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Speed and call quality testTest delay, jitter and speed, with a focus on phone calls.My IP addressYour public IPv4 and IPv6 addresses, provider and address range.WhoIs lookupWho owns a domain or IP address, when it expires, and its DNS.DNS reportEvery DNS record for a domain, with email setup checked.IP subnet calculatorWork out a network's range, mask and hosts, and split it into subnets.

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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
fc32::/16
First address
fc32::
Last address
fc32: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
fc32:0000:0000:0000:0000:0000:0000:0000
Type
Unique local (ULA) fc00::/7
Private IPv6, like RFC 1918; usually fd00::/8
Reverse DNS zone
2.3.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)

fc32::/16 makes 65,536 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1fc32::/32fc32:0:ffff:ffff:ffff:ffff:ffff:ffff
2fc32:1::/32fc32:1:ffff:ffff:ffff:ffff:ffff:ffff
3fc32:2::/32fc32:2:ffff:ffff:ffff:ffff:ffff:ffff
4fc32:3::/32fc32:3:ffff:ffff:ffff:ffff:ffff:ffff
5fc32:4::/32fc32:4:ffff:ffff:ffff:ffff:ffff:ffff
6fc32:5::/32fc32:5:ffff:ffff:ffff:ffff:ffff:ffff
7fc32:6::/32fc32:6:ffff:ffff:ffff:ffff:ffff:ffff
8fc32:7::/32fc32:7:ffff:ffff:ffff:ffff:ffff:ffff
9fc32:8::/32fc32:8:ffff:ffff:ffff:ffff:ffff:ffff
10fc32:9::/32fc32:9:ffff:ffff:ffff:ffff:ffff:ffff
11fc32:a::/32fc32:a:ffff:ffff:ffff:ffff:ffff:ffff
12fc32:b::/32fc32:b:ffff:ffff:ffff:ffff:ffff:ffff
13fc32:c::/32fc32:c:ffff:ffff:ffff:ffff:ffff:ffff
14fc32:d::/32fc32:d:ffff:ffff:ffff:ffff:ffff:ffff
15fc32:e::/32fc32:e:ffff:ffff:ffff:ffff:ffff:ffff
16fc32:f::/32fc32:f:ffff:ffff:ffff:ffff:ffff:ffff
17fc32:10::/32fc32:10:ffff:ffff:ffff:ffff:ffff:ffff
18fc32:11::/32fc32:11:ffff:ffff:ffff:ffff:ffff:ffff
19fc32:12::/32fc32:12:ffff:ffff:ffff:ffff:ffff:ffff
20fc32:13::/32fc32:13:ffff:ffff:ffff:ffff:ffff:ffff
21fc32:14::/32fc32:14:ffff:ffff:ffff:ffff:ffff:ffff
22fc32:15::/32fc32:15:ffff:ffff:ffff:ffff:ffff:ffff
23fc32:16::/32fc32:16:ffff:ffff:ffff:ffff:ffff:ffff
24fc32:17::/32fc32:17:ffff:ffff:ffff:ffff:ffff:ffff
25fc32:18::/32fc32:18:ffff:ffff:ffff:ffff:ffff:ffff
26fc32:19::/32fc32:19:ffff:ffff:ffff:ffff:ffff:ffff
27fc32:1a::/32fc32:1a:ffff:ffff:ffff:ffff:ffff:ffff
28fc32:1b::/32fc32:1b:ffff:ffff:ffff:ffff:ffff:ffff
29fc32:1c::/32fc32:1c:ffff:ffff:ffff:ffff:ffff:ffff
