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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/18
Addresses2^110
/64 networks2^46
Network
261e::/18
First address
261e::
Last address
261e:3fff:ffff:ffff:ffff:ffff:ffff:ffff
Addresses
1,298,074,214,633,706,907,132,624,082,305,024 (2^110)
/64 networks (LANs)
70,368,744,177,664 (2^46)
Full form
261e:0000:0000:0000:0000:0000:0000:0000
Type
Global unicast 2000::/3
Public internet addresses
Reverse DNS zones
0.e.1.6.2.ip6.arpa
1.e.1.6.2.ip6.arpa
2.e.1.6.2.ip6.arpa
3.e.1.6.2.ip6.arpa
/18 is not on a 4-bit boundary, so it takes 4 /20 zones.
Split into smaller subnets/32
/19 (2)/20 (4)/21 (8)/22 (16)/24 (64)/28 (1,024)/32 (16,384)

261e::/18 makes 16,384 subnets of /32; the first 256 are listed.

Subnets
#SubnetLast address
1261e::/32261e:0:ffff:ffff:ffff:ffff:ffff:ffff
2261e:1::/32261e:1:ffff:ffff:ffff:ffff:ffff:ffff
3261e:2::/32261e:2:ffff:ffff:ffff:ffff:ffff:ffff
4261e:3::/32261e:3:ffff:ffff:ffff:ffff:ffff:ffff
5261e:4::/32261e:4:ffff:ffff:ffff:ffff:ffff:ffff
6261e:5::/32261e:5:ffff:ffff:ffff:ffff:ffff:ffff
7261e:6::/32261e:6:ffff:ffff:ffff:ffff:ffff:ffff
8261e:7::/32261e:7:ffff:ffff:ffff:ffff:ffff:ffff
9261e:8::/32261e:8:ffff:ffff:ffff:ffff:ffff:ffff
10261e:9::/32261e:9:ffff:ffff:ffff:ffff:ffff:ffff
11261e:a::/32261e:a:ffff:ffff:ffff:ffff:ffff:ffff
12261e:b::/32261e:b:ffff:ffff:ffff:ffff:ffff:ffff
13261e:c::/32261e:c:ffff:ffff:ffff:ffff:ffff:ffff
14261e:d::/32261e:d:ffff:ffff:ffff:ffff:ffff:ffff
15261e:e::/32261e:e:ffff:ffff:ffff:ffff:ffff:ffff
16261e:f::/32261e:f:ffff:ffff:ffff:ffff:ffff:ffff
17261e:10::/32261e:10:ffff:ffff:ffff:ffff:ffff:ffff
18261e:11::/32261e:11:ffff:ffff:ffff:ffff:ffff:ffff
19261e:12::/32261e:12:ffff:ffff:ffff:ffff:ffff:ffff
20261e:13::/32261e:13:ffff:ffff:ffff:ffff:ffff:ffff
21261e:14::/32261e:14:ffff:ffff:ffff:ffff:ffff:ffff
22261e:15::/32261e:15:ffff:ffff:ffff:ffff:ffff:ffff
23261e:16::/32261e:16:ffff:ffff:ffff:ffff:ffff:ffff
24261e:17::/32261e:17:ffff:ffff:ffff:ffff:ffff:ffff
25261e:18::/32261e:18:ffff:ffff:ffff:ffff:ffff:ffff
26261e:19::/32261e:19:ffff:ffff:ffff:ffff:ffff:ffff
27261e:1a::/32261e:1a:ffff:ffff:ffff:ffff:ffff:ffff
28261e:1b::/32261e:1b:ffff:ffff:ffff:ffff:ffff:ffff
29261e:1c::/32261e:1c:ffff:ffff:ffff:ffff:ffff:ffff
30261e:1d::/32261e:1d:ffff:ffff:ffff:ffff:ffff:ffff
31261e:1e::/32261e:1e:ffff:ffff:ffff:ffff:ffff:ffff
