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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/20
Addresses2^108
/64 networks2^44
Network
fe8a:7000::/20
First address
fe8a:7000::
Last address
fe8a:7fff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
324,518,553,658,426,726,783,156,020,576,256 (2^108)
/64 networks (LANs)
17,592,186,044,416 (2^44)
Full form
fe8a:7000:0000:0000:0000:0000:0000:0000
Type
Link-local fe80::/10
Every IPv6 interface has one; not routed
Reverse DNS zone
7.a.8.e.f.ip6.arpa
Split into smaller subnets/28
/21 (2)/22 (4)/23 (8)/24 (16)/28 (256)/32 (4,096)/36 (65,536)

fe8a:7000::/20 makes 256 subnets of /28.

Subnets
#SubnetLast address
1fe8a:7000::/28fe8a:700f:ffff:ffff:ffff:ffff:ffff:ffff
2fe8a:7010::/28fe8a:701f:ffff:ffff:ffff:ffff:ffff:ffff
3fe8a:7020::/28fe8a:702f:ffff:ffff:ffff:ffff:ffff:ffff
4fe8a:7030::/28fe8a:703f:ffff:ffff:ffff:ffff:ffff:ffff
5fe8a:7040::/28fe8a:704f:ffff:ffff:ffff:ffff:ffff:ffff
6fe8a:7050::/28fe8a:705f:ffff:ffff:ffff:ffff:ffff:ffff
7fe8a:7060::/28fe8a:706f:ffff:ffff:ffff:ffff:ffff:ffff
8fe8a:7070::/28fe8a:707f:ffff:ffff:ffff:ffff:ffff:ffff
9fe8a:7080::/28fe8a:708f:ffff:ffff:ffff:ffff:ffff:ffff
10fe8a:7090::/28fe8a:709f:ffff:ffff:ffff:ffff:ffff:ffff
11fe8a:70a0::/28fe8a:70af:ffff:ffff:ffff:ffff:ffff:ffff
12fe8a:70b0::/28fe8a:70bf:ffff:ffff:ffff:ffff:ffff:ffff
13fe8a:70c0::/28fe8a:70cf:ffff:ffff:ffff:ffff:ffff:ffff
14fe8a:70d0::/28fe8a:70df:ffff:ffff:ffff:ffff:ffff:ffff
15fe8a:70e0::/28fe8a:70ef:ffff:ffff:ffff:ffff:ffff:ffff
16fe8a:70f0::/28fe8a:70ff:ffff:ffff:ffff:ffff:ffff:ffff
17fe8a:7100::/28fe8a:710f:ffff:ffff:ffff:ffff:ffff:ffff
18fe8a:7110::/28fe8a:711f:ffff:ffff:ffff:ffff:ffff:ffff
19fe8a:7120::/28fe8a:712f:ffff:ffff:ffff:ffff:ffff:ffff
20fe8a:7130::/28fe8a:713f:ffff:ffff:ffff:ffff:ffff:ffff
21fe8a:7140::/28fe8a:714f:ffff:ffff:ffff:ffff:ffff:ffff
22fe8a:7150::/28fe8a:715f:ffff:ffff:ffff:ffff:ffff:ffff
23fe8a:7160::/28fe8a:716f:ffff:ffff:ffff:ffff:ffff:ffff
24fe8a:7170::/28fe8a:717f:ffff:ffff:ffff:ffff:ffff:ffff
25fe8a:7180::/28fe8a:718f:ffff:ffff:ffff:ffff:ffff:ffff
26fe8a:7190::/28fe8a:719f:ffff:ffff:ffff:ffff:ffff:ffff
27fe8a:71a0::/28fe8a:71af:ffff:ffff:ffff:ffff:ffff:ffff
