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

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

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