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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/12
Addresses2^116
/64 networks2^52
Network
ffd0::/12
First address
ffd0::
Last address
ffdf:ffff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
83,076,749,736,557,242,056,487,941,267,521,536 (2^116)
/64 networks (LANs)
4,503,599,627,370,496 (2^52)
Full form
ffd0:0000:0000:0000:0000:0000:0000:0000
Type
Multicast ff00::/8
One-to-many traffic; replaces broadcast
Reverse DNS zone
d.f.f.ip6.arpa
Split into smaller subnets/20
/13 (2)/14 (4)/15 (8)/16 (16)/20 (256)/24 (4,096)/28 (65,536)

ffd0::/12 makes 256 subnets of /20.

Subnets
#SubnetLast address
1ffd0::/20ffd0:fff:ffff:ffff:ffff:ffff:ffff:ffff
2ffd0:1000::/20ffd0:1fff:ffff:ffff:ffff:ffff:ffff:ffff
3ffd0:2000::/20ffd0:2fff:ffff:ffff:ffff:ffff:ffff:ffff
4ffd0:3000::/20ffd0:3fff:ffff:ffff:ffff:ffff:ffff:ffff
5ffd0:4000::/20ffd0:4fff:ffff:ffff:ffff:ffff:ffff:ffff
6ffd0:5000::/20ffd0:5fff:ffff:ffff:ffff:ffff:ffff:ffff
7ffd0:6000::/20ffd0:6fff:ffff:ffff:ffff:ffff:ffff:ffff
8ffd0:7000::/20ffd0:7fff:ffff:ffff:ffff:ffff:ffff:ffff
9ffd0:8000::/20ffd0:8fff:ffff:ffff:ffff:ffff:ffff:ffff
10ffd0:9000::/20ffd0:9fff:ffff:ffff:ffff:ffff:ffff:ffff
11ffd0:a000::/20ffd0:afff:ffff:ffff:ffff:ffff:ffff:ffff
12ffd0:b000::/20ffd0:bfff:ffff:ffff:ffff:ffff:ffff:ffff
13ffd0:c000::/20ffd0:cfff:ffff:ffff:ffff:ffff:ffff:ffff
14ffd0:d000::/20ffd0:dfff:ffff:ffff:ffff:ffff:ffff:ffff
15ffd0:e000::/20ffd0:efff:ffff:ffff:ffff:ffff:ffff:ffff
16ffd0:f000::/20ffd0:ffff:ffff:ffff:ffff:ffff:ffff:ffff
17ffd1::/20ffd1:fff:ffff:ffff:ffff:ffff:ffff:ffff
18ffd1:1000::/20ffd1:1fff:ffff:ffff:ffff:ffff:ffff:ffff
19ffd1:2000::/20ffd1:2fff:ffff:ffff:ffff:ffff:ffff:ffff
20ffd1:3000::/20ffd1:3fff:ffff:ffff:ffff:ffff:ffff:ffff
21ffd1:4000::/20ffd1:4fff:ffff:ffff:ffff:ffff:ffff:ffff
22ffd1:5000::/20ffd1:5fff:ffff:ffff:ffff:ffff:ffff:ffff
23ffd1:6000::/20ffd1:6fff:ffff:ffff:ffff:ffff:ffff:ffff
24ffd1:7000::/20ffd1:7fff:ffff:ffff:ffff:ffff:ffff:ffff
25ffd1:8000::/20ffd1:8fff:ffff:ffff:ffff:ffff:ffff:ffff
26ffd1:9000::/20ffd1:9fff:ffff:ffff:ffff:ffff:ffff:ffff
27ffd1:a000::/20ffd1:afff:ffff:ffff:ffff:ffff:ffff:ffff
