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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
fe87:c000::/20
First address
fe87:c000::
Last address
fe87:cfff: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
fe87:c000:0000:0000:0000:0000:0000:0000
Type
Link-local fe80::/10
Every IPv6 interface has one; not routed
Reverse DNS zone
c.7.8.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)

fe87:c000::/20 makes 256 subnets of /28.

Subnets
#SubnetLast address
1fe87:c000::/28fe87:c00f:ffff:ffff:ffff:ffff:ffff:ffff
2fe87:c010::/28fe87:c01f:ffff:ffff:ffff:ffff:ffff:ffff
3fe87:c020::/28fe87:c02f:ffff:ffff:ffff:ffff:ffff:ffff
4fe87:c030::/28fe87:c03f:ffff:ffff:ffff:ffff:ffff:ffff
5fe87:c040::/28fe87:c04f:ffff:ffff:ffff:ffff:ffff:ffff
6fe87:c050::/28fe87:c05f:ffff:ffff:ffff:ffff:ffff:ffff
7fe87:c060::/28fe87:c06f:ffff:ffff:ffff:ffff:ffff:ffff
8fe87:c070::/28fe87:c07f:ffff:ffff:ffff:ffff:ffff:ffff
9fe87:c080::/28fe87:c08f:ffff:ffff:ffff:ffff:ffff:ffff
10fe87:c090::/28fe87:c09f:ffff:ffff:ffff:ffff:ffff:ffff
11fe87:c0a0::/28fe87:c0af:ffff:ffff:ffff:ffff:ffff:ffff
12fe87:c0b0::/28fe87:c0bf:ffff:ffff:ffff:ffff:ffff:ffff
13fe87:c0c0::/28fe87:c0cf:ffff:ffff:ffff:ffff:ffff:ffff
14fe87:c0d0::/28fe87:c0df:ffff:ffff:ffff:ffff:ffff:ffff
15fe87:c0e0::/28fe87:c0ef:ffff:ffff:ffff:ffff:ffff:ffff
16fe87:c0f0::/28fe87:c0ff:ffff:ffff:ffff:ffff:ffff:ffff
17fe87:c100::/28fe87:c10f:ffff:ffff:ffff:ffff:ffff:ffff
18fe87:c110::/28fe87:c11f:ffff:ffff:ffff:ffff:ffff:ffff
19fe87:c120::/28fe87:c12f:ffff:ffff:ffff:ffff:ffff:ffff
20fe87:c130::/28fe87:c13f:ffff:ffff:ffff:ffff:ffff:ffff
21fe87:c140::/28fe87:c14f:ffff:ffff:ffff:ffff:ffff:ffff
22fe87:c150::/28fe87:c15f:ffff:ffff:ffff:ffff:ffff:ffff
23fe87:c160::/28fe87:c16f:ffff:ffff:ffff:ffff:ffff:ffff
24fe87:c170::/28fe87:c17f:ffff:ffff:ffff:ffff:ffff:ffff
25fe87:c180::/28fe87:c18f:ffff:ffff:ffff:ffff:ffff:ffff
26fe87:c190::/28fe87:c19f:ffff:ffff:ffff:ffff:ffff:ffff
27fe87:c1a0::/28fe87:c1af:ffff:ffff:ffff:ffff:ffff:ffff
28fe87:c1b0::/28fe87:c1bf:ffff:ffff:ffff:ffff:ffff:ffff
29fe87:c1c0::/28fe87:c1cf:ffff:ffff:ffff:ffff:ffff:ffff
30fe87:c1d0::/28fe87:c1df:ffff:ffff:ffff:ffff:ffff:ffff
