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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
ffb7::/16
First address
ffb7::
Last address
ffb7: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
ffb7:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
7.b.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)

ffb7::/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetLast address
1ffb7::/28ffb7:f:ffff:ffff:ffff:ffff:ffff:ffff
2ffb7:10::/28ffb7:1f:ffff:ffff:ffff:ffff:ffff:ffff
3ffb7:20::/28ffb7:2f:ffff:ffff:ffff:ffff:ffff:ffff
4ffb7:30::/28ffb7:3f:ffff:ffff:ffff:ffff:ffff:ffff
5ffb7:40::/28ffb7:4f:ffff:ffff:ffff:ffff:ffff:ffff
6ffb7:50::/28ffb7:5f:ffff:ffff:ffff:ffff:ffff:ffff
7ffb7:60::/28ffb7:6f:ffff:ffff:ffff:ffff:ffff:ffff
8ffb7:70::/28ffb7:7f:ffff:ffff:ffff:ffff:ffff:ffff
9ffb7:80::/28ffb7:8f:ffff:ffff:ffff:ffff:ffff:ffff
10ffb7:90::/28ffb7:9f:ffff:ffff:ffff:ffff:ffff:ffff
11ffb7:a0::/28ffb7:af:ffff:ffff:ffff:ffff:ffff:ffff
12ffb7:b0::/28ffb7:bf:ffff:ffff:ffff:ffff:ffff:ffff
13ffb7:c0::/28ffb7:cf:ffff:ffff:ffff:ffff:ffff:ffff
14ffb7:d0::/28ffb7:df:ffff:ffff:ffff:ffff:ffff:ffff
15ffb7:e0::/28ffb7:ef:ffff:ffff:ffff:ffff:ffff:ffff
16ffb7:f0::/28ffb7:ff:ffff:ffff:ffff:ffff:ffff:ffff
17ffb7:100::/28ffb7:10f:ffff:ffff:ffff:ffff:ffff:ffff
18ffb7:110::/28ffb7:11f:ffff:ffff:ffff:ffff:ffff:ffff
19ffb7:120::/28ffb7:12f:ffff:ffff:ffff:ffff:ffff:ffff
20ffb7:130::/28ffb7:13f:ffff:ffff:ffff:ffff:ffff:ffff
21ffb7:140::/28ffb7:14f:ffff:ffff:ffff:ffff:ffff:ffff
22ffb7:150::/28ffb7:15f:ffff:ffff:ffff:ffff:ffff:ffff
23ffb7:160::/28ffb7:16f:ffff:ffff:ffff:ffff:ffff:ffff
24ffb7:170::/28ffb7:17f:ffff:ffff:ffff:ffff:ffff:ffff
25ffb7:180::/28ffb7:18f:ffff:ffff:ffff:ffff:ffff:ffff
26ffb7:190::/28ffb7:19f:ffff:ffff:ffff:ffff:ffff:ffff
27ffb7:1a0::/28ffb7:1af:ffff:ffff:ffff:ffff:ffff:ffff
28ffb7:1b0::/28ffb7:1bf:ffff:ffff:ffff:ffff:ffff:ffff
29ffb7:1c0::/28ffb7:1cf:ffff:ffff:ffff:ffff:ffff:ffff
30ffb7:1d0::/28ffb7:1df:ffff:ffff:ffff:ffff:ffff:ffff
31ffb7:1e0::/28ffb7:1ef:ffff:ffff:ffff:ffff:ffff:ffff