28ffd1:b000::/20ffd1:bfff:ffff:ffff:ffff:ffff:ffff:ffff
29ffd1:c000::/20ffd1:cfff:ffff:ffff:ffff:ffff:ffff:ffff
30ffd1:d000::/20ffd1:dfff:ffff:ffff:ffff:ffff:ffff:ffff
31ffd1:e000::/20ffd1:efff:ffff:ffff:ffff:ffff:ffff:ffff
32ffd1:f000::/20ffd1:ffff:ffff:ffff:ffff:ffff:ffff:ffff
33ffd2::/20ffd2:fff:ffff:ffff:ffff:ffff:ffff:ffff
34ffd2:1000::/20ffd2:1fff:ffff:ffff:ffff:ffff:ffff:ffff
35ffd2:2000::/20ffd2:2fff:ffff:ffff:ffff:ffff:ffff:ffff
36ffd2:3000::/20ffd2:3fff:ffff:ffff:ffff:ffff:ffff:ffff
37ffd2:4000::/20ffd2:4fff:ffff:ffff:ffff:ffff:ffff:ffff
38ffd2:5000::/20ffd2:5fff:ffff:ffff:ffff:ffff:ffff:ffff
39ffd2:6000::/20ffd2:6fff:ffff:ffff:ffff:ffff:ffff:ffff
40ffd2:7000::/20ffd2:7fff:ffff:ffff:ffff:ffff:ffff:ffff
41ffd2:8000::/20ffd2:8fff:ffff:ffff:ffff:ffff:ffff:ffff
42ffd2:9000::/20ffd2:9fff:ffff:ffff:ffff:ffff:ffff:ffff
43ffd2:a000::/20ffd2:afff:ffff:ffff:ffff:ffff:ffff:ffff
44ffd2:b000::/20ffd2:bfff:ffff:ffff:ffff:ffff:ffff:ffff
45ffd2:c000::/20ffd2:cfff:ffff:ffff:ffff:ffff:ffff:ffff
46ffd2:d000::/20ffd2:dfff:ffff:ffff:ffff:ffff:ffff:ffff
47ffd2:e000::/20ffd2:efff:ffff:ffff:ffff:ffff:ffff:ffff
48ffd2:f000::/20ffd2:ffff:ffff:ffff:ffff:ffff:ffff:ffff
49ffd3::/20ffd3:fff:ffff:ffff:ffff:ffff:ffff:ffff
50ffd3:1000::/20ffd3:1fff:ffff:ffff:ffff:ffff:ffff:ffff
51ffd3:2000::/20ffd3:2fff:ffff:ffff:ffff:ffff:ffff:ffff
52ffd3:3000::/20ffd3:3fff:ffff:ffff:ffff:ffff:ffff:ffff
53ffd3:4000::/20ffd3:4fff:ffff:ffff:ffff:ffff:ffff:ffff
54ffd3:5000::/20ffd3:5fff:ffff:ffff:ffff:ffff:ffff:ffff
55ffd3:6000::/20ffd3:6fff:ffff:ffff:ffff:ffff:ffff:ffff
56ffd3:7000::/20ffd3:7fff:ffff:ffff:ffff:ffff:ffff:ffff
57ffd3:8000::/20ffd3:8fff:ffff:ffff:ffff:ffff:ffff:ffff
58ffd3:9000::/20ffd3:9fff:ffff:ffff:ffff:ffff:ffff:ffff
59ffd3:a000::/20ffd3:afff:ffff:ffff:ffff:ffff:ffff:ffff
60ffd3:b000::/20ffd3:bfff:ffff:ffff:ffff:ffff:ffff:ffff
61ffd3:c000::/20ffd3:cfff:ffff:ffff:ffff:ffff:ffff:ffff
62ffd3:d000::/20ffd3:dfff:ffff:ffff:ffff:ffff:ffff:ffff
63ffd3:e000::/20ffd3:efff:ffff:ffff:ffff:ffff:ffff:ffff
64ffd3:f000::/20ffd3:ffff:ffff:ffff:ffff:ffff:ffff:ffff
65ffd4::/20ffd4:fff:ffff:ffff:ffff:ffff:ffff:ffff
66ffd4:1000::/20ffd4:1fff:ffff:ffff:ffff:ffff:ffff:ffff
