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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
fc7e::/16
First address
fc7e::
Last address
fc7e: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
fc7e: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.7.c.f.ip6.arpa
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

fc7e::/16 makes 256 subnets of /24.

Subnets
#SubnetLast address
1fc7e::/24fc7e:ff:ffff:ffff:ffff:ffff:ffff:ffff
2fc7e:100::/24fc7e:1ff:ffff:ffff:ffff:ffff:ffff:ffff
3fc7e:200::/24fc7e:2ff:ffff:ffff:ffff:ffff:ffff:ffff
4fc7e:300::/24fc7e:3ff:ffff:ffff:ffff:ffff:ffff:ffff
5fc7e:400::/24fc7e:4ff:ffff:ffff:ffff:ffff:ffff:ffff
6fc7e:500::/24fc7e:5ff:ffff:ffff:ffff:ffff:ffff:ffff
7fc7e:600::/24fc7e:6ff:ffff:ffff:ffff:ffff:ffff:ffff
8fc7e:700::/24fc7e:7ff:ffff:ffff:ffff:ffff:ffff:ffff
9fc7e:800::/24fc7e:8ff:ffff:ffff:ffff:ffff:ffff:ffff
10fc7e:900::/24fc7e:9ff:ffff:ffff:ffff:ffff:ffff:ffff
11fc7e:a00::/24fc7e:aff:ffff:ffff:ffff:ffff:ffff:ffff
12fc7e:b00::/24fc7e:bff:ffff:ffff:ffff:ffff:ffff:ffff
13fc7e:c00::/24fc7e:cff:ffff:ffff:ffff:ffff:ffff:ffff
14fc7e:d00::/24fc7e:dff:ffff:ffff:ffff:ffff:ffff:ffff
15fc7e:e00::/24fc7e:eff:ffff:ffff:ffff:ffff:ffff:ffff
16fc7e:f00::/24fc7e:fff:ffff:ffff:ffff:ffff:ffff:ffff
17fc7e:1000::/24fc7e:10ff:ffff:ffff:ffff:ffff:ffff:ffff
18fc7e:1100::/24fc7e:11ff:ffff:ffff:ffff:ffff:ffff:ffff
19fc7e:1200::/24fc7e:12ff:ffff:ffff:ffff:ffff:ffff:ffff
20fc7e:1300::/24fc7e:13ff:ffff:ffff:ffff:ffff:ffff:ffff
21fc7e:1400::/24fc7e:14ff:ffff:ffff:ffff:ffff:ffff:ffff
22fc7e:1500::/24fc7e:15ff:ffff:ffff:ffff:ffff:ffff:ffff
23fc7e:1600::/24fc7e:16ff:ffff:ffff:ffff:ffff:ffff:ffff
24fc7e:1700::/24fc7e:17ff:ffff:ffff:ffff:ffff:ffff:ffff
25fc7e:1800::/24fc7e:18ff:ffff:ffff:ffff:ffff:ffff:ffff
26fc7e:1900::/24fc7e:19ff:ffff:ffff:ffff:ffff:ffff:ffff
27fc7e:1a00::/24fc7e:1aff:ffff:ffff:ffff:ffff:ffff:ffff
28fc7e:1b00::/24fc7e:1bff:ffff:ffff:ffff:ffff:ffff:ffff
29fc7e:1c00::/24fc7e:1cff:ffff:ffff:ffff:ffff:ffff:ffff
30fc7e:1d00::/24fc7e:1dff:ffff:ffff:ffff:ffff:ffff:ffff
31fc7e:1e00::/24fc7e:1eff:ffff:ffff:ffff:ffff:ffff:ffff
32fc7e:1f00::/24fc7e:1fff:ffff:ffff:ffff:ffff:ffff:ffff