32ffb7:1f0::/28ffb7:1ff:ffff:ffff:ffff:ffff:ffff:ffff
33ffb7:200::/28ffb7:20f:ffff:ffff:ffff:ffff:ffff:ffff
34ffb7:210::/28ffb7:21f:ffff:ffff:ffff:ffff:ffff:ffff
35ffb7:220::/28ffb7:22f:ffff:ffff:ffff:ffff:ffff:ffff
36ffb7:230::/28ffb7:23f:ffff:ffff:ffff:ffff:ffff:ffff
37ffb7:240::/28ffb7:24f:ffff:ffff:ffff:ffff:ffff:ffff
38ffb7:250::/28ffb7:25f:ffff:ffff:ffff:ffff:ffff:ffff
39ffb7:260::/28ffb7:26f:ffff:ffff:ffff:ffff:ffff:ffff
40ffb7:270::/28ffb7:27f:ffff:ffff:ffff:ffff:ffff:ffff
41ffb7:280::/28ffb7:28f:ffff:ffff:ffff:ffff:ffff:ffff
42ffb7:290::/28ffb7:29f:ffff:ffff:ffff:ffff:ffff:ffff
43ffb7:2a0::/28ffb7:2af:ffff:ffff:ffff:ffff:ffff:ffff
44ffb7:2b0::/28ffb7:2bf:ffff:ffff:ffff:ffff:ffff:ffff
45ffb7:2c0::/28ffb7:2cf:ffff:ffff:ffff:ffff:ffff:ffff
46ffb7:2d0::/28ffb7:2df:ffff:ffff:ffff:ffff:ffff:ffff
47ffb7:2e0::/28ffb7:2ef:ffff:ffff:ffff:ffff:ffff:ffff
48ffb7:2f0::/28ffb7:2ff:ffff:ffff:ffff:ffff:ffff:ffff
49ffb7:300::/28ffb7:30f:ffff:ffff:ffff:ffff:ffff:ffff
50ffb7:310::/28ffb7:31f:ffff:ffff:ffff:ffff:ffff:ffff
51ffb7:320::/28ffb7:32f:ffff:ffff:ffff:ffff:ffff:ffff
52ffb7:330::/28ffb7:33f:ffff:ffff:ffff:ffff:ffff:ffff
53ffb7:340::/28ffb7:34f:ffff:ffff:ffff:ffff:ffff:ffff
54ffb7:350::/28ffb7:35f:ffff:ffff:ffff:ffff:ffff:ffff
55ffb7:360::/28ffb7:36f:ffff:ffff:ffff:ffff:ffff:ffff
56ffb7:370::/28ffb7:37f:ffff:ffff:ffff:ffff:ffff:ffff
57ffb7:380::/28ffb7:38f:ffff:ffff:ffff:ffff:ffff:ffff
58ffb7:390::/28ffb7:39f:ffff:ffff:ffff:ffff:ffff:ffff
59ffb7:3a0::/28ffb7:3af:ffff:ffff:ffff:ffff:ffff:ffff
60ffb7:3b0::/28ffb7:3bf:ffff:ffff:ffff:ffff:ffff:ffff
61ffb7:3c0::/28ffb7:3cf:ffff:ffff:ffff:ffff:ffff:ffff
62ffb7:3d0::/28ffb7:3df:ffff:ffff:ffff:ffff:ffff:ffff
63ffb7:3e0::/28ffb7:3ef:ffff:ffff:ffff:ffff:ffff:ffff
64ffb7:3f0::/28ffb7:3ff:ffff:ffff:ffff:ffff:ffff:ffff
65ffb7:400::/28ffb7:40f:ffff:ffff:ffff:ffff:ffff:ffff
66ffb7:410::/28ffb7:41f:ffff:ffff:ffff:ffff:ffff:ffff
67ffb7:420::/28ffb7:42f:ffff:ffff:ffff:ffff:ffff:ffff
68ffb7:430::/28ffb7:43f:ffff:ffff:ffff:ffff:ffff:ffff
69ffb7:440::/28ffb7:44f:ffff:ffff:ffff:ffff:ffff:ffff