67ffd4:2000::/20ffd4:2fff:ffff:ffff:ffff:ffff:ffff:ffff
68ffd4:3000::/20ffd4:3fff:ffff:ffff:ffff:ffff:ffff:ffff
69ffd4:4000::/20ffd4:4fff:ffff:ffff:ffff:ffff:ffff:ffff
70ffd4:5000::/20ffd4:5fff:ffff:ffff:ffff:ffff:ffff:ffff
71ffd4:6000::/20ffd4:6fff:ffff:ffff:ffff:ffff:ffff:ffff
72ffd4:7000::/20ffd4:7fff:ffff:ffff:ffff:ffff:ffff:ffff
73ffd4:8000::/20ffd4:8fff:ffff:ffff:ffff:ffff:ffff:ffff
74ffd4:9000::/20ffd4:9fff:ffff:ffff:ffff:ffff:ffff:ffff
75ffd4:a000::/20ffd4:afff:ffff:ffff:ffff:ffff:ffff:ffff
76ffd4:b000::/20ffd4:bfff:ffff:ffff:ffff:ffff:ffff:ffff
77ffd4:c000::/20ffd4:cfff:ffff:ffff:ffff:ffff:ffff:ffff
78ffd4:d000::/20ffd4:dfff:ffff:ffff:ffff:ffff:ffff:ffff
79ffd4:e000::/20ffd4:efff:ffff:ffff:ffff:ffff:ffff:ffff
80ffd4:f000::/20ffd4:ffff:ffff:ffff:ffff:ffff:ffff:ffff
81ffd5::/20ffd5:fff:ffff:ffff:ffff:ffff:ffff:ffff
82ffd5:1000::/20ffd5:1fff:ffff:ffff:ffff:ffff:ffff:ffff
83ffd5:2000::/20ffd5:2fff:ffff:ffff:ffff:ffff:ffff:ffff
84ffd5:3000::/20ffd5:3fff:ffff:ffff:ffff:ffff:ffff:ffff
85ffd5:4000::/20ffd5:4fff:ffff:ffff:ffff:ffff:ffff:ffff
86ffd5:5000::/20ffd5:5fff:ffff:ffff:ffff:ffff:ffff:ffff
87ffd5:6000::/20ffd5:6fff:ffff:ffff:ffff:ffff:ffff:ffff
88ffd5:7000::/20ffd5:7fff:ffff:ffff:ffff:ffff:ffff:ffff
89ffd5:8000::/20ffd5:8fff:ffff:ffff:ffff:ffff:ffff:ffff
90ffd5:9000::/20ffd5:9fff:ffff:ffff:ffff:ffff:ffff:ffff
91ffd5:a000::/20ffd5:afff:ffff:ffff:ffff:ffff:ffff:ffff
92ffd5:b000::/20ffd5:bfff:ffff:ffff:ffff:ffff:ffff:ffff
93ffd5:c000::/20ffd5:cfff:ffff:ffff:ffff:ffff:ffff:ffff
94ffd5:d000::/20ffd5:dfff:ffff:ffff:ffff:ffff:ffff:ffff
95ffd5:e000::/20ffd5:efff:ffff:ffff:ffff:ffff:ffff:ffff
96ffd5:f000::/20ffd5:ffff:ffff:ffff:ffff:ffff:ffff:ffff
97ffd6::/20ffd6:fff:ffff:ffff:ffff:ffff:ffff:ffff
98ffd6:1000::/20ffd6:1fff:ffff:ffff:ffff:ffff:ffff:ffff
99ffd6:2000::/20ffd6:2fff:ffff:ffff:ffff:ffff:ffff:ffff
100ffd6:3000::/20ffd6:3fff:ffff:ffff:ffff:ffff:ffff:ffff
101ffd6:4000::/20ffd6:4fff:ffff:ffff:ffff:ffff:ffff:ffff
102ffd6:5000::/20ffd6:5fff:ffff:ffff:ffff:ffff:ffff:ffff
103ffd6:6000::/20ffd6:6fff:ffff:ffff:ffff:ffff:ffff:ffff
104ffd6:7000::/20ffd6:7fff:ffff:ffff:ffff:ffff:ffff:ffff