28fe8a:71b0::/28fe8a:71bf:ffff:ffff:ffff:ffff:ffff:ffff
29fe8a:71c0::/28fe8a:71cf:ffff:ffff:ffff:ffff:ffff:ffff
30fe8a:71d0::/28fe8a:71df:ffff:ffff:ffff:ffff:ffff:ffff
31fe8a:71e0::/28fe8a:71ef:ffff:ffff:ffff:ffff:ffff:ffff
32fe8a:71f0::/28fe8a:71ff:ffff:ffff:ffff:ffff:ffff:ffff
33fe8a:7200::/28fe8a:720f:ffff:ffff:ffff:ffff:ffff:ffff
34fe8a:7210::/28fe8a:721f:ffff:ffff:ffff:ffff:ffff:ffff
35fe8a:7220::/28fe8a:722f:ffff:ffff:ffff:ffff:ffff:ffff
36fe8a:7230::/28fe8a:723f:ffff:ffff:ffff:ffff:ffff:ffff
37fe8a:7240::/28fe8a:724f:ffff:ffff:ffff:ffff:ffff:ffff
38fe8a:7250::/28fe8a:725f:ffff:ffff:ffff:ffff:ffff:ffff
39fe8a:7260::/28fe8a:726f:ffff:ffff:ffff:ffff:ffff:ffff
40fe8a:7270::/28fe8a:727f:ffff:ffff:ffff:ffff:ffff:ffff
41fe8a:7280::/28fe8a:728f:ffff:ffff:ffff:ffff:ffff:ffff
42fe8a:7290::/28fe8a:729f:ffff:ffff:ffff:ffff:ffff:ffff
43fe8a:72a0::/28fe8a:72af:ffff:ffff:ffff:ffff:ffff:ffff
44fe8a:72b0::/28fe8a:72bf:ffff:ffff:ffff:ffff:ffff:ffff
45fe8a:72c0::/28fe8a:72cf:ffff:ffff:ffff:ffff:ffff:ffff
46fe8a:72d0::/28fe8a:72df:ffff:ffff:ffff:ffff:ffff:ffff
47fe8a:72e0::/28fe8a:72ef:ffff:ffff:ffff:ffff:ffff:ffff
48fe8a:72f0::/28fe8a:72ff:ffff:ffff:ffff:ffff:ffff:ffff
49fe8a:7300::/28fe8a:730f:ffff:ffff:ffff:ffff:ffff:ffff
50fe8a:7310::/28fe8a:731f:ffff:ffff:ffff:ffff:ffff:ffff
51fe8a:7320::/28fe8a:732f:ffff:ffff:ffff:ffff:ffff:ffff
52fe8a:7330::/28fe8a:733f:ffff:ffff:ffff:ffff:ffff:ffff
53fe8a:7340::/28fe8a:734f:ffff:ffff:ffff:ffff:ffff:ffff
54fe8a:7350::/28fe8a:735f:ffff:ffff:ffff:ffff:ffff:ffff
55fe8a:7360::/28fe8a:736f:ffff:ffff:ffff:ffff:ffff:ffff
56fe8a:7370::/28fe8a:737f:ffff:ffff:ffff:ffff:ffff:ffff
57fe8a:7380::/28fe8a:738f:ffff:ffff:ffff:ffff:ffff:ffff
58fe8a:7390::/28fe8a:739f:ffff:ffff:ffff:ffff:ffff:ffff
59fe8a:73a0::/28fe8a:73af:ffff:ffff:ffff:ffff:ffff:ffff
60fe8a:73b0::/28fe8a:73bf:ffff:ffff:ffff:ffff:ffff:ffff
61fe8a:73c0::/28fe8a:73cf:ffff:ffff:ffff:ffff:ffff:ffff
62fe8a:73d0::/28fe8a:73df:ffff:ffff:ffff:ffff:ffff:ffff
63fe8a:73e0::/28fe8a:73ef:ffff:ffff:ffff:ffff:ffff:ffff
64fe8a:73f0::/28fe8a:73ff:ffff:ffff:ffff:ffff:ffff:ffff
65fe8a:7400::/28fe8a:740f:ffff:ffff:ffff:ffff:ffff:ffff