70ffb7:450::/28ffb7:45f:ffff:ffff:ffff:ffff:ffff:ffff
71ffb7:460::/28ffb7:46f:ffff:ffff:ffff:ffff:ffff:ffff
72ffb7:470::/28ffb7:47f:ffff:ffff:ffff:ffff:ffff:ffff
73ffb7:480::/28ffb7:48f:ffff:ffff:ffff:ffff:ffff:ffff
74ffb7:490::/28ffb7:49f:ffff:ffff:ffff:ffff:ffff:ffff
75ffb7:4a0::/28ffb7:4af:ffff:ffff:ffff:ffff:ffff:ffff
76ffb7:4b0::/28ffb7:4bf:ffff:ffff:ffff:ffff:ffff:ffff
77ffb7:4c0::/28ffb7:4cf:ffff:ffff:ffff:ffff:ffff:ffff
78ffb7:4d0::/28ffb7:4df:ffff:ffff:ffff:ffff:ffff:ffff
79ffb7:4e0::/28ffb7:4ef:ffff:ffff:ffff:ffff:ffff:ffff
80ffb7:4f0::/28ffb7:4ff:ffff:ffff:ffff:ffff:ffff:ffff
81ffb7:500::/28ffb7:50f:ffff:ffff:ffff:ffff:ffff:ffff
82ffb7:510::/28ffb7:51f:ffff:ffff:ffff:ffff:ffff:ffff
83ffb7:520::/28ffb7:52f:ffff:ffff:ffff:ffff:ffff:ffff
84ffb7:530::/28ffb7:53f:ffff:ffff:ffff:ffff:ffff:ffff
85ffb7:540::/28ffb7:54f:ffff:ffff:ffff:ffff:ffff:ffff
86ffb7:550::/28ffb7:55f:ffff:ffff:ffff:ffff:ffff:ffff
87ffb7:560::/28ffb7:56f:ffff:ffff:ffff:ffff:ffff:ffff
88ffb7:570::/28ffb7:57f:ffff:ffff:ffff:ffff:ffff:ffff
89ffb7:580::/28ffb7:58f:ffff:ffff:ffff:ffff:ffff:ffff
90ffb7:590::/28ffb7:59f:ffff:ffff:ffff:ffff:ffff:ffff
91ffb7:5a0::/28ffb7:5af:ffff:ffff:ffff:ffff:ffff:ffff
92ffb7:5b0::/28ffb7:5bf:ffff:ffff:ffff:ffff:ffff:ffff
93ffb7:5c0::/28ffb7:5cf:ffff:ffff:ffff:ffff:ffff:ffff
94ffb7:5d0::/28ffb7:5df:ffff:ffff:ffff:ffff:ffff:ffff
95ffb7:5e0::/28ffb7:5ef:ffff:ffff:ffff:ffff:ffff:ffff
96ffb7:5f0::/28ffb7:5ff:ffff:ffff:ffff:ffff:ffff:ffff
97ffb7:600::/28ffb7:60f:ffff:ffff:ffff:ffff:ffff:ffff
98ffb7:610::/28ffb7:61f:ffff:ffff:ffff:ffff:ffff:ffff
99ffb7:620::/28ffb7:62f:ffff:ffff:ffff:ffff:ffff:ffff
100ffb7:630::/28ffb7:63f:ffff:ffff:ffff:ffff:ffff:ffff
101ffb7:640::/28ffb7:64f:ffff:ffff:ffff:ffff:ffff:ffff
102ffb7:650::/28ffb7:65f:ffff:ffff:ffff:ffff:ffff:ffff
103ffb7:660::/28ffb7:66f:ffff:ffff:ffff:ffff:ffff:ffff
104ffb7:670::/28ffb7:67f:ffff:ffff:ffff:ffff:ffff:ffff
105ffb7:680::/28ffb7:68f:ffff:ffff:ffff:ffff:ffff:ffff
106ffb7:690::/28ffb7:69f:ffff:ffff:ffff:ffff:ffff:ffff
107ffb7:6a0::/28ffb7:6af:ffff:ffff:ffff:ffff:ffff:ffff