31fe87:c1e0::/28fe87:c1ef:ffff:ffff:ffff:ffff:ffff:ffff
32fe87:c1f0::/28fe87:c1ff:ffff:ffff:ffff:ffff:ffff:ffff
33fe87:c200::/28fe87:c20f:ffff:ffff:ffff:ffff:ffff:ffff
34fe87:c210::/28fe87:c21f:ffff:ffff:ffff:ffff:ffff:ffff
35fe87:c220::/28fe87:c22f:ffff:ffff:ffff:ffff:ffff:ffff
36fe87:c230::/28fe87:c23f:ffff:ffff:ffff:ffff:ffff:ffff
37fe87:c240::/28fe87:c24f:ffff:ffff:ffff:ffff:ffff:ffff
38fe87:c250::/28fe87:c25f:ffff:ffff:ffff:ffff:ffff:ffff
39fe87:c260::/28fe87:c26f:ffff:ffff:ffff:ffff:ffff:ffff
40fe87:c270::/28fe87:c27f:ffff:ffff:ffff:ffff:ffff:ffff
41fe87:c280::/28fe87:c28f:ffff:ffff:ffff:ffff:ffff:ffff
42fe87:c290::/28fe87:c29f:ffff:ffff:ffff:ffff:ffff:ffff
43fe87:c2a0::/28fe87:c2af:ffff:ffff:ffff:ffff:ffff:ffff
44fe87:c2b0::/28fe87:c2bf:ffff:ffff:ffff:ffff:ffff:ffff
45fe87:c2c0::/28fe87:c2cf:ffff:ffff:ffff:ffff:ffff:ffff
46fe87:c2d0::/28fe87:c2df:ffff:ffff:ffff:ffff:ffff:ffff
47fe87:c2e0::/28fe87:c2ef:ffff:ffff:ffff:ffff:ffff:ffff
48fe87:c2f0::/28fe87:c2ff:ffff:ffff:ffff:ffff:ffff:ffff
49fe87:c300::/28fe87:c30f:ffff:ffff:ffff:ffff:ffff:ffff
50fe87:c310::/28fe87:c31f:ffff:ffff:ffff:ffff:ffff:ffff
51fe87:c320::/28fe87:c32f:ffff:ffff:ffff:ffff:ffff:ffff
52fe87:c330::/28fe87:c33f:ffff:ffff:ffff:ffff:ffff:ffff
53fe87:c340::/28fe87:c34f:ffff:ffff:ffff:ffff:ffff:ffff
54fe87:c350::/28fe87:c35f:ffff:ffff:ffff:ffff:ffff:ffff
55fe87:c360::/28fe87:c36f:ffff:ffff:ffff:ffff:ffff:ffff
56fe87:c370::/28fe87:c37f:ffff:ffff:ffff:ffff:ffff:ffff
57fe87:c380::/28fe87:c38f:ffff:ffff:ffff:ffff:ffff:ffff
58fe87:c390::/28fe87:c39f:ffff:ffff:ffff:ffff:ffff:ffff
59fe87:c3a0::/28fe87:c3af:ffff:ffff:ffff:ffff:ffff:ffff
60fe87:c3b0::/28fe87:c3bf:ffff:ffff:ffff:ffff:ffff:ffff
61fe87:c3c0::/28fe87:c3cf:ffff:ffff:ffff:ffff:ffff:ffff
62fe87:c3d0::/28fe87:c3df:ffff:ffff:ffff:ffff:ffff:ffff
63fe87:c3e0::/28fe87:c3ef:ffff:ffff:ffff:ffff:ffff:ffff
64fe87:c3f0::/28fe87:c3ff:ffff:ffff:ffff:ffff:ffff:ffff
65fe87:c400::/28fe87:c40f:ffff:ffff:ffff:ffff:ffff:ffff
66fe87:c410::/28fe87:c41f:ffff:ffff:ffff:ffff:ffff:ffff
67fe87:c420::/28fe87:c42f:ffff:ffff:ffff:ffff:ffff:ffff
68fe87:c430::/28fe87:c43f:ffff:ffff:ffff:ffff:ffff:ffff
