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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
fc6a::/16
First address
fc6a::
Last address
fc6a: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
fc6a:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
a.6.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)

fc6a::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fc6a::/32fc6a:0:ffff:ffff:ffff:ffff:ffff:ffff
2fc6a:1::/32fc6a:1:ffff:ffff:ffff:ffff:ffff:ffff
3fc6a:2::/32fc6a:2:ffff:ffff:ffff:ffff:ffff:ffff
4fc6a:3::/32fc6a:3:ffff:ffff:ffff:ffff:ffff:ffff
5fc6a:4::/32fc6a:4:ffff:ffff:ffff:ffff:ffff:ffff
6fc6a:5::/32fc6a:5:ffff:ffff:ffff:ffff:ffff:ffff
7fc6a:6::/32fc6a:6:ffff:ffff:ffff:ffff:ffff:ffff
8fc6a:7::/32fc6a:7:ffff:ffff:ffff:ffff:ffff:ffff
9fc6a:8::/32fc6a:8:ffff:ffff:ffff:ffff:ffff:ffff
10fc6a:9::/32fc6a:9:ffff:ffff:ffff:ffff:ffff:ffff
11fc6a:a::/32fc6a:a:ffff:ffff:ffff:ffff:ffff:ffff
12fc6a:b::/32fc6a:b:ffff:ffff:ffff:ffff:ffff:ffff
13fc6a:c::/32fc6a:c:ffff:ffff:ffff:ffff:ffff:ffff
14fc6a:d::/32fc6a:d:ffff:ffff:ffff:ffff:ffff:ffff
15fc6a:e::/32fc6a:e:ffff:ffff:ffff:ffff:ffff:ffff
16fc6a:f::/32fc6a:f:ffff:ffff:ffff:ffff:ffff:ffff
17fc6a:10::/32fc6a:10:ffff:ffff:ffff:ffff:ffff:ffff
18fc6a:11::/32fc6a:11:ffff:ffff:ffff:ffff:ffff:ffff
19fc6a:12::/32fc6a:12:ffff:ffff:ffff:ffff:ffff:ffff
20fc6a:13::/32fc6a:13:ffff:ffff:ffff:ffff:ffff:ffff
21fc6a:14::/32fc6a:14:ffff:ffff:ffff:ffff:ffff:ffff
22fc6a:15::/32fc6a:15:ffff:ffff:ffff:ffff:ffff:ffff
23fc6a:16::/32fc6a:16:ffff:ffff:ffff:ffff:ffff:ffff
24fc6a:17::/32fc6a:17:ffff:ffff:ffff:ffff:ffff:ffff
25fc6a:18::/32fc6a:18:ffff:ffff:ffff:ffff:ffff:ffff
26fc6a:19::/32fc6a:19:ffff:ffff:ffff:ffff:ffff:ffff
27fc6a:1a::/32fc6a:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fc6a:1b::/32fc6a:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fc6a:1c::/32fc6a:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fc6a:1d::/32fc6a:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fc6a:1e::/32fc6a:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fc6a:1f::/32fc6a:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fc6a:20::/32fc6a:20:ffff:ffff:ffff:ffff:ffff:ffff
34fc6a:21::/32fc6a:21:ffff:ffff:ffff:ffff:ffff:ffff
35fc6a:22::/32fc6a:22:ffff:ffff:ffff:ffff:ffff:ffff
36fc6a:23::/32fc6a:23:ffff:ffff:ffff:ffff:ffff:ffff
37fc6a:24::/32fc6a:24:ffff:ffff:ffff:ffff:ffff:ffff
38fc6a:25::/32fc6a:25:ffff:ffff:ffff:ffff:ffff:ffff
39fc6a:26::/32fc6a:26:ffff:ffff:ffff:ffff:ffff:ffff
40fc6a:27::/32fc6a:27:ffff:ffff:ffff:ffff:ffff:ffff
41fc6a:28::/32fc6a:28:ffff:ffff:ffff:ffff:ffff:ffff
42fc6a:29::/32fc6a:29:ffff:ffff:ffff:ffff:ffff:ffff
43fc6a:2a::/32fc6a:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fc6a:2b::/32fc6a:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fc6a:2c::/32fc6a:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fc6a:2d::/32fc6a:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fc6a:2e::/32fc6a:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fc6a:2f::/32fc6a:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fc6a:30::/32fc6a:30:ffff:ffff:ffff:ffff:ffff:ffff
50fc6a:31::/32fc6a:31:ffff:ffff:ffff:ffff:ffff:ffff
51fc6a:32::/32fc6a:32:ffff:ffff:ffff:ffff:ffff:ffff
52fc6a:33::/32fc6a:33:ffff:ffff:ffff:ffff:ffff:ffff
53fc6a:34::/32fc6a:34:ffff:ffff:ffff:ffff:ffff:ffff
54fc6a:35::/32fc6a:35:ffff:ffff:ffff:ffff:ffff:ffff
55fc6a:36::/32fc6a:36:ffff:ffff:ffff:ffff:ffff:ffff
56fc6a:37::/32fc6a:37:ffff:ffff:ffff:ffff:ffff:ffff
57fc6a:38::/32fc6a:38:ffff:ffff:ffff:ffff:ffff:ffff
58fc6a:39::/32fc6a:39:ffff:ffff:ffff:ffff:ffff:ffff
59fc6a:3a::/32fc6a:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fc6a:3b::/32fc6a:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fc6a:3c::/32fc6a:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fc6a:3d::/32fc6a:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fc6a:3e::/32fc6a:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fc6a:3f::/32fc6a:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fc6a:40::/32fc6a:40:ffff:ffff:ffff:ffff:ffff:ffff
