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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
ffd7::/16
First address
ffd7::
Last address
ffd7: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
ffd7:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
7.d.f.f.ip6.arpa
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/24 (256)/28 (4,096)/32 (65,536)

ffd7::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
1ffd7::/28ffd7:f:ffff:ffff:ffff:ffff:ffff:ffff
2ffd7:10::/28ffd7:1f:ffff:ffff:ffff:ffff:ffff:ffff
3ffd7:20::/28ffd7:2f:ffff:ffff:ffff:ffff:ffff:ffff
4ffd7:30::/28ffd7:3f:ffff:ffff:ffff:ffff:ffff:ffff
5ffd7:40::/28ffd7:4f:ffff:ffff:ffff:ffff:ffff:ffff
6ffd7:50::/28ffd7:5f:ffff:ffff:ffff:ffff:ffff:ffff
7ffd7:60::/28ffd7:6f:ffff:ffff:ffff:ffff:ffff:ffff
8ffd7:70::/28ffd7:7f:ffff:ffff:ffff:ffff:ffff:ffff
9ffd7:80::/28ffd7:8f:ffff:ffff:ffff:ffff:ffff:ffff
10ffd7:90::/28ffd7:9f:ffff:ffff:ffff:ffff:ffff:ffff
11ffd7:a0::/28ffd7:af:ffff:ffff:ffff:ffff:ffff:ffff
12ffd7:b0::/28ffd7:bf:ffff:ffff:ffff:ffff:ffff:ffff
13ffd7:c0::/28ffd7:cf:ffff:ffff:ffff:ffff:ffff:ffff
14ffd7:d0::/28ffd7:df:ffff:ffff:ffff:ffff:ffff:ffff
15ffd7:e0::/28ffd7:ef:ffff:ffff:ffff:ffff:ffff:ffff
16ffd7:f0::/28ffd7:ff:ffff:ffff:ffff:ffff:ffff:ffff
17ffd7:100::/28ffd7:10f:ffff:ffff:ffff:ffff:ffff:ffff
18ffd7:110::/28ffd7:11f:ffff:ffff:ffff:ffff:ffff:ffff
19ffd7:120::/28ffd7:12f:ffff:ffff:ffff:ffff:ffff:ffff
20ffd7:130::/28ffd7:13f:ffff:ffff:ffff:ffff:ffff:ffff
21ffd7:140::/28ffd7:14f:ffff:ffff:ffff:ffff:ffff:ffff
22ffd7:150::/28ffd7:15f:ffff:ffff:ffff:ffff:ffff:ffff
23ffd7:160::/28ffd7:16f:ffff:ffff:ffff:ffff:ffff:ffff
24ffd7:170::/28ffd7:17f:ffff:ffff:ffff:ffff:ffff:ffff
25ffd7:180::/28ffd7:18f:ffff:ffff:ffff:ffff:ffff:ffff
26ffd7:190::/28ffd7:19f:ffff:ffff:ffff:ffff:ffff:ffff
27ffd7:1a0::/28ffd7:1af:ffff:ffff:ffff:ffff:ffff:ffff
28ffd7:1b0::/28ffd7:1bf:ffff:ffff:ffff:ffff:ffff:ffff
29ffd7:1c0::/28ffd7:1cf:ffff:ffff:ffff:ffff:ffff:ffff
30ffd7:1d0::/28ffd7:1df:ffff:ffff:ffff:ffff:ffff:ffff
31ffd7:1e0::/28ffd7:1ef:ffff:ffff:ffff:ffff:ffff:ffff
