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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
fc2f::/16
First address
fc2f::
Last address
fc2f: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
fc2f:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
f.2.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)

fc2f::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fc2f::/32fc2f:0:ffff:ffff:ffff:ffff:ffff:ffff
2fc2f:1::/32fc2f:1:ffff:ffff:ffff:ffff:ffff:ffff
3fc2f:2::/32fc2f:2:ffff:ffff:ffff:ffff:ffff:ffff
4fc2f:3::/32fc2f:3:ffff:ffff:ffff:ffff:ffff:ffff
5fc2f:4::/32fc2f:4:ffff:ffff:ffff:ffff:ffff:ffff
6fc2f:5::/32fc2f:5:ffff:ffff:ffff:ffff:ffff:ffff
7fc2f:6::/32fc2f:6:ffff:ffff:ffff:ffff:ffff:ffff
8fc2f:7::/32fc2f:7:ffff:ffff:ffff:ffff:ffff:ffff
9fc2f:8::/32fc2f:8:ffff:ffff:ffff:ffff:ffff:ffff
10fc2f:9::/32fc2f:9:ffff:ffff:ffff:ffff:ffff:ffff
11fc2f:a::/32fc2f:a:ffff:ffff:ffff:ffff:ffff:ffff
12fc2f:b::/32fc2f:b:ffff:ffff:ffff:ffff:ffff:ffff
13fc2f:c::/32fc2f:c:ffff:ffff:ffff:ffff:ffff:ffff
14fc2f:d::/32fc2f:d:ffff:ffff:ffff:ffff:ffff:ffff
15fc2f:e::/32fc2f:e:ffff:ffff:ffff:ffff:ffff:ffff
16fc2f:f::/32fc2f:f:ffff:ffff:ffff:ffff:ffff:ffff
17fc2f:10::/32fc2f:10:ffff:ffff:ffff:ffff:ffff:ffff
18fc2f:11::/32fc2f:11:ffff:ffff:ffff:ffff:ffff:ffff
19fc2f:12::/32fc2f:12:ffff:ffff:ffff:ffff:ffff:ffff
20fc2f:13::/32fc2f:13:ffff:ffff:ffff:ffff:ffff:ffff
21fc2f:14::/32fc2f:14:ffff:ffff:ffff:ffff:ffff:ffff
22fc2f:15::/32fc2f:15:ffff:ffff:ffff:ffff:ffff:ffff
23fc2f:16::/32fc2f:16:ffff:ffff:ffff:ffff:ffff:ffff
24fc2f:17::/32fc2f:17:ffff:ffff:ffff:ffff:ffff:ffff
25fc2f:18::/32fc2f:18:ffff:ffff:ffff:ffff:ffff:ffff
26fc2f:19::/32fc2f:19:ffff:ffff:ffff:ffff:ffff:ffff
27fc2f:1a::/32fc2f:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fc2f:1b::/32fc2f:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fc2f:1c::/32fc2f:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fc2f:1d::/32fc2f:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fc2f:1e::/32fc2f:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fc2f:1f::/32fc2f:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fc2f:20::/32fc2f:20:ffff:ffff:ffff:ffff:ffff:ffff
34fc2f:21::/32fc2f:21:ffff:ffff:ffff:ffff:ffff:ffff
35fc2f:22::/32fc2f:22:ffff:ffff:ffff:ffff:ffff:ffff
36fc2f:23::/32fc2f:23:ffff:ffff:ffff:ffff:ffff:ffff
37fc2f:24::/32fc2f:24:ffff:ffff:ffff:ffff:ffff:ffff
38fc2f:25::/32fc2f:25:ffff:ffff:ffff:ffff:ffff:ffff
39fc2f:26::/32fc2f:26:ffff:ffff:ffff:ffff:ffff:ffff
40fc2f:27::/32fc2f:27:ffff:ffff:ffff:ffff:ffff:ffff
41fc2f:28::/32fc2f:28:ffff:ffff:ffff:ffff:ffff:ffff
42fc2f:29::/32fc2f:29:ffff:ffff:ffff:ffff:ffff:ffff
43fc2f:2a::/32fc2f:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fc2f:2b::/32fc2f:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fc2f:2c::/32fc2f:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fc2f:2d::/32fc2f:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fc2f:2e::/32fc2f:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fc2f:2f::/32fc2f:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fc2f:30::/32fc2f:30:ffff:ffff:ffff:ffff:ffff:ffff
50fc2f:31::/32fc2f:31:ffff:ffff:ffff:ffff:ffff:ffff
51fc2f:32::/32fc2f:32:ffff:ffff:ffff:ffff:ffff:ffff
52fc2f:33::/32fc2f:33:ffff:ffff:ffff:ffff:ffff:ffff
53fc2f:34::/32fc2f:34:ffff:ffff:ffff:ffff:ffff:ffff
54fc2f:35::/32fc2f:35:ffff:ffff:ffff:ffff:ffff:ffff
55fc2f:36::/32fc2f:36:ffff:ffff:ffff:ffff:ffff:ffff
56fc2f:37::/32fc2f:37:ffff:ffff:ffff:ffff:ffff:ffff
57fc2f:38::/32fc2f:38:ffff:ffff:ffff:ffff:ffff:ffff
58fc2f:39::/32fc2f:39:ffff:ffff:ffff:ffff:ffff:ffff
59fc2f:3a::/32fc2f:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fc2f:3b::/32fc2f:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fc2f:3c::/32fc2f:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fc2f:3d::/32fc2f:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fc2f:3e::/32fc2f:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fc2f:3f::/32fc2f:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fc2f:40::/32fc2f:40:ffff:ffff:ffff:ffff:ffff:ffff