66fc6a:41::/32fc6a:41:ffff:ffff:ffff:ffff:ffff:ffff
67fc6a:42::/32fc6a:42:ffff:ffff:ffff:ffff:ffff:ffff
68fc6a:43::/32fc6a:43:ffff:ffff:ffff:ffff:ffff:ffff
69fc6a:44::/32fc6a:44:ffff:ffff:ffff:ffff:ffff:ffff
70fc6a:45::/32fc6a:45:ffff:ffff:ffff:ffff:ffff:ffff
71fc6a:46::/32fc6a:46:ffff:ffff:ffff:ffff:ffff:ffff
72fc6a:47::/32fc6a:47:ffff:ffff:ffff:ffff:ffff:ffff
73fc6a:48::/32fc6a:48:ffff:ffff:ffff:ffff:ffff:ffff
74fc6a:49::/32fc6a:49:ffff:ffff:ffff:ffff:ffff:ffff
75fc6a:4a::/32fc6a:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fc6a:4b::/32fc6a:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fc6a:4c::/32fc6a:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fc6a:4d::/32fc6a:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fc6a:4e::/32fc6a:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fc6a:4f::/32fc6a:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fc6a:50::/32fc6a:50:ffff:ffff:ffff:ffff:ffff:ffff
82fc6a:51::/32fc6a:51:ffff:ffff:ffff:ffff:ffff:ffff
83fc6a:52::/32fc6a:52:ffff:ffff:ffff:ffff:ffff:ffff
84fc6a:53::/32fc6a:53:ffff:ffff:ffff:ffff:ffff:ffff
85fc6a:54::/32fc6a:54:ffff:ffff:ffff:ffff:ffff:ffff
86fc6a:55::/32fc6a:55:ffff:ffff:ffff:ffff:ffff:ffff
87fc6a:56::/32fc6a:56:ffff:ffff:ffff:ffff:ffff:ffff
88fc6a:57::/32fc6a:57:ffff:ffff:ffff:ffff:ffff:ffff
89fc6a:58::/32fc6a:58:ffff:ffff:ffff:ffff:ffff:ffff
90fc6a:59::/32fc6a:59:ffff:ffff:ffff:ffff:ffff:ffff
91fc6a:5a::/32fc6a:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fc6a:5b::/32fc6a:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fc6a:5c::/32fc6a:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fc6a:5d::/32fc6a:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fc6a:5e::/32fc6a:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fc6a:5f::/32fc6a:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fc6a:60::/32fc6a:60:ffff:ffff:ffff:ffff:ffff:ffff
98fc6a:61::/32fc6a:61:ffff:ffff:ffff:ffff:ffff:ffff
99fc6a:62::/32fc6a:62:ffff:ffff:ffff:ffff:ffff:ffff
100fc6a:63::/32fc6a:63:ffff:ffff:ffff:ffff:ffff:ffff
101fc6a:64::/32fc6a:64:ffff:ffff:ffff:ffff:ffff:ffff
102fc6a:65::/32fc6a:65:ffff:ffff:ffff:ffff:ffff:ffff
103fc6a:66::/32fc6a:66:ffff:ffff:ffff:ffff:ffff:ffff
104fc6a:67::/32fc6a:67:ffff:ffff:ffff:ffff:ffff:ffff
105fc6a:68::/32fc6a:68:ffff:ffff:ffff:ffff:ffff:ffff
106fc6a:69::/32fc6a:69:ffff:ffff:ffff:ffff:ffff:ffff
107fc6a:6a::/32fc6a:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fc6a:6b::/32fc6a:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fc6a:6c::/32fc6a:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fc6a:6d::/32fc6a:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fc6a:6e::/32fc6a:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fc6a:6f::/32fc6a:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fc6a:70::/32fc6a:70:ffff:ffff:ffff:ffff:ffff:ffff
114fc6a:71::/32fc6a:71:ffff:ffff:ffff:ffff:ffff:ffff
115fc6a:72::/32fc6a:72:ffff:ffff:ffff:ffff:ffff:ffff
116fc6a:73::/32fc6a:73:ffff:ffff:ffff:ffff:ffff:ffff
117fc6a:74::/32fc6a:74:ffff:ffff:ffff:ffff:ffff:ffff
118fc6a:75::/32fc6a:75:ffff:ffff:ffff:ffff:ffff:ffff
119fc6a:76::/32fc6a:76:ffff:ffff:ffff:ffff:ffff:ffff
120fc6a:77::/32fc6a:77:ffff:ffff:ffff:ffff:ffff:ffff
121fc6a:78::/32fc6a:78:ffff:ffff:ffff:ffff:ffff:ffff
122fc6a:79::/32fc6a:79:ffff:ffff:ffff:ffff:ffff:ffff
123fc6a:7a::/32fc6a:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fc6a:7b::/32fc6a:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fc6a:7c::/32fc6a:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fc6a:7d::/32fc6a:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fc6a:7e::/32fc6a:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fc6a:7f::/32fc6a:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fc6a:80::/32fc6a:80:ffff:ffff:ffff:ffff:ffff:ffff
130fc6a:81::/32fc6a:81:ffff:ffff:ffff:ffff:ffff:ffff
131fc6a:82::/32fc6a:82:ffff:ffff:ffff:ffff:ffff:ffff
132fc6a:83::/32fc6a:83:ffff:ffff:ffff:ffff:ffff:ffff
133fc6a:84::/32fc6a:84:ffff:ffff:ffff:ffff:ffff:ffff
134fc6a:85::/32fc6a:85:ffff:ffff:ffff:ffff:ffff:ffff
135fc6a:86::/32fc6a:86:ffff:ffff:ffff:ffff:ffff:ffff