30fc32:1d::/32fc32:1d:ffff:ffff:ffff:ffff:ffff:ffff
31fc32:1e::/32fc32:1e:ffff:ffff:ffff:ffff:ffff:ffff
32fc32:1f::/32fc32:1f:ffff:ffff:ffff:ffff:ffff:ffff
33fc32:20::/32fc32:20:ffff:ffff:ffff:ffff:ffff:ffff
34fc32:21::/32fc32:21:ffff:ffff:ffff:ffff:ffff:ffff
35fc32:22::/32fc32:22:ffff:ffff:ffff:ffff:ffff:ffff
36fc32:23::/32fc32:23:ffff:ffff:ffff:ffff:ffff:ffff
37fc32:24::/32fc32:24:ffff:ffff:ffff:ffff:ffff:ffff
38fc32:25::/32fc32:25:ffff:ffff:ffff:ffff:ffff:ffff
39fc32:26::/32fc32:26:ffff:ffff:ffff:ffff:ffff:ffff
40fc32:27::/32fc32:27:ffff:ffff:ffff:ffff:ffff:ffff
41fc32:28::/32fc32:28:ffff:ffff:ffff:ffff:ffff:ffff
42fc32:29::/32fc32:29:ffff:ffff:ffff:ffff:ffff:ffff
43fc32:2a::/32fc32:2a:ffff:ffff:ffff:ffff:ffff:ffff
44fc32:2b::/32fc32:2b:ffff:ffff:ffff:ffff:ffff:ffff
45fc32:2c::/32fc32:2c:ffff:ffff:ffff:ffff:ffff:ffff
46fc32:2d::/32fc32:2d:ffff:ffff:ffff:ffff:ffff:ffff
47fc32:2e::/32fc32:2e:ffff:ffff:ffff:ffff:ffff:ffff
48fc32:2f::/32fc32:2f:ffff:ffff:ffff:ffff:ffff:ffff
49fc32:30::/32fc32:30:ffff:ffff:ffff:ffff:ffff:ffff
50fc32:31::/32fc32:31:ffff:ffff:ffff:ffff:ffff:ffff
51fc32:32::/32fc32:32:ffff:ffff:ffff:ffff:ffff:ffff
52fc32:33::/32fc32:33:ffff:ffff:ffff:ffff:ffff:ffff
53fc32:34::/32fc32:34:ffff:ffff:ffff:ffff:ffff:ffff
54fc32:35::/32fc32:35:ffff:ffff:ffff:ffff:ffff:ffff
55fc32:36::/32fc32:36:ffff:ffff:ffff:ffff:ffff:ffff
56fc32:37::/32fc32:37:ffff:ffff:ffff:ffff:ffff:ffff
57fc32:38::/32fc32:38:ffff:ffff:ffff:ffff:ffff:ffff
58fc32:39::/32fc32:39:ffff:ffff:ffff:ffff:ffff:ffff
59fc32:3a::/32fc32:3a:ffff:ffff:ffff:ffff:ffff:ffff
60fc32:3b::/32fc32:3b:ffff:ffff:ffff:ffff:ffff:ffff
61fc32:3c::/32fc32:3c:ffff:ffff:ffff:ffff:ffff:ffff
62fc32:3d::/32fc32:3d:ffff:ffff:ffff:ffff:ffff:ffff
63fc32:3e::/32fc32:3e:ffff:ffff:ffff:ffff:ffff:ffff
64fc32:3f::/32fc32:3f:ffff:ffff:ffff:ffff:ffff:ffff
65fc32:40::/32fc32:40:ffff:ffff:ffff:ffff:ffff:ffff
66fc32:41::/32fc32:41:ffff:ffff:ffff:ffff:ffff:ffff
67fc32:42::/32fc32:42:ffff:ffff:ffff:ffff:ffff:ffff
68fc32:43::/32fc32:43:ffff:ffff:ffff:ffff:ffff:ffff
69fc32:44::/32fc32:44:ffff:ffff:ffff:ffff:ffff:ffff
70fc32:45::/32fc32:45:ffff:ffff:ffff:ffff:ffff:ffff
71fc32:46::/32fc32:46:ffff:ffff:ffff:ffff:ffff:ffff
72fc32:47::/32fc32:47:ffff:ffff:ffff:ffff:ffff:ffff
73fc32:48::/32fc32:48:ffff:ffff:ffff:ffff:ffff:ffff
74fc32:49::/32fc32:49:ffff:ffff:ffff:ffff:ffff:ffff
75fc32:4a::/32fc32:4a:ffff:ffff:ffff:ffff:ffff:ffff
