:87::/32fc89:87:ffff:ffff:ffff:ffff:ffff:ffff
137fc89:88::/32fc89:88:ffff:ffff:ffff:ffff:ffff:ffff
138fc89:89::/32fc89:89:ffff:ffff:ffff:ffff:ffff:ffff
139fc89:8a::/32fc89:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fc89:8b::/32fc89:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fc89:8c::/32fc89:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fc89:8d::/32fc89:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fc89:8e::/32fc89:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fc89:8f::/32fc89:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fc89:90::/32fc89:90:ffff:ffff:ffff:ffff:ffff:ffff
146fc89:91::/32fc89:91:ffff:ffff:ffff:ffff:ffff:ffff
147fc89:92::/32fc89:92:ffff:ffff:ffff:ffff:ffff:ffff
148fc89:93::/32fc89:93:ffff:ffff:ffff:ffff:ffff:ffff
149fc89:94::/32fc89:94:ffff:ffff:ffff:ffff:ffff:ffff
150fc89:95::/32fc89:95:ffff:ffff:ffff:ffff:ffff:ffff
151fc89:96::/32fc89:96:ffff:ffff:ffff:ffff:ffff:ffff
152fc89:97::/32fc89:97:ffff:ffff:ffff:ffff:ffff:ffff
153fc89:98::/32fc89:98:ffff:ffff:ffff:ffff:ffff:ffff
154fc89:99::/32fc89:99:ffff:ffff:ffff:ffff:ffff:ffff
155fc89:9a::/32fc89:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fc89:9b::/32fc89:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fc89:9c::/32fc89:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fc89:9d::/32fc89:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fc89:9e::/32fc89:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fc89:9f::/32fc89:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fc89:a0::/32fc89:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fc89:a1::/32fc89:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fc89:a2::/32fc89:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fc89:a3::/32fc89:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fc89:a4::/32fc89:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fc89:a5::/32fc89:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fc89:a6::/32fc89:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fc89:a7::/32fc89:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fc89:a8::/32fc89:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fc89:a9::/32fc89:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fc89:aa::/32fc89:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fc89:ab::/32fc89:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fc89:ac::/32fc89:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fc89:ad::/32fc89:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fc89:ae::/32fc89:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fc89:af::/32fc89:af:ffff:ffff:ffff:ffff:ffff:ffff
177fc89:b0::/32fc89:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fc89:b1::/32fc89:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fc89:b2::/32fc89:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fc89:b3::/32fc89:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fc89:b4::/32fc89:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fc89:b5::/32fc89:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fc89:b6::/32fc89:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fc89:b7::/32fc89:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fc89:b8::/32fc89:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fc89:b9::/32fc89:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fc89:ba::/32fc89:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fc89:bb::/32fc89:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fc89:bc::/32fc89:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fc89:bd::/32fc89:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fc89:be::/32fc89:be:ffff:ffff:ffff:ffff:ffff:ffff
192fc89:bf::/32fc89:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fc89:c0::/32fc89:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fc89:c1::/32fc89:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fc89:c2::/32fc89:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fc89:c3::/32fc89:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fc89:c4::/32fc89:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fc89:c5::/32fc89:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fc89:c6::/32fc89:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fc89:c7::/32fc89:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fc89:c8::/32fc89:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fc89:c9::/32fc89:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fc89:ca::/32fc89:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fc89:cb::/32fc89:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fc89:cc::/32fc89:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fc89:cd::/32fc89:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fc89:ce::/32fc89:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fc89:cf::/32fc89:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fc89:d0::/32fc89:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fc89:d1::/32fc89:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fc89:d2::/32fc89:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fc89:d3::/32fc89:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fc89:d4::/32fc89:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fc89:d5::/32fc89:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fc89:d6::/32fc89:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fc89:d7::/32fc89:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fc89:d8::/32fc89:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fc89:d9::/32fc89:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fc89:da::/32fc89:da:ffff:ffff:ffff:ffff:ffff:ffff
220fc89:db::/32fc89:db:ffff:ffff:ffff:ffff:ffff:ffff
221fc89:dc::/32fc89:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fc89:dd::/32fc89:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fc89:de::/32fc89:de:ffff:ffff:ffff:ffff:ffff:ffff
224fc89:df::/32fc89:df:ffff:ffff:ffff:ffff:ffff:ffff
225fc89:e0::/32fc89:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fc89:e1::/32fc89:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fc89:e2::/32fc89:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fc89:e3::/32fc89:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fc89:e4::/32fc89:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fc89:e5::/32fc89:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fc89:e6::/32fc89:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fc89:e7::/32fc89:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fc89:e8::/32fc89:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fc89:e9::/32fc89:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fc89:ea::/32fc89:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fc89:eb::/32fc89:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fc89:ec::/32fc89:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fc89:ed::/32fc89:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fc89:ee::/32fc89:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fc89:ef::/32fc89:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fc89:f0::/32fc89:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fc89:f1::/32fc89:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fc89:f2::/32fc89:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fc89:f3::/32fc89:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fc89:f4::/32fc89:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fc89:f5::/32fc89:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fc89:f6::/32fc89:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fc89:f7::/32fc89:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fc89:f8::/32fc89:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fc89:f9::/32fc89:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fc89:fa::/32fc89:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fc89:fb::/32fc89:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fc89:fc::/32fc89:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fc89:fd::/32fc89:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fc89:fe::/32fc89:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fc89:ff::/32fc89: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.