33fc7e:2000::/24fc7e:20ff:ffff:ffff:ffff:ffff:ffff:ffff
34fc7e:2100::/24fc7e:21ff:ffff:ffff:ffff:ffff:ffff:ffff
35fc7e:2200::/24fc7e:22ff:ffff:ffff:ffff:ffff:ffff:ffff
36fc7e:2300::/24fc7e:23ff:ffff:ffff:ffff:ffff:ffff:ffff
37fc7e:2400::/24fc7e:24ff:ffff:ffff:ffff:ffff:ffff:ffff
38fc7e:2500::/24fc7e:25ff:ffff:ffff:ffff:ffff:ffff:ffff
39fc7e:2600::/24fc7e:26ff:ffff:ffff:ffff:ffff:ffff:ffff
40fc7e:2700::/24fc7e:27ff:ffff:ffff:ffff:ffff:ffff:ffff
41fc7e:2800::/24fc7e:28ff:ffff:ffff:ffff:ffff:ffff:ffff
42fc7e:2900::/24fc7e:29ff:ffff:ffff:ffff:ffff:ffff:ffff
43fc7e:2a00::/24fc7e:2aff:ffff:ffff:ffff:ffff:ffff:ffff
44fc7e:2b00::/24fc7e:2bff:ffff:ffff:ffff:ffff:ffff:ffff
45fc7e:2c00::/24fc7e:2cff:ffff:ffff:ffff:ffff:ffff:ffff
46fc7e:2d00::/24fc7e:2dff:ffff:ffff:ffff:ffff:ffff:ffff
47fc7e:2e00::/24fc7e:2eff:ffff:ffff:ffff:ffff:ffff:ffff
48fc7e:2f00::/24fc7e:2fff:ffff:ffff:ffff:ffff:ffff:ffff
49fc7e:3000::/24fc7e:30ff:ffff:ffff:ffff:ffff:ffff:ffff
50fc7e:3100::/24fc7e:31ff:ffff:ffff:ffff:ffff:ffff:ffff
51fc7e:3200::/24fc7e:32ff:ffff:ffff:ffff:ffff:ffff:ffff
52fc7e:3300::/24fc7e:33ff:ffff:ffff:ffff:ffff:ffff:ffff
53fc7e:3400::/24fc7e:34ff:ffff:ffff:ffff:ffff:ffff:ffff
54fc7e:3500::/24fc7e:35ff:ffff:ffff:ffff:ffff:ffff:ffff
55fc7e:3600::/24fc7e:36ff:ffff:ffff:ffff:ffff:ffff:ffff
56fc7e:3700::/24fc7e:37ff:ffff:ffff:ffff:ffff:ffff:ffff
57fc7e:3800::/24fc7e:38ff:ffff:ffff:ffff:ffff:ffff:ffff
58fc7e:3900::/24fc7e:39ff:ffff:ffff:ffff:ffff:ffff:ffff
59fc7e:3a00::/24fc7e:3aff:ffff:ffff:ffff:ffff:ffff:ffff
60fc7e:3b00::/24fc7e:3bff:ffff:ffff:ffff:ffff:ffff:ffff
61fc7e:3c00::/24fc7e:3cff:ffff:ffff:ffff:ffff:ffff:ffff
62fc7e:3d00::/24fc7e:3dff:ffff:ffff:ffff:ffff:ffff:ffff
63fc7e:3e00::/24fc7e:3eff:ffff:ffff:ffff:ffff:ffff:ffff
64fc7e:3f00::/24fc7e:3fff:ffff:ffff:ffff:ffff:ffff:ffff
65fc7e:4000::/24fc7e:40ff:ffff:ffff:ffff:ffff:ffff:ffff
66fc7e:4100::/24fc7e:41ff:ffff:ffff:ffff:ffff:ffff:ffff
67fc7e:4200::/24fc7e:42ff:ffff:ffff:ffff:ffff:ffff:ffff
68fc7e:4300::/24fc7e:43ff:ffff:ffff:ffff:ffff:ffff:ffff
69fc7e:4400::/24fc7e:44ff:ffff:ffff:ffff:ffff:ffff:ffff
70fc7e:4500::/24fc7e:45ff:ffff:ffff:ffff:ffff:ffff:ffff