108ffb7:6b0::/28ffb7:6bf:ffff:ffff:ffff:ffff:ffff:ffff
109ffb7:6c0::/28ffb7:6cf:ffff:ffff:ffff:ffff:ffff:ffff
110ffb7:6d0::/28ffb7:6df:ffff:ffff:ffff:ffff:ffff:ffff
111ffb7:6e0::/28ffb7:6ef:ffff:ffff:ffff:ffff:ffff:ffff
112ffb7:6f0::/28ffb7:6ff:ffff:ffff:ffff:ffff:ffff:ffff
113ffb7:700::/28ffb7:70f:ffff:ffff:ffff:ffff:ffff:ffff
114ffb7:710::/28ffb7:71f:ffff:ffff:ffff:ffff:ffff:ffff
115ffb7:720::/28ffb7:72f:ffff:ffff:ffff:ffff:ffff:ffff
116ffb7:730::/28ffb7:73f:ffff:ffff:ffff:ffff:ffff:ffff
117ffb7:740::/28ffb7:74f:ffff:ffff:ffff:ffff:ffff:ffff
118ffb7:750::/28ffb7:75f:ffff:ffff:ffff:ffff:ffff:ffff
119ffb7:760::/28ffb7:76f:ffff:ffff:ffff:ffff:ffff:ffff
120ffb7:770::/28ffb7:77f:ffff:ffff:ffff:ffff:ffff:ffff
121ffb7:780::/28ffb7:78f:ffff:ffff:ffff:ffff:ffff:ffff
122ffb7:790::/28ffb7:79f:ffff:ffff:ffff:ffff:ffff:ffff
123ffb7:7a0::/28ffb7:7af:ffff:ffff:ffff:ffff:ffff:ffff
124ffb7:7b0::/28ffb7:7bf:ffff:ffff:ffff:ffff:ffff:ffff
125ffb7:7c0::/28ffb7:7cf:ffff:ffff:ffff:ffff:ffff:ffff
126ffb7:7d0::/28ffb7:7df:ffff:ffff:ffff:ffff:ffff:ffff
127ffb7:7e0::/28ffb7:7ef:ffff:ffff:ffff:ffff:ffff:ffff
128ffb7:7f0::/28ffb7:7ff:ffff:ffff:ffff:ffff:ffff:ffff
129ffb7:800::/28ffb7:80f:ffff:ffff:ffff:ffff:ffff:ffff
130ffb7:810::/28ffb7:81f:ffff:ffff:ffff:ffff:ffff:ffff
131ffb7:820::/28ffb7:82f:ffff:ffff:ffff:ffff:ffff:ffff
132ffb7:830::/28ffb7:83f:ffff:ffff:ffff:ffff:ffff:ffff
133ffb7:840::/28ffb7:84f:ffff:ffff:ffff:ffff:ffff:ffff
134ffb7:850::/28ffb7:85f:ffff:ffff:ffff:ffff:ffff:ffff
135ffb7:860::/28ffb7:86f:ffff:ffff:ffff:ffff:ffff:ffff
136ffb7:870::/28ffb7:87f:ffff:ffff:ffff:ffff:ffff:ffff
137ffb7:880::/28ffb7:88f:ffff:ffff:ffff:ffff:ffff:ffff
138ffb7:890::/28ffb7:89f:ffff:ffff:ffff:ffff:ffff:ffff
139ffb7:8a0::/28ffb7:8af:ffff:ffff:ffff:ffff:ffff:ffff
140ffb7:8b0::/28ffb7:8bf:ffff:ffff:ffff:ffff:ffff:ffff
141ffb7:8c0::/28ffb7:8cf:ffff:ffff:ffff:ffff:ffff:ffff
142ffb7:8d0::/28ffb7:8df:ffff:ffff:ffff:ffff:ffff:ffff
143ffb7:8e0::/28ffb7:8ef:ffff:ffff:ffff:ffff:ffff:ffff
144ffb7:8f0::/28ffb7:8ff:ffff:ffff:ffff:ffff:ffff:ffff