69fe87:c440::/28fe87:c44f:ffff:ffff:ffff:ffff:ffff:ffff
70fe87:c450::/28fe87:c45f:ffff:ffff:ffff:ffff:ffff:ffff
71fe87:c460::/28fe87:c46f:ffff:ffff:ffff:ffff:ffff:ffff
72fe87:c470::/28fe87:c47f:ffff:ffff:ffff:ffff:ffff:ffff
73fe87:c480::/28fe87:c48f:ffff:ffff:ffff:ffff:ffff:ffff
74fe87:c490::/28fe87:c49f:ffff:ffff:ffff:ffff:ffff:ffff
75fe87:c4a0::/28fe87:c4af:ffff:ffff:ffff:ffff:ffff:ffff
76fe87:c4b0::/28fe87:c4bf:ffff:ffff:ffff:ffff:ffff:ffff
77fe87:c4c0::/28fe87:c4cf:ffff:ffff:ffff:ffff:ffff:ffff
78fe87:c4d0::/28fe87:c4df:ffff:ffff:ffff:ffff:ffff:ffff
79fe87:c4e0::/28fe87:c4ef:ffff:ffff:ffff:ffff:ffff:ffff
80fe87:c4f0::/28fe87:c4ff:ffff:ffff:ffff:ffff:ffff:ffff
81fe87:c500::/28fe87:c50f:ffff:ffff:ffff:ffff:ffff:ffff
82fe87:c510::/28fe87:c51f:ffff:ffff:ffff:ffff:ffff:ffff
83fe87:c520::/28fe87:c52f:ffff:ffff:ffff:ffff:ffff:ffff
84fe87:c530::/28fe87:c53f:ffff:ffff:ffff:ffff:ffff:ffff
85fe87:c540::/28fe87:c54f:ffff:ffff:ffff:ffff:ffff:ffff
86fe87:c550::/28fe87:c55f:ffff:ffff:ffff:ffff:ffff:ffff
87fe87:c560::/28fe87:c56f:ffff:ffff:ffff:ffff:ffff:ffff
88fe87:c570::/28fe87:c57f:ffff:ffff:ffff:ffff:ffff:ffff
89fe87:c580::/28fe87:c58f:ffff:ffff:ffff:ffff:ffff:ffff
90fe87:c590::/28fe87:c59f:ffff:ffff:ffff:ffff:ffff:ffff
91fe87:c5a0::/28fe87:c5af:ffff:ffff:ffff:ffff:ffff:ffff
92fe87:c5b0::/28fe87:c5bf:ffff:ffff:ffff:ffff:ffff:ffff
93fe87:c5c0::/28fe87:c5cf:ffff:ffff:ffff:ffff:ffff:ffff
94fe87:c5d0::/28fe87:c5df:ffff:ffff:ffff:ffff:ffff:ffff
95fe87:c5e0::/28fe87:c5ef:ffff:ffff:ffff:ffff:ffff:ffff
96fe87:c5f0::/28fe87:c5ff:ffff:ffff:ffff:ffff:ffff:ffff
97fe87:c600::/28fe87:c60f:ffff:ffff:ffff:ffff:ffff:ffff
98fe87:c610::/28fe87:c61f:ffff:ffff:ffff:ffff:ffff:ffff
99fe87:c620::/28fe87:c62f:ffff:ffff:ffff:ffff:ffff:ffff
100fe87:c630::/28fe87:c63f:ffff:ffff:ffff:ffff:ffff:ffff
101fe87:c640::/28fe87:c64f:ffff:ffff:ffff:ffff:ffff:ffff
102fe87:c650::/28fe87:c65f:ffff:ffff:ffff:ffff:ffff:ffff
103fe87:c660::/28fe87:c66f:ffff:ffff:ffff:ffff:ffff:ffff
104fe87:c670::/28fe87:c67f:ffff:ffff:ffff:ffff:ffff:ffff
105fe87:c680::/28fe87:c68f:ffff:ffff:ffff:ffff:ffff:ffff
106fe87:c690::/28fe87:c69f:ffff:ffff:ffff:ffff:ffff:ffff