76fc32:4b::/32fc32:4b:ffff:ffff:ffff:ffff:ffff:ffff
77fc32:4c::/32fc32:4c:ffff:ffff:ffff:ffff:ffff:ffff
78fc32:4d::/32fc32:4d:ffff:ffff:ffff:ffff:ffff:ffff
79fc32:4e::/32fc32:4e:ffff:ffff:ffff:ffff:ffff:ffff
80fc32:4f::/32fc32:4f:ffff:ffff:ffff:ffff:ffff:ffff
81fc32:50::/32fc32:50:ffff:ffff:ffff:ffff:ffff:ffff
82fc32:51::/32fc32:51:ffff:ffff:ffff:ffff:ffff:ffff
83fc32:52::/32fc32:52:ffff:ffff:ffff:ffff:ffff:ffff
84fc32:53::/32fc32:53:ffff:ffff:ffff:ffff:ffff:ffff
85fc32:54::/32fc32:54:ffff:ffff:ffff:ffff:ffff:ffff
86fc32:55::/32fc32:55:ffff:ffff:ffff:ffff:ffff:ffff
87fc32:56::/32fc32:56:ffff:ffff:ffff:ffff:ffff:ffff
88fc32:57::/32fc32:57:ffff:ffff:ffff:ffff:ffff:ffff
89fc32:58::/32fc32:58:ffff:ffff:ffff:ffff:ffff:ffff
90fc32:59::/32fc32:59:ffff:ffff:ffff:ffff:ffff:ffff
91fc32:5a::/32fc32:5a:ffff:ffff:ffff:ffff:ffff:ffff
92fc32:5b::/32fc32:5b:ffff:ffff:ffff:ffff:ffff:ffff
93fc32:5c::/32fc32:5c:ffff:ffff:ffff:ffff:ffff:ffff
94fc32:5d::/32fc32:5d:ffff:ffff:ffff:ffff:ffff:ffff
95fc32:5e::/32fc32:5e:ffff:ffff:ffff:ffff:ffff:ffff
96fc32:5f::/32fc32:5f:ffff:ffff:ffff:ffff:ffff:ffff
97fc32:60::/32fc32:60:ffff:ffff:ffff:ffff:ffff:ffff
98fc32:61::/32fc32:61:ffff:ffff:ffff:ffff:ffff:ffff
99fc32:62::/32fc32:62:ffff:ffff:ffff:ffff:ffff:ffff
100fc32:63::/32fc32:63:ffff:ffff:ffff:ffff:ffff:ffff
101fc32:64::/32fc32:64:ffff:ffff:ffff:ffff:ffff:ffff
102fc32:65::/32fc32:65:ffff:ffff:ffff:ffff:ffff:ffff
103fc32:66::/32fc32:66:ffff:ffff:ffff:ffff:ffff:ffff
104fc32:67::/32fc32:67:ffff:ffff:ffff:ffff:ffff:ffff
105fc32:68::/32fc32:68:ffff:ffff:ffff:ffff:ffff:ffff
106fc32:69::/32fc32:69:ffff:ffff:ffff:ffff:ffff:ffff
107fc32:6a::/32fc32:6a:ffff:ffff:ffff:ffff:ffff:ffff
108fc32:6b::/32fc32:6b:ffff:ffff:ffff:ffff:ffff:ffff
109fc32:6c::/32fc32:6c:ffff:ffff:ffff:ffff:ffff:ffff
110fc32:6d::/32fc32:6d:ffff:ffff:ffff:ffff:ffff:ffff
111fc32:6e::/32fc32:6e:ffff:ffff:ffff:ffff:ffff:ffff
112fc32:6f::/32fc32:6f:ffff:ffff:ffff:ffff:ffff:ffff
113fc32:70::/32fc32:70:ffff:ffff:ffff:ffff:ffff:ffff
114fc32:71::/32fc32:71:ffff:ffff:ffff:ffff:ffff:ffff
115fc32:72::/32fc32:72:ffff:ffff:ffff:ffff:ffff:ffff
116fc32:73::/32fc32:73:ffff:ffff:ffff:ffff:ffff:ffff
117fc32:74::/32fc32:74:ffff:ffff:ffff:ffff:ffff:ffff
118fc32:75::/32fc32:75:ffff:ffff:ffff:ffff:ffff:ffff
119fc32:76::/32fc32:76:ffff:ffff:ffff:ffff:ffff:ffff
120fc32:77::/32fc32:77:ffff:ffff:ffff:ffff:ffff:ffff
121fc32:78::/32fc32:78:ffff:ffff:ffff:ffff:ffff:ffff