145ffb7:900::/28ffb7:90f:ffff:ffff:ffff:ffff:ffff:ffff
146ffb7:910::/28ffb7:91f:ffff:ffff:ffff:ffff:ffff:ffff
147ffb7:920::/28ffb7:92f:ffff:ffff:ffff:ffff:ffff:ffff
148ffb7:930::/28ffb7:93f:ffff:ffff:ffff:ffff:ffff:ffff
149ffb7:940::/28ffb7:94f:ffff:ffff:ffff:ffff:ffff:ffff
150ffb7:950::/28ffb7:95f:ffff:ffff:ffff:ffff:ffff:ffff
151ffb7:960::/28ffb7:96f:ffff:ffff:ffff:ffff:ffff:ffff
152ffb7:970::/28ffb7:97f:ffff:ffff:ffff:ffff:ffff:ffff
153ffb7:980::/28ffb7:98f:ffff:ffff:ffff:ffff:ffff:ffff
154ffb7:990::/28ffb7:99f:ffff:ffff:ffff:ffff:ffff:ffff
155ffb7:9a0::/28ffb7:9af:ffff:ffff:ffff:ffff:ffff:ffff
156ffb7:9b0::/28ffb7:9bf:ffff:ffff:ffff:ffff:ffff:ffff
157ffb7:9c0::/28ffb7:9cf:ffff:ffff:ffff:ffff:ffff:ffff
158ffb7:9d0::/28ffb7:9df:ffff:ffff:ffff:ffff:ffff:ffff
159ffb7:9e0::/28ffb7:9ef:ffff:ffff:ffff:ffff:ffff:ffff
160ffb7:9f0::/28ffb7:9ff:ffff:ffff:ffff:ffff:ffff:ffff
161ffb7:a00::/28ffb7:a0f:ffff:ffff:ffff:ffff:ffff:ffff
162ffb7:a10::/28ffb7:a1f:ffff:ffff:ffff:ffff:ffff:ffff
163ffb7:a20::/28ffb7:a2f:ffff:ffff:ffff:ffff:ffff:ffff
164ffb7:a30::/28ffb7:a3f:ffff:ffff:ffff:ffff:ffff:ffff
165ffb7:a40::/28ffb7:a4f:ffff:ffff:ffff:ffff:ffff:ffff
166ffb7:a50::/28ffb7:a5f:ffff:ffff:ffff:ffff:ffff:ffff
167ffb7:a60::/28ffb7:a6f:ffff:ffff:ffff:ffff:ffff:ffff
168ffb7:a70::/28ffb7:a7f:ffff:ffff:ffff:ffff:ffff:ffff
169ffb7:a80::/28ffb7:a8f:ffff:ffff:ffff:ffff:ffff:ffff
170ffb7:a90::/28ffb7:a9f:ffff:ffff:ffff:ffff:ffff:ffff
171ffb7:aa0::/28ffb7:aaf:ffff:ffff:ffff:ffff:ffff:ffff
172ffb7:ab0::/28ffb7:abf:ffff:ffff:ffff:ffff:ffff:ffff
173ffb7:ac0::/28ffb7:acf:ffff:ffff:ffff:ffff:ffff:ffff
174ffb7:ad0::/28ffb7:adf:ffff:ffff:ffff:ffff:ffff:ffff
175ffb7:ae0::/28ffb7:aef:ffff:ffff:ffff:ffff:ffff:ffff
176ffb7:af0::/28ffb7:aff:ffff:ffff:ffff:ffff:ffff:ffff
177ffb7:b00::/28ffb7:b0f:ffff:ffff:ffff:ffff:ffff:ffff
178ffb7:b10::/28ffb7:b1f:ffff:ffff:ffff:ffff:ffff:ffff
179ffb7:b20::/28ffb7:b2f:ffff:ffff:ffff:ffff:ffff:ffff
180ffb7:b30::/28ffb7:b3f:ffff:ffff:ffff:ffff:ffff:ffff
181ffb7:b40::/28ffb7:b4f:ffff:ffff:ffff:ffff:ffff:ffff
182ffb7:b50::/28ffb7:b5f:ffff:ffff:ffff:ffff:ffff:ffff