107fe87:c6a0::/28fe87:c6af:ffff:ffff:ffff:ffff:ffff:ffff
108fe87:c6b0::/28fe87:c6bf:ffff:ffff:ffff:ffff:ffff:ffff
109fe87:c6c0::/28fe87:c6cf:ffff:ffff:ffff:ffff:ffff:ffff
110fe87:c6d0::/28fe87:c6df:ffff:ffff:ffff:ffff:ffff:ffff
111fe87:c6e0::/28fe87:c6ef:ffff:ffff:ffff:ffff:ffff:ffff
112fe87:c6f0::/28fe87:c6ff:ffff:ffff:ffff:ffff:ffff:ffff
113fe87:c700::/28fe87:c70f:ffff:ffff:ffff:ffff:ffff:ffff
114fe87:c710::/28fe87:c71f:ffff:ffff:ffff:ffff:ffff:ffff
115fe87:c720::/28fe87:c72f:ffff:ffff:ffff:ffff:ffff:ffff
116fe87:c730::/28fe87:c73f:ffff:ffff:ffff:ffff:ffff:ffff
117fe87:c740::/28fe87:c74f:ffff:ffff:ffff:ffff:ffff:ffff
118fe87:c750::/28fe87:c75f:ffff:ffff:ffff:ffff:ffff:ffff
119fe87:c760::/28fe87:c76f:ffff:ffff:ffff:ffff:ffff:ffff
120fe87:c770::/28fe87:c77f:ffff:ffff:ffff:ffff:ffff:ffff
121fe87:c780::/28fe87:c78f:ffff:ffff:ffff:ffff:ffff:ffff
122fe87:c790::/28fe87:c79f:ffff:ffff:ffff:ffff:ffff:ffff
123fe87:c7a0::/28fe87:c7af:ffff:ffff:ffff:ffff:ffff:ffff
124fe87:c7b0::/28fe87:c7bf:ffff:ffff:ffff:ffff:ffff:ffff
125fe87:c7c0::/28fe87:c7cf:ffff:ffff:ffff:ffff:ffff:ffff
126fe87:c7d0::/28fe87:c7df:ffff:ffff:ffff:ffff:ffff:ffff
127fe87:c7e0::/28fe87:c7ef:ffff:ffff:ffff:ffff:ffff:ffff
128fe87:c7f0::/28fe87:c7ff:ffff:ffff:ffff:ffff:ffff:ffff
129fe87:c800::/28fe87:c80f:ffff:ffff:ffff:ffff:ffff:ffff
130fe87:c810::/28fe87:c81f:ffff:ffff:ffff:ffff:ffff:ffff
131fe87:c820::/28fe87:c82f:ffff:ffff:ffff:ffff:ffff:ffff
132fe87:c830::/28fe87:c83f:ffff:ffff:ffff:ffff:ffff:ffff
133fe87:c840::/28fe87:c84f:ffff:ffff:ffff:ffff:ffff:ffff
134fe87:c850::/28fe87:c85f:ffff:ffff:ffff:ffff:ffff:ffff
135fe87:c860::/28fe87:c86f:ffff:ffff:ffff:ffff:ffff:ffff
136fe87:c870::/28fe87:c87f:ffff:ffff:ffff:ffff:ffff:ffff
137fe87:c880::/28fe87:c88f:ffff:ffff:ffff:ffff:ffff:ffff
138fe87:c890::/28fe87:c89f:ffff:ffff:ffff:ffff:ffff:ffff
139fe87:c8a0::/28fe87:c8af:ffff:ffff:ffff:ffff:ffff:ffff
140fe87:c8b0::/28fe87:c8bf:ffff:ffff:ffff:ffff:ffff:ffff
141fe87:c8c0::/28fe87:c8cf:ffff:ffff:ffff:ffff:ffff:ffff
142fe87:c8d0::/28fe87:c8df:ffff:ffff:ffff:ffff:ffff:ffff
143fe87:c8e0::/28fe87:c8ef:ffff:ffff:ffff:ffff:ffff:ffff
144fe87:c8f0::/28fe87:c8ff:ffff:ffff:ffff:ffff:ffff:ffff