122fc32:79::/32fc32:79:ffff:ffff:ffff:ffff:ffff:ffff
123fc32:7a::/32fc32:7a:ffff:ffff:ffff:ffff:ffff:ffff
124fc32:7b::/32fc32:7b:ffff:ffff:ffff:ffff:ffff:ffff
125fc32:7c::/32fc32:7c:ffff:ffff:ffff:ffff:ffff:ffff
126fc32:7d::/32fc32:7d:ffff:ffff:ffff:ffff:ffff:ffff
127fc32:7e::/32fc32:7e:ffff:ffff:ffff:ffff:ffff:ffff
128fc32:7f::/32fc32:7f:ffff:ffff:ffff:ffff:ffff:ffff
129fc32:80::/32fc32:80:ffff:ffff:ffff:ffff:ffff:ffff
130fc32:81::/32fc32:81:ffff:ffff:ffff:ffff:ffff:ffff
131fc32:82::/32fc32:82:ffff:ffff:ffff:ffff:ffff:ffff
132fc32:83::/32fc32:83:ffff:ffff:ffff:ffff:ffff:ffff
133fc32:84::/32fc32:84:ffff:ffff:ffff:ffff:ffff:ffff
134fc32:85::/32fc32:85:ffff:ffff:ffff:ffff:ffff:ffff
135fc32:86::/32fc32:86:ffff:ffff:ffff:ffff:ffff:ffff
136fc32:87::/32fc32:87:ffff:ffff:ffff:ffff:ffff:ffff
137fc32:88::/32fc32:88:ffff:ffff:ffff:ffff:ffff:ffff
138fc32:89::/32fc32:89:ffff:ffff:ffff:ffff:ffff:ffff
139fc32:8a::/32fc32:8a:ffff:ffff:ffff:ffff:ffff:ffff
140fc32:8b::/32fc32:8b:ffff:ffff:ffff:ffff:ffff:ffff
141fc32:8c::/32fc32:8c:ffff:ffff:ffff:ffff:ffff:ffff
142fc32:8d::/32fc32:8d:ffff:ffff:ffff:ffff:ffff:ffff
143fc32:8e::/32fc32:8e:ffff:ffff:ffff:ffff:ffff:ffff
144fc32:8f::/32fc32:8f:ffff:ffff:ffff:ffff:ffff:ffff
145fc32:90::/32fc32:90:ffff:ffff:ffff:ffff:ffff:ffff
146fc32:91::/32fc32:91:ffff:ffff:ffff:ffff:ffff:ffff
147fc32:92::/32fc32:92:ffff:ffff:ffff:ffff:ffff:ffff
148fc32:93::/32fc32:93:ffff:ffff:ffff:ffff:ffff:ffff
149fc32:94::/32fc32:94:ffff:ffff:ffff:ffff:ffff:ffff
150fc32:95::/32fc32:95:ffff:ffff:ffff:ffff:ffff:ffff
151fc32:96::/32fc32:96:ffff:ffff:ffff:ffff:ffff:ffff
152fc32:97::/32fc32:97:ffff:ffff:ffff:ffff:ffff:ffff
153fc32:98::/32fc32:98:ffff:ffff:ffff:ffff:ffff:ffff
154fc32:99::/32fc32:99:ffff:ffff:ffff:ffff:ffff:ffff
155fc32:9a::/32fc32:9a:ffff:ffff:ffff:ffff:ffff:ffff
156fc32:9b::/32fc32:9b:ffff:ffff:ffff:ffff:ffff:ffff
157fc32:9c::/32fc32:9c:ffff:ffff:ffff:ffff:ffff:ffff
158fc32:9d::/32fc32:9d:ffff:ffff:ffff:ffff:ffff:ffff
159fc32:9e::/32fc32:9e:ffff:ffff:ffff:ffff:ffff:ffff
160fc32:9f::/32fc32:9f:ffff:ffff:ffff:ffff:ffff:ffff
161fc32:a0::/32fc32:a0:ffff:ffff:ffff:ffff:ffff:ffff
162fc32:a1::/32fc32:a1:ffff:ffff:ffff:ffff:ffff:ffff
163fc32:a2::/32fc32:a2:ffff:ffff:ffff:ffff:ffff:ffff
164fc32:a3::/32fc32:a3:ffff:ffff:ffff:ffff:ffff:ffff
165fc32:a4::/32fc32:a4:ffff:ffff:ffff:ffff:ffff:ffff
166fc32:a5::/32fc32:a5:ffff:ffff:ffff:ffff:ffff:ffff