66fe8a:7410::/28fe8a:741f:ffff:ffff:ffff:ffff:ffff:ffff
67fe8a:7420::/28fe8a:742f:ffff:ffff:ffff:ffff:ffff:ffff
68fe8a:7430::/28fe8a:743f:ffff:ffff:ffff:ffff:ffff:ffff
69fe8a:7440::/28fe8a:744f:ffff:ffff:ffff:ffff:ffff:ffff
70fe8a:7450::/28fe8a:745f:ffff:ffff:ffff:ffff:ffff:ffff
71fe8a:7460::/28fe8a:746f:ffff:ffff:ffff:ffff:ffff:ffff
72fe8a:7470::/28fe8a:747f:ffff:ffff:ffff:ffff:ffff:ffff
73fe8a:7480::/28fe8a:748f:ffff:ffff:ffff:ffff:ffff:ffff
74fe8a:7490::/28fe8a:749f:ffff:ffff:ffff:ffff:ffff:ffff
75fe8a:74a0::/28fe8a:74af:ffff:ffff:ffff:ffff:ffff:ffff
76fe8a:74b0::/28fe8a:74bf:ffff:ffff:ffff:ffff:ffff:ffff
77fe8a:74c0::/28fe8a:74cf:ffff:ffff:ffff:ffff:ffff:ffff
78fe8a:74d0::/28fe8a:74df:ffff:ffff:ffff:ffff:ffff:ffff
79fe8a:74e0::/28fe8a:74ef:ffff:ffff:ffff:ffff:ffff:ffff
80fe8a:74f0::/28fe8a:74ff:ffff:ffff:ffff:ffff:ffff:ffff
81fe8a:7500::/28fe8a:750f:ffff:ffff:ffff:ffff:ffff:ffff
82fe8a:7510::/28fe8a:751f:ffff:ffff:ffff:ffff:ffff:ffff
83fe8a:7520::/28fe8a:752f:ffff:ffff:ffff:ffff:ffff:ffff
84fe8a:7530::/28fe8a:753f:ffff:ffff:ffff:ffff:ffff:ffff
85fe8a:7540::/28fe8a:754f:ffff:ffff:ffff:ffff:ffff:ffff
86fe8a:7550::/28fe8a:755f:ffff:ffff:ffff:ffff:ffff:ffff
87fe8a:7560::/28fe8a:756f:ffff:ffff:ffff:ffff:ffff:ffff
88fe8a:7570::/28fe8a:757f:ffff:ffff:ffff:ffff:ffff:ffff
89fe8a:7580::/28fe8a:758f:ffff:ffff:ffff:ffff:ffff:ffff
90fe8a:7590::/28fe8a:759f:ffff:ffff:ffff:ffff:ffff:ffff
91fe8a:75a0::/28fe8a:75af:ffff:ffff:ffff:ffff:ffff:ffff
92fe8a:75b0::/28fe8a:75bf:ffff:ffff:ffff:ffff:ffff:ffff
93fe8a:75c0::/28fe8a:75cf:ffff:ffff:ffff:ffff:ffff:ffff
94fe8a:75d0::/28fe8a:75df:ffff:ffff:ffff:ffff:ffff:ffff
95fe8a:75e0::/28fe8a:75ef:ffff:ffff:ffff:ffff:ffff:ffff
96fe8a:75f0::/28fe8a:75ff:ffff:ffff:ffff:ffff:ffff:ffff
97fe8a:7600::/28fe8a:760f:ffff:ffff:ffff:ffff:ffff:ffff
98fe8a:7610::/28fe8a:761f:ffff:ffff:ffff:ffff:ffff:ffff
99fe8a:7620::/28fe8a:762f:ffff:ffff:ffff:ffff:ffff:ffff
100fe8a:7630::/28fe8a:763f:ffff:ffff:ffff:ffff:ffff:ffff
101fe8a:7640::/28fe8a:764f:ffff:ffff:ffff:ffff:ffff:ffff
102fe8a:7650::/28fe8a:765f:ffff:ffff:ffff:ffff:ffff:ffff
103fe8a:7660::/28fe8a:766f:ffff:ffff:ffff:ffff:ffff:ffff
104fe8a:7670::/28fe8a:767f:ffff:ffff:ffff:ffff:ffff:ffff
