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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
ffd5::/16
First address
ffd5::
Last address
ffd5: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
ffd5:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
5.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)

ffd5::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
1ffd5::/28ffd5:f:ffff:ffff:ffff:ffff:ffff:ffff
2ffd5:10::/28ffd5:1f:ffff:ffff:ffff:ffff:ffff:ffff
3ffd5:20::/28ffd5:2f:ffff:ffff:ffff:ffff:ffff:ffff
4ffd5:30::/28ffd5:3f:ffff:ffff:ffff:ffff:ffff:ffff
5ffd5:40::/28ffd5:4f:ffff:ffff:ffff:ffff:ffff:ffff
6ffd5:50::/28ffd5:5f:ffff:ffff:ffff:ffff:ffff:ffff
7ffd5:60::/28ffd5:6f:ffff:ffff:ffff:ffff:ffff:ffff
8ffd5:70::/28ffd5:7f:ffff:ffff:ffff:ffff:ffff:ffff
9ffd5:80::/28ffd5:8f:ffff:ffff:ffff:ffff:ffff:ffff
10ffd5:90::/28ffd5:9f:ffff:ffff:ffff:ffff:ffff:ffff
11ffd5:a0::/28ffd5:af:ffff:ffff:ffff:ffff:ffff:ffff
12ffd5:b0::/28ffd5:bf:ffff:ffff:ffff:ffff:ffff:ffff
13ffd5:c0::/28ffd5:cf:ffff:ffff:ffff:ffff:ffff:ffff
14ffd5:d0::/28ffd5:df:ffff:ffff:ffff:ffff:ffff:ffff
15ffd5:e0::/28ffd5:ef:ffff:ffff:ffff:ffff:ffff:ffff
16ffd5:f0::/28ffd5:ff:ffff:ffff:ffff:ffff:ffff:ffff
17ffd5:100::/28ffd5:10f:ffff:ffff:ffff:ffff:ffff:ffff
18ffd5:110::/28ffd5:11f:ffff:ffff:ffff:ffff:ffff:ffff
19ffd5:120::/28ffd5:12f:ffff:ffff:ffff:ffff:ffff:ffff
20ffd5:130::/28ffd5:13f:ffff:ffff:ffff:ffff:ffff:ffff
21ffd5:140::/28ffd5:14f:ffff:ffff:ffff:ffff:ffff:ffff
22ffd5:150::/28ffd5:15f:ffff:ffff:ffff:ffff:ffff:ffff
23ffd5:160::/28ffd5:16f:ffff:ffff:ffff:ffff:ffff:ffff
24ffd5:170::/28ffd5:17f:ffff:ffff:ffff:ffff:ffff:ffff
25ffd5:180::/28ffd5:18f:ffff:ffff:ffff:ffff:ffff:ffff
26ffd5:190::/28ffd5:19f:ffff:ffff:ffff:ffff:ffff:ffff
27ffd5:1a0::/28ffd5:1af:ffff:ffff:ffff:ffff:ffff:ffff
28ffd5:1b0::/28ffd5:1bf:ffff:ffff:ffff:ffff:ffff:ffff
29ffd5:1c0::/28ffd5:1cf:ffff:ffff:ffff:ffff:ffff:ffff
30ffd5:1d0::/28ffd5:1df:ffff:ffff:ffff:ffff:ffff:ffff
31ffd5:1e0::/28ffd5:1ef:ffff:ffff:ffff:ffff:ffff:ffff
32ffd5:1f0::/28ffd5:1ff:ffff:ffff:ffff:ffff:ffff:ffff