105ffd6:8000::/20ffd6:8fff:ffff:ffff:ffff:ffff:ffff:ffff
106ffd6:9000::/20ffd6:9fff:ffff:ffff:ffff:ffff:ffff:ffff
107ffd6:a000::/20ffd6:afff:ffff:ffff:ffff:ffff:ffff:ffff
108ffd6:b000::/20ffd6:bfff:ffff:ffff:ffff:ffff:ffff:ffff
109ffd6:c000::/20ffd6:cfff:ffff:ffff:ffff:ffff:ffff:ffff
110ffd6:d000::/20ffd6:dfff:ffff:ffff:ffff:ffff:ffff:ffff
111ffd6:e000::/20ffd6:efff:ffff:ffff:ffff:ffff:ffff:ffff
112ffd6:f000::/20ffd6:ffff:ffff:ffff:ffff:ffff:ffff:ffff
113ffd7::/20ffd7:fff:ffff:ffff:ffff:ffff:ffff:ffff
114ffd7:1000::/20ffd7:1fff:ffff:ffff:ffff:ffff:ffff:ffff
115ffd7:2000::/20ffd7:2fff:ffff:ffff:ffff:ffff:ffff:ffff
116ffd7:3000::/20ffd7:3fff:ffff:ffff:ffff:ffff:ffff:ffff
117ffd7:4000::/20ffd7:4fff:ffff:ffff:ffff:ffff:ffff:ffff
118ffd7:5000::/20ffd7:5fff:ffff:ffff:ffff:ffff:ffff:ffff
119ffd7:6000::/20ffd7:6fff:ffff:ffff:ffff:ffff:ffff:ffff
120ffd7:7000::/20ffd7:7fff:ffff:ffff:ffff:ffff:ffff:ffff
121ffd7:8000::/20ffd7:8fff:ffff:ffff:ffff:ffff:ffff:ffff
122ffd7:9000::/20ffd7:9fff:ffff:ffff:ffff:ffff:ffff:ffff
123ffd7:a000::/20ffd7:afff:ffff:ffff:ffff:ffff:ffff:ffff
124ffd7:b000::/20ffd7:bfff:ffff:ffff:ffff:ffff:ffff:ffff
125ffd7:c000::/20ffd7:cfff:ffff:ffff:ffff:ffff:ffff:ffff
126ffd7:d000::/20ffd7:dfff:ffff:ffff:ffff:ffff:ffff:ffff
127ffd7:e000::/20ffd7:efff:ffff:ffff:ffff:ffff:ffff:ffff
128ffd7:f000::/20ffd7:ffff:ffff:ffff:ffff:ffff:ffff:ffff
129ffd8::/20ffd8:fff:ffff:ffff:ffff:ffff:ffff:ffff
130ffd8:1000::/20ffd8:1fff:ffff:ffff:ffff:ffff:ffff:ffff
131ffd8:2000::/20ffd8:2fff:ffff:ffff:ffff:ffff:ffff:ffff
132ffd8:3000::/20ffd8:3fff:ffff:ffff:ffff:ffff:ffff:ffff
133ffd8:4000::/20ffd8:4fff:ffff:ffff:ffff:ffff:ffff:ffff
134ffd8:5000::/20ffd8:5fff:ffff:ffff:ffff:ffff:ffff:ffff
135ffd8:6000::/20ffd8:6fff:ffff:ffff:ffff:ffff:ffff:ffff
136ffd8:7000::/20ffd8:7fff:ffff:ffff:ffff:ffff:ffff:ffff
137ffd8:8000::/20ffd8:8fff:ffff:ffff:ffff:ffff:ffff:ffff
138ffd8:9000::/20ffd8:9fff:ffff:ffff:ffff:ffff:ffff:ffff
139ffd8:a000::/20ffd8:afff:ffff:ffff:ffff:ffff:ffff:ffff
140ffd8:b000::/20ffd8:bfff:ffff:ffff:ffff:ffff:ffff:ffff
141ffd8:c000::/20ffd8:cfff:ffff:ffff:ffff:ffff:ffff:ffff
142ffd8:d000::/20ffd8:dfff:ffff:ffff:ffff:ffff:ffff:ffff