32ffd7:1f0::/28ffd7:1ff:ffff:ffff:ffff:ffff:ffff:ffff
33ffd7:200::/28ffd7:20f:ffff:ffff:ffff:ffff:ffff:ffff
34ffd7:210::/28ffd7:21f:ffff:ffff:ffff:ffff:ffff:ffff
35ffd7:220::/28ffd7:22f:ffff:ffff:ffff:ffff:ffff:ffff
36ffd7:230::/28ffd7:23f:ffff:ffff:ffff:ffff:ffff:ffff
37ffd7:240::/28ffd7:24f:ffff:ffff:ffff:ffff:ffff:ffff
38ffd7:250::/28ffd7:25f:ffff:ffff:ffff:ffff:ffff:ffff
39ffd7:260::/28ffd7:26f:ffff:ffff:ffff:ffff:ffff:ffff
40ffd7:270::/28ffd7:27f:ffff:ffff:ffff:ffff:ffff:ffff
41ffd7:280::/28ffd7:28f:ffff:ffff:ffff:ffff:ffff:ffff
42ffd7:290::/28ffd7:29f:ffff:ffff:ffff:ffff:ffff:ffff
43ffd7:2a0::/28ffd7:2af:ffff:ffff:ffff:ffff:ffff:ffff
44ffd7:2b0::/28ffd7:2bf:ffff:ffff:ffff:ffff:ffff:ffff
45ffd7:2c0::/28ffd7:2cf:ffff:ffff:ffff:ffff:ffff:ffff
46ffd7:2d0::/28ffd7:2df:ffff:ffff:ffff:ffff:ffff:ffff
47ffd7:2e0::/28ffd7:2ef:ffff:ffff:ffff:ffff:ffff:ffff
48ffd7:2f0::/28ffd7:2ff:ffff:ffff:ffff:ffff:ffff:ffff
49ffd7:300::/28ffd7:30f:ffff:ffff:ffff:ffff:ffff:ffff
50ffd7:310::/28ffd7:31f:ffff:ffff:ffff:ffff:ffff:ffff
51ffd7:320::/28ffd7:32f:ffff:ffff:ffff:ffff:ffff:ffff
52ffd7:330::/28ffd7:33f:ffff:ffff:ffff:ffff:ffff:ffff
53ffd7:340::/28ffd7:34f:ffff:ffff:ffff:ffff:ffff:ffff
54ffd7:350::/28ffd7:35f:ffff:ffff:ffff:ffff:ffff:ffff
55ffd7:360::/28ffd7:36f:ffff:ffff:ffff:ffff:ffff:ffff
56ffd7:370::/28ffd7:37f:ffff:ffff:ffff:ffff:ffff:ffff
57ffd7:380::/28ffd7:38f:ffff:ffff:ffff:ffff:ffff:ffff
58ffd7:390::/28ffd7:39f:ffff:ffff:ffff:ffff:ffff:ffff
59ffd7:3a0::/28ffd7:3af:ffff:ffff:ffff:ffff:ffff:ffff
60ffd7:3b0::/28ffd7:3bf:ffff:ffff:ffff:ffff:ffff:ffff
61ffd7:3c0::/28ffd7:3cf:ffff:ffff:ffff:ffff:ffff:ffff
62ffd7:3d0::/28ffd7:3df:ffff:ffff:ffff:ffff:ffff:ffff
63ffd7:3e0::/28ffd7:3ef:ffff:ffff:ffff:ffff:ffff:ffff
64ffd7:3f0::/28ffd7:3ff:ffff:ffff:ffff:ffff:ffff:ffff
65ffd7:400::/28ffd7:40f:ffff:ffff:ffff:ffff:ffff:ffff
66ffd7:410::/28ffd7:41f:ffff:ffff:ffff:ffff:ffff:ffff
67ffd7:420::/28ffd7:42f:ffff:ffff:ffff:ffff:ffff:ffff
68ffd7:430::/28ffd7:43f:ffff:ffff:ffff:ffff:ffff:ffff
69ffd7:440::/28ffd7:44f:ffff:ffff:ffff:ffff:ffff:ffff