33ffd5:200::/28ffd5:20f:ffff:ffff:ffff:ffff:ffff:ffff
34ffd5:210::/28ffd5:21f:ffff:ffff:ffff:ffff:ffff:ffff
35ffd5:220::/28ffd5:22f:ffff:ffff:ffff:ffff:ffff:ffff
36ffd5:230::/28ffd5:23f:ffff:ffff:ffff:ffff:ffff:ffff
37ffd5:240::/28ffd5:24f:ffff:ffff:ffff:ffff:ffff:ffff
38ffd5:250::/28ffd5:25f:ffff:ffff:ffff:ffff:ffff:ffff
39ffd5:260::/28ffd5:26f:ffff:ffff:ffff:ffff:ffff:ffff
40ffd5:270::/28ffd5:27f:ffff:ffff:ffff:ffff:ffff:ffff
41ffd5:280::/28ffd5:28f:ffff:ffff:ffff:ffff:ffff:ffff
42ffd5:290::/28ffd5:29f:ffff:ffff:ffff:ffff:ffff:ffff
43ffd5:2a0::/28ffd5:2af:ffff:ffff:ffff:ffff:ffff:ffff
44ffd5:2b0::/28ffd5:2bf:ffff:ffff:ffff:ffff:ffff:ffff
45ffd5:2c0::/28ffd5:2cf:ffff:ffff:ffff:ffff:ffff:ffff
46ffd5:2d0::/28ffd5:2df:ffff:ffff:ffff:ffff:ffff:ffff
47ffd5:2e0::/28ffd5:2ef:ffff:ffff:ffff:ffff:ffff:ffff
48ffd5:2f0::/28ffd5:2ff:ffff:ffff:ffff:ffff:ffff:ffff
49ffd5:300::/28ffd5:30f:ffff:ffff:ffff:ffff:ffff:ffff
50ffd5:310::/28ffd5:31f:ffff:ffff:ffff:ffff:ffff:ffff
51ffd5:320::/28ffd5:32f:ffff:ffff:ffff:ffff:ffff:ffff
52ffd5:330::/28ffd5:33f:ffff:ffff:ffff:ffff:ffff:ffff
53ffd5:340::/28ffd5:34f:ffff:ffff:ffff:ffff:ffff:ffff
54ffd5:350::/28ffd5:35f:ffff:ffff:ffff:ffff:ffff:ffff
55ffd5:360::/28ffd5:36f:ffff:ffff:ffff:ffff:ffff:ffff
56ffd5:370::/28ffd5:37f:ffff:ffff:ffff:ffff:ffff:ffff
57ffd5:380::/28ffd5:38f:ffff:ffff:ffff:ffff:ffff:ffff
58ffd5:390::/28ffd5:39f:ffff:ffff:ffff:ffff:ffff:ffff
59ffd5:3a0::/28ffd5:3af:ffff:ffff:ffff:ffff:ffff:ffff
60ffd5:3b0::/28ffd5:3bf:ffff:ffff:ffff:ffff:ffff:ffff
61ffd5:3c0::/28ffd5:3cf:ffff:ffff:ffff:ffff:ffff:ffff
62ffd5:3d0::/28ffd5:3df:ffff:ffff:ffff:ffff:ffff:ffff
63ffd5:3e0::/28ffd5:3ef:ffff:ffff:ffff:ffff:ffff:ffff
64ffd5:3f0::/28ffd5:3ff:ffff:ffff:ffff:ffff:ffff:ffff
65ffd5:400::/28ffd5:40f:ffff:ffff:ffff:ffff:ffff:ffff
66ffd5:410::/28ffd5:41f:ffff:ffff:ffff:ffff:ffff:ffff
67ffd5:420::/28ffd5:42f:ffff:ffff:ffff:ffff:ffff:ffff
68ffd5:430::/28ffd5:43f:ffff:ffff:ffff:ffff:ffff:ffff
69ffd5:440::/28ffd5:44f:ffff:ffff:ffff:ffff:ffff:ffff
70ffd5:450::/28ffd5:45f:ffff:ffff:ffff:ffff:ffff:ffff