143ffd8:e000::/20ffd8:efff:ffff:ffff:ffff:ffff:ffff:ffff
144ffd8:f000::/20ffd8:ffff:ffff:ffff:ffff:ffff:ffff:ffff
145ffd9::/20ffd9:fff:ffff:ffff:ffff:ffff:ffff:ffff
146ffd9:1000::/20ffd9:1fff:ffff:ffff:ffff:ffff:ffff:ffff
147ffd9:2000::/20ffd9:2fff:ffff:ffff:ffff:ffff:ffff:ffff
148ffd9:3000::/20ffd9:3fff:ffff:ffff:ffff:ffff:ffff:ffff
149ffd9:4000::/20ffd9:4fff:ffff:ffff:ffff:ffff:ffff:ffff
150ffd9:5000::/20ffd9:5fff:ffff:ffff:ffff:ffff:ffff:ffff
151ffd9:6000::/20ffd9:6fff:ffff:ffff:ffff:ffff:ffff:ffff
152ffd9:7000::/20ffd9:7fff:ffff:ffff:ffff:ffff:ffff:ffff
153ffd9:8000::/20ffd9:8fff:ffff:ffff:ffff:ffff:ffff:ffff
154ffd9:9000::/20ffd9:9fff:ffff:ffff:ffff:ffff:ffff:ffff
155ffd9:a000::/20ffd9:afff:ffff:ffff:ffff:ffff:ffff:ffff
156ffd9:b000::/20ffd9:bfff:ffff:ffff:ffff:ffff:ffff:ffff
157ffd9:c000::/20ffd9:cfff:ffff:ffff:ffff:ffff:ffff:ffff
158ffd9:d000::/20ffd9:dfff:ffff:ffff:ffff:ffff:ffff:ffff
159ffd9:e000::/20ffd9:efff:ffff:ffff:ffff:ffff:ffff:ffff
160ffd9:f000::/20ffd9:ffff:ffff:ffff:ffff:ffff:ffff:ffff
161ffda::/20ffda:fff:ffff:ffff:ffff:ffff:ffff:ffff
162ffda:1000::/20ffda:1fff:ffff:ffff:ffff:ffff:ffff:ffff
163ffda:2000::/20ffda:2fff:ffff:ffff:ffff:ffff:ffff:ffff
164ffda:3000::/20ffda:3fff:ffff:ffff:ffff:ffff:ffff:ffff
165ffda:4000::/20ffda:4fff:ffff:ffff:ffff:ffff:ffff:ffff
166ffda:5000::/20ffda:5fff:ffff:ffff:ffff:ffff:ffff:ffff
167ffda:6000::/20ffda:6fff:ffff:ffff:ffff:ffff:ffff:ffff
168ffda:7000::/20ffda:7fff:ffff:ffff:ffff:ffff:ffff:ffff
169ffda:8000::/20ffda:8fff:ffff:ffff:ffff:ffff:ffff:ffff
170ffda:9000::/20ffda:9fff:ffff:ffff:ffff:ffff:ffff:ffff
171ffda:a000::/20ffda:afff:ffff:ffff:ffff:ffff:ffff:ffff
172ffda:b000::/20ffda:bfff:ffff:ffff:ffff:ffff:ffff:ffff
173ffda:c000::/20ffda:cfff:ffff:ffff:ffff:ffff:ffff:ffff
174ffda:d000::/20ffda:dfff:ffff:ffff:ffff:ffff:ffff:ffff
175ffda:e000::/20ffda:efff:ffff:ffff:ffff:ffff:ffff:ffff
176ffda:f000::/20ffda:ffff:ffff:ffff:ffff:ffff:ffff:ffff
177ffdb::/20ffdb:fff:ffff:ffff:ffff:ffff:ffff:ffff
178ffdb:1000::/20ffdb:1fff:ffff:ffff:ffff:ffff:ffff:ffff
179ffdb:2000::/20ffdb:2fff:ffff:ffff:ffff:ffff:ffff:ffff
180ffdb:3000::/20ffdb:3fff:ffff:ffff:ffff:ffff:ffff:ffff