145fe87:c900::/28fe87:c90f:ffff:ffff:ffff:ffff:ffff:ffff
146fe87:c910::/28fe87:c91f:ffff:ffff:ffff:ffff:ffff:ffff
147fe87:c920::/28fe87:c92f:ffff:ffff:ffff:ffff:ffff:ffff
148fe87:c930::/28fe87:c93f:ffff:ffff:ffff:ffff:ffff:ffff
149fe87:c940::/28fe87:c94f:ffff:ffff:ffff:ffff:ffff:ffff
150fe87:c950::/28fe87:c95f:ffff:ffff:ffff:ffff:ffff:ffff
151fe87:c960::/28fe87:c96f:ffff:ffff:ffff:ffff:ffff:ffff
152fe87:c970::/28fe87:c97f:ffff:ffff:ffff:ffff:ffff:ffff
153fe87:c980::/28fe87:c98f:ffff:ffff:ffff:ffff:ffff:ffff
154fe87:c990::/28fe87:c99f:ffff:ffff:ffff:ffff:ffff:ffff
155fe87:c9a0::/28fe87:c9af:ffff:ffff:ffff:ffff:ffff:ffff
156fe87:c9b0::/28fe87:c9bf:ffff:ffff:ffff:ffff:ffff:ffff
157fe87:c9c0::/28fe87:c9cf:ffff:ffff:ffff:ffff:ffff:ffff
158fe87:c9d0::/28fe87:c9df:ffff:ffff:ffff:ffff:ffff:ffff
159fe87:c9e0::/28fe87:c9ef:ffff:ffff:ffff:ffff:ffff:ffff
160fe87:c9f0::/28fe87:c9ff:ffff:ffff:ffff:ffff:ffff:ffff
161fe87:ca00::/28fe87:ca0f:ffff:ffff:ffff:ffff:ffff:ffff
162fe87:ca10::/28fe87:ca1f:ffff:ffff:ffff:ffff:ffff:ffff
163fe87:ca20::/28fe87:ca2f:ffff:ffff:ffff:ffff:ffff:ffff
164fe87:ca30::/28fe87:ca3f:ffff:ffff:ffff:ffff:ffff:ffff
165fe87:ca40::/28fe87:ca4f:ffff:ffff:ffff:ffff:ffff:ffff
166fe87:ca50::/28fe87:ca5f:ffff:ffff:ffff:ffff:ffff:ffff
167fe87:ca60::/28fe87:ca6f:ffff:ffff:ffff:ffff:ffff:ffff
168fe87:ca70::/28fe87:ca7f:ffff:ffff:ffff:ffff:ffff:ffff
169fe87:ca80::/28fe87:ca8f:ffff:ffff:ffff:ffff:ffff:ffff
170fe87:ca90::/28fe87:ca9f:ffff:ffff:ffff:ffff:ffff:ffff
171fe87:caa0::/28fe87:caaf:ffff:ffff:ffff:ffff:ffff:ffff
172fe87:cab0::/28fe87:cabf:ffff:ffff:ffff:ffff:ffff:ffff
173fe87:cac0::/28fe87:cacf:ffff:ffff:ffff:ffff:ffff:ffff
174fe87:cad0::/28fe87:cadf:ffff:ffff:ffff:ffff:ffff:ffff
175fe87:cae0::/28fe87:caef:ffff:ffff:ffff:ffff:ffff:ffff
176fe87:caf0::/28fe87:caff:ffff:ffff:ffff:ffff:ffff:ffff
177fe87:cb00::/28fe87:cb0f:ffff:ffff:ffff:ffff:ffff:ffff
178fe87:cb10::/28fe87:cb1f:ffff:ffff:ffff:ffff:ffff:ffff
179fe87:cb20::/28fe87:cb2f:ffff:ffff:ffff:ffff:ffff:ffff
180fe87:cb30::/28fe87:cb3f:ffff:ffff:ffff:ffff:ffff:ffff
181fe87:cb40::/28fe87:cb4f:ffff:ffff:ffff:ffff:ffff:ffff