32261e:1f::/32261e:1f:ffff:ffff:ffff:ffff:ffff:ffff
33261e:20::/32261e:20:ffff:ffff:ffff:ffff:ffff:ffff
34261e:21::/32261e:21:ffff:ffff:ffff:ffff:ffff:ffff
35261e:22::/32261e:22:ffff:ffff:ffff:ffff:ffff:ffff
36261e:23::/32261e:23:ffff:ffff:ffff:ffff:ffff:ffff
37261e:24::/32261e:24:ffff:ffff:ffff:ffff:ffff:ffff
38261e:25::/32261e:25:ffff:ffff:ffff:ffff:ffff:ffff
39261e:26::/32261e:26:ffff:ffff:ffff:ffff:ffff:ffff
40261e:27::/32261e:27:ffff:ffff:ffff:ffff:ffff:ffff
41261e:28::/32261e:28:ffff:ffff:ffff:ffff:ffff:ffff
42261e:29::/32261e:29:ffff:ffff:ffff:ffff:ffff:ffff
43261e:2a::/32261e:2a:ffff:ffff:ffff:ffff:ffff:ffff
44261e:2b::/32261e:2b:ffff:ffff:ffff:ffff:ffff:ffff
45261e:2c::/32261e:2c:ffff:ffff:ffff:ffff:ffff:ffff
46261e:2d::/32261e:2d:ffff:ffff:ffff:ffff:ffff:ffff
47261e:2e::/32261e:2e:ffff:ffff:ffff:ffff:ffff:ffff
48261e:2f::/32261e:2f:ffff:ffff:ffff:ffff:ffff:ffff
49261e:30::/32261e:30:ffff:ffff:ffff:ffff:ffff:ffff
50261e:31::/32261e:31:ffff:ffff:ffff:ffff:ffff:ffff
51261e:32::/32261e:32:ffff:ffff:ffff:ffff:ffff:ffff
52261e:33::/32261e:33:ffff:ffff:ffff:ffff:ffff:ffff
53261e:34::/32261e:34:ffff:ffff:ffff:ffff:ffff:ffff
54261e:35::/32261e:35:ffff:ffff:ffff:ffff:ffff:ffff
55261e:36::/32261e:36:ffff:ffff:ffff:ffff:ffff:ffff
56261e:37::/32261e:37:ffff:ffff:ffff:ffff:ffff:ffff
57261e:38::/32261e:38:ffff:ffff:ffff:ffff:ffff:ffff
58261e:39::/32261e:39:ffff:ffff:ffff:ffff:ffff:ffff
59261e:3a::/32261e:3a:ffff:ffff:ffff:ffff:ffff:ffff
60261e:3b::/32261e:3b:ffff:ffff:ffff:ffff:ffff:ffff
61261e:3c::/32261e:3c:ffff:ffff:ffff:ffff:ffff:ffff
62261e:3d::/32261e:3d:ffff:ffff:ffff:ffff:ffff:ffff
63261e:3e::/32261e:3e:ffff:ffff:ffff:ffff:ffff:ffff
64261e:3f::/32261e:3f:ffff:ffff:ffff:ffff:ffff:ffff
65261e:40::/32261e:40:ffff:ffff:ffff:ffff:ffff:ffff
66261e:41::/32261e:41:ffff:ffff:ffff:ffff:ffff:ffff
67261e:42::/32261e:42:ffff:ffff:ffff:ffff:ffff:ffff
68261e:43::/32261e:43:ffff:ffff:ffff:ffff:ffff:ffff
69261e:44::/32261e:44:ffff:ffff:ffff:ffff:ffff:ffff
70261e:45::/32261e:45:ffff:ffff:ffff:ffff:ffff:ffff
71261e:46::/32261e:46:ffff:ffff:ffff:ffff:ffff:ffff
72261e:47::/32261e:47:ffff:ffff:ffff:ffff:ffff:ffff
73261e:48::/32261e:48:ffff:ffff:ffff:ffff:ffff:ffff
74261e:49::/32261e:49:ffff:ffff:ffff:ffff:ffff:ffff
75261e:4a::/32261e:4a:ffff:ffff:ffff:ffff:ffff:ffff
76261e:4b::/32261e:4b:ffff:ffff:ffff:ffff:ffff:ffff
77261e:4c::/32261e:4c:ffff:ffff:ffff:ffff:ffff:ffff