70ffd7:450::/28ffd7:45f:ffff:ffff:ffff:ffff:ffff:ffff
71ffd7:460::/28ffd7:46f:ffff:ffff:ffff:ffff:ffff:ffff
72ffd7:470::/28ffd7:47f:ffff:ffff:ffff:ffff:ffff:ffff
73ffd7:480::/28ffd7:48f:ffff:ffff:ffff:ffff:ffff:ffff
74ffd7:490::/28ffd7:49f:ffff:ffff:ffff:ffff:ffff:ffff
75ffd7:4a0::/28ffd7:4af:ffff:ffff:ffff:ffff:ffff:ffff
76ffd7:4b0::/28ffd7:4bf:ffff:ffff:ffff:ffff:ffff:ffff
77ffd7:4c0::/28ffd7:4cf:ffff:ffff:ffff:ffff:ffff:ffff
78ffd7:4d0::/28ffd7:4df:ffff:ffff:ffff:ffff:ffff:ffff
79ffd7:4e0::/28ffd7:4ef:ffff:ffff:ffff:ffff:ffff:ffff
80ffd7:4f0::/28ffd7:4ff:ffff:ffff:ffff:ffff:ffff:ffff
81ffd7:500::/28ffd7:50f:ffff:ffff:ffff:ffff:ffff:ffff
82ffd7:510::/28ffd7:51f:ffff:ffff:ffff:ffff:ffff:ffff
83ffd7:520::/28ffd7:52f:ffff:ffff:ffff:ffff:ffff:ffff
84ffd7:530::/28ffd7:53f:ffff:ffff:ffff:ffff:ffff:ffff
85ffd7:540::/28ffd7:54f:ffff:ffff:ffff:ffff:ffff:ffff
86ffd7:550::/28ffd7:55f:ffff:ffff:ffff:ffff:ffff:ffff
87ffd7:560::/28ffd7:56f:ffff:ffff:ffff:ffff:ffff:ffff
88ffd7:570::/28ffd7:57f:ffff:ffff:ffff:ffff:ffff:ffff
89ffd7:580::/28ffd7:58f:ffff:ffff:ffff:ffff:ffff:ffff
90ffd7:590::/28ffd7:59f:ffff:ffff:ffff:ffff:ffff:ffff
91ffd7:5a0::/28ffd7:5af:ffff:ffff:ffff:ffff:ffff:ffff
92ffd7:5b0::/28ffd7:5bf:ffff:ffff:ffff:ffff:ffff:ffff
93ffd7:5c0::/28ffd7:5cf:ffff:ffff:ffff:ffff:ffff:ffff
94ffd7:5d0::/28ffd7:5df:ffff:ffff:ffff:ffff:ffff:ffff
95ffd7:5e0::/28ffd7:5ef:ffff:ffff:ffff:ffff:ffff:ffff
96ffd7:5f0::/28ffd7:5ff:ffff:ffff:ffff:ffff:ffff:ffff
97ffd7:600::/28ffd7:60f:ffff:ffff:ffff:ffff:ffff:ffff
98ffd7:610::/28ffd7:61f:ffff:ffff:ffff:ffff:ffff:ffff
99ffd7:620::/28ffd7:62f:ffff:ffff:ffff:ffff:ffff:ffff
100ffd7:630::/28ffd7:63f:ffff:ffff:ffff:ffff:ffff:ffff
101ffd7:640::/28ffd7:64f:ffff:ffff:ffff:ffff:ffff:ffff
102ffd7:650::/28ffd7:65f:ffff:ffff:ffff:ffff:ffff:ffff
103ffd7:660::/28ffd7:66f:ffff:ffff:ffff:ffff:ffff:ffff
104ffd7:670::/28ffd7:67f:ffff:ffff:ffff:ffff:ffff:ffff
105ffd7:680::/28ffd7:68f:ffff:ffff:ffff:ffff:ffff:ffff
106ffd7:690::/28ffd7:69f:ffff:ffff:ffff:ffff:ffff:ffff
107ffd7:6a0::/28ffd7:6af:ffff:ffff:ffff:ffff:ffff:ffff