71ffd5:460::/28ffd5:46f:ffff:ffff:ffff:ffff:ffff:ffff
72ffd5:470::/28ffd5:47f:ffff:ffff:ffff:ffff:ffff:ffff
73ffd5:480::/28ffd5:48f:ffff:ffff:ffff:ffff:ffff:ffff
74ffd5:490::/28ffd5:49f:ffff:ffff:ffff:ffff:ffff:ffff
75ffd5:4a0::/28ffd5:4af:ffff:ffff:ffff:ffff:ffff:ffff
76ffd5:4b0::/28ffd5:4bf:ffff:ffff:ffff:ffff:ffff:ffff
77ffd5:4c0::/28ffd5:4cf:ffff:ffff:ffff:ffff:ffff:ffff
78ffd5:4d0::/28ffd5:4df:ffff:ffff:ffff:ffff:ffff:ffff
79ffd5:4e0::/28ffd5:4ef:ffff:ffff:ffff:ffff:ffff:ffff
80ffd5:4f0::/28ffd5:4ff:ffff:ffff:ffff:ffff:ffff:ffff
81ffd5:500::/28ffd5:50f:ffff:ffff:ffff:ffff:ffff:ffff
82ffd5:510::/28ffd5:51f:ffff:ffff:ffff:ffff:ffff:ffff
83ffd5:520::/28ffd5:52f:ffff:ffff:ffff:ffff:ffff:ffff
84ffd5:530::/28ffd5:53f:ffff:ffff:ffff:ffff:ffff:ffff
85ffd5:540::/28ffd5:54f:ffff:ffff:ffff:ffff:ffff:ffff
86ffd5:550::/28ffd5:55f:ffff:ffff:ffff:ffff:ffff:ffff
87ffd5:560::/28ffd5:56f:ffff:ffff:ffff:ffff:ffff:ffff
88ffd5:570::/28ffd5:57f:ffff:ffff:ffff:ffff:ffff:ffff
89ffd5:580::/28ffd5:58f:ffff:ffff:ffff:ffff:ffff:ffff
90ffd5:590::/28ffd5:59f:ffff:ffff:ffff:ffff:ffff:ffff
91ffd5:5a0::/28ffd5:5af:ffff:ffff:ffff:ffff:ffff:ffff
92ffd5:5b0::/28ffd5:5bf:ffff:ffff:ffff:ffff:ffff:ffff
93ffd5:5c0::/28ffd5:5cf:ffff:ffff:ffff:ffff:ffff:ffff
94ffd5:5d0::/28ffd5:5df:ffff:ffff:ffff:ffff:ffff:ffff
95ffd5:5e0::/28ffd5:5ef:ffff:ffff:ffff:ffff:ffff:ffff
96ffd5:5f0::/28ffd5:5ff:ffff:ffff:ffff:ffff:ffff:ffff
97ffd5:600::/28ffd5:60f:ffff:ffff:ffff:ffff:ffff:ffff
98ffd5:610::/28ffd5:61f:ffff:ffff:ffff:ffff:ffff:ffff
99ffd5:620::/28ffd5:62f:ffff:ffff:ffff:ffff:ffff:ffff
100ffd5:630::/28ffd5:63f:ffff:ffff:ffff:ffff:ffff:ffff
101ffd5:640::/28ffd5:64f:ffff:ffff:ffff:ffff:ffff:ffff
102ffd5:650::/28ffd5:65f:ffff:ffff:ffff:ffff:ffff:ffff
103ffd5:660::/28ffd5:66f:ffff:ffff:ffff:ffff:ffff:ffff
104ffd5:670::/28ffd5:67f:ffff:ffff:ffff:ffff:ffff:ffff
105ffd5:680::/28ffd5:68f:ffff:ffff:ffff:ffff:ffff:ffff
106ffd5:690::/28ffd5:69f:ffff:ffff:ffff:ffff:ffff:ffff
107ffd5:6a0::/28ffd5:6af:ffff:ffff:ffff:ffff:ffff:ffff