105fe8a:7680::/28fe8a:768f:ffff:ffff:ffff:ffff:ffff:ffff
106fe8a:7690::/28fe8a:769f:ffff:ffff:ffff:ffff:ffff:ffff
107fe8a:76a0::/28fe8a:76af:ffff:ffff:ffff:ffff:ffff:ffff
108fe8a:76b0::/28fe8a:76bf:ffff:ffff:ffff:ffff:ffff:ffff
109fe8a:76c0::/28fe8a:76cf:ffff:ffff:ffff:ffff:ffff:ffff
110fe8a:76d0::/28fe8a:76df:ffff:ffff:ffff:ffff:ffff:ffff
111fe8a:76e0::/28fe8a:76ef:ffff:ffff:ffff:ffff:ffff:ffff
112fe8a:76f0::/28fe8a:76ff:ffff:ffff:ffff:ffff:ffff:ffff
113fe8a:7700::/28fe8a:770f:ffff:ffff:ffff:ffff:ffff:ffff
114fe8a:7710::/28fe8a:771f:ffff:ffff:ffff:ffff:ffff:ffff
115fe8a:7720::/28fe8a:772f:ffff:ffff:ffff:ffff:ffff:ffff
116fe8a:7730::/28fe8a:773f:ffff:ffff:ffff:ffff:ffff:ffff
117fe8a:7740::/28fe8a:774f:ffff:ffff:ffff:ffff:ffff:ffff
118fe8a:7750::/28fe8a:775f:ffff:ffff:ffff:ffff:ffff:ffff
119fe8a:7760::/28fe8a:776f:ffff:ffff:ffff:ffff:ffff:ffff
120fe8a:7770::/28fe8a:777f:ffff:ffff:ffff:ffff:ffff:ffff
121fe8a:7780::/28fe8a:778f:ffff:ffff:ffff:ffff:ffff:ffff
122fe8a:7790::/28fe8a:779f:ffff:ffff:ffff:ffff:ffff:ffff
123fe8a:77a0::/28fe8a:77af:ffff:ffff:ffff:ffff:ffff:ffff
124fe8a:77b0::/28fe8a:77bf:ffff:ffff:ffff:ffff:ffff:ffff
125fe8a:77c0::/28fe8a:77cf:ffff:ffff:ffff:ffff:ffff:ffff
126fe8a:77d0::/28fe8a:77df:ffff:ffff:ffff:ffff:ffff:ffff
127fe8a:77e0::/28fe8a:77ef:ffff:ffff:ffff:ffff:ffff:ffff
128fe8a:77f0::/28fe8a:77ff:ffff:ffff:ffff:ffff:ffff:ffff
129fe8a:7800::/28fe8a:780f:ffff:ffff:ffff:ffff:ffff:ffff
130fe8a:7810::/28fe8a:781f:ffff:ffff:ffff:ffff:ffff:ffff
131fe8a:7820::/28fe8a:782f:ffff:ffff:ffff:ffff:ffff:ffff
132fe8a:7830::/28fe8a:783f:ffff:ffff:ffff:ffff:ffff:ffff
133fe8a:7840::/28fe8a:784f:ffff:ffff:ffff:ffff:ffff:ffff
134fe8a:7850::/28fe8a:785f:ffff:ffff:ffff:ffff:ffff:ffff
135fe8a:7860::/28fe8a:786f:ffff:ffff:ffff:ffff:ffff:ffff
136fe8a:7870::/28fe8a:787f:ffff:ffff:ffff:ffff:ffff:ffff
137fe8a:7880::/28fe8a:788f:ffff:ffff:ffff:ffff:ffff:ffff
138fe8a:7890::/28fe8a:789f:ffff:ffff:ffff:ffff:ffff:ffff
139fe8a:78a0::/28fe8a:78af:ffff:ffff:ffff:ffff:ffff:ffff
140fe8a:78b0::/28fe8a:78bf:ffff:ffff:ffff:ffff:ffff:ffff
141fe8a:78c0::/28fe8a:78cf:ffff:ffff:ffff:ffff:ffff:ffff
142fe8a:78d0::/28fe8a:78df:ffff:ffff:ffff:ffff:ffff:ffff