78261e:4d::/32261e:4d:ffff:ffff:ffff:ffff:ffff:ffff
79261e:4e::/32261e:4e:ffff:ffff:ffff:ffff:ffff:ffff
80261e:4f::/32261e:4f:ffff:ffff:ffff:ffff:ffff:ffff
81261e:50::/32261e:50:ffff:ffff:ffff:ffff:ffff:ffff
82261e:51::/32261e:51:ffff:ffff:ffff:ffff:ffff:ffff
83261e:52::/32261e:52:ffff:ffff:ffff:ffff:ffff:ffff
84261e:53::/32261e:53:ffff:ffff:ffff:ffff:ffff:ffff
85261e:54::/32261e:54:ffff:ffff:ffff:ffff:ffff:ffff
86261e:55::/32261e:55:ffff:ffff:ffff:ffff:ffff:ffff
87261e:56::/32261e:56:ffff:ffff:ffff:ffff:ffff:ffff
88261e:57::/32261e:57:ffff:ffff:ffff:ffff:ffff:ffff
89261e:58::/32261e:58:ffff:ffff:ffff:ffff:ffff:ffff
90261e:59::/32261e:59:ffff:ffff:ffff:ffff:ffff:ffff
91261e:5a::/32261e:5a:ffff:ffff:ffff:ffff:ffff:ffff
92261e:5b::/32261e:5b:ffff:ffff:ffff:ffff:ffff:ffff
93261e:5c::/32261e:5c:ffff:ffff:ffff:ffff:ffff:ffff
94261e:5d::/32261e:5d:ffff:ffff:ffff:ffff:ffff:ffff
95261e:5e::/32261e:5e:ffff:ffff:ffff:ffff:ffff:ffff
96261e:5f::/32261e:5f:ffff:ffff:ffff:ffff:ffff:ffff
97261e:60::/32261e:60:ffff:ffff:ffff:ffff:ffff:ffff
98261e:61::/32261e:61:ffff:ffff:ffff:ffff:ffff:ffff
99261e:62::/32261e:62:ffff:ffff:ffff:ffff:ffff:ffff
100261e:63::/32261e:63:ffff:ffff:ffff:ffff:ffff:ffff
101261e:64::/32261e:64:ffff:ffff:ffff:ffff:ffff:ffff
102261e:65::/32261e:65:ffff:ffff:ffff:ffff:ffff:ffff
103261e:66::/32261e:66:ffff:ffff:ffff:ffff:ffff:ffff
104261e:67::/32261e:67:ffff:ffff:ffff:ffff:ffff:ffff
105261e:68::/32261e:68:ffff:ffff:ffff:ffff:ffff:ffff
106261e:69::/32261e:69:ffff:ffff:ffff:ffff:ffff:ffff
107261e:6a::/32261e:6a:ffff:ffff:ffff:ffff:ffff:ffff
108261e:6b::/32261e:6b:ffff:ffff:ffff:ffff:ffff:ffff
109261e:6c::/32261e:6c:ffff:ffff:ffff:ffff:ffff:ffff
110261e:6d::/32261e:6d:ffff:ffff:ffff:ffff:ffff:ffff
111261e:6e::/32261e:6e:ffff:ffff:ffff:ffff:ffff:ffff
112261e:6f::/32261e:6f:ffff:ffff:ffff:ffff:ffff:ffff
113261e:70::/32261e:70:ffff:ffff:ffff:ffff:ffff:ffff
114261e:71::/32261e:71:ffff:ffff:ffff:ffff:ffff:ffff
115261e:72::/32261e:72:ffff:ffff:ffff:ffff:ffff:ffff
116261e:73::/32261e:73:ffff:ffff:ffff:ffff:ffff:ffff
117261e:74::/32261e:74:ffff:ffff:ffff:ffff:ffff:ffff
118261e:75::/32261e:75:ffff:ffff:ffff:ffff:ffff:ffff
119261e:76::/32261e:76:ffff:ffff:ffff:ffff:ffff:ffff
120261e:77::/32261e:77:ffff:ffff:ffff:ffff:ffff:ffff
121261e:78::/32261e:78:ffff:ffff:ffff:ffff:ffff:ffff
122261e:79::/32261e:79:ffff:ffff:ffff:ffff:ffff:ffff