183ffb7:b60::/28ffb7:b6f:ffff:ffff:ffff:ffff:ffff:ffff
184ffb7:b70::/28ffb7:b7f:ffff:ffff:ffff:ffff:ffff:ffff
185ffb7:b80::/28ffb7:b8f:ffff:ffff:ffff:ffff:ffff:ffff
186ffb7:b90::/28ffb7:b9f:ffff:ffff:ffff:ffff:ffff:ffff
187ffb7:ba0::/28ffb7:baf:ffff:ffff:ffff:ffff:ffff:ffff
188ffb7:bb0::/28ffb7:bbf:ffff:ffff:ffff:ffff:ffff:ffff
189ffb7:bc0::/28ffb7:bcf:ffff:ffff:ffff:ffff:ffff:ffff
190ffb7:bd0::/28ffb7:bdf:ffff:ffff:ffff:ffff:ffff:ffff
191ffb7:be0::/28ffb7:bef:ffff:ffff:ffff:ffff:ffff:ffff
192ffb7:bf0::/28ffb7:bff:ffff:ffff:ffff:ffff:ffff:ffff
193ffb7:c00::/28ffb7:c0f:ffff:ffff:ffff:ffff:ffff:ffff
194ffb7:c10::/28ffb7:c1f:ffff:ffff:ffff:ffff:ffff:ffff
195ffb7:c20::/28ffb7:c2f:ffff:ffff:ffff:ffff:ffff:ffff
196ffb7:c30::/28ffb7:c3f:ffff:ffff:ffff:ffff:ffff:ffff
197ffb7:c40::/28ffb7:c4f:ffff:ffff:ffff:ffff:ffff:ffff
198ffb7:c50::/28ffb7:c5f:ffff:ffff:ffff:ffff:ffff:ffff
199ffb7:c60::/28ffb7:c6f:ffff:ffff:ffff:ffff:ffff:ffff
200ffb7:c70::/28ffb7:c7f:ffff:ffff:ffff:ffff:ffff:ffff
201ffb7:c80::/28ffb7:c8f:ffff:ffff:ffff:ffff:ffff:ffff
202ffb7:c90::/28ffb7:c9f:ffff:ffff:ffff:ffff:ffff:ffff
203ffb7:ca0::/28ffb7:caf:ffff:ffff:ffff:ffff:ffff:ffff
204ffb7:cb0::/28ffb7:cbf:ffff:ffff:ffff:ffff:ffff:ffff
205ffb7:cc0::/28ffb7:ccf:ffff:ffff:ffff:ffff:ffff:ffff
206ffb7:cd0::/28ffb7:cdf:ffff:ffff:ffff:ffff:ffff:ffff
207ffb7:ce0::/28ffb7:cef:ffff:ffff:ffff:ffff:ffff:ffff
208ffb7:cf0::/28ffb7:cff:ffff:ffff:ffff:ffff:ffff:ffff
209ffb7:d00::/28ffb7:d0f:ffff:ffff:ffff:ffff:ffff:ffff
210ffb7:d10::/28ffb7:d1f:ffff:ffff:ffff:ffff:ffff:ffff
211ffb7:d20::/28ffb7:d2f:ffff:ffff:ffff:ffff:ffff:ffff
212ffb7:d30::/28ffb7:d3f:ffff:ffff:ffff:ffff:ffff:ffff
213ffb7:d40::/28ffb7:d4f:ffff:ffff:ffff:ffff:ffff:ffff
214ffb7:d50::/28ffb7:d5f:ffff:ffff:ffff:ffff:ffff:ffff
215ffb7:d60::/28ffb7:d6f:ffff:ffff:ffff:ffff:ffff:ffff
216ffb7:d70::/28ffb7:d7f:ffff:ffff:ffff:ffff:ffff:ffff
217ffb7:d80::/28ffb7:d8f:ffff:ffff:ffff:ffff:ffff:ffff
218ffb7:d90::/28ffb7:d9f:ffff:ffff:ffff:ffff:ffff:ffff
219ffb7:da0::/28ffb7:daf:ffff:ffff:ffff:ffff:ffff:ffff