136fc6a:87::/32fc6a:87:ffff:ffff:ffff:ffff:ffff:ffff
137fc6a:88::/32fc6a:88:ffff:ffff:ffff:ffff:ffff:ffff
138fc6a:89::/32fc6a:89:ffff:ffff:ffff:ffff:ffff:ffff
139fc6a:8a::/32fc6a:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fc6a:8b::/32fc6a:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fc6a:8c::/32fc6a:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fc6a:8d::/32fc6a:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fc6a:8e::/32fc6a:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fc6a:8f::/32fc6a:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fc6a:90::/32fc6a:90:ffff:ffff:ffff:ffff:ffff:ffff
146fc6a:91::/32fc6a:91:ffff:ffff:ffff:ffff:ffff:ffff
147fc6a:92::/32fc6a:92:ffff:ffff:ffff:ffff:ffff:ffff
148fc6a:93::/32fc6a:93:ffff:ffff:ffff:ffff:ffff:ffff
149fc6a:94::/32fc6a:94:ffff:ffff:ffff:ffff:ffff:ffff
150fc6a:95::/32fc6a:95:ffff:ffff:ffff:ffff:ffff:ffff
151fc6a:96::/32fc6a:96:ffff:ffff:ffff:ffff:ffff:ffff
152fc6a:97::/32fc6a:97:ffff:ffff:ffff:ffff:ffff:ffff
153fc6a:98::/32fc6a:98:ffff:ffff:ffff:ffff:ffff:ffff
154fc6a:99::/32fc6a:99:ffff:ffff:ffff:ffff:ffff:ffff
155fc6a:9a::/32fc6a:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fc6a:9b::/32fc6a:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fc6a:9c::/32fc6a:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fc6a:9d::/32fc6a:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fc6a:9e::/32fc6a:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fc6a:9f::/32fc6a:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fc6a:a0::/32fc6a:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fc6a:a1::/32fc6a:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fc6a:a2::/32fc6a:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fc6a:a3::/32fc6a:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fc6a:a4::/32fc6a:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fc6a:a5::/32fc6a:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fc6a:a6::/32fc6a:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fc6a:a7::/32fc6a:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fc6a:a8::/32fc6a:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fc6a:a9::/32fc6a:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fc6a:aa::/32fc6a:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fc6a:ab::/32fc6a:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fc6a:ac::/32fc6a:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fc6a:ad::/32fc6a:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fc6a:ae::/32fc6a:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fc6a:af::/32fc6a:af:ffff:ffff:ffff:ffff:ffff:ffff
177fc6a:b0::/32fc6a:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fc6a:b1::/32fc6a:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fc6a:b2::/32fc6a:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fc6a:b3::/32fc6a:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fc6a:b4::/32fc6a:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fc6a:b5::/32fc6a:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fc6a:b6::/32fc6a:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fc6a:b7::/32fc6a:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fc6a:b8::/32fc6a:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fc6a:b9::/32fc6a:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fc6a:ba::/32fc6a:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fc6a:bb::/32fc6a:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fc6a:bc::/32fc6a:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fc6a:bd::/32fc6a:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fc6a:be::/32fc6a:be:ffff:ffff:ffff:ffff:ffff:ffff