167fc32:a6::/32fc32:a6:ffff:ffff:ffff:ffff:ffff:ffff
168fc32:a7::/32fc32:a7:ffff:ffff:ffff:ffff:ffff:ffff
169fc32:a8::/32fc32:a8:ffff:ffff:ffff:ffff:ffff:ffff
170fc32:a9::/32fc32:a9:ffff:ffff:ffff:ffff:ffff:ffff
171fc32:aa::/32fc32:aa:ffff:ffff:ffff:ffff:ffff:ffff
172fc32:ab::/32fc32:ab:ffff:ffff:ffff:ffff:ffff:ffff
173fc32:ac::/32fc32:ac:ffff:ffff:ffff:ffff:ffff:ffff
174fc32:ad::/32fc32:ad:ffff:ffff:ffff:ffff:ffff:ffff
175fc32:ae::/32fc32:ae:ffff:ffff:ffff:ffff:ffff:ffff
176fc32:af::/32fc32:af:ffff:ffff:ffff:ffff:ffff:ffff
177fc32:b0::/32fc32:b0:ffff:ffff:ffff:ffff:ffff:ffff
178fc32:b1::/32fc32:b1:ffff:ffff:ffff:ffff:ffff:ffff
179fc32:b2::/32fc32:b2:ffff:ffff:ffff:ffff:ffff:ffff
180fc32:b3::/32fc32:b3:ffff:ffff:ffff:ffff:ffff:ffff
181fc32:b4::/32fc32:b4:ffff:ffff:ffff:ffff:ffff:ffff
182fc32:b5::/32fc32:b5:ffff:ffff:ffff:ffff:ffff:ffff
183fc32:b6::/32fc32:b6:ffff:ffff:ffff:ffff:ffff:ffff
184fc32:b7::/32fc32:b7:ffff:ffff:ffff:ffff:ffff:ffff
185fc32:b8::/32fc32:b8:ffff:ffff:ffff:ffff:ffff:ffff
186fc32:b9::/32fc32:b9:ffff:ffff:ffff:ffff:ffff:ffff
187fc32:ba::/32fc32:ba:ffff:ffff:ffff:ffff:ffff:ffff
188fc32:bb::/32fc32:bb:ffff:ffff:ffff:ffff:ffff:ffff
189fc32:bc::/32fc32:bc:ffff:ffff:ffff:ffff:ffff:ffff
190fc32:bd::/32fc32:bd:ffff:ffff:ffff:ffff:ffff:ffff
191fc32:be::/32fc32:be:ffff:ffff:ffff:ffff:ffff:ffff
192fc32:bf::/32fc32:bf:ffff:ffff:ffff:ffff:ffff:ffff
193fc32:c0::/32fc32:c0:ffff:ffff:ffff:ffff:ffff:ffff
194fc32:c1::/32fc32:c1:ffff:ffff:ffff:ffff:ffff:ffff
195fc32:c2::/32fc32:c2:ffff:ffff:ffff:ffff:ffff:ffff
196fc32:c3::/32fc32:c3:ffff:ffff:ffff:ffff:ffff:ffff
197fc32:c4::/32fc32:c4:ffff:ffff:ffff:ffff:ffff:ffff
198fc32:c5::/32fc32:c5:ffff:ffff:ffff:ffff:ffff:ffff
199fc32:c6::/32fc32:c6:ffff:ffff:ffff:ffff:ffff:ffff
200fc32:c7::/32fc32:c7:ffff:ffff:ffff:ffff:ffff:ffff
201fc32:c8::/32fc32:c8:ffff:ffff:ffff:ffff:ffff:ffff
202fc32:c9::/32fc32:c9:ffff:ffff:ffff:ffff:ffff:ffff
203fc32:ca::/32fc32:ca:ffff:ffff:ffff:ffff:ffff:ffff
204fc32:cb::/32fc32:cb:ffff:ffff:ffff:ffff:ffff:ffff
205fc32:cc::/32fc32:cc:ffff:ffff:ffff:ffff:ffff:ffff
206fc32:cd::/32fc32:cd:ffff:ffff:ffff:ffff:ffff:ffff
207fc32:ce::/32fc32:ce:ffff:ffff:ffff:ffff:ffff:ffff
208fc32:cf::/32fc32:cf:ffff:ffff:ffff:ffff:ffff:ffff
209fc32:d0::/32fc32:d0:ffff:ffff:ffff:ffff:ffff:ffff
210fc32:d1::/32fc32:d1:ffff:ffff:ffff:ffff:ffff:ffff
211fc32:d2::/32fc32:d2:ffff:ffff:ffff:ffff:ffff:ffff