108ffd5:6b0::/28ffd5:6bf:ffff:ffff:ffff:ffff:ffff:ffff
109ffd5:6c0::/28ffd5:6cf:ffff:ffff:ffff:ffff:ffff:ffff
110ffd5:6d0::/28ffd5:6df:ffff:ffff:ffff:ffff:ffff:ffff
111ffd5:6e0::/28ffd5:6ef:ffff:ffff:ffff:ffff:ffff:ffff
112ffd5:6f0::/28ffd5:6ff:ffff:ffff:ffff:ffff:ffff:ffff
113ffd5:700::/28ffd5:70f:ffff:ffff:ffff:ffff:ffff:ffff
114ffd5:710::/28ffd5:71f:ffff:ffff:ffff:ffff:ffff:ffff
115ffd5:720::/28ffd5:72f:ffff:ffff:ffff:ffff:ffff:ffff
116ffd5:730::/28ffd5:73f:ffff:ffff:ffff:ffff:ffff:ffff
117ffd5:740::/28ffd5:74f:ffff:ffff:ffff:ffff:ffff:ffff
118ffd5:750::/28ffd5:75f:ffff:ffff:ffff:ffff:ffff:ffff
119ffd5:760::/28ffd5:76f:ffff:ffff:ffff:ffff:ffff:ffff
120ffd5:770::/28ffd5:77f:ffff:ffff:ffff:ffff:ffff:ffff
121ffd5:780::/28ffd5:78f:ffff:ffff:ffff:ffff:ffff:ffff
122ffd5:790::/28ffd5:79f:ffff:ffff:ffff:ffff:ffff:ffff
123ffd5:7a0::/28ffd5:7af:ffff:ffff:ffff:ffff:ffff:ffff
124ffd5:7b0::/28ffd5:7bf:ffff:ffff:ffff:ffff:ffff:ffff
125ffd5:7c0::/28ffd5:7cf:ffff:ffff:ffff:ffff:ffff:ffff
126ffd5:7d0::/28ffd5:7df:ffff:ffff:ffff:ffff:ffff:ffff
127ffd5:7e0::/28ffd5:7ef:ffff:ffff:ffff:ffff:ffff:ffff
128ffd5:7f0::/28ffd5:7ff:ffff:ffff:ffff:ffff:ffff:ffff
129ffd5:800::/28ffd5:80f:ffff:ffff:ffff:ffff:ffff:ffff
130ffd5:810::/28ffd5:81f:ffff:ffff:ffff:ffff:ffff:ffff
131ffd5:820::/28ffd5:82f:ffff:ffff:ffff:ffff:ffff:ffff
132ffd5:830::/28ffd5:83f:ffff:ffff:ffff:ffff:ffff:ffff
133ffd5:840::/28ffd5:84f:ffff:ffff:ffff:ffff:ffff:ffff
134ffd5:850::/28ffd5:85f:ffff:ffff:ffff:ffff:ffff:ffff
135ffd5:860::/28ffd5:86f:ffff:ffff:ffff:ffff:ffff:ffff
136ffd5:870::/28ffd5:87f:ffff:ffff:ffff:ffff:ffff:ffff
137ffd5:880::/28ffd5:88f:ffff:ffff:ffff:ffff:ffff:ffff
138ffd5:890::/28ffd5:89f:ffff:ffff:ffff:ffff:ffff:ffff
139ffd5:8a0::/28ffd5:8af:ffff:ffff:ffff:ffff:ffff:ffff
140ffd5:8b0::/28ffd5:8bf:ffff:ffff:ffff:ffff:ffff:ffff
141ffd5:8c0::/28ffd5:8cf:ffff:ffff:ffff:ffff:ffff:ffff
142ffd5:8d0::/28ffd5:8df:ffff:ffff:ffff:ffff:ffff:ffff
143ffd5:8e0::/28ffd5:8ef:ffff:ffff:ffff:ffff:ffff:ffff
144ffd5:8f0::/28ffd5:8ff:ffff:ffff:ffff:ffff:ffff:ffff
145ffd5:900::/28ffd5:90f:ffff:ffff:ffff:ffff:ffff:ffff