143fe8a:78e0::/28fe8a:78ef:ffff:ffff:ffff:ffff:ffff:ffff
144fe8a:78f0::/28fe8a:78ff:ffff:ffff:ffff:ffff:ffff:ffff
145fe8a:7900::/28fe8a:790f:ffff:ffff:ffff:ffff:ffff:ffff
146fe8a:7910::/28fe8a:791f:ffff:ffff:ffff:ffff:ffff:ffff
147fe8a:7920::/28fe8a:792f:ffff:ffff:ffff:ffff:ffff:ffff
148fe8a:7930::/28fe8a:793f:ffff:ffff:ffff:ffff:ffff:ffff
149fe8a:7940::/28fe8a:794f:ffff:ffff:ffff:ffff:ffff:ffff
150fe8a:7950::/28fe8a:795f:ffff:ffff:ffff:ffff:ffff:ffff
151fe8a:7960::/28fe8a:796f:ffff:ffff:ffff:ffff:ffff:ffff
152fe8a:7970::/28fe8a:797f:ffff:ffff:ffff:ffff:ffff:ffff
153fe8a:7980::/28fe8a:798f:ffff:ffff:ffff:ffff:ffff:ffff
154fe8a:7990::/28fe8a:799f:ffff:ffff:ffff:ffff:ffff:ffff
155fe8a:79a0::/28fe8a:79af:ffff:ffff:ffff:ffff:ffff:ffff
156fe8a:79b0::/28fe8a:79bf:ffff:ffff:ffff:ffff:ffff:ffff
157fe8a:79c0::/28fe8a:79cf:ffff:ffff:ffff:ffff:ffff:ffff
158fe8a:79d0::/28fe8a:79df:ffff:ffff:ffff:ffff:ffff:ffff
159fe8a:79e0::/28fe8a:79ef:ffff:ffff:ffff:ffff:ffff:ffff
160fe8a:79f0::/28fe8a:79ff:ffff:ffff:ffff:ffff:ffff:ffff
161fe8a:7a00::/28fe8a:7a0f:ffff:ffff:ffff:ffff:ffff:ffff
162fe8a:7a10::/28fe8a:7a1f:ffff:ffff:ffff:ffff:ffff:ffff
163fe8a:7a20::/28fe8a:7a2f:ffff:ffff:ffff:ffff:ffff:ffff
164fe8a:7a30::/28fe8a:7a3f:ffff:ffff:ffff:ffff:ffff:ffff
165fe8a:7a40::/28fe8a:7a4f:ffff:ffff:ffff:ffff:ffff:ffff
166fe8a:7a50::/28fe8a:7a5f:ffff:ffff:ffff:ffff:ffff:ffff
167fe8a:7a60::/28fe8a:7a6f:ffff:ffff:ffff:ffff:ffff:ffff
168fe8a:7a70::/28fe8a:7a7f:ffff:ffff:ffff:ffff:ffff:ffff
169fe8a:7a80::/28fe8a:7a8f:ffff:ffff:ffff:ffff:ffff:ffff
170fe8a:7a90::/28fe8a:7a9f:ffff:ffff:ffff:ffff:ffff:ffff
171fe8a:7aa0::/28fe8a:7aaf:ffff:ffff:ffff:ffff:ffff:ffff
172fe8a:7ab0::/28fe8a:7abf:ffff:ffff:ffff:ffff:ffff:ffff
173fe8a:7ac0::/28fe8a:7acf:ffff:ffff:ffff:ffff:ffff:ffff
174fe8a:7ad0::/28fe8a:7adf:ffff:ffff:ffff:ffff:ffff:ffff
175fe8a:7ae0::/28fe8a:7aef:ffff:ffff:ffff:ffff:ffff:ffff
176fe8a:7af0::/28fe8a:7aff:ffff:ffff:ffff:ffff:ffff:ffff
177fe8a:7b00::/28fe8a:7b0f:ffff:ffff:ffff:ffff:ffff:ffff
178fe8a:7b10::/28fe8a:7b1f:ffff:ffff:ffff:ffff:ffff:ffff
179fe8a:7b20::/28fe8a:7b2f:ffff:ffff:ffff:ffff:ffff:ffff
180fe8a:7b30::/28fe8a:7b3f:ffff:ffff:ffff:ffff:ffff:ffff
