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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
fcb2::/16
First address
fcb2::
Last address
fcb2: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
fcb2:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
2.b.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)

fcb2::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fcb2::/32fcb2:0:ffff:ffff:ffff:ffff:ffff:ffff
2fcb2:1::/32fcb2:1:ffff:ffff:ffff:ffff:ffff:ffff
3fcb2:2::/32fcb2:2:ffff:ffff:ffff:ffff:ffff:ffff
4fcb2:3::/32fcb2:3:ffff:ffff:ffff:ffff:ffff:ffff
5fcb2:4::/32fcb2:4:ffff:ffff:ffff:ffff:ffff:ffff
6fcb2:5::/32fcb2:5:ffff:ffff:ffff:ffff:ffff:ffff
7fcb2:6::/32fcb2:6:ffff:ffff:ffff:ffff:ffff:ffff
8fcb2:7::/32fcb2:7:ffff:ffff:ffff:ffff:ffff:ffff
9fcb2:8::/32fcb2:8:ffff:ffff:ffff:ffff:ffff:ffff
10fcb2:9::/32fcb2:9:ffff:ffff:ffff:ffff:ffff:ffff
11fcb2:a::/32fcb2:a:ffff:ffff:ffff:ffff:ffff:ffff
12fcb2:b::/32fcb2:b:ffff:ffff:ffff:ffff:ffff:ffff
13fcb2:c::/32fcb2:c:ffff:ffff:ffff:ffff:ffff:ffff
14fcb2:d::/32fcb2:d:ffff:ffff:ffff:ffff:ffff:ffff
15fcb2:e::/32fcb2:e:ffff:ffff:ffff:ffff:ffff:ffff
16fcb2:f::/32fcb2:f:ffff:ffff:ffff:ffff:ffff:ffff
17fcb2:10::/32fcb2:10:ffff:ffff:ffff:ffff:ffff:ffff
18fcb2:11::/32fcb2:11:ffff:ffff:ffff:ffff:ffff:ffff
19fcb2:12::/32fcb2:12:ffff:ffff:ffff:ffff:ffff:ffff
20fcb2:13::/32fcb2:13:ffff:ffff:ffff:ffff:ffff:ffff
21fcb2:14::/32fcb2:14:ffff:ffff:ffff:ffff:ffff:ffff
22fcb2:15::/32fcb2:15:ffff:ffff:ffff:ffff:ffff:ffff
23fcb2:16::/32fcb2:16:ffff:ffff:ffff:ffff:ffff:ffff
24fcb2:17::/32fcb2:17:ffff:ffff:ffff:ffff:ffff:ffff
25fcb2:18::/32fcb2:18:ffff:ffff:ffff:ffff:ffff:ffff
26fcb2:19::/32fcb2:19:ffff:ffff:ffff:ffff:ffff:ffff
27fcb2:1a::/32fcb2:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fcb2:1b::/32fcb2:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fcb2:1c::/32fcb2:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fcb2:1d::/32fcb2:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fcb2:1e::/32fcb2:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fcb2:1f::/32fcb2:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fcb2:20::/32fcb2:20:ffff:ffff:ffff:ffff:ffff:ffff
34fcb2:21::/32fcb2:21:ffff:ffff:ffff:ffff:ffff:ffff
35fcb2:22::/32fcb2:22:ffff:ffff:ffff:ffff:ffff:ffff
36fcb2:23::/32fcb2:23:ffff:ffff:ffff:ffff:ffff:ffff
37fcb2:24::/32fcb2:24:ffff:ffff:ffff:ffff:ffff:ffff
38fcb2:25::/32fcb2:25:ffff:ffff:ffff:ffff:ffff:ffff
39fcb2:26::/32fcb2:26:ffff:ffff:ffff:ffff:ffff:ffff
40fcb2:27::/32fcb2:27:ffff:ffff:ffff:ffff:ffff:ffff
41fcb2:28::/32fcb2:28:ffff:ffff:ffff:ffff:ffff:ffff
42fcb2:29::/32fcb2:29:ffff:ffff:ffff:ffff:ffff:ffff
43fcb2:2a::/32fcb2:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fcb2:2b::/32fcb2:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fcb2:2c::/32fcb2:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fcb2:2d::/32fcb2:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fcb2:2e::/32fcb2:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fcb2:2f::/32fcb2:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fcb2:30::/32fcb2:30:ffff:ffff:ffff:ffff:ffff:ffff
50fcb2:31::/32fcb2:31:ffff:ffff:ffff:ffff:ffff:ffff
51fcb2:32::/32fcb2:32:ffff:ffff:ffff:ffff:ffff:ffff
52fcb2:33::/32fcb2:33:ffff:ffff:ffff:ffff:ffff:ffff
53fcb2:34::/32fcb2:34:ffff:ffff:ffff:ffff:ffff:ffff
54fcb2:35::/32fcb2:35:ffff:ffff:ffff:ffff:ffff:ffff
55fcb2:36::/32fcb2:36:ffff:ffff:ffff:ffff:ffff:ffff
56fcb2:37::/32fcb2:37:ffff:ffff:ffff:ffff:ffff:ffff
57fcb2:38::/32fcb2:38:ffff:ffff:ffff:ffff:ffff:ffff
58fcb2:39::/32fcb2:39:ffff:ffff:ffff:ffff:ffff:ffff
59fcb2:3a::/32fcb2:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fcb2:3b::/32fcb2:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fcb2:3c::/32fcb2:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fcb2:3d::/32fcb2:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fcb2:3e::/32fcb2:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fcb2:3f::/32fcb2:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fcb2:40::/32fcb2:40:ffff:ffff:ffff:ffff:ffff:ffff
