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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
fc5a::/16
First address
fc5a::
Last address
fc5a: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
fc5a: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.5.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)

fc5a::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fc5a::/32fc5a:0:ffff:ffff:ffff:ffff:ffff:ffff
2fc5a:1::/32fc5a:1:ffff:ffff:ffff:ffff:ffff:ffff
3fc5a:2::/32fc5a:2:ffff:ffff:ffff:ffff:ffff:ffff
4fc5a:3::/32fc5a:3:ffff:ffff:ffff:ffff:ffff:ffff
5fc5a:4::/32fc5a:4:ffff:ffff:ffff:ffff:ffff:ffff
6fc5a:5::/32fc5a:5:ffff:ffff:ffff:ffff:ffff:ffff
7fc5a:6::/32fc5a:6:ffff:ffff:ffff:ffff:ffff:ffff
8fc5a:7::/32fc5a:7:ffff:ffff:ffff:ffff:ffff:ffff
9fc5a:8::/32fc5a:8:ffff:ffff:ffff:ffff:ffff:ffff
10fc5a:9::/32fc5a:9:ffff:ffff:ffff:ffff:ffff:ffff
11fc5a:a::/32fc5a:a:ffff:ffff:ffff:ffff:ffff:ffff
12fc5a:b::/32fc5a:b:ffff:ffff:ffff:ffff:ffff:ffff
13fc5a:c::/32fc5a:c:ffff:ffff:ffff:ffff:ffff:ffff
14fc5a:d::/32fc5a:d:ffff:ffff:ffff:ffff:ffff:ffff
15fc5a:e::/32fc5a:e:ffff:ffff:ffff:ffff:ffff:ffff
16fc5a:f::/32fc5a:f:ffff:ffff:ffff:ffff:ffff:ffff
17fc5a:10::/32fc5a:10:ffff:ffff:ffff:ffff:ffff:ffff
18fc5a:11::/32fc5a:11:ffff:ffff:ffff:ffff:ffff:ffff
19fc5a:12::/32fc5a:12:ffff:ffff:ffff:ffff:ffff:ffff
20fc5a:13::/32fc5a:13:ffff:ffff:ffff:ffff:ffff:ffff
21fc5a:14::/32fc5a:14:ffff:ffff:ffff:ffff:ffff:ffff
22fc5a:15::/32fc5a:15:ffff:ffff:ffff:ffff:ffff:ffff
23fc5a:16::/32fc5a:16:ffff:ffff:ffff:ffff:ffff:ffff
24fc5a:17::/32fc5a:17:ffff:ffff:ffff:ffff:ffff:ffff
25fc5a:18::/32fc5a:18:ffff:ffff:ffff:ffff:ffff:ffff
26fc5a:19::/32fc5a:19:ffff:ffff:ffff:ffff:ffff:ffff
27fc5a:1a::/32fc5a:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fc5a:1b::/32fc5a:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fc5a:1c::/32fc5a:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fc5a:1d::/32fc5a:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fc5a:1e::/32fc5a:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fc5a:1f::/32fc5a:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fc5a:20::/32fc5a:20:ffff:ffff:ffff:ffff:ffff:ffff
34fc5a:21::/32fc5a:21:ffff:ffff:ffff:ffff:ffff:ffff
35fc5a:22::/32fc5a:22:ffff:ffff:ffff:ffff:ffff:ffff
36fc5a:23::/32fc5a:23:ffff:ffff:ffff:ffff:ffff:ffff
37fc5a:24::/32fc5a:24:ffff:ffff:ffff:ffff:ffff:ffff
38fc5a:25::/32fc5a:25:ffff:ffff:ffff:ffff:ffff:ffff
39fc5a:26::/32fc5a:26:ffff:ffff:ffff:ffff:ffff:ffff
40fc5a:27::/32fc5a:27:ffff:ffff:ffff:ffff:ffff:ffff
41fc5a:28::/32fc5a:28:ffff:ffff:ffff:ffff:ffff:ffff
42fc5a:29::/32fc5a:29:ffff:ffff:ffff:ffff:ffff:ffff
43fc5a:2a::/32fc5a:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fc5a:2b::/32fc5a:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fc5a:2c::/32fc5a:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fc5a:2d::/32fc5a:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fc5a:2e::/32fc5a:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fc5a:2f::/32fc5a:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fc5a:30::/32fc5a:30:ffff:ffff:ffff:ffff:ffff:ffff
50fc5a:31::/32fc5a:31:ffff:ffff:ffff:ffff:ffff:ffff
51fc5a:32::/32fc5a:32:ffff:ffff:ffff:ffff:ffff:ffff
52fc5a:33::/32fc5a:33:ffff:ffff:ffff:ffff:ffff:ffff
53fc5a:34::/32fc5a:34:ffff:ffff:ffff:ffff:ffff:ffff
54fc5a:35::/32fc5a:35:ffff:ffff:ffff:ffff:ffff:ffff
55fc5a:36::/32fc5a:36:ffff:ffff:ffff:ffff:ffff:ffff
56fc5a:37::/32fc5a:37:ffff:ffff:ffff:ffff:ffff:ffff
57fc5a:38::/32fc5a:38:ffff:ffff:ffff:ffff:ffff:ffff
58fc5a:39::/32fc5a:39:ffff:ffff:ffff:ffff:ffff:ffff
59fc5a:3a::/32fc5a:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fc5a:3b::/32fc5a:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fc5a:3c::/32fc5a:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fc5a:3d::/32fc5a:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fc5a:3e::/32fc5a:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fc5a:3f::/32fc5a:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fc5a:40::/32fc5a:40:ffff:ffff:ffff:ffff:ffff:ffff
66fc5a:41::/32fc5a:41:ffff:ffff:ffff:ffff:ffff:ffff