71fc7e:4600::/24fc7e:46ff:ffff:ffff:ffff:ffff:ffff:ffff
72fc7e:4700::/24fc7e:47ff:ffff:ffff:ffff:ffff:ffff:ffff
73fc7e:4800::/24fc7e:48ff:ffff:ffff:ffff:ffff:ffff:ffff
74fc7e:4900::/24fc7e:49ff:ffff:ffff:ffff:ffff:ffff:ffff
75fc7e:4a00::/24fc7e:4aff:ffff:ffff:ffff:ffff:ffff:ffff
76fc7e:4b00::/24fc7e:4bff:ffff:ffff:ffff:ffff:ffff:ffff
77fc7e:4c00::/24fc7e:4cff:ffff:ffff:ffff:ffff:ffff:ffff
78fc7e:4d00::/24fc7e:4dff:ffff:ffff:ffff:ffff:ffff:ffff
79fc7e:4e00::/24fc7e:4eff:ffff:ffff:ffff:ffff:ffff:ffff
80fc7e:4f00::/24fc7e:4fff:ffff:ffff:ffff:ffff:ffff:ffff
81fc7e:5000::/24fc7e:50ff:ffff:ffff:ffff:ffff:ffff:ffff
82fc7e:5100::/24fc7e:51ff:ffff:ffff:ffff:ffff:ffff:ffff
83fc7e:5200::/24fc7e:52ff:ffff:ffff:ffff:ffff:ffff:ffff
84fc7e:5300::/24fc7e:53ff:ffff:ffff:ffff:ffff:ffff:ffff
85fc7e:5400::/24fc7e:54ff:ffff:ffff:ffff:ffff:ffff:ffff
86fc7e:5500::/24fc7e:55ff:ffff:ffff:ffff:ffff:ffff:ffff
87fc7e:5600::/24fc7e:56ff:ffff:ffff:ffff:ffff:ffff:ffff
88fc7e:5700::/24fc7e:57ff:ffff:ffff:ffff:ffff:ffff:ffff
89fc7e:5800::/24fc7e:58ff:ffff:ffff:ffff:ffff:ffff:ffff
90fc7e:5900::/24fc7e:59ff:ffff:ffff:ffff:ffff:ffff:ffff
91fc7e:5a00::/24fc7e:5aff:ffff:ffff:ffff:ffff:ffff:ffff
92fc7e:5b00::/24fc7e:5bff:ffff:ffff:ffff:ffff:ffff:ffff
93fc7e:5c00::/24fc7e:5cff:ffff:ffff:ffff:ffff:ffff:ffff
94fc7e:5d00::/24fc7e:5dff:ffff:ffff:ffff:ffff:ffff:ffff
95fc7e:5e00::/24fc7e:5eff:ffff:ffff:ffff:ffff:ffff:ffff
96fc7e:5f00::/24fc7e:5fff:ffff:ffff:ffff:ffff:ffff:ffff
97fc7e:6000::/24fc7e:60ff:ffff:ffff:ffff:ffff:ffff:ffff
98fc7e:6100::/24fc7e:61ff:ffff:ffff:ffff:ffff:ffff:ffff
99fc7e:6200::/24fc7e:62ff:ffff:ffff:ffff:ffff:ffff:ffff
100fc7e:6300::/24fc7e:63ff:ffff:ffff:ffff:ffff:ffff:ffff
101fc7e:6400::/24fc7e:64ff:ffff:ffff:ffff:ffff:ffff:ffff
102fc7e:6500::/24fc7e:65ff:ffff:ffff:ffff:ffff:ffff:ffff
103fc7e:6600::/24fc7e:66ff:ffff:ffff:ffff:ffff:ffff:ffff
104fc7e:6700::/24fc7e:67ff:ffff:ffff:ffff:ffff:ffff:ffff
105fc7e:6800::/24fc7e:68ff:ffff:ffff:ffff:ffff:ffff:ffff
106fc7e:6900::/24fc7e:69ff:ffff:ffff:ffff:ffff:ffff:ffff
107fc7e:6a00::/24fc7e:6aff:ffff:ffff:ffff:ffff:ffff:ffff
108fc7e:6b00::/24fc7e:6bff:ffff:ffff:ffff:ffff:ffff:ffff
109fc7e:6c00::/24fc7e:6cff:ffff:ffff:ffff:ffff:ffff:ffff