66fcb2:41::/32fcb2:41:ffff:ffff:ffff:ffff:ffff:ffff
67fcb2:42::/32fcb2:42:ffff:ffff:ffff:ffff:ffff:ffff
68fcb2:43::/32fcb2:43:ffff:ffff:ffff:ffff:ffff:ffff
69fcb2:44::/32fcb2:44:ffff:ffff:ffff:ffff:ffff:ffff
70fcb2:45::/32fcb2:45:ffff:ffff:ffff:ffff:ffff:ffff
71fcb2:46::/32fcb2:46:ffff:ffff:ffff:ffff:ffff:ffff
72fcb2:47::/32fcb2:47:ffff:ffff:ffff:ffff:ffff:ffff
73fcb2:48::/32fcb2:48:ffff:ffff:ffff:ffff:ffff:ffff
74fcb2:49::/32fcb2:49:ffff:ffff:ffff:ffff:ffff:ffff
75fcb2:4a::/32fcb2:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fcb2:4b::/32fcb2:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fcb2:4c::/32fcb2:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fcb2:4d::/32fcb2:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fcb2:4e::/32fcb2:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fcb2:4f::/32fcb2:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fcb2:50::/32fcb2:50:ffff:ffff:ffff:ffff:ffff:ffff
82fcb2:51::/32fcb2:51:ffff:ffff:ffff:ffff:ffff:ffff
83fcb2:52::/32fcb2:52:ffff:ffff:ffff:ffff:ffff:ffff
84fcb2:53::/32fcb2:53:ffff:ffff:ffff:ffff:ffff:ffff
85fcb2:54::/32fcb2:54:ffff:ffff:ffff:ffff:ffff:ffff
86fcb2:55::/32fcb2:55:ffff:ffff:ffff:ffff:ffff:ffff
87fcb2:56::/32fcb2:56:ffff:ffff:ffff:ffff:ffff:ffff
88fcb2:57::/32fcb2:57:ffff:ffff:ffff:ffff:ffff:ffff
89fcb2:58::/32fcb2:58:ffff:ffff:ffff:ffff:ffff:ffff
90fcb2:59::/32fcb2:59:ffff:ffff:ffff:ffff:ffff:ffff
91fcb2:5a::/32fcb2:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fcb2:5b::/32fcb2:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fcb2:5c::/32fcb2:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fcb2:5d::/32fcb2:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fcb2:5e::/32fcb2:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fcb2:5f::/32fcb2:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fcb2:60::/32fcb2:60:ffff:ffff:ffff:ffff:ffff:ffff
98fcb2:61::/32fcb2:61:ffff:ffff:ffff:ffff:ffff:ffff
99fcb2:62::/32fcb2:62:ffff:ffff:ffff:ffff:ffff:ffff
100fcb2:63::/32fcb2:63:ffff:ffff:ffff:ffff:ffff:ffff
101fcb2:64::/32fcb2:64:ffff:ffff:ffff:ffff:ffff:ffff
102fcb2:65::/32fcb2:65:ffff:ffff:ffff:ffff:ffff:ffff
103fcb2:66::/32fcb2:66:ffff:ffff:ffff:ffff:ffff:ffff
104fcb2:67::/32fcb2:67:ffff:ffff:ffff:ffff:ffff:ffff
105fcb2:68::/32fcb2:68:ffff:ffff:ffff:ffff:ffff:ffff
106fcb2:69::/32fcb2:69:ffff:ffff:ffff:ffff:ffff:ffff
107fcb2:6a::/32fcb2:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fcb2:6b::/32fcb2:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fcb2:6c::/32fcb2:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fcb2:6d::/32fcb2:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fcb2:6e::/32fcb2:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fcb2:6f::/32fcb2:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fcb2:70::/32fcb2:70:ffff:ffff:ffff:ffff:ffff:ffff
114fcb2:71::/32fcb2:71:ffff:ffff:ffff:ffff:ffff:ffff
115fcb2:72::/32fcb2:72:ffff:ffff:ffff:ffff:ffff:ffff
116fcb2:73::/32fcb2:73:ffff:ffff:ffff:ffff:ffff:ffff
117fcb2:74::/32fcb2:74:ffff:ffff:ffff:ffff:ffff:ffff
118fcb2:75::/32fcb2:75:ffff:ffff:ffff:ffff:ffff:ffff
119fcb2:76::/32fcb2:76:ffff:ffff:ffff:ffff:ffff:ffff
120fcb2:77::/32fcb2:77:ffff:ffff:ffff:ffff:ffff:ffff
121fcb2:78::/32fcb2:78:ffff:ffff:ffff:ffff:ffff:ffff
122fcb2:79::/32fcb2:79:ffff:ffff:ffff:ffff:ffff:ffff
123fcb2:7a::/32fcb2:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fcb2:7b::/32fcb2:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fcb2:7c::/32fcb2:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fcb2:7d::/32fcb2:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fcb2:7e::/32fcb2:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fcb2:7f::/32fcb2:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fcb2:80::/32fcb2:80:ffff:ffff:ffff:ffff:ffff:ffff
130fcb2:81::/32fcb2:81:ffff:ffff:ffff:ffff:ffff:ffff
131fcb2:82::/32fcb2:82:ffff:ffff:ffff:ffff:ffff:ffff
132fcb2:83::/32fcb2:83:ffff:ffff:ffff:ffff:ffff:ffff
133fcb2:84::/32fcb2:84:ffff:ffff:ffff:ffff:ffff:ffff
134fcb2:85::/32fcb2:85:ffff:ffff:ffff:ffff:ffff:ffff
135fcb2:86::/32fcb2:86:ffff:ffff:ffff:ffff:ffff:ffff