66fc2f:41::/32fc2f:41:ffff:ffff:ffff:ffff:ffff:ffff
67fc2f:42::/32fc2f:42:ffff:ffff:ffff:ffff:ffff:ffff
68fc2f:43::/32fc2f:43:ffff:ffff:ffff:ffff:ffff:ffff
69fc2f:44::/32fc2f:44:ffff:ffff:ffff:ffff:ffff:ffff
70fc2f:45::/32fc2f:45:ffff:ffff:ffff:ffff:ffff:ffff
71fc2f:46::/32fc2f:46:ffff:ffff:ffff:ffff:ffff:ffff
72fc2f:47::/32fc2f:47:ffff:ffff:ffff:ffff:ffff:ffff
73fc2f:48::/32fc2f:48:ffff:ffff:ffff:ffff:ffff:ffff
74fc2f:49::/32fc2f:49:ffff:ffff:ffff:ffff:ffff:ffff
75fc2f:4a::/32fc2f:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fc2f:4b::/32fc2f:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fc2f:4c::/32fc2f:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fc2f:4d::/32fc2f:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fc2f:4e::/32fc2f:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fc2f:4f::/32fc2f:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fc2f:50::/32fc2f:50:ffff:ffff:ffff:ffff:ffff:ffff
82fc2f:51::/32fc2f:51:ffff:ffff:ffff:ffff:ffff:ffff
83fc2f:52::/32fc2f:52:ffff:ffff:ffff:ffff:ffff:ffff
84fc2f:53::/32fc2f:53:ffff:ffff:ffff:ffff:ffff:ffff
85fc2f:54::/32fc2f:54:ffff:ffff:ffff:ffff:ffff:ffff
86fc2f:55::/32fc2f:55:ffff:ffff:ffff:ffff:ffff:ffff
87fc2f:56::/32fc2f:56:ffff:ffff:ffff:ffff:ffff:ffff
88fc2f:57::/32fc2f:57:ffff:ffff:ffff:ffff:ffff:ffff
89fc2f:58::/32fc2f:58:ffff:ffff:ffff:ffff:ffff:ffff
90fc2f:59::/32fc2f:59:ffff:ffff:ffff:ffff:ffff:ffff
91fc2f:5a::/32fc2f:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fc2f:5b::/32fc2f:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fc2f:5c::/32fc2f:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fc2f:5d::/32fc2f:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fc2f:5e::/32fc2f:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fc2f:5f::/32fc2f:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fc2f:60::/32fc2f:60:ffff:ffff:ffff:ffff:ffff:ffff
98fc2f:61::/32fc2f:61:ffff:ffff:ffff:ffff:ffff:ffff
99fc2f:62::/32fc2f:62:ffff:ffff:ffff:ffff:ffff:ffff
100fc2f:63::/32fc2f:63:ffff:ffff:ffff:ffff:ffff:ffff
101fc2f:64::/32fc2f:64:ffff:ffff:ffff:ffff:ffff:ffff
102fc2f:65::/32fc2f:65:ffff:ffff:ffff:ffff:ffff:ffff
103fc2f:66::/32fc2f:66:ffff:ffff:ffff:ffff:ffff:ffff
104fc2f:67::/32fc2f:67:ffff:ffff:ffff:ffff:ffff:ffff
105fc2f:68::/32fc2f:68:ffff:ffff:ffff:ffff:ffff:ffff
106fc2f:69::/32fc2f:69:ffff:ffff:ffff:ffff:ffff:ffff
107fc2f:6a::/32fc2f:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fc2f:6b::/32fc2f:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fc2f:6c::/32fc2f:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fc2f:6d::/32fc2f:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fc2f:6e::/32fc2f:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fc2f:6f::/32fc2f:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fc2f:70::/32fc2f:70:ffff:ffff:ffff:ffff:ffff:ffff
114fc2f:71::/32fc2f:71:ffff:ffff:ffff:ffff:ffff:ffff
115fc2f:72::/32fc2f:72:ffff:ffff:ffff:ffff:ffff:ffff
116fc2f:73::/32fc2f:73:ffff:ffff:ffff:ffff:ffff:ffff
117fc2f:74::/32fc2f:74:ffff:ffff:ffff:ffff:ffff:ffff
118fc2f:75::/32fc2f:75:ffff:ffff:ffff:ffff:ffff:ffff
119fc2f:76::/32fc2f:76:ffff:ffff:ffff:ffff:ffff:ffff
120fc2f:77::/32fc2f:77:ffff:ffff:ffff:ffff:ffff:ffff
121fc2f:78::/32fc2f:78:ffff:ffff:ffff:ffff:ffff:ffff
122fc2f:79::/32fc2f:79:ffff:ffff:ffff:ffff:ffff:ffff
123fc2f:7a::/32fc2f:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fc2f:7b::/32fc2f:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fc2f:7c::/32fc2f:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fc2f:7d::/32fc2f:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fc2f:7e::/32fc2f:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fc2f:7f::/32fc2f:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fc2f:80::/32fc2f:80:ffff:ffff:ffff:ffff:ffff:ffff
130fc2f:81::/32fc2f:81:ffff:ffff:ffff:ffff:ffff:ffff
131fc2f:82::/32fc2f:82:ffff:ffff:ffff:ffff:ffff:ffff
132fc2f:83::/32fc2f:83:ffff:ffff:ffff:ffff:ffff:ffff
133fc2f:84::/32fc2f:84:ffff:ffff:ffff:ffff:ffff:ffff
134fc2f:85::/32fc2f:85:ffff:ffff:ffff:ffff:ffff:ffff
135fc2f:86::/32fc2f:86:ffff:ffff:ffff:ffff:ffff:ffff