181fe8a:7b40::/28fe8a:7b4f:ffff:ffff:ffff:ffff:ffff:ffff
182fe8a:7b50::/28fe8a:7b5f:ffff:ffff:ffff:ffff:ffff:ffff
183fe8a:7b60::/28fe8a:7b6f:ffff:ffff:ffff:ffff:ffff:ffff
184fe8a:7b70::/28fe8a:7b7f:ffff:ffff:ffff:ffff:ffff:ffff
185fe8a:7b80::/28fe8a:7b8f:ffff:ffff:ffff:ffff:ffff:ffff
186fe8a:7b90::/28fe8a:7b9f:ffff:ffff:ffff:ffff:ffff:ffff
187fe8a:7ba0::/28fe8a:7baf:ffff:ffff:ffff:ffff:ffff:ffff
188fe8a:7bb0::/28fe8a:7bbf:ffff:ffff:ffff:ffff:ffff:ffff
189fe8a:7bc0::/28fe8a:7bcf:ffff:ffff:ffff:ffff:ffff:ffff
190fe8a:7bd0::/28fe8a:7bdf:ffff:ffff:ffff:ffff:ffff:ffff
191fe8a:7be0::/28fe8a:7bef:ffff:ffff:ffff:ffff:ffff:ffff
192fe8a:7bf0::/28fe8a:7bff:ffff:ffff:ffff:ffff:ffff:ffff
193fe8a:7c00::/28fe8a:7c0f:ffff:ffff:ffff:ffff:ffff:ffff
194fe8a:7c10::/28fe8a:7c1f:ffff:ffff:ffff:ffff:ffff:ffff
195fe8a:7c20::/28fe8a:7c2f:ffff:ffff:ffff:ffff:ffff:ffff
196fe8a:7c30::/28fe8a:7c3f:ffff:ffff:ffff:ffff:ffff:ffff
197fe8a:7c40::/28fe8a:7c4f:ffff:ffff:ffff:ffff:ffff:ffff
198fe8a:7c50::/28fe8a:7c5f:ffff:ffff:ffff:ffff:ffff:ffff
199fe8a:7c60::/28fe8a:7c6f:ffff:ffff:ffff:ffff:ffff:ffff
200fe8a:7c70::/28fe8a:7c7f:ffff:ffff:ffff:ffff:ffff:ffff
201fe8a:7c80::/28fe8a:7c8f:ffff:ffff:ffff:ffff:ffff:ffff
202fe8a:7c90::/28fe8a:7c9f:ffff:ffff:ffff:ffff:ffff:ffff
203fe8a:7ca0::/28fe8a:7caf:ffff:ffff:ffff:ffff:ffff:ffff
204fe8a:7cb0::/28fe8a:7cbf:ffff:ffff:ffff:ffff:ffff:ffff
205fe8a:7cc0::/28fe8a:7ccf:ffff:ffff:ffff:ffff:ffff:ffff
206fe8a:7cd0::/28fe8a:7cdf:ffff:ffff:ffff:ffff:ffff:ffff
207fe8a:7ce0::/28fe8a:7cef:ffff:ffff:ffff:ffff:ffff:ffff
208fe8a:7cf0::/28fe8a:7cff:ffff:ffff:ffff:ffff:ffff:ffff
209fe8a:7d00::/28fe8a:7d0f:ffff:ffff:ffff:ffff:ffff:ffff
210fe8a:7d10::/28fe8a:7d1f:ffff:ffff:ffff:ffff:ffff:ffff
211fe8a:7d20::/28fe8a:7d2f:ffff:ffff:ffff:ffff:ffff:ffff
212fe8a:7d30::/28fe8a:7d3f:ffff:ffff:ffff:ffff:ffff:ffff
213fe8a:7d40::/28fe8a:7d4f:ffff:ffff:ffff:ffff:ffff:ffff
214fe8a:7d50::/28fe8a:7d5f:ffff:ffff:ffff:ffff:ffff:ffff
215fe8a:7d60::/28fe8a:7d6f:ffff:ffff:ffff:ffff:ffff:ffff
216fe8a:7d70::/28fe8a:7d7f:ffff:ffff:ffff:ffff:ffff:ffff
217fe8a:7d80::/28fe8a:7d8f:ffff:ffff:ffff:ffff:ffff:ffff
218fe8a:7d90::/28fe8a:7d9f:ffff:ffff:ffff:ffff:ffff:ffff