136fcb2:87::/32fcb2:87:ffff:ffff:ffff:ffff:ffff:ffff
137fcb2:88::/32fcb2:88:ffff:ffff:ffff:ffff:ffff:ffff
138fcb2:89::/32fcb2:89:ffff:ffff:ffff:ffff:ffff:ffff
139fcb2:8a::/32fcb2:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fcb2:8b::/32fcb2:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fcb2:8c::/32fcb2:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fcb2:8d::/32fcb2:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fcb2:8e::/32fcb2:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fcb2:8f::/32fcb2:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fcb2:90::/32fcb2:90:ffff:ffff:ffff:ffff:ffff:ffff
146fcb2:91::/32fcb2:91:ffff:ffff:ffff:ffff:ffff:ffff
147fcb2:92::/32fcb2:92:ffff:ffff:ffff:ffff:ffff:ffff
148fcb2:93::/32fcb2:93:ffff:ffff:ffff:ffff:ffff:ffff
149fcb2:94::/32fcb2:94:ffff:ffff:ffff:ffff:ffff:ffff
150fcb2:95::/32fcb2:95:ffff:ffff:ffff:ffff:ffff:ffff
151fcb2:96::/32fcb2:96:ffff:ffff:ffff:ffff:ffff:ffff
152fcb2:97::/32fcb2:97:ffff:ffff:ffff:ffff:ffff:ffff
153fcb2:98::/32fcb2:98:ffff:ffff:ffff:ffff:ffff:ffff
154fcb2:99::/32fcb2:99:ffff:ffff:ffff:ffff:ffff:ffff
155fcb2:9a::/32fcb2:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fcb2:9b::/32fcb2:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fcb2:9c::/32fcb2:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fcb2:9d::/32fcb2:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fcb2:9e::/32fcb2:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fcb2:9f::/32fcb2:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fcb2:a0::/32fcb2:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fcb2:a1::/32fcb2:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fcb2:a2::/32fcb2:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fcb2:a3::/32fcb2:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fcb2:a4::/32fcb2:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fcb2:a5::/32fcb2:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fcb2:a6::/32fcb2:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fcb2:a7::/32fcb2:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fcb2:a8::/32fcb2:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fcb2:a9::/32fcb2:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fcb2:aa::/32fcb2:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fcb2:ab::/32fcb2:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fcb2:ac::/32fcb2:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fcb2:ad::/32fcb2:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fcb2:ae::/32fcb2:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fcb2:af::/32fcb2:af:ffff:ffff:ffff:ffff:ffff:ffff
177fcb2:b0::/32fcb2:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fcb2:b1::/32fcb2:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fcb2:b2::/32fcb2:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fcb2:b3::/32fcb2:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fcb2:b4::/32fcb2:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fcb2:b5::/32fcb2:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fcb2:b6::/32fcb2:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fcb2:b7::/32fcb2:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fcb2:b8::/32fcb2:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fcb2:b9::/32fcb2:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fcb2:ba::/32fcb2:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fcb2:bb::/32fcb2:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fcb2:bc::/32fcb2:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fcb2:bd::/32fcb2:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fcb2:be::/32fcb2:be:ffff:ffff:ffff:ffff:ffff:ffff