136fc2f:87::/32fc2f:87:ffff:ffff:ffff:ffff:ffff:ffff
137fc2f:88::/32fc2f:88:ffff:ffff:ffff:ffff:ffff:ffff
138fc2f:89::/32fc2f:89:ffff:ffff:ffff:ffff:ffff:ffff
139fc2f:8a::/32fc2f:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fc2f:8b::/32fc2f:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fc2f:8c::/32fc2f:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fc2f:8d::/32fc2f:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fc2f:8e::/32fc2f:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fc2f:8f::/32fc2f:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fc2f:90::/32fc2f:90:ffff:ffff:ffff:ffff:ffff:ffff
146fc2f:91::/32fc2f:91:ffff:ffff:ffff:ffff:ffff:ffff
147fc2f:92::/32fc2f:92:ffff:ffff:ffff:ffff:ffff:ffff
148fc2f:93::/32fc2f:93:ffff:ffff:ffff:ffff:ffff:ffff
149fc2f:94::/32fc2f:94:ffff:ffff:ffff:ffff:ffff:ffff
150fc2f:95::/32fc2f:95:ffff:ffff:ffff:ffff:ffff:ffff
151fc2f:96::/32fc2f:96:ffff:ffff:ffff:ffff:ffff:ffff
152fc2f:97::/32fc2f:97:ffff:ffff:ffff:ffff:ffff:ffff
153fc2f:98::/32fc2f:98:ffff:ffff:ffff:ffff:ffff:ffff
154fc2f:99::/32fc2f:99:ffff:ffff:ffff:ffff:ffff:ffff
155fc2f:9a::/32fc2f:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fc2f:9b::/32fc2f:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fc2f:9c::/32fc2f:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fc2f:9d::/32fc2f:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fc2f:9e::/32fc2f:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fc2f:9f::/32fc2f:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fc2f:a0::/32fc2f:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fc2f:a1::/32fc2f:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fc2f:a2::/32fc2f:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fc2f:a3::/32fc2f:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fc2f:a4::/32fc2f:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fc2f:a5::/32fc2f:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fc2f:a6::/32fc2f:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fc2f:a7::/32fc2f:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fc2f:a8::/32fc2f:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fc2f:a9::/32fc2f:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fc2f:aa::/32fc2f:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fc2f:ab::/32fc2f:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fc2f:ac::/32fc2f:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fc2f:ad::/32fc2f:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fc2f:ae::/32fc2f:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fc2f:af::/32fc2f:af:ffff:ffff:ffff:ffff:ffff:ffff
177fc2f:b0::/32fc2f:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fc2f:b1::/32fc2f:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fc2f:b2::/32fc2f:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fc2f:b3::/32fc2f:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fc2f:b4::/32fc2f:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fc2f:b5::/32fc2f:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fc2f:b6::/32fc2f:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fc2f:b7::/32fc2f:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fc2f:b8::/32fc2f:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fc2f:b9::/32fc2f:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fc2f:ba::/32fc2f:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fc2f:bb::/32fc2f:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fc2f:bc::/32fc2f:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fc2f:bd::/32fc2f:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fc2f:be::/32fc2f:be:ffff:ffff:ffff:ffff:ffff:ffff