110fc7e:6d00::/24fc7e:6dff:ffff:ffff:ffff:ffff:ffff:ffff
111fc7e:6e00::/24fc7e:6eff:ffff:ffff:ffff:ffff:ffff:ffff
112fc7e:6f00::/24fc7e:6fff:ffff:ffff:ffff:ffff:ffff:ffff
113fc7e:7000::/24fc7e:70ff:ffff:ffff:ffff:ffff:ffff:ffff
114fc7e:7100::/24fc7e:71ff:ffff:ffff:ffff:ffff:ffff:ffff
115fc7e:7200::/24fc7e:72ff:ffff:ffff:ffff:ffff:ffff:ffff
116fc7e:7300::/24fc7e:73ff:ffff:ffff:ffff:ffff:ffff:ffff
117fc7e:7400::/24fc7e:74ff:ffff:ffff:ffff:ffff:ffff:ffff
118fc7e:7500::/24fc7e:75ff:ffff:ffff:ffff:ffff:ffff:ffff
119fc7e:7600::/24fc7e:76ff:ffff:ffff:ffff:ffff:ffff:ffff
120fc7e:7700::/24fc7e:77ff:ffff:ffff:ffff:ffff:ffff:ffff
121fc7e:7800::/24fc7e:78ff:ffff:ffff:ffff:ffff:ffff:ffff
122fc7e:7900::/24fc7e:79ff:ffff:ffff:ffff:ffff:ffff:ffff
123fc7e:7a00::/24fc7e:7aff:ffff:ffff:ffff:ffff:ffff:ffff
124fc7e:7b00::/24fc7e:7bff:ffff:ffff:ffff:ffff:ffff:ffff
125fc7e:7c00::/24fc7e:7cff:ffff:ffff:ffff:ffff:ffff:ffff
126fc7e:7d00::/24fc7e:7dff:ffff:ffff:ffff:ffff:ffff:ffff
127fc7e:7e00::/24fc7e:7eff:ffff:ffff:ffff:ffff:ffff:ffff
128fc7e:7f00::/24fc7e:7fff:ffff:ffff:ffff:ffff:ffff:ffff
129fc7e:8000::/24fc7e:80ff:ffff:ffff:ffff:ffff:ffff:ffff
130fc7e:8100::/24fc7e:81ff:ffff:ffff:ffff:ffff:ffff:ffff
131fc7e:8200::/24fc7e:82ff:ffff:ffff:ffff:ffff:ffff:ffff
132fc7e:8300::/24fc7e:83ff:ffff:ffff:ffff:ffff:ffff:ffff
133fc7e:8400::/24fc7e:84ff:ffff:ffff:ffff:ffff:ffff:ffff
134fc7e:8500::/24fc7e:85ff:ffff:ffff:ffff:ffff:ffff:ffff
135fc7e:8600::/24fc7e:86ff:ffff:ffff:ffff:ffff:ffff:ffff
136fc7e:8700::/24fc7e:87ff:ffff:ffff:ffff:ffff:ffff:ffff
137fc7e:8800::/24fc7e:88ff:ffff:ffff:ffff:ffff:ffff:ffff
138fc7e:8900::/24fc7e:89ff:ffff:ffff:ffff:ffff:ffff:ffff
139fc7e:8a00::/24fc7e:8aff:ffff:ffff:ffff:ffff:ffff:ffff
140fc7e:8b00::/24fc7e:8bff:ffff:ffff:ffff:ffff:ffff:ffff
141fc7e:8c00::/24fc7e:8cff:ffff:ffff:ffff:ffff:ffff:ffff
142fc7e:8d00::/24fc7e:8dff:ffff:ffff:ffff:ffff:ffff:ffff
143fc7e:8e00::/24fc7e:8eff:ffff:ffff:ffff:ffff:ffff:ffff
144fc7e:8f00::/24fc7e:8fff:ffff:ffff:ffff:ffff:ffff:ffff
145fc7e:9000::/24fc7e:90ff:ffff:ffff:ffff:ffff:ffff:ffff
146fc7e:9100::/24fc7e:91ff:ffff:ffff:ffff:ffff:ffff:ffff