108ffd7:6b0::/28ffd7:6bf:ffff:ffff:ffff:ffff:ffff:ffff
109ffd7:6c0::/28ffd7:6cf:ffff:ffff:ffff:ffff:ffff:ffff
110ffd7:6d0::/28ffd7:6df:ffff:ffff:ffff:ffff:ffff:ffff
111ffd7:6e0::/28ffd7:6ef:ffff:ffff:ffff:ffff:ffff:ffff
112ffd7:6f0::/28ffd7:6ff:ffff:ffff:ffff:ffff:ffff:ffff
113ffd7:700::/28ffd7:70f:ffff:ffff:ffff:ffff:ffff:ffff
114ffd7:710::/28ffd7:71f:ffff:ffff:ffff:ffff:ffff:ffff
115ffd7:720::/28ffd7:72f:ffff:ffff:ffff:ffff:ffff:ffff
116ffd7:730::/28ffd7:73f:ffff:ffff:ffff:ffff:ffff:ffff
117ffd7:740::/28ffd7:74f:ffff:ffff:ffff:ffff:ffff:ffff
118ffd7:750::/28ffd7:75f:ffff:ffff:ffff:ffff:ffff:ffff
119ffd7:760::/28ffd7:76f:ffff:ffff:ffff:ffff:ffff:ffff
120ffd7:770::/28ffd7:77f:ffff:ffff:ffff:ffff:ffff:ffff
121ffd7:780::/28ffd7:78f:ffff:ffff:ffff:ffff:ffff:ffff
122ffd7:790::/28ffd7:79f:ffff:ffff:ffff:ffff:ffff:ffff
123ffd7:7a0::/28ffd7:7af:ffff:ffff:ffff:ffff:ffff:ffff
124ffd7:7b0::/28ffd7:7bf:ffff:ffff:ffff:ffff:ffff:ffff
125ffd7:7c0::/28ffd7:7cf:ffff:ffff:ffff:ffff:ffff:ffff
126ffd7:7d0::/28ffd7:7df:ffff:ffff:ffff:ffff:ffff:ffff
127ffd7:7e0::/28ffd7:7ef:ffff:ffff:ffff:ffff:ffff:ffff
128ffd7:7f0::/28ffd7:7ff:ffff:ffff:ffff:ffff:ffff:ffff
129ffd7:800::/28ffd7:80f:ffff:ffff:ffff:ffff:ffff:ffff
130ffd7:810::/28ffd7:81f:ffff:ffff:ffff:ffff:ffff:ffff
131ffd7:820::/28ffd7:82f:ffff:ffff:ffff:ffff:ffff:ffff
132ffd7:830::/28ffd7:83f:ffff:ffff:ffff:ffff:ffff:ffff
133ffd7:840::/28ffd7:84f:ffff:ffff:ffff:ffff:ffff:ffff
134ffd7:850::/28ffd7:85f:ffff:ffff:ffff:ffff:ffff:ffff
135ffd7:860::/28ffd7:86f:ffff:ffff:ffff:ffff:ffff:ffff
136ffd7:870::/28ffd7:87f:ffff:ffff:ffff:ffff:ffff:ffff
137ffd7:880::/28ffd7:88f:ffff:ffff:ffff:ffff:ffff:ffff
138ffd7:890::/28ffd7:89f:ffff:ffff:ffff:ffff:ffff:ffff
139ffd7:8a0::/28ffd7:8af:ffff:ffff:ffff:ffff:ffff:ffff
140ffd7:8b0::/28ffd7:8bf:ffff:ffff:ffff:ffff:ffff:ffff
141ffd7:8c0::/28ffd7:8cf:ffff:ffff:ffff:ffff:ffff:ffff
142ffd7:8d0::/28ffd7:8df:ffff:ffff:ffff:ffff:ffff:ffff
143ffd7:8e0::/28ffd7:8ef:ffff:ffff:ffff:ffff:ffff:ffff
144ffd7:8f0::/28ffd7:8ff:ffff:ffff:ffff:ffff:ffff:ffff