146ffd5:910::/28ffd5:91f:ffff:ffff:ffff:ffff:ffff:ffff
147ffd5:920::/28ffd5:92f:ffff:ffff:ffff:ffff:ffff:ffff
148ffd5:930::/28ffd5:93f:ffff:ffff:ffff:ffff:ffff:ffff
149ffd5:940::/28ffd5:94f:ffff:ffff:ffff:ffff:ffff:ffff
150ffd5:950::/28ffd5:95f:ffff:ffff:ffff:ffff:ffff:ffff
151ffd5:960::/28ffd5:96f:ffff:ffff:ffff:ffff:ffff:ffff
152ffd5:970::/28ffd5:97f:ffff:ffff:ffff:ffff:ffff:ffff
153ffd5:980::/28ffd5:98f:ffff:ffff:ffff:ffff:ffff:ffff
154ffd5:990::/28ffd5:99f:ffff:ffff:ffff:ffff:ffff:ffff
155ffd5:9a0::/28ffd5:9af:ffff:ffff:ffff:ffff:ffff:ffff
156ffd5:9b0::/28ffd5:9bf:ffff:ffff:ffff:ffff:ffff:ffff
157ffd5:9c0::/28ffd5:9cf:ffff:ffff:ffff:ffff:ffff:ffff
158ffd5:9d0::/28ffd5:9df:ffff:ffff:ffff:ffff:ffff:ffff
159ffd5:9e0::/28ffd5:9ef:ffff:ffff:ffff:ffff:ffff:ffff
160ffd5:9f0::/28ffd5:9ff:ffff:ffff:ffff:ffff:ffff:ffff
161ffd5:a00::/28ffd5:a0f:ffff:ffff:ffff:ffff:ffff:ffff
162ffd5:a10::/28ffd5:a1f:ffff:ffff:ffff:ffff:ffff:ffff
163ffd5:a20::/28ffd5:a2f:ffff:ffff:ffff:ffff:ffff:ffff
164ffd5:a30::/28ffd5:a3f:ffff:ffff:ffff:ffff:ffff:ffff
165ffd5:a40::/28ffd5:a4f:ffff:ffff:ffff:ffff:ffff:ffff
166ffd5:a50::/28ffd5:a5f:ffff:ffff:ffff:ffff:ffff:ffff
167ffd5:a60::/28ffd5:a6f:ffff:ffff:ffff:ffff:ffff:ffff
168ffd5:a70::/28ffd5:a7f:ffff:ffff:ffff:ffff:ffff:ffff
169ffd5:a80::/28ffd5:a8f:ffff:ffff:ffff:ffff:ffff:ffff
170ffd5:a90::/28ffd5:a9f:ffff:ffff:ffff:ffff:ffff:ffff
171ffd5:aa0::/28ffd5:aaf:ffff:ffff:ffff:ffff:ffff:ffff
172ffd5:ab0::/28ffd5:abf:ffff:ffff:ffff:ffff:ffff:ffff
173ffd5:ac0::/28ffd5:acf:ffff:ffff:ffff:ffff:ffff:ffff
174ffd5:ad0::/28ffd5:adf:ffff:ffff:ffff:ffff:ffff:ffff
175ffd5:ae0::/28ffd5:aef:ffff:ffff:ffff:ffff:ffff:ffff
176ffd5:af0::/28ffd5:aff:ffff:ffff:ffff:ffff:ffff:ffff
177ffd5:b00::/28ffd5:b0f:ffff:ffff:ffff:ffff:ffff:ffff
178ffd5:b10::/28ffd5:b1f:ffff:ffff:ffff:ffff:ffff:ffff
179ffd5:b20::/28ffd5:b2f:ffff:ffff:ffff:ffff:ffff:ffff
180ffd5:b30::/28ffd5:b3f:ffff:ffff:ffff:ffff:ffff:ffff
181ffd5:b40::/28ffd5:b4f:ffff:ffff:ffff:ffff:ffff:ffff
182ffd5:b50::/28ffd5:b5f:ffff:ffff:ffff:ffff:ffff:ffff