147fc7e:9200::/24fc7e:92ff:ffff:ffff:ffff:ffff:ffff:ffff
148fc7e:9300::/24fc7e:93ff:ffff:ffff:ffff:ffff:ffff:ffff
149fc7e:9400::/24fc7e:94ff:ffff:ffff:ffff:ffff:ffff:ffff
150fc7e:9500::/24fc7e:95ff:ffff:ffff:ffff:ffff:ffff:ffff
151fc7e:9600::/24fc7e:96ff:ffff:ffff:ffff:ffff:ffff:ffff
152fc7e:9700::/24fc7e:97ff:ffff:ffff:ffff:ffff:ffff:ffff
153fc7e:9800::/24fc7e:98ff:ffff:ffff:ffff:ffff:ffff:ffff
154fc7e:9900::/24fc7e:99ff:ffff:ffff:ffff:ffff:ffff:ffff
155fc7e:9a00::/24fc7e:9aff:ffff:ffff:ffff:ffff:ffff:ffff
156fc7e:9b00::/24fc7e:9bff:ffff:ffff:ffff:ffff:ffff:ffff
157fc7e:9c00::/24fc7e:9cff:ffff:ffff:ffff:ffff:ffff:ffff
158fc7e:9d00::/24fc7e:9dff:ffff:ffff:ffff:ffff:ffff:ffff
159fc7e:9e00::/24fc7e:9eff:ffff:ffff:ffff:ffff:ffff:ffff
160fc7e:9f00::/24fc7e:9fff:ffff:ffff:ffff:ffff:ffff:ffff
161fc7e:a000::/24fc7e:a0ff:ffff:ffff:ffff:ffff:ffff:ffff
162fc7e:a100::/24fc7e:a1ff:ffff:ffff:ffff:ffff:ffff:ffff
163fc7e:a200::/24fc7e:a2ff:ffff:ffff:ffff:ffff:ffff:ffff
164fc7e:a300::/24fc7e:a3ff:ffff:ffff:ffff:ffff:ffff:ffff
165fc7e:a400::/24fc7e:a4ff:ffff:ffff:ffff:ffff:ffff:ffff
166fc7e:a500::/24fc7e:a5ff:ffff:ffff:ffff:ffff:ffff:ffff
167fc7e:a600::/24fc7e:a6ff:ffff:ffff:ffff:ffff:ffff:ffff
168fc7e:a700::/24fc7e:a7ff:ffff:ffff:ffff:ffff:ffff:ffff
169fc7e:a800::/24fc7e:a8ff:ffff:ffff:ffff:ffff:ffff:ffff
170fc7e:a900::/24fc7e:a9ff:ffff:ffff:ffff:ffff:ffff:ffff
171fc7e:aa00::/24fc7e:aaff:ffff:ffff:ffff:ffff:ffff:ffff
172fc7e:ab00::/24fc7e:abff:ffff:ffff:ffff:ffff:ffff:ffff
173fc7e:ac00::/24fc7e:acff:ffff:ffff:ffff:ffff:ffff:ffff
174fc7e:ad00::/24fc7e:adff:ffff:ffff:ffff:ffff:ffff:ffff
175fc7e:ae00::/24fc7e:aeff:ffff:ffff:ffff:ffff:ffff:ffff
176fc7e:af00::/24fc7e:afff:ffff:ffff:ffff:ffff:ffff:ffff
177fc7e:b000::/24fc7e:b0ff:ffff:ffff:ffff:ffff:ffff:ffff
178fc7e:b100::/24fc7e:b1ff:ffff:ffff:ffff:ffff:ffff:ffff
179fc7e:b200::/24fc7e:b2ff:ffff:ffff:ffff:ffff:ffff:ffff
180fc7e:b300::/24fc7e:b3ff:ffff:ffff:ffff:ffff:ffff:ffff
181fc7e:b400::/24fc7e:b4ff:ffff:ffff:ffff:ffff:ffff:ffff
182fc7e:b500::/24fc7e:b5ff:ffff:ffff:ffff:ffff:ffff:ffff
183fc7e:b600::/24fc7e:b6ff:ffff:ffff:ffff:ffff:ffff:ffff
184fc7e:b700::/24fc7e:b7ff:ffff:ffff:ffff:ffff:ffff:ffff