182fe87:cb50::/28fe87:cb5f:ffff:ffff:ffff:ffff:ffff:ffff
183fe87:cb60::/28fe87:cb6f:ffff:ffff:ffff:ffff:ffff:ffff
184fe87:cb70::/28fe87:cb7f:ffff:ffff:ffff:ffff:ffff:ffff
185fe87:cb80::/28fe87:cb8f:ffff:ffff:ffff:ffff:ffff:ffff
186fe87:cb90::/28fe87:cb9f:ffff:ffff:ffff:ffff:ffff:ffff
187fe87:cba0::/28fe87:cbaf:ffff:ffff:ffff:ffff:ffff:ffff
188fe87:cbb0::/28fe87:cbbf:ffff:ffff:ffff:ffff:ffff:ffff
189fe87:cbc0::/28fe87:cbcf:ffff:ffff:ffff:ffff:ffff:ffff
190fe87:cbd0::/28fe87:cbdf:ffff:ffff:ffff:ffff:ffff:ffff
191fe87:cbe0::/28fe87:cbef:ffff:ffff:ffff:ffff:ffff:ffff
192fe87:cbf0::/28fe87:cbff:ffff:ffff:ffff:ffff:ffff:ffff
193fe87:cc00::/28fe87:cc0f:ffff:ffff:ffff:ffff:ffff:ffff
194fe87:cc10::/28fe87:cc1f:ffff:ffff:ffff:ffff:ffff:ffff
195fe87:cc20::/28fe87:cc2f:ffff:ffff:ffff:ffff:ffff:ffff
196fe87:cc30::/28fe87:cc3f:ffff:ffff:ffff:ffff:ffff:ffff
197fe87:cc40::/28fe87:cc4f:ffff:ffff:ffff:ffff:ffff:ffff
198fe87:cc50::/28fe87:cc5f:ffff:ffff:ffff:ffff:ffff:ffff
199fe87:cc60::/28fe87:cc6f:ffff:ffff:ffff:ffff:ffff:ffff
200fe87:cc70::/28fe87:cc7f:ffff:ffff:ffff:ffff:ffff:ffff
201fe87:cc80::/28fe87:cc8f:ffff:ffff:ffff:ffff:ffff:ffff
202fe87:cc90::/28fe87:cc9f:ffff:ffff:ffff:ffff:ffff:ffff
203fe87:cca0::/28fe87:ccaf:ffff:ffff:ffff:ffff:ffff:ffff
204fe87:ccb0::/28fe87:ccbf:ffff:ffff:ffff:ffff:ffff:ffff
205fe87:ccc0::/28fe87:cccf:ffff:ffff:ffff:ffff:ffff:ffff
206fe87:ccd0::/28fe87:ccdf:ffff:ffff:ffff:ffff:ffff:ffff
207fe87:cce0::/28fe87:ccef:ffff:ffff:ffff:ffff:ffff:ffff
208fe87:ccf0::/28fe87:ccff:ffff:ffff:ffff:ffff:ffff:ffff
209fe87:cd00::/28fe87:cd0f:ffff:ffff:ffff:ffff:ffff:ffff
210fe87:cd10::/28fe87:cd1f:ffff:ffff:ffff:ffff:ffff:ffff
211fe87:cd20::/28fe87:cd2f:ffff:ffff:ffff:ffff:ffff:ffff
212fe87:cd30::/28fe87:cd3f:ffff:ffff:ffff:ffff:ffff:ffff
213fe87:cd40::/28fe87:cd4f:ffff:ffff:ffff:ffff:ffff:ffff
214fe87:cd50::/28fe87:cd5f:ffff:ffff:ffff:ffff:ffff:ffff
215fe87:cd60::/28fe87:cd6f:ffff:ffff:ffff:ffff:ffff:ffff
216fe87:cd70::/28fe87:cd7f:ffff:ffff:ffff:ffff:ffff:ffff
217fe87:cd80::/28fe87:cd8f:ffff:ffff:ffff:ffff:ffff:ffff
218fe87:cd90::/28fe87:cd9f:ffff:ffff:ffff:ffff:ffff:ffff
219fe87:cda0::/28fe87:cdaf:ffff:ffff:ffff:ffff:ffff:ffff