145ffd7:900::/28ffd7:90f:ffff:ffff:ffff:ffff:ffff:ffff
146ffd7:910::/28ffd7:91f:ffff:ffff:ffff:ffff:ffff:ffff
147ffd7:920::/28ffd7:92f:ffff:ffff:ffff:ffff:ffff:ffff
148ffd7:930::/28ffd7:93f:ffff:ffff:ffff:ffff:ffff:ffff
149ffd7:940::/28ffd7:94f:ffff:ffff:ffff:ffff:ffff:ffff
150ffd7:950::/28ffd7:95f:ffff:ffff:ffff:ffff:ffff:ffff
151ffd7:960::/28ffd7:96f:ffff:ffff:ffff:ffff:ffff:ffff
152ffd7:970::/28ffd7:97f:ffff:ffff:ffff:ffff:ffff:ffff
153ffd7:980::/28ffd7:98f:ffff:ffff:ffff:ffff:ffff:ffff
154ffd7:990::/28ffd7:99f:ffff:ffff:ffff:ffff:ffff:ffff
155ffd7:9a0::/28ffd7:9af:ffff:ffff:ffff:ffff:ffff:ffff
156ffd7:9b0::/28ffd7:9bf:ffff:ffff:ffff:ffff:ffff:ffff
157ffd7:9c0::/28ffd7:9cf:ffff:ffff:ffff:ffff:ffff:ffff
158ffd7:9d0::/28ffd7:9df:ffff:ffff:ffff:ffff:ffff:ffff
159ffd7:9e0::/28ffd7:9ef:ffff:ffff:ffff:ffff:ffff:ffff
160ffd7:9f0::/28ffd7:9ff:ffff:ffff:ffff:ffff:ffff:ffff
161ffd7:a00::/28ffd7:a0f:ffff:ffff:ffff:ffff:ffff:ffff
162ffd7:a10::/28ffd7:a1f:ffff:ffff:ffff:ffff:ffff:ffff
163ffd7:a20::/28ffd7:a2f:ffff:ffff:ffff:ffff:ffff:ffff
164ffd7:a30::/28ffd7:a3f:ffff:ffff:ffff:ffff:ffff:ffff
165ffd7:a40::/28ffd7:a4f:ffff:ffff:ffff:ffff:ffff:ffff
166ffd7:a50::/28ffd7:a5f:ffff:ffff:ffff:ffff:ffff:ffff
167ffd7:a60::/28ffd7:a6f:ffff:ffff:ffff:ffff:ffff:ffff
168ffd7:a70::/28ffd7:a7f:ffff:ffff:ffff:ffff:ffff:ffff
169ffd7:a80::/28ffd7:a8f:ffff:ffff:ffff:ffff:ffff:ffff
170ffd7:a90::/28ffd7:a9f:ffff:ffff:ffff:ffff:ffff:ffff
171ffd7:aa0::/28ffd7:aaf:ffff:ffff:ffff:ffff:ffff:ffff
172ffd7:ab0::/28ffd7:abf:ffff:ffff:ffff:ffff:ffff:ffff
173ffd7:ac0::/28ffd7:acf:ffff:ffff:ffff:ffff:ffff:ffff
174ffd7:ad0::/28ffd7:adf:ffff:ffff:ffff:ffff:ffff:ffff
175ffd7:ae0::/28ffd7:aef:ffff:ffff:ffff:ffff:ffff:ffff
176ffd7:af0::/28ffd7:aff:ffff:ffff:ffff:ffff:ffff:ffff
177ffd7:b00::/28ffd7:b0f:ffff:ffff:ffff:ffff:ffff:ffff
178ffd7:b10::/28ffd7:b1f:ffff:ffff:ffff:ffff:ffff:ffff
179ffd7:b20::/28ffd7:b2f:ffff:ffff:ffff:ffff:ffff:ffff
180ffd7:b30::/28ffd7:b3f:ffff:ffff:ffff:ffff:ffff:ffff
181ffd7:b40::/28ffd7:b4f:ffff:ffff:ffff:ffff:ffff:ffff
182ffd7:b50::/28ffd7:b5f:ffff:ffff:ffff:ffff:ffff:ffff