192fc2f:bf::/32fc2f:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fc2f:c0::/32fc2f:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fc2f:c1::/32fc2f:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fc2f:c2::/32fc2f:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fc2f:c3::/32fc2f:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fc2f:c4::/32fc2f:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fc2f:c5::/32fc2f:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fc2f:c6::/32fc2f:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fc2f:c7::/32fc2f:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fc2f:c8::/32fc2f:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fc2f:c9::/32fc2f:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fc2f:ca::/32fc2f:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fc2f:cb::/32fc2f:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fc2f:cc::/32fc2f:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fc2f:cd::/32fc2f:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fc2f:ce::/32fc2f:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fc2f:cf::/32fc2f:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fc2f:d0::/32fc2f:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fc2f:d1::/32fc2f:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fc2f:d2::/32fc2f:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fc2f:d3::/32fc2f:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fc2f:d4::/32fc2f:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fc2f:d5::/32fc2f:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fc2f:d6::/32fc2f:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fc2f:d7::/32fc2f:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fc2f:d8::/32fc2f:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fc2f:d9::/32fc2f:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fc2f:da::/32fc2f:da:ffff:ffff:ffff:ffff:ffff:ffff
220fc2f:db::/32fc2f:db:ffff:ffff:ffff:ffff:ffff:ffff
221fc2f:dc::/32fc2f:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fc2f:dd::/32fc2f:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fc2f:de::/32fc2f:de:ffff:ffff:ffff:ffff:ffff:ffff
224fc2f:df::/32fc2f:df:ffff:ffff:ffff:ffff:ffff:ffff
225fc2f:e0::/32fc2f:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fc2f:e1::/32fc2f:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fc2f:e2::/32fc2f:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fc2f:e3::/32fc2f:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fc2f:e4::/32fc2f:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fc2f:e5::/32fc2f:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fc2f:e6::/32fc2f:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fc2f:e7::/32fc2f:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fc2f:e8::/32fc2f:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fc2f:e9::/32fc2f:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fc2f:ea::/32fc2f:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fc2f:eb::/32fc2f:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fc2f:ec::/32fc2f:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fc2f:ed::/32fc2f:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fc2f:ee::/32fc2f:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fc2f:ef::/32fc2f:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fc2f:f0::/32fc2f:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fc2f:f1::/32fc2f:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fc2f:f2::/32fc2f:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fc2f:f3::/32fc2f:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fc2f:f4::/32fc2f:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fc2f:f5::/32fc2f:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fc2f:f6::/32fc2f:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fc2f:f7::/32fc2f:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fc2f:f8::/32fc2f:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fc2f:f9::/32fc2f:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fc2f:fa::/32fc2f:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fc2f:fb::/32fc2f:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fc2f:fc::/32fc2f:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fc2f:fd::/32fc2f:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fc2f:fe::/32fc2f:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fc2f:ff::/32fc2f: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.