192fcb2:bf::/32fcb2:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fcb2:c0::/32fcb2:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fcb2:c1::/32fcb2:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fcb2:c2::/32fcb2:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fcb2:c3::/32fcb2:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fcb2:c4::/32fcb2:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fcb2:c5::/32fcb2:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fcb2:c6::/32fcb2:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fcb2:c7::/32fcb2:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fcb2:c8::/32fcb2:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fcb2:c9::/32fcb2:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fcb2:ca::/32fcb2:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fcb2:cb::/32fcb2:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fcb2:cc::/32fcb2:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fcb2:cd::/32fcb2:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fcb2:ce::/32fcb2:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fcb2:cf::/32fcb2:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fcb2:d0::/32fcb2:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fcb2:d1::/32fcb2:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fcb2:d2::/32fcb2:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fcb2:d3::/32fcb2:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fcb2:d4::/32fcb2:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fcb2:d5::/32fcb2:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fcb2:d6::/32fcb2:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fcb2:d7::/32fcb2:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fcb2:d8::/32fcb2:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fcb2:d9::/32fcb2:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fcb2:da::/32fcb2:da:ffff:ffff:ffff:ffff:ffff:ffff
220fcb2:db::/32fcb2:db:ffff:ffff:ffff:ffff:ffff:ffff
221fcb2:dc::/32fcb2:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fcb2:dd::/32fcb2:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fcb2:de::/32fcb2:de:ffff:ffff:ffff:ffff:ffff:ffff
224fcb2:df::/32fcb2:df:ffff:ffff:ffff:ffff:ffff:ffff
225fcb2:e0::/32fcb2:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fcb2:e1::/32fcb2:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fcb2:e2::/32fcb2:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fcb2:e3::/32fcb2:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fcb2:e4::/32fcb2:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fcb2:e5::/32fcb2:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fcb2:e6::/32fcb2:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fcb2:e7::/32fcb2:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fcb2:e8::/32fcb2:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fcb2:e9::/32fcb2:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fcb2:ea::/32fcb2:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fcb2:eb::/32fcb2:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fcb2:ec::/32fcb2:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fcb2:ed::/32fcb2:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fcb2:ee::/32fcb2:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fcb2:ef::/32fcb2:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fcb2:f0::/32fcb2:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fcb2:f1::/32fcb2:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fcb2:f2::/32fcb2:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fcb2:f3::/32fcb2:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fcb2:f4::/32fcb2:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fcb2:f5::/32fcb2:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fcb2:f6::/32fcb2:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fcb2:f7::/32fcb2:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fcb2:f8::/32fcb2:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fcb2:f9::/32fcb2:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fcb2:fa::/32fcb2:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fcb2:fb::/32fcb2:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fcb2:fc::/32fcb2:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fcb2:fd::/32fcb2:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fcb2:fe::/32fcb2:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fcb2:ff::/32fcb2: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.