183ffd5:b60::/28ffd5:b6f:ffff:ffff:ffff:ffff:ffff:ffff
184ffd5:b70::/28ffd5:b7f:ffff:ffff:ffff:ffff:ffff:ffff
185ffd5:b80::/28ffd5:b8f:ffff:ffff:ffff:ffff:ffff:ffff
186ffd5:b90::/28ffd5:b9f:ffff:ffff:ffff:ffff:ffff:ffff
187ffd5:ba0::/28ffd5:baf:ffff:ffff:ffff:ffff:ffff:ffff
188ffd5:bb0::/28ffd5:bbf:ffff:ffff:ffff:ffff:ffff:ffff
189ffd5:bc0::/28ffd5:bcf:ffff:ffff:ffff:ffff:ffff:ffff
190ffd5:bd0::/28ffd5:bdf:ffff:ffff:ffff:ffff:ffff:ffff
191ffd5:be0::/28ffd5:bef:ffff:ffff:ffff:ffff:ffff:ffff
192ffd5:bf0::/28ffd5:bff:ffff:ffff:ffff:ffff:ffff:ffff
193ffd5:c00::/28ffd5:c0f:ffff:ffff:ffff:ffff:ffff:ffff
194ffd5:c10::/28ffd5:c1f:ffff:ffff:ffff:ffff:ffff:ffff
195ffd5:c20::/28ffd5:c2f:ffff:ffff:ffff:ffff:ffff:ffff
196ffd5:c30::/28ffd5:c3f:ffff:ffff:ffff:ffff:ffff:ffff
197ffd5:c40::/28ffd5:c4f:ffff:ffff:ffff:ffff:ffff:ffff
198ffd5:c50::/28ffd5:c5f:ffff:ffff:ffff:ffff:ffff:ffff
199ffd5:c60::/28ffd5:c6f:ffff:ffff:ffff:ffff:ffff:ffff
200ffd5:c70::/28ffd5:c7f:ffff:ffff:ffff:ffff:ffff:ffff
201ffd5:c80::/28ffd5:c8f:ffff:ffff:ffff:ffff:ffff:ffff
202ffd5:c90::/28ffd5:c9f:ffff:ffff:ffff:ffff:ffff:ffff
203ffd5:ca0::/28ffd5:caf:ffff:ffff:ffff:ffff:ffff:ffff
204ffd5:cb0::/28ffd5:cbf:ffff:ffff:ffff:ffff:ffff:ffff
205ffd5:cc0::/28ffd5:ccf:ffff:ffff:ffff:ffff:ffff:ffff
206ffd5:cd0::/28ffd5:cdf:ffff:ffff:ffff:ffff:ffff:ffff
207ffd5:ce0::/28ffd5:cef:ffff:ffff:ffff:ffff:ffff:ffff
208ffd5:cf0::/28ffd5:cff:ffff:ffff:ffff:ffff:ffff:ffff
209ffd5:d00::/28ffd5:d0f:ffff:ffff:ffff:ffff:ffff:ffff
210ffd5:d10::/28ffd5:d1f:ffff:ffff:ffff:ffff:ffff:ffff
211ffd5:d20::/28ffd5:d2f:ffff:ffff:ffff:ffff:ffff:ffff
212ffd5:d30::/28ffd5:d3f:ffff:ffff:ffff:ffff:ffff:ffff
213ffd5:d40::/28ffd5:d4f:ffff:ffff:ffff:ffff:ffff:ffff
214ffd5:d50::/28ffd5:d5f:ffff:ffff:ffff:ffff:ffff:ffff
215ffd5:d60::/28ffd5:d6f:ffff:ffff:ffff:ffff:ffff:ffff
216ffd5:d70::/28ffd5:d7f:ffff:ffff:ffff:ffff:ffff:ffff
217ffd5:d80::/28ffd5:d8f:ffff:ffff:ffff:ffff:ffff:ffff
218ffd5:d90::/28ffd5:d9f:ffff:ffff:ffff:ffff:ffff:ffff
219ffd5:da0::/28ffd5:daf:ffff:ffff:ffff:ffff:ffff:ffff