220fe87:cdb0::/28fe87:cdbf:ffff:ffff:ffff:ffff:ffff:ffff
221fe87:cdc0::/28fe87:cdcf:ffff:ffff:ffff:ffff:ffff:ffff
222fe87:cdd0::/28fe87:cddf:ffff:ffff:ffff:ffff:ffff:ffff
223fe87:cde0::/28fe87:cdef:ffff:ffff:ffff:ffff:ffff:ffff
224fe87:cdf0::/28fe87:cdff:ffff:ffff:ffff:ffff:ffff:ffff
225fe87:ce00::/28fe87:ce0f:ffff:ffff:ffff:ffff:ffff:ffff
226fe87:ce10::/28fe87:ce1f:ffff:ffff:ffff:ffff:ffff:ffff
227fe87:ce20::/28fe87:ce2f:ffff:ffff:ffff:ffff:ffff:ffff
228fe87:ce30::/28fe87:ce3f:ffff:ffff:ffff:ffff:ffff:ffff
229fe87:ce40::/28fe87:ce4f:ffff:ffff:ffff:ffff:ffff:ffff
230fe87:ce50::/28fe87:ce5f:ffff:ffff:ffff:ffff:ffff:ffff
231fe87:ce60::/28fe87:ce6f:ffff:ffff:ffff:ffff:ffff:ffff
232fe87:ce70::/28fe87:ce7f:ffff:ffff:ffff:ffff:ffff:ffff
233fe87:ce80::/28fe87:ce8f:ffff:ffff:ffff:ffff:ffff:ffff
234fe87:ce90::/28fe87:ce9f:ffff:ffff:ffff:ffff:ffff:ffff
235fe87:cea0::/28fe87:ceaf:ffff:ffff:ffff:ffff:ffff:ffff
236fe87:ceb0::/28fe87:cebf:ffff:ffff:ffff:ffff:ffff:ffff
237fe87:cec0::/28fe87:cecf:ffff:ffff:ffff:ffff:ffff:ffff
238fe87:ced0::/28fe87:cedf:ffff:ffff:ffff:ffff:ffff:ffff
239fe87:cee0::/28fe87:ceef:ffff:ffff:ffff:ffff:ffff:ffff
240fe87:cef0::/28fe87:ceff:ffff:ffff:ffff:ffff:ffff:ffff
241fe87:cf00::/28fe87:cf0f:ffff:ffff:ffff:ffff:ffff:ffff
242fe87:cf10::/28fe87:cf1f:ffff:ffff:ffff:ffff:ffff:ffff
243fe87:cf20::/28fe87:cf2f:ffff:ffff:ffff:ffff:ffff:ffff
244fe87:cf30::/28fe87:cf3f:ffff:ffff:ffff:ffff:ffff:ffff
245fe87:cf40::/28fe87:cf4f:ffff:ffff:ffff:ffff:ffff:ffff
246fe87:cf50::/28fe87:cf5f:ffff:ffff:ffff:ffff:ffff:ffff
247fe87:cf60::/28fe87:cf6f:ffff:ffff:ffff:ffff:ffff:ffff
248fe87:cf70::/28fe87:cf7f:ffff:ffff:ffff:ffff:ffff:ffff
249fe87:cf80::/28fe87:cf8f:ffff:ffff:ffff:ffff:ffff:ffff
250fe87:cf90::/28fe87:cf9f:ffff:ffff:ffff:ffff:ffff:ffff
251fe87:cfa0::/28fe87:cfaf:ffff:ffff:ffff:ffff:ffff:ffff
252fe87:cfb0::/28fe87:cfbf:ffff:ffff:ffff:ffff:ffff:ffff
253fe87:cfc0::/28fe87:cfcf:ffff:ffff:ffff:ffff:ffff:ffff
254fe87:cfd0::/28fe87:cfdf:ffff:ffff:ffff:ffff:ffff:ffff
255fe87:cfe0::/28fe87:cfef:ffff:ffff:ffff:ffff:ffff:ffff
256fe87:cff0::/28fe87:cfff: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.