220ffb7:db0::/28ffb7:dbf:ffff:ffff:ffff:ffff:ffff:ffff
221ffb7:dc0::/28ffb7:dcf:ffff:ffff:ffff:ffff:ffff:ffff
222ffb7:dd0::/28ffb7:ddf:ffff:ffff:ffff:ffff:ffff:ffff
223ffb7:de0::/28ffb7:def:ffff:ffff:ffff:ffff:ffff:ffff
224ffb7:df0::/28ffb7:dff:ffff:ffff:ffff:ffff:ffff:ffff
225ffb7:e00::/28ffb7:e0f:ffff:ffff:ffff:ffff:ffff:ffff
226ffb7:e10::/28ffb7:e1f:ffff:ffff:ffff:ffff:ffff:ffff
227ffb7:e20::/28ffb7:e2f:ffff:ffff:ffff:ffff:ffff:ffff
228ffb7:e30::/28ffb7:e3f:ffff:ffff:ffff:ffff:ffff:ffff
229ffb7:e40::/28ffb7:e4f:ffff:ffff:ffff:ffff:ffff:ffff
230ffb7:e50::/28ffb7:e5f:ffff:ffff:ffff:ffff:ffff:ffff
231ffb7:e60::/28ffb7:e6f:ffff:ffff:ffff:ffff:ffff:ffff
232ffb7:e70::/28ffb7:e7f:ffff:ffff:ffff:ffff:ffff:ffff
233ffb7:e80::/28ffb7:e8f:ffff:ffff:ffff:ffff:ffff:ffff
234ffb7:e90::/28ffb7:e9f:ffff:ffff:ffff:ffff:ffff:ffff
235ffb7:ea0::/28ffb7:eaf:ffff:ffff:ffff:ffff:ffff:ffff
236ffb7:eb0::/28ffb7:ebf:ffff:ffff:ffff:ffff:ffff:ffff
237ffb7:ec0::/28ffb7:ecf:ffff:ffff:ffff:ffff:ffff:ffff
238ffb7:ed0::/28ffb7:edf:ffff:ffff:ffff:ffff:ffff:ffff
239ffb7:ee0::/28ffb7:eef:ffff:ffff:ffff:ffff:ffff:ffff
240ffb7:ef0::/28ffb7:eff:ffff:ffff:ffff:ffff:ffff:ffff
241ffb7:f00::/28ffb7:f0f:ffff:ffff:ffff:ffff:ffff:ffff
242ffb7:f10::/28ffb7:f1f:ffff:ffff:ffff:ffff:ffff:ffff
243ffb7:f20::/28ffb7:f2f:ffff:ffff:ffff:ffff:ffff:ffff
244ffb7:f30::/28ffb7:f3f:ffff:ffff:ffff:ffff:ffff:ffff
245ffb7:f40::/28ffb7:f4f:ffff:ffff:ffff:ffff:ffff:ffff
246ffb7:f50::/28ffb7:f5f:ffff:ffff:ffff:ffff:ffff:ffff
247ffb7:f60::/28ffb7:f6f:ffff:ffff:ffff:ffff:ffff:ffff
248ffb7:f70::/28ffb7:f7f:ffff:ffff:ffff:ffff:ffff:ffff
249ffb7:f80::/28ffb7:f8f:ffff:ffff:ffff:ffff:ffff:ffff
250ffb7:f90::/28ffb7:f9f:ffff:ffff:ffff:ffff:ffff:ffff
251ffb7:fa0::/28ffb7:faf:ffff:ffff:ffff:ffff:ffff:ffff
252ffb7:fb0::/28ffb7:fbf:ffff:ffff:ffff:ffff:ffff:ffff
253ffb7:fc0::/28ffb7:fcf:ffff:ffff:ffff:ffff:ffff:ffff
254ffb7:fd0::/28ffb7:fdf:ffff:ffff:ffff:ffff:ffff:ffff
255ffb7:fe0::/28ffb7:fef:ffff:ffff:ffff:ffff:ffff:ffff
256ffb7:ff0::/28ffb7: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.