123261e:7a::/32261e:7a:ffff:ffff:ffff:ffff:ffff:ffff
124261e:7b::/32261e:7b:ffff:ffff:ffff:ffff:ffff:ffff
125261e:7c::/32261e:7c:ffff:ffff:ffff:ffff:ffff:ffff
126261e:7d::/32261e:7d:ffff:ffff:ffff:ffff:ffff:ffff
127261e:7e::/32261e:7e:ffff:ffff:ffff:ffff:ffff:ffff
128261e:7f::/32261e:7f:ffff:ffff:ffff:ffff:ffff:ffff
129261e:80::/32261e:80:ffff:ffff:ffff:ffff:ffff:ffff
130261e:81::/32261e:81:ffff:ffff:ffff:ffff:ffff:ffff
131261e:82::/32261e:82:ffff:ffff:ffff:ffff:ffff:ffff
132261e:83::/32261e:83:ffff:ffff:ffff:ffff:ffff:ffff
133261e:84::/32261e:84:ffff:ffff:ffff:ffff:ffff:ffff
134261e:85::/32261e:85:ffff:ffff:ffff:ffff:ffff:ffff
135261e:86::/32261e:86:ffff:ffff:ffff:ffff:ffff:ffff
136261e:87::/32261e:87:ffff:ffff:ffff:ffff:ffff:ffff
137261e:88::/32261e:88:ffff:ffff:ffff:ffff:ffff:ffff
138261e:89::/32261e:89:ffff:ffff:ffff:ffff:ffff:ffff
139261e:8a::/32261e:8a:ffff:ffff:ffff:ffff:ffff:ffff
140261e:8b::/32261e:8b:ffff:ffff:ffff:ffff:ffff:ffff
141261e:8c::/32261e:8c:ffff:ffff:ffff:ffff:ffff:ffff
142261e:8d::/32261e:8d:ffff:ffff:ffff:ffff:ffff:ffff
143261e:8e::/32261e:8e:ffff:ffff:ffff:ffff:ffff:ffff
144261e:8f::/32261e:8f:ffff:ffff:ffff:ffff:ffff:ffff
145261e:90::/32261e:90:ffff:ffff:ffff:ffff:ffff:ffff
146261e:91::/32261e:91:ffff:ffff:ffff:ffff:ffff:ffff
147261e:92::/32261e:92:ffff:ffff:ffff:ffff:ffff:ffff
148261e:93::/32261e:93:ffff:ffff:ffff:ffff:ffff:ffff
149261e:94::/32261e:94:ffff:ffff:ffff:ffff:ffff:ffff
150261e:95::/32261e:95:ffff:ffff:ffff:ffff:ffff:ffff
151261e:96::/32261e:96:ffff:ffff:ffff:ffff:ffff:ffff
152261e:97::/32261e:97:ffff:ffff:ffff:ffff:ffff:ffff
153261e:98::/32261e:98:ffff:ffff:ffff:ffff:ffff:ffff
154261e:99::/32261e:99:ffff:ffff:ffff:ffff:ffff:ffff
155261e:9a::/32261e:9a:ffff:ffff:ffff:ffff:ffff:ffff
156261e:9b::/32261e:9b:ffff:ffff:ffff:ffff:ffff:ffff
157261e:9c::/32261e:9c:ffff:ffff:ffff:ffff:ffff:ffff
158261e:9d::/32261e:9d:ffff:ffff:ffff:ffff:ffff:ffff
159261e:9e::/32261e:9e:ffff:ffff:ffff:ffff:ffff:ffff
160261e:9f::/32261e:9f:ffff:ffff:ffff:ffff:ffff:ffff
161261e:a0::/32261e:a0:ffff:ffff:ffff:ffff:ffff:ffff
162261e:a1::/32261e:a1:ffff:ffff:ffff:ffff:ffff:ffff
163261e:a2::/32261e:a2:ffff:ffff:ffff:ffff:ffff:ffff
164261e:a3::/32261e:a3:ffff:ffff:ffff:ffff:ffff:ffff
165261e:a4::/32261e:a4:ffff:ffff:ffff:ffff:ffff:ffff
166261e:a5::/32261e:a5:ffff:ffff:ffff:ffff:ffff:ffff
167261e:a6::/32261e:a6:ffff:ffff:ffff:ffff:ffff:ffff