220ffd5:db0::/28ffd5:dbf:ffff:ffff:ffff:ffff:ffff:ffff
221ffd5:dc0::/28ffd5:dcf:ffff:ffff:ffff:ffff:ffff:ffff
222ffd5:dd0::/28ffd5:ddf:ffff:ffff:ffff:ffff:ffff:ffff
223ffd5:de0::/28ffd5:def:ffff:ffff:ffff:ffff:ffff:ffff
224ffd5:df0::/28ffd5:dff:ffff:ffff:ffff:ffff:ffff:ffff
225ffd5:e00::/28ffd5:e0f:ffff:ffff:ffff:ffff:ffff:ffff
226ffd5:e10::/28ffd5:e1f:ffff:ffff:ffff:ffff:ffff:ffff
227ffd5:e20::/28ffd5:e2f:ffff:ffff:ffff:ffff:ffff:ffff
228ffd5:e30::/28ffd5:e3f:ffff:ffff:ffff:ffff:ffff:ffff
229ffd5:e40::/28ffd5:e4f:ffff:ffff:ffff:ffff:ffff:ffff
230ffd5:e50::/28ffd5:e5f:ffff:ffff:ffff:ffff:ffff:ffff
231ffd5:e60::/28ffd5:e6f:ffff:ffff:ffff:ffff:ffff:ffff
232ffd5:e70::/28ffd5:e7f:ffff:ffff:ffff:ffff:ffff:ffff
233ffd5:e80::/28ffd5:e8f:ffff:ffff:ffff:ffff:ffff:ffff
234ffd5:e90::/28ffd5:e9f:ffff:ffff:ffff:ffff:ffff:ffff
235ffd5:ea0::/28ffd5:eaf:ffff:ffff:ffff:ffff:ffff:ffff
236ffd5:eb0::/28ffd5:ebf:ffff:ffff:ffff:ffff:ffff:ffff
237ffd5:ec0::/28ffd5:ecf:ffff:ffff:ffff:ffff:ffff:ffff
238ffd5:ed0::/28ffd5:edf:ffff:ffff:ffff:ffff:ffff:ffff
239ffd5:ee0::/28ffd5:eef:ffff:ffff:ffff:ffff:ffff:ffff
240ffd5:ef0::/28ffd5:eff:ffff:ffff:ffff:ffff:ffff:ffff
241ffd5:f00::/28ffd5:f0f:ffff:ffff:ffff:ffff:ffff:ffff
242ffd5:f10::/28ffd5:f1f:ffff:ffff:ffff:ffff:ffff:ffff
243ffd5:f20::/28ffd5:f2f:ffff:ffff:ffff:ffff:ffff:ffff
244ffd5:f30::/28ffd5:f3f:ffff:ffff:ffff:ffff:ffff:ffff
245ffd5:f40::/28ffd5:f4f:ffff:ffff:ffff:ffff:ffff:ffff
246ffd5:f50::/28ffd5:f5f:ffff:ffff:ffff:ffff:ffff:ffff
247ffd5:f60::/28ffd5:f6f:ffff:ffff:ffff:ffff:ffff:ffff
248ffd5:f70::/28ffd5:f7f:ffff:ffff:ffff:ffff:ffff:ffff
249ffd5:f80::/28ffd5:f8f:ffff:ffff:ffff:ffff:ffff:ffff
250ffd5:f90::/28ffd5:f9f:ffff:ffff:ffff:ffff:ffff:ffff
251ffd5:fa0::/28ffd5:faf:ffff:ffff:ffff:ffff:ffff:ffff
252ffd5:fb0::/28ffd5:fbf:ffff:ffff:ffff:ffff:ffff:ffff
253ffd5:fc0::/28ffd5:fcf:ffff:ffff:ffff:ffff:ffff:ffff
254ffd5:fd0::/28ffd5:fdf:ffff:ffff:ffff:ffff:ffff:ffff
255ffd5:fe0::/28ffd5:fef:ffff:ffff:ffff:ffff:ffff:ffff
256ffd5:ff0::/28ffd5: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.