67fc5a:42::/32fc5a:42:ffff:ffff:ffff:ffff:ffff:ffff
68fc5a:43::/32fc5a:43:ffff:ffff:ffff:ffff:ffff:ffff
69fc5a:44::/32fc5a:44:ffff:ffff:ffff:ffff:ffff:ffff
70fc5a:45::/32fc5a:45:ffff:ffff:ffff:ffff:ffff:ffff
71fc5a:46::/32fc5a:46:ffff:ffff:ffff:ffff:ffff:ffff
72fc5a:47::/32fc5a:47:ffff:ffff:ffff:ffff:ffff:ffff
73fc5a:48::/32fc5a:48:ffff:ffff:ffff:ffff:ffff:ffff
74fc5a:49::/32fc5a:49:ffff:ffff:ffff:ffff:ffff:ffff
75fc5a:4a::/32fc5a:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fc5a:4b::/32fc5a:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fc5a:4c::/32fc5a:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fc5a:4d::/32fc5a:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fc5a:4e::/32fc5a:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fc5a:4f::/32fc5a:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fc5a:50::/32fc5a:50:ffff:ffff:ffff:ffff:ffff:ffff
82fc5a:51::/32fc5a:51:ffff:ffff:ffff:ffff:ffff:ffff
83fc5a:52::/32fc5a:52:ffff:ffff:ffff:ffff:ffff:ffff
84fc5a:53::/32fc5a:53:ffff:ffff:ffff:ffff:ffff:ffff
85fc5a:54::/32fc5a:54:ffff:ffff:ffff:ffff:ffff:ffff
86fc5a:55::/32fc5a:55:ffff:ffff:ffff:ffff:ffff:ffff
87fc5a:56::/32fc5a:56:ffff:ffff:ffff:ffff:ffff:ffff
88fc5a:57::/32fc5a:57:ffff:ffff:ffff:ffff:ffff:ffff
89fc5a:58::/32fc5a:58:ffff:ffff:ffff:ffff:ffff:ffff
90fc5a:59::/32fc5a:59:ffff:ffff:ffff:ffff:ffff:ffff
91fc5a:5a::/32fc5a:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fc5a:5b::/32fc5a:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fc5a:5c::/32fc5a:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fc5a:5d::/32fc5a:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fc5a:5e::/32fc5a:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fc5a:5f::/32fc5a:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fc5a:60::/32fc5a:60:ffff:ffff:ffff:ffff:ffff:ffff
98fc5a:61::/32fc5a:61:ffff:ffff:ffff:ffff:ffff:ffff
99fc5a:62::/32fc5a:62:ffff:ffff:ffff:ffff:ffff:ffff
100fc5a:63::/32fc5a:63:ffff:ffff:ffff:ffff:ffff:ffff
101fc5a:64::/32fc5a:64:ffff:ffff:ffff:ffff:ffff:ffff
102fc5a:65::/32fc5a:65:ffff:ffff:ffff:ffff:ffff:ffff
103fc5a:66::/32fc5a:66:ffff:ffff:ffff:ffff:ffff:ffff
104fc5a:67::/32fc5a:67:ffff:ffff:ffff:ffff:ffff:ffff
105fc5a:68::/32fc5a:68:ffff:ffff:ffff:ffff:ffff:ffff
106fc5a:69::/32fc5a:69:ffff:ffff:ffff:ffff:ffff:ffff
107fc5a:6a::/32fc5a:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fc5a:6b::/32fc5a:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fc5a:6c::/32fc5a:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fc5a:6d::/32fc5a:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fc5a:6e::/32fc5a:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fc5a:6f::/32fc5a:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fc5a:70::/32fc5a:70:ffff:ffff:ffff:ffff:ffff:ffff
114fc5a:71::/32fc5a:71:ffff:ffff:ffff:ffff:ffff:ffff
115fc5a:72::/32fc5a:72:ffff:ffff:ffff:ffff:ffff:ffff
116fc5a:73::/32fc5a:73:ffff:ffff:ffff:ffff:ffff:ffff
117fc5a:74::/32fc5a:74:ffff:ffff:ffff:ffff:ffff:ffff
118fc5a:75::/32fc5a:75:ffff:ffff:ffff:ffff:ffff:ffff
119fc5a:76::/32fc5a:76:ffff:ffff:ffff:ffff:ffff:ffff
120fc5a:77::/32fc5a:77:ffff:ffff:ffff:ffff:ffff:ffff
121fc5a:78::/32fc5a:78:ffff:ffff:ffff:ffff:ffff:ffff
122fc5a:79::/32fc5a:79:ffff:ffff:ffff:ffff:ffff:ffff
123fc5a:7a::/32fc5a:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fc5a:7b::/32fc5a:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fc5a:7c::/32fc5a:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fc5a:7d::/32fc5a:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fc5a:7e::/32fc5a:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fc5a:7f::/32fc5a:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fc5a:80::/32fc5a:80:ffff:ffff:ffff:ffff:ffff:ffff
130fc5a:81::/32fc5a:81:ffff:ffff:ffff:ffff:ffff:ffff
131fc5a:82::/32fc5a:82:ffff:ffff:ffff:ffff:ffff:ffff
132fc5a:83::/32fc5a:83:ffff:ffff:ffff:ffff:ffff:ffff
133fc5a:84::/32fc5a:84:ffff:ffff:ffff:ffff:ffff:ffff
134fc5a:85::/32fc5a:85:ffff:ffff:ffff:ffff:ffff:ffff
135fc5a:86::/32fc5a:86:ffff:ffff:ffff:ffff:ffff:ffff