168261e:a7::/32261e:a7:ffff:ffff:ffff:ffff:ffff:ffff
169261e:a8::/32261e:a8:ffff:ffff:ffff:ffff:ffff:ffff
170261e:a9::/32261e:a9:ffff:ffff:ffff:ffff:ffff:ffff
171261e:aa::/32261e:aa:ffff:ffff:ffff:ffff:ffff:ffff
172261e:ab::/32261e:ab:ffff:ffff:ffff:ffff:ffff:ffff
173261e:ac::/32261e:ac:ffff:ffff:ffff:ffff:ffff:ffff
174261e:ad::/32261e:ad:ffff:ffff:ffff:ffff:ffff:ffff
175261e:ae::/32261e:ae:ffff:ffff:ffff:ffff:ffff:ffff
176261e:af::/32261e:af:ffff:ffff:ffff:ffff:ffff:ffff
177261e:b0::/32261e:b0:ffff:ffff:ffff:ffff:ffff:ffff
178261e:b1::/32261e:b1:ffff:ffff:ffff:ffff:ffff:ffff
179261e:b2::/32261e:b2:ffff:ffff:ffff:ffff:ffff:ffff
180261e:b3::/32261e:b3:ffff:ffff:ffff:ffff:ffff:ffff
181261e:b4::/32261e:b4:ffff:ffff:ffff:ffff:ffff:ffff
182261e:b5::/32261e:b5:ffff:ffff:ffff:ffff:ffff:ffff
183261e:b6::/32261e:b6:ffff:ffff:ffff:ffff:ffff:ffff
184261e:b7::/32261e:b7:ffff:ffff:ffff:ffff:ffff:ffff
185261e:b8::/32261e:b8:ffff:ffff:ffff:ffff:ffff:ffff
186261e:b9::/32261e:b9:ffff:ffff:ffff:ffff:ffff:ffff
187261e:ba::/32261e:ba:ffff:ffff:ffff:ffff:ffff:ffff
188261e:bb::/32261e:bb:ffff:ffff:ffff:ffff:ffff:ffff
189261e:bc::/32261e:bc:ffff:ffff:ffff:ffff:ffff:ffff
190261e:bd::/32261e:bd:ffff:ffff:ffff:ffff:ffff:ffff
191261e:be::/32261e:be:ffff:ffff:ffff:ffff:ffff:ffff
192261e:bf::/32261e:bf:ffff:ffff:ffff:ffff:ffff:ffff
193261e:c0::/32261e:c0:ffff:ffff:ffff:ffff:ffff:ffff
194261e:c1::/32261e:c1:ffff:ffff:ffff:ffff:ffff:ffff
195261e:c2::/32261e:c2:ffff:ffff:ffff:ffff:ffff:ffff
196261e:c3::/32261e:c3:ffff:ffff:ffff:ffff:ffff:ffff
197261e:c4::/32261e:c4:ffff:ffff:ffff:ffff:ffff:ffff
198261e:c5::/32261e:c5:ffff:ffff:ffff:ffff:ffff:ffff
199261e:c6::/32261e:c6:ffff:ffff:ffff:ffff:ffff:ffff
200261e:c7::/32261e:c7:ffff:ffff:ffff:ffff:ffff:ffff
201261e:c8::/32261e:c8:ffff:ffff:ffff:ffff:ffff:ffff
202261e:c9::/32261e:c9:ffff:ffff:ffff:ffff:ffff:ffff
203261e:ca::/32261e:ca:ffff:ffff:ffff:ffff:ffff:ffff
204261e:cb::/32261e:cb:ffff:ffff:ffff:ffff:ffff:ffff
205261e:cc::/32261e:cc:ffff:ffff:ffff:ffff:ffff:ffff
206261e:cd::/32261e:cd:ffff:ffff:ffff:ffff:ffff:ffff
207261e:ce::/32261e:ce:ffff:ffff:ffff:ffff:ffff:ffff
208261e:cf::/32261e:cf:ffff:ffff:ffff:ffff:ffff:ffff
209261e:d0::/32261e:d0:ffff:ffff:ffff:ffff:ffff:ffff
210261e:d1::/32261e:d1:ffff:ffff:ffff:ffff:ffff:ffff
211261e:d2::/32261e:d2:ffff:ffff:ffff:ffff:ffff:ffff
212261e:d3::/32261e:d3:ffff:ffff:ffff:ffff:ffff:ffff