185fc7e:b800::/24fc7e:b8ff:ffff:ffff:ffff:ffff:ffff:ffff
186fc7e:b900::/24fc7e:b9ff:ffff:ffff:ffff:ffff:ffff:ffff
187fc7e:ba00::/24fc7e:baff:ffff:ffff:ffff:ffff:ffff:ffff
188fc7e:bb00::/24fc7e:bbff:ffff:ffff:ffff:ffff:ffff:ffff
189fc7e:bc00::/24fc7e:bcff:ffff:ffff:ffff:ffff:ffff:ffff
190fc7e:bd00::/24fc7e:bdff:ffff:ffff:ffff:ffff:ffff:ffff
191fc7e:be00::/24fc7e:beff:ffff:ffff:ffff:ffff:ffff:ffff
192fc7e:bf00::/24fc7e:bfff:ffff:ffff:ffff:ffff:ffff:ffff
193fc7e:c000::/24fc7e:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
194fc7e:c100::/24fc7e:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
195fc7e:c200::/24fc7e:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
196fc7e:c300::/24fc7e:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
197fc7e:c400::/24fc7e:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
198fc7e:c500::/24fc7e:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
199fc7e:c600::/24fc7e:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
200fc7e:c700::/24fc7e:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
201fc7e:c800::/24fc7e:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
202fc7e:c900::/24fc7e:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
203fc7e:ca00::/24fc7e:caff:ffff:ffff:ffff:ffff:ffff:ffff
204fc7e:cb00::/24fc7e:cbff:ffff:ffff:ffff:ffff:ffff:ffff
205fc7e:cc00::/24fc7e:ccff:ffff:ffff:ffff:ffff:ffff:ffff
206fc7e:cd00::/24fc7e:cdff:ffff:ffff:ffff:ffff:ffff:ffff
207fc7e:ce00::/24fc7e:ceff:ffff:ffff:ffff:ffff:ffff:ffff
208fc7e:cf00::/24fc7e:cfff:ffff:ffff:ffff:ffff:ffff:ffff
209fc7e:d000::/24fc7e:d0ff:ffff:ffff:ffff:ffff:ffff:ffff
210fc7e:d100::/24fc7e:d1ff:ffff:ffff:ffff:ffff:ffff:ffff
211fc7e:d200::/24fc7e:d2ff:ffff:ffff:ffff:ffff:ffff:ffff
212fc7e:d300::/24fc7e:d3ff:ffff:ffff:ffff:ffff:ffff:ffff
213fc7e:d400::/24fc7e:d4ff:ffff:ffff:ffff:ffff:ffff:ffff
214fc7e:d500::/24fc7e:d5ff:ffff:ffff:ffff:ffff:ffff:ffff
215fc7e:d600::/24fc7e:d6ff:ffff:ffff:ffff:ffff:ffff:ffff
216fc7e:d700::/24fc7e:d7ff:ffff:ffff:ffff:ffff:ffff:ffff
217fc7e:d800::/24fc7e:d8ff:ffff:ffff:ffff:ffff:ffff:ffff
218fc7e:d900::/24fc7e:d9ff:ffff:ffff:ffff:ffff:ffff:ffff
219fc7e:da00::/24fc7e:daff:ffff:ffff:ffff:ffff:ffff:ffff