136fc5a:87::/32fc5a:87:ffff:ffff:ffff:ffff:ffff:ffff
137fc5a:88::/32fc5a:88:ffff:ffff:ffff:ffff:ffff:ffff
138fc5a:89::/32fc5a:89:ffff:ffff:ffff:ffff:ffff:ffff
139fc5a:8a::/32fc5a:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fc5a:8b::/32fc5a:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fc5a:8c::/32fc5a:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fc5a:8d::/32fc5a:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fc5a:8e::/32fc5a:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fc5a:8f::/32fc5a:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fc5a:90::/32fc5a:90:ffff:ffff:ffff:ffff:ffff:ffff
146fc5a:91::/32fc5a:91:ffff:ffff:ffff:ffff:ffff:ffff
147fc5a:92::/32fc5a:92:ffff:ffff:ffff:ffff:ffff:ffff
148fc5a:93::/32fc5a:93:ffff:ffff:ffff:ffff:ffff:ffff
149fc5a:94::/32fc5a:94:ffff:ffff:ffff:ffff:ffff:ffff
150fc5a:95::/32fc5a:95:ffff:ffff:ffff:ffff:ffff:ffff
151fc5a:96::/32fc5a:96:ffff:ffff:ffff:ffff:ffff:ffff
152fc5a:97::/32fc5a:97:ffff:ffff:ffff:ffff:ffff:ffff
153fc5a:98::/32fc5a:98:ffff:ffff:ffff:ffff:ffff:ffff
154fc5a:99::/32fc5a:99:ffff:ffff:ffff:ffff:ffff:ffff
155fc5a:9a::/32fc5a:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fc5a:9b::/32fc5a:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fc5a:9c::/32fc5a:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fc5a:9d::/32fc5a:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fc5a:9e::/32fc5a:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fc5a:9f::/32fc5a:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fc5a:a0::/32fc5a:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fc5a:a1::/32fc5a:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fc5a:a2::/32fc5a:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fc5a:a3::/32fc5a:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fc5a:a4::/32fc5a:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fc5a:a5::/32fc5a:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fc5a:a6::/32fc5a:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fc5a:a7::/32fc5a:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fc5a:a8::/32fc5a:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fc5a:a9::/32fc5a:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fc5a:aa::/32fc5a:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fc5a:ab::/32fc5a:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fc5a:ac::/32fc5a:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fc5a:ad::/32fc5a:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fc5a:ae::/32fc5a:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fc5a:af::/32fc5a:af:ffff:ffff:ffff:ffff:ffff:ffff
177fc5a:b0::/32fc5a:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fc5a:b1::/32fc5a:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fc5a:b2::/32fc5a:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fc5a:b3::/32fc5a:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fc5a:b4::/32fc5a:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fc5a:b5::/32fc5a:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fc5a:b6::/32fc5a:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fc5a:b7::/32fc5a:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fc5a:b8::/32fc5a:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fc5a:b9::/32fc5a:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fc5a:ba::/32fc5a:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fc5a:bb::/32fc5a:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fc5a:bc::/32fc5a:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fc5a:bd::/32fc5a:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fc5a:be::/32fc5a:be:ffff:ffff:ffff:ffff:ffff:ffff