192fc6a:bf::/32fc6a:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fc6a:c0::/32fc6a:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fc6a:c1::/32fc6a:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fc6a:c2::/32fc6a:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fc6a:c3::/32fc6a:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fc6a:c4::/32fc6a:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fc6a:c5::/32fc6a:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fc6a:c6::/32fc6a:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fc6a:c7::/32fc6a:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fc6a:c8::/32fc6a:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fc6a:c9::/32fc6a:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fc6a:ca::/32fc6a:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fc6a:cb::/32fc6a:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fc6a:cc::/32fc6a:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fc6a:cd::/32fc6a:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fc6a:ce::/32fc6a:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fc6a:cf::/32fc6a:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fc6a:d0::/32fc6a:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fc6a:d1::/32fc6a:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fc6a:d2::/32fc6a:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fc6a:d3::/32fc6a:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fc6a:d4::/32fc6a:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fc6a:d5::/32fc6a:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fc6a:d6::/32fc6a:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fc6a:d7::/32fc6a:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fc6a:d8::/32fc6a:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fc6a:d9::/32fc6a:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fc6a:da::/32fc6a:da:ffff:ffff:ffff:ffff:ffff:ffff
220fc6a:db::/32fc6a:db:ffff:ffff:ffff:ffff:ffff:ffff
221fc6a:dc::/32fc6a:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fc6a:dd::/32fc6a:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fc6a:de::/32fc6a:de:ffff:ffff:ffff:ffff:ffff:ffff
224fc6a:df::/32fc6a:df:ffff:ffff:ffff:ffff:ffff:ffff
225fc6a:e0::/32fc6a:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fc6a:e1::/32fc6a:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fc6a:e2::/32fc6a:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fc6a:e3::/32fc6a:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fc6a:e4::/32fc6a:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fc6a:e5::/32fc6a:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fc6a:e6::/32fc6a:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fc6a:e7::/32fc6a:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fc6a:e8::/32fc6a:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fc6a:e9::/32fc6a:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fc6a:ea::/32fc6a:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fc6a:eb::/32fc6a:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fc6a:ec::/32fc6a:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fc6a:ed::/32fc6a:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fc6a:ee::/32fc6a:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fc6a:ef::/32fc6a:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fc6a:f0::/32fc6a:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fc6a:f1::/32fc6a:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fc6a:f2::/32fc6a:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fc6a:f3::/32fc6a:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fc6a:f4::/32fc6a:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fc6a:f5::/32fc6a:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fc6a:f6::/32fc6a:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fc6a:f7::/32fc6a:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fc6a:f8::/32fc6a:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fc6a:f9::/32fc6a:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fc6a:fa::/32fc6a:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fc6a:fb::/32fc6a:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fc6a:fc::/32fc6a:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fc6a:fd::/32fc6a:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fc6a:fe::/32fc6a:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fc6a:ff::/32fc6a: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.