220fc7e:db00::/24fc7e:dbff:ffff:ffff:ffff:ffff:ffff:ffff
221fc7e:dc00::/24fc7e:dcff:ffff:ffff:ffff:ffff:ffff:ffff
222fc7e:dd00::/24fc7e:ddff:ffff:ffff:ffff:ffff:ffff:ffff
223fc7e:de00::/24fc7e:deff:ffff:ffff:ffff:ffff:ffff:ffff
224fc7e:df00::/24fc7e:dfff:ffff:ffff:ffff:ffff:ffff:ffff
225fc7e:e000::/24fc7e:e0ff:ffff:ffff:ffff:ffff:ffff:ffff
226fc7e:e100::/24fc7e:e1ff:ffff:ffff:ffff:ffff:ffff:ffff
227fc7e:e200::/24fc7e:e2ff:ffff:ffff:ffff:ffff:ffff:ffff
228fc7e:e300::/24fc7e:e3ff:ffff:ffff:ffff:ffff:ffff:ffff
229fc7e:e400::/24fc7e:e4ff:ffff:ffff:ffff:ffff:ffff:ffff
230fc7e:e500::/24fc7e:e5ff:ffff:ffff:ffff:ffff:ffff:ffff
231fc7e:e600::/24fc7e:e6ff:ffff:ffff:ffff:ffff:ffff:ffff
232fc7e:e700::/24fc7e:e7ff:ffff:ffff:ffff:ffff:ffff:ffff
233fc7e:e800::/24fc7e:e8ff:ffff:ffff:ffff:ffff:ffff:ffff
234fc7e:e900::/24fc7e:e9ff:ffff:ffff:ffff:ffff:ffff:ffff
235fc7e:ea00::/24fc7e:eaff:ffff:ffff:ffff:ffff:ffff:ffff
236fc7e:eb00::/24fc7e:ebff:ffff:ffff:ffff:ffff:ffff:ffff
237fc7e:ec00::/24fc7e:ecff:ffff:ffff:ffff:ffff:ffff:ffff
238fc7e:ed00::/24fc7e:edff:ffff:ffff:ffff:ffff:ffff:ffff
239fc7e:ee00::/24fc7e:eeff:ffff:ffff:ffff:ffff:ffff:ffff
240fc7e:ef00::/24fc7e:efff:ffff:ffff:ffff:ffff:ffff:ffff
241fc7e:f000::/24fc7e:f0ff:ffff:ffff:ffff:ffff:ffff:ffff
242fc7e:f100::/24fc7e:f1ff:ffff:ffff:ffff:ffff:ffff:ffff
243fc7e:f200::/24fc7e:f2ff:ffff:ffff:ffff:ffff:ffff:ffff
244fc7e:f300::/24fc7e:f3ff:ffff:ffff:ffff:ffff:ffff:ffff
245fc7e:f400::/24fc7e:f4ff:ffff:ffff:ffff:ffff:ffff:ffff
246fc7e:f500::/24fc7e:f5ff:ffff:ffff:ffff:ffff:ffff:ffff
247fc7e:f600::/24fc7e:f6ff:ffff:ffff:ffff:ffff:ffff:ffff
248fc7e:f700::/24fc7e:f7ff:ffff:ffff:ffff:ffff:ffff:ffff
249fc7e:f800::/24fc7e:f8ff:ffff:ffff:ffff:ffff:ffff:ffff
250fc7e:f900::/24fc7e:f9ff:ffff:ffff:ffff:ffff:ffff:ffff
251fc7e:fa00::/24fc7e:faff:ffff:ffff:ffff:ffff:ffff:ffff
252fc7e:fb00::/24fc7e:fbff:ffff:ffff:ffff:ffff:ffff:ffff
253fc7e:fc00::/24fc7e:fcff:ffff:ffff:ffff:ffff:ffff:ffff
254fc7e:fd00::/24fc7e:fdff:ffff:ffff:ffff:ffff:ffff:ffff
255fc7e:fe00::/24fc7e:feff:ffff:ffff:ffff:ffff:ffff:ffff
256fc7e:ff00::/24fc7e:ffff: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.