192fc5a:bf::/32fc5a:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fc5a:c0::/32fc5a:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fc5a:c1::/32fc5a:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fc5a:c2::/32fc5a:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fc5a:c3::/32fc5a:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fc5a:c4::/32fc5a:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fc5a:c5::/32fc5a:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fc5a:c6::/32fc5a:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fc5a:c7::/32fc5a:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fc5a:c8::/32fc5a:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fc5a:c9::/32fc5a:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fc5a:ca::/32fc5a:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fc5a:cb::/32fc5a:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fc5a:cc::/32fc5a:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fc5a:cd::/32fc5a:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fc5a:ce::/32fc5a:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fc5a:cf::/32fc5a:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fc5a:d0::/32fc5a:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fc5a:d1::/32fc5a:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fc5a:d2::/32fc5a:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fc5a:d3::/32fc5a:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fc5a:d4::/32fc5a:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fc5a:d5::/32fc5a:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fc5a:d6::/32fc5a:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fc5a:d7::/32fc5a:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fc5a:d8::/32fc5a:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fc5a:d9::/32fc5a:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fc5a:da::/32fc5a:da:ffff:ffff:ffff:ffff:ffff:ffff
220fc5a:db::/32fc5a:db:ffff:ffff:ffff:ffff:ffff:ffff
221fc5a:dc::/32fc5a:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fc5a:dd::/32fc5a:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fc5a:de::/32fc5a:de:ffff:ffff:ffff:ffff:ffff:ffff
224fc5a:df::/32fc5a:df:ffff:ffff:ffff:ffff:ffff:ffff
225fc5a:e0::/32fc5a:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fc5a:e1::/32fc5a:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fc5a:e2::/32fc5a:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fc5a:e3::/32fc5a:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fc5a:e4::/32fc5a:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fc5a:e5::/32fc5a:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fc5a:e6::/32fc5a:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fc5a:e7::/32fc5a:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fc5a:e8::/32fc5a:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fc5a:e9::/32fc5a:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fc5a:ea::/32fc5a:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fc5a:eb::/32fc5a:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fc5a:ec::/32fc5a:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fc5a:ed::/32fc5a:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fc5a:ee::/32fc5a:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fc5a:ef::/32fc5a:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fc5a:f0::/32fc5a:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fc5a:f1::/32fc5a:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fc5a:f2::/32fc5a:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fc5a:f3::/32fc5a:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fc5a:f4::/32fc5a:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fc5a:f5::/32fc5a:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fc5a:f6::/32fc5a:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fc5a:f7::/32fc5a:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fc5a:f8::/32fc5a:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fc5a:f9::/32fc5a:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fc5a:fa::/32fc5a:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fc5a:fb::/32fc5a:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fc5a:fc::/32fc5a:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fc5a:fd::/32fc5a:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fc5a:fe::/32fc5a:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fc5a:ff::/32fc5a: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.