219fe8a:7da0::/28fe8a:7daf:ffff:ffff:ffff:ffff:ffff:ffff
220fe8a:7db0::/28fe8a:7dbf:ffff:ffff:ffff:ffff:ffff:ffff
221fe8a:7dc0::/28fe8a:7dcf:ffff:ffff:ffff:ffff:ffff:ffff
222fe8a:7dd0::/28fe8a:7ddf:ffff:ffff:ffff:ffff:ffff:ffff
223fe8a:7de0::/28fe8a:7def:ffff:ffff:ffff:ffff:ffff:ffff
224fe8a:7df0::/28fe8a:7dff:ffff:ffff:ffff:ffff:ffff:ffff
225fe8a:7e00::/28fe8a:7e0f:ffff:ffff:ffff:ffff:ffff:ffff
226fe8a:7e10::/28fe8a:7e1f:ffff:ffff:ffff:ffff:ffff:ffff
227fe8a:7e20::/28fe8a:7e2f:ffff:ffff:ffff:ffff:ffff:ffff
228fe8a:7e30::/28fe8a:7e3f:ffff:ffff:ffff:ffff:ffff:ffff
229fe8a:7e40::/28fe8a:7e4f:ffff:ffff:ffff:ffff:ffff:ffff
230fe8a:7e50::/28fe8a:7e5f:ffff:ffff:ffff:ffff:ffff:ffff
231fe8a:7e60::/28fe8a:7e6f:ffff:ffff:ffff:ffff:ffff:ffff
232fe8a:7e70::/28fe8a:7e7f:ffff:ffff:ffff:ffff:ffff:ffff
233fe8a:7e80::/28fe8a:7e8f:ffff:ffff:ffff:ffff:ffff:ffff
234fe8a:7e90::/28fe8a:7e9f:ffff:ffff:ffff:ffff:ffff:ffff
235fe8a:7ea0::/28fe8a:7eaf:ffff:ffff:ffff:ffff:ffff:ffff
236fe8a:7eb0::/28fe8a:7ebf:ffff:ffff:ffff:ffff:ffff:ffff
237fe8a:7ec0::/28fe8a:7ecf:ffff:ffff:ffff:ffff:ffff:ffff
238fe8a:7ed0::/28fe8a:7edf:ffff:ffff:ffff:ffff:ffff:ffff
239fe8a:7ee0::/28fe8a:7eef:ffff:ffff:ffff:ffff:ffff:ffff
240fe8a:7ef0::/28fe8a:7eff:ffff:ffff:ffff:ffff:ffff:ffff
241fe8a:7f00::/28fe8a:7f0f:ffff:ffff:ffff:ffff:ffff:ffff
242fe8a:7f10::/28fe8a:7f1f:ffff:ffff:ffff:ffff:ffff:ffff
243fe8a:7f20::/28fe8a:7f2f:ffff:ffff:ffff:ffff:ffff:ffff
244fe8a:7f30::/28fe8a:7f3f:ffff:ffff:ffff:ffff:ffff:ffff
245fe8a:7f40::/28fe8a:7f4f:ffff:ffff:ffff:ffff:ffff:ffff
246fe8a:7f50::/28fe8a:7f5f:ffff:ffff:ffff:ffff:ffff:ffff
247fe8a:7f60::/28fe8a:7f6f:ffff:ffff:ffff:ffff:ffff:ffff
248fe8a:7f70::/28fe8a:7f7f:ffff:ffff:ffff:ffff:ffff:ffff
249fe8a:7f80::/28fe8a:7f8f:ffff:ffff:ffff:ffff:ffff:ffff
250fe8a:7f90::/28fe8a:7f9f:ffff:ffff:ffff:ffff:ffff:ffff
251fe8a:7fa0::/28fe8a:7faf:ffff:ffff:ffff:ffff:ffff:ffff
252fe8a:7fb0::/28fe8a:7fbf:ffff:ffff:ffff:ffff:ffff:ffff
253fe8a:7fc0::/28fe8a:7fcf:ffff:ffff:ffff:ffff:ffff:ffff
254fe8a:7fd0::/28fe8a:7fdf:ffff:ffff:ffff:ffff:ffff:ffff
255fe8a:7fe0::/28fe8a:7fef:ffff:ffff:ffff:ffff:ffff:ffff
256fe8a:7ff0::/28fe8a:7fff: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.