183ffd7:b60::/28ffd7:b6f:ffff:ffff:ffff:ffff:ffff:ffff
184ffd7:b70::/28ffd7:b7f:ffff:ffff:ffff:ffff:ffff:ffff
185ffd7:b80::/28ffd7:b8f:ffff:ffff:ffff:ffff:ffff:ffff
186ffd7:b90::/28ffd7:b9f:ffff:ffff:ffff:ffff:ffff:ffff
187ffd7:ba0::/28ffd7:baf:ffff:ffff:ffff:ffff:ffff:ffff
188ffd7:bb0::/28ffd7:bbf:ffff:ffff:ffff:ffff:ffff:ffff
189ffd7:bc0::/28ffd7:bcf:ffff:ffff:ffff:ffff:ffff:ffff
190ffd7:bd0::/28ffd7:bdf:ffff:ffff:ffff:ffff:ffff:ffff
191ffd7:be0::/28ffd7:bef:ffff:ffff:ffff:ffff:ffff:ffff
192ffd7:bf0::/28ffd7:bff:ffff:ffff:ffff:ffff:ffff:ffff
193ffd7:c00::/28ffd7:c0f:ffff:ffff:ffff:ffff:ffff:ffff
194ffd7:c10::/28ffd7:c1f:ffff:ffff:ffff:ffff:ffff:ffff
195ffd7:c20::/28ffd7:c2f:ffff:ffff:ffff:ffff:ffff:ffff
196ffd7:c30::/28ffd7:c3f:ffff:ffff:ffff:ffff:ffff:ffff
197ffd7:c40::/28ffd7:c4f:ffff:ffff:ffff:ffff:ffff:ffff
198ffd7:c50::/28ffd7:c5f:ffff:ffff:ffff:ffff:ffff:ffff
199ffd7:c60::/28ffd7:c6f:ffff:ffff:ffff:ffff:ffff:ffff
200ffd7:c70::/28ffd7:c7f:ffff:ffff:ffff:ffff:ffff:ffff
201ffd7:c80::/28ffd7:c8f:ffff:ffff:ffff:ffff:ffff:ffff
202ffd7:c90::/28ffd7:c9f:ffff:ffff:ffff:ffff:ffff:ffff
203ffd7:ca0::/28ffd7:caf:ffff:ffff:ffff:ffff:ffff:ffff
204ffd7:cb0::/28ffd7:cbf:ffff:ffff:ffff:ffff:ffff:ffff
205ffd7:cc0::/28ffd7:ccf:ffff:ffff:ffff:ffff:ffff:ffff
206ffd7:cd0::/28ffd7:cdf:ffff:ffff:ffff:ffff:ffff:ffff
207ffd7:ce0::/28ffd7:cef:ffff:ffff:ffff:ffff:ffff:ffff
208ffd7:cf0::/28ffd7:cff:ffff:ffff:ffff:ffff:ffff:ffff
209ffd7:d00::/28ffd7:d0f:ffff:ffff:ffff:ffff:ffff:ffff
210ffd7:d10::/28ffd7:d1f:ffff:ffff:ffff:ffff:ffff:ffff
211ffd7:d20::/28ffd7:d2f:ffff:ffff:ffff:ffff:ffff:ffff
212ffd7:d30::/28ffd7:d3f:ffff:ffff:ffff:ffff:ffff:ffff
213ffd7:d40::/28ffd7:d4f:ffff:ffff:ffff:ffff:ffff:ffff
214ffd7:d50::/28ffd7:d5f:ffff:ffff:ffff:ffff:ffff:ffff
215ffd7:d60::/28ffd7:d6f:ffff:ffff:ffff:ffff:ffff:ffff
216ffd7:d70::/28ffd7:d7f:ffff:ffff:ffff:ffff:ffff:ffff
217ffd7:d80::/28ffd7:d8f:ffff:ffff:ffff:ffff:ffff:ffff
218ffd7:d90::/28ffd7:d9f:ffff:ffff:ffff:ffff:ffff:ffff
219ffd7:da0::/28ffd7:daf:ffff:ffff:ffff:ffff:ffff:ffff