181ffdb:4000::/20ffdb:4fff:ffff:ffff:ffff:ffff:ffff:ffff
182ffdb:5000::/20ffdb:5fff:ffff:ffff:ffff:ffff:ffff:ffff
183ffdb:6000::/20ffdb:6fff:ffff:ffff:ffff:ffff:ffff:ffff
184ffdb:7000::/20ffdb:7fff:ffff:ffff:ffff:ffff:ffff:ffff
185ffdb:8000::/20ffdb:8fff:ffff:ffff:ffff:ffff:ffff:ffff
186ffdb:9000::/20ffdb:9fff:ffff:ffff:ffff:ffff:ffff:ffff
187ffdb:a000::/20ffdb:afff:ffff:ffff:ffff:ffff:ffff:ffff
188ffdb:b000::/20ffdb:bfff:ffff:ffff:ffff:ffff:ffff:ffff
189ffdb:c000::/20ffdb:cfff:ffff:ffff:ffff:ffff:ffff:ffff
190ffdb:d000::/20ffdb:dfff:ffff:ffff:ffff:ffff:ffff:ffff
191ffdb:e000::/20ffdb:efff:ffff:ffff:ffff:ffff:ffff:ffff
192ffdb:f000::/20ffdb:ffff:ffff:ffff:ffff:ffff:ffff:ffff
193ffdc::/20ffdc:fff:ffff:ffff:ffff:ffff:ffff:ffff
194ffdc:1000::/20ffdc:1fff:ffff:ffff:ffff:ffff:ffff:ffff
195ffdc:2000::/20ffdc:2fff:ffff:ffff:ffff:ffff:ffff:ffff
196ffdc:3000::/20ffdc:3fff:ffff:ffff:ffff:ffff:ffff:ffff
197ffdc:4000::/20ffdc:4fff:ffff:ffff:ffff:ffff:ffff:ffff
198ffdc:5000::/20ffdc:5fff:ffff:ffff:ffff:ffff:ffff:ffff
199ffdc:6000::/20ffdc:6fff:ffff:ffff:ffff:ffff:ffff:ffff
200ffdc:7000::/20ffdc:7fff:ffff:ffff:ffff:ffff:ffff:ffff
201ffdc:8000::/20ffdc:8fff:ffff:ffff:ffff:ffff:ffff:ffff
202ffdc:9000::/20ffdc:9fff:ffff:ffff:ffff:ffff:ffff:ffff
203ffdc:a000::/20ffdc:afff:ffff:ffff:ffff:ffff:ffff:ffff
204ffdc:b000::/20ffdc:bfff:ffff:ffff:ffff:ffff:ffff:ffff
205ffdc:c000::/20ffdc:cfff:ffff:ffff:ffff:ffff:ffff:ffff
206ffdc:d000::/20ffdc:dfff:ffff:ffff:ffff:ffff:ffff:ffff
207ffdc:e000::/20ffdc:efff:ffff:ffff:ffff:ffff:ffff:ffff
208ffdc:f000::/20ffdc:ffff:ffff:ffff:ffff:ffff:ffff:ffff
209ffdd::/20ffdd:fff:ffff:ffff:ffff:ffff:ffff:ffff
210ffdd:1000::/20ffdd:1fff:ffff:ffff:ffff:ffff:ffff:ffff
211ffdd:2000::/20ffdd:2fff:ffff:ffff:ffff:ffff:ffff:ffff
212ffdd:3000::/20ffdd:3fff:ffff:ffff:ffff:ffff:ffff:ffff
213ffdd:4000::/20ffdd:4fff:ffff:ffff:ffff:ffff:ffff:ffff
214ffdd:5000::/20ffdd:5fff:ffff:ffff:ffff:ffff:ffff:ffff
215ffdd:6000::/20ffdd:6fff:ffff:ffff:ffff:ffff:ffff:ffff
216ffdd:7000::/20ffdd:7fff:ffff:ffff:ffff:ffff:ffff:ffff
217ffdd:8000::/20ffdd:8fff:ffff:ffff:ffff:ffff:ffff:ffff
218ffdd:9000::/20ffdd:9fff:ffff:ffff:ffff:ffff:ffff:ffff