212fc32:d3::/32fc32:d3:ffff:ffff:ffff:ffff:ffff:ffff
213fc32:d4::/32fc32:d4:ffff:ffff:ffff:ffff:ffff:ffff
214fc32:d5::/32fc32:d5:ffff:ffff:ffff:ffff:ffff:ffff
215fc32:d6::/32fc32:d6:ffff:ffff:ffff:ffff:ffff:ffff
216fc32:d7::/32fc32:d7:ffff:ffff:ffff:ffff:ffff:ffff
217fc32:d8::/32fc32:d8:ffff:ffff:ffff:ffff:ffff:ffff
218fc32:d9::/32fc32:d9:ffff:ffff:ffff:ffff:ffff:ffff
219fc32:da::/32fc32:da:ffff:ffff:ffff:ffff:ffff:ffff
220fc32:db::/32fc32:db:ffff:ffff:ffff:ffff:ffff:ffff
221fc32:dc::/32fc32:dc:ffff:ffff:ffff:ffff:ffff:ffff
222fc32:dd::/32fc32:dd:ffff:ffff:ffff:ffff:ffff:ffff
223fc32:de::/32fc32:de:ffff:ffff:ffff:ffff:ffff:ffff
224fc32:df::/32fc32:df:ffff:ffff:ffff:ffff:ffff:ffff
225fc32:e0::/32fc32:e0:ffff:ffff:ffff:ffff:ffff:ffff
226fc32:e1::/32fc32:e1:ffff:ffff:ffff:ffff:ffff:ffff
227fc32:e2::/32fc32:e2:ffff:ffff:ffff:ffff:ffff:ffff
228fc32:e3::/32fc32:e3:ffff:ffff:ffff:ffff:ffff:ffff
229fc32:e4::/32fc32:e4:ffff:ffff:ffff:ffff:ffff:ffff
230fc32:e5::/32fc32:e5:ffff:ffff:ffff:ffff:ffff:ffff
231fc32:e6::/32fc32:e6:ffff:ffff:ffff:ffff:ffff:ffff
232fc32:e7::/32fc32:e7:ffff:ffff:ffff:ffff:ffff:ffff
233fc32:e8::/32fc32:e8:ffff:ffff:ffff:ffff:ffff:ffff
234fc32:e9::/32fc32:e9:ffff:ffff:ffff:ffff:ffff:ffff
235fc32:ea::/32fc32:ea:ffff:ffff:ffff:ffff:ffff:ffff
236fc32:eb::/32fc32:eb:ffff:ffff:ffff:ffff:ffff:ffff
237fc32:ec::/32fc32:ec:ffff:ffff:ffff:ffff:ffff:ffff
238fc32:ed::/32fc32:ed:ffff:ffff:ffff:ffff:ffff:ffff
239fc32:ee::/32fc32:ee:ffff:ffff:ffff:ffff:ffff:ffff
240fc32:ef::/32fc32:ef:ffff:ffff:ffff:ffff:ffff:ffff
241fc32:f0::/32fc32:f0:ffff:ffff:ffff:ffff:ffff:ffff
242fc32:f1::/32fc32:f1:ffff:ffff:ffff:ffff:ffff:ffff
243fc32:f2::/32fc32:f2:ffff:ffff:ffff:ffff:ffff:ffff
244fc32:f3::/32fc32:f3:ffff:ffff:ffff:ffff:ffff:ffff
245fc32:f4::/32fc32:f4:ffff:ffff:ffff:ffff:ffff:ffff
246fc32:f5::/32fc32:f5:ffff:ffff:ffff:ffff:ffff:ffff
247fc32:f6::/32fc32:f6:ffff:ffff:ffff:ffff:ffff:ffff
248fc32:f7::/32fc32:f7:ffff:ffff:ffff:ffff:ffff:ffff
249fc32:f8::/32fc32:f8:ffff:ffff:ffff:ffff:ffff:ffff
250fc32:f9::/32fc32:f9:ffff:ffff:ffff:ffff:ffff:ffff
251fc32:fa::/32fc32:fa:ffff:ffff:ffff:ffff:ffff:ffff
252fc32:fb::/32fc32:fb:ffff:ffff:ffff:ffff:ffff:ffff
253fc32:fc::/32fc32:fc:ffff:ffff:ffff:ffff:ffff:ffff
254fc32:fd::/32fc32:fd:ffff:ffff:ffff:ffff:ffff:ffff
255fc32:fe::/32fc32:fe:ffff:ffff:ffff:ffff:ffff:ffff
256fc32:ff::/32fc32: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.