220ffd7:db0::/28ffd7:dbf:ffff:ffff:ffff:ffff:ffff:ffff
221ffd7:dc0::/28ffd7:dcf:ffff:ffff:ffff:ffff:ffff:ffff
222ffd7:dd0::/28ffd7:ddf:ffff:ffff:ffff:ffff:ffff:ffff
223ffd7:de0::/28ffd7:def:ffff:ffff:ffff:ffff:ffff:ffff
224ffd7:df0::/28ffd7:dff:ffff:ffff:ffff:ffff:ffff:ffff
225ffd7:e00::/28ffd7:e0f:ffff:ffff:ffff:ffff:ffff:ffff
226ffd7:e10::/28ffd7:e1f:ffff:ffff:ffff:ffff:ffff:ffff
227ffd7:e20::/28ffd7:e2f:ffff:ffff:ffff:ffff:ffff:ffff
228ffd7:e30::/28ffd7:e3f:ffff:ffff:ffff:ffff:ffff:ffff
229ffd7:e40::/28ffd7:e4f:ffff:ffff:ffff:ffff:ffff:ffff
230ffd7:e50::/28ffd7:e5f:ffff:ffff:ffff:ffff:ffff:ffff
231ffd7:e60::/28ffd7:e6f:ffff:ffff:ffff:ffff:ffff:ffff
232ffd7:e70::/28ffd7:e7f:ffff:ffff:ffff:ffff:ffff:ffff
233ffd7:e80::/28ffd7:e8f:ffff:ffff:ffff:ffff:ffff:ffff
234ffd7:e90::/28ffd7:e9f:ffff:ffff:ffff:ffff:ffff:ffff
235ffd7:ea0::/28ffd7:eaf:ffff:ffff:ffff:ffff:ffff:ffff
236ffd7:eb0::/28ffd7:ebf:ffff:ffff:ffff:ffff:ffff:ffff
237ffd7:ec0::/28ffd7:ecf:ffff:ffff:ffff:ffff:ffff:ffff
238ffd7:ed0::/28ffd7:edf:ffff:ffff:ffff:ffff:ffff:ffff
239ffd7:ee0::/28ffd7:eef:ffff:ffff:ffff:ffff:ffff:ffff
240ffd7:ef0::/28ffd7:eff:ffff:ffff:ffff:ffff:ffff:ffff
241ffd7:f00::/28ffd7:f0f:ffff:ffff:ffff:ffff:ffff:ffff
242ffd7:f10::/28ffd7:f1f:ffff:ffff:ffff:ffff:ffff:ffff
243ffd7:f20::/28ffd7:f2f:ffff:ffff:ffff:ffff:ffff:ffff
244ffd7:f30::/28ffd7:f3f:ffff:ffff:ffff:ffff:ffff:ffff
245ffd7:f40::/28ffd7:f4f:ffff:ffff:ffff:ffff:ffff:ffff
246ffd7:f50::/28ffd7:f5f:ffff:ffff:ffff:ffff:ffff:ffff
247ffd7:f60::/28ffd7:f6f:ffff:ffff:ffff:ffff:ffff:ffff
248ffd7:f70::/28ffd7:f7f:ffff:ffff:ffff:ffff:ffff:ffff
249ffd7:f80::/28ffd7:f8f:ffff:ffff:ffff:ffff:ffff:ffff
250ffd7:f90::/28ffd7:f9f:ffff:ffff:ffff:ffff:ffff:ffff
251ffd7:fa0::/28ffd7:faf:ffff:ffff:ffff:ffff:ffff:ffff
252ffd7:fb0::/28ffd7:fbf:ffff:ffff:ffff:ffff:ffff:ffff
253ffd7:fc0::/28ffd7:fcf:ffff:ffff:ffff:ffff:ffff:ffff
254ffd7:fd0::/28ffd7:fdf:ffff:ffff:ffff:ffff:ffff:ffff
255ffd7:fe0::/28ffd7:fef:ffff:ffff:ffff:ffff:ffff:ffff
256ffd7:ff0::/28ffd7:fff: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.