219ffdd:a000::/20ffdd:afff:ffff:ffff:ffff:ffff:ffff:ffff
220ffdd:b000::/20ffdd:bfff:ffff:ffff:ffff:ffff:ffff:ffff
221ffdd:c000::/20ffdd:cfff:ffff:ffff:ffff:ffff:ffff:ffff
222ffdd:d000::/20ffdd:dfff:ffff:ffff:ffff:ffff:ffff:ffff
223ffdd:e000::/20ffdd:efff:ffff:ffff:ffff:ffff:ffff:ffff
224ffdd:f000::/20ffdd:ffff:ffff:ffff:ffff:ffff:ffff:ffff
225ffde::/20ffde:fff:ffff:ffff:ffff:ffff:ffff:ffff
226ffde:1000::/20ffde:1fff:ffff:ffff:ffff:ffff:ffff:ffff
227ffde:2000::/20ffde:2fff:ffff:ffff:ffff:ffff:ffff:ffff
228ffde:3000::/20ffde:3fff:ffff:ffff:ffff:ffff:ffff:ffff
229ffde:4000::/20ffde:4fff:ffff:ffff:ffff:ffff:ffff:ffff
230ffde:5000::/20ffde:5fff:ffff:ffff:ffff:ffff:ffff:ffff
231ffde:6000::/20ffde:6fff:ffff:ffff:ffff:ffff:ffff:ffff
232ffde:7000::/20ffde:7fff:ffff:ffff:ffff:ffff:ffff:ffff
233ffde:8000::/20ffde:8fff:ffff:ffff:ffff:ffff:ffff:ffff
234ffde:9000::/20ffde:9fff:ffff:ffff:ffff:ffff:ffff:ffff
235ffde:a000::/20ffde:afff:ffff:ffff:ffff:ffff:ffff:ffff
236ffde:b000::/20ffde:bfff:ffff:ffff:ffff:ffff:ffff:ffff
237ffde:c000::/20ffde:cfff:ffff:ffff:ffff:ffff:ffff:ffff
238ffde:d000::/20ffde:dfff:ffff:ffff:ffff:ffff:ffff:ffff
239ffde:e000::/20ffde:efff:ffff:ffff:ffff:ffff:ffff:ffff
240ffde:f000::/20ffde:ffff:ffff:ffff:ffff:ffff:ffff:ffff
241ffdf::/20ffdf:fff:ffff:ffff:ffff:ffff:ffff:ffff
242ffdf:1000::/20ffdf:1fff:ffff:ffff:ffff:ffff:ffff:ffff
243ffdf:2000::/20ffdf:2fff:ffff:ffff:ffff:ffff:ffff:ffff
244ffdf:3000::/20ffdf:3fff:ffff:ffff:ffff:ffff:ffff:ffff
245ffdf:4000::/20ffdf:4fff:ffff:ffff:ffff:ffff:ffff:ffff
246ffdf:5000::/20ffdf:5fff:ffff:ffff:ffff:ffff:ffff:ffff
247ffdf:6000::/20ffdf:6fff:ffff:ffff:ffff:ffff:ffff:ffff
248ffdf:7000::/20ffdf:7fff:ffff:ffff:ffff:ffff:ffff:ffff
249ffdf:8000::/20ffdf:8fff:ffff:ffff:ffff:ffff:ffff:ffff
250ffdf:9000::/20ffdf:9fff:ffff:ffff:ffff:ffff:ffff:ffff
251ffdf:a000::/20ffdf:afff:ffff:ffff:ffff:ffff:ffff:ffff
252ffdf:b000::/20ffdf:bfff:ffff:ffff:ffff:ffff:ffff:ffff
253ffdf:c000::/20ffdf:cfff:ffff:ffff:ffff:ffff:ffff:ffff
254ffdf:d000::/20ffdf:dfff:ffff:ffff:ffff:ffff:ffff:ffff
255ffdf:e000::/20ffdf:efff:ffff:ffff:ffff:ffff:ffff:ffff
256ffdf:f000::/20ffdf:ffff: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.