213261e:d4::/32261e:d4:ffff:ffff:ffff:ffff:ffff:ffff
214261e:d5::/32261e:d5:ffff:ffff:ffff:ffff:ffff:ffff
215261e:d6::/32261e:d6:ffff:ffff:ffff:ffff:ffff:ffff
216261e:d7::/32261e:d7:ffff:ffff:ffff:ffff:ffff:ffff
217261e:d8::/32261e:d8:ffff:ffff:ffff:ffff:ffff:ffff
218261e:d9::/32261e:d9:ffff:ffff:ffff:ffff:ffff:ffff
219261e:da::/32261e:da:ffff:ffff:ffff:ffff:ffff:ffff
220261e:db::/32261e:db:ffff:ffff:ffff:ffff:ffff:ffff
221261e:dc::/32261e:dc:ffff:ffff:ffff:ffff:ffff:ffff
222261e:dd::/32261e:dd:ffff:ffff:ffff:ffff:ffff:ffff
223261e:de::/32261e:de:ffff:ffff:ffff:ffff:ffff:ffff
224261e:df::/32261e:df:ffff:ffff:ffff:ffff:ffff:ffff
225261e:e0::/32261e:e0:ffff:ffff:ffff:ffff:ffff:ffff
226261e:e1::/32261e:e1:ffff:ffff:ffff:ffff:ffff:ffff
227261e:e2::/32261e:e2:ffff:ffff:ffff:ffff:ffff:ffff
228261e:e3::/32261e:e3:ffff:ffff:ffff:ffff:ffff:ffff
229261e:e4::/32261e:e4:ffff:ffff:ffff:ffff:ffff:ffff
230261e:e5::/32261e:e5:ffff:ffff:ffff:ffff:ffff:ffff
231261e:e6::/32261e:e6:ffff:ffff:ffff:ffff:ffff:ffff
232261e:e7::/32261e:e7:ffff:ffff:ffff:ffff:ffff:ffff
233261e:e8::/32261e:e8:ffff:ffff:ffff:ffff:ffff:ffff
234261e:e9::/32261e:e9:ffff:ffff:ffff:ffff:ffff:ffff
235261e:ea::/32261e:ea:ffff:ffff:ffff:ffff:ffff:ffff
236261e:eb::/32261e:eb:ffff:ffff:ffff:ffff:ffff:ffff
237261e:ec::/32261e:ec:ffff:ffff:ffff:ffff:ffff:ffff
238261e:ed::/32261e:ed:ffff:ffff:ffff:ffff:ffff:ffff
239261e:ee::/32261e:ee:ffff:ffff:ffff:ffff:ffff:ffff
240261e:ef::/32261e:ef:ffff:ffff:ffff:ffff:ffff:ffff
241261e:f0::/32261e:f0:ffff:ffff:ffff:ffff:ffff:ffff
242261e:f1::/32261e:f1:ffff:ffff:ffff:ffff:ffff:ffff
243261e:f2::/32261e:f2:ffff:ffff:ffff:ffff:ffff:ffff
244261e:f3::/32261e:f3:ffff:ffff:ffff:ffff:ffff:ffff
245261e:f4::/32261e:f4:ffff:ffff:ffff:ffff:ffff:ffff
246261e:f5::/32261e:f5:ffff:ffff:ffff:ffff:ffff:ffff
247261e:f6::/32261e:f6:ffff:ffff:ffff:ffff:ffff:ffff
248261e:f7::/32261e:f7:ffff:ffff:ffff:ffff:ffff:ffff
249261e:f8::/32261e:f8:ffff:ffff:ffff:ffff:ffff:ffff
250261e:f9::/32261e:f9:ffff:ffff:ffff:ffff:ffff:ffff
251261e:fa::/32261e:fa:ffff:ffff:ffff:ffff:ffff:ffff
252261e:fb::/32261e:fb:ffff:ffff:ffff:ffff:ffff:ffff
253261e:fc::/32261e:fc:ffff:ffff:ffff:ffff:ffff:ffff
254261e:fd::/32261e:fd:ffff:ffff:ffff:ffff:ffff:ffff
255261e:fe::/32261e:fe:ffff:ffff:ffff:ffff:ffff:ffff
256261e:ff::/32261e:ff: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.