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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.

Network117.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
117.0.0.0
Broadcast address
117.255.255.255
First usable
117.0.0.1
Last usable
117.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 75000000 · Integer 1962934272 to 1979711487
Reverse DNS zone
117.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110101..00000000.00000000.00000000117.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network01110101..00000000.00000000.00000000117.0.0.0
Broadcast01110101..11111111.11111111.11111111117.255.255.255
Split into smaller subnets/17
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

117.0.0.0/8 makes 512 subnets of /17; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1117.0.0.0/17117.0.0.1 to 117.0.127.254117.0.127.25532,766
2117.0.128.0/17117.0.128.1 to 117.0.255.254117.0.255.25532,766
3117.1.0.0/17117.1.0.1 to 117.1.127.254117.1.127.25532,766
4117.1.128.0/17117.1.128.1 to 117.1.255.254117.1.255.25532,766
5117.2.0.0/17117.2.0.1 to 117.2.127.254117.2.127.25532,766
6117.2.128.0/17117.2.128.1 to 117.2.255.254117.2.255.25532,766
7117.3.0.0/17117.3.0.1 to 117.3.127.254117.3.127.25532,766
8117.3.128.0/17117.3.128.1 to 117.3.255.254117.3.255.25532,766
9117.4.0.0/17117.4.0.1 to 117.4.127.254117.4.127.25532,766
10117.4.128.0/17117.4.128.1 to 117.4.255.254117.4.255.25532,766
11117.5.0.0/17117.5.0.1 to 117.5.127.254117.5.127.25532,766
12117.5.128.0/17117.5.128.1 to 117.5.255.254117.5.255.25532,766
13117.6.0.0/17117.6.0.1 to 117.6.127.254117.6.127.25532,766
14117.6.128.0/17117.6.128.1 to 117.6.255.254117.6.255.25532,766
15117.7.0.0/17117.7.0.1 to 117.7.127.254117.7.127.25532,766
16117.7.128.0/17117.7.128.1 to 117.7.255.254117.7.255.25532,766
17117.8.0.0/17117.8.0.1 to 117.8.127.254117.8.127.25532,766
18117.8.128.0/17117.8.128.1 to 117.8.255.254117.8.255.25532,766
19117.9.0.0/17117.9.0.1 to 117.9.127.254117.9.127.25532,766
20117.9.128.0/17117.9.128.1 to 117.9.255.254117.9.255.25532,766
21117.10.0.0/17117.10.0.1 to 117.10.127.254117.10.127.25532,766
22117.10.128.0/17117.10.128.1 to 117.10.255.254117.10.255.25532,766
23117.11.0.0/17117.11.0.1 to 117.11.127.254117.11.127.25532,766
24117.11.128.0/17117.11.128.1 to 117.11.255.254117.11.255.25532,766
25117.12.0.0/17117.12.0.1 to 117.12.127.254117.12.127.25532,766
26117.12.128.0/17117.12.128.1 to 117.12.255.254117.12.255.25532,766
27117.13.0.0/17117.13.0.1 to 117.13.127.254117.13.127.25532,766
28117.13.128.0/17117.13.128.1 to 117.13.255.254117.13.255.25532,766
29117.14.0.0/17117.14.0.1 to 117.14.127.254117.14.127.25532,766
30117.14.128.0/17117.14.128.1 to 117.14.255.254117.14.255.25532,766
31117.15.0.0/17117.15.0.1 to 117.15.127.254117.15.127.25532,766
32117.15.128.0/17117.15.128.1 to 117.15.255.254117.15.255.25532,766
33117.16.0.0/17117.16.0.1 to 117.16.127.254117.16.127.25532,766
34117.16.128.0/17117.16.128.1 to 117.16.255.254117.16.255.25532,766
35117.17.0.0/17117.17.0.1 to 117.17.127.254117.17.127.25532,766
36117.17.128.0/17117.17.128.1 to 117.17.255.254117.17.255.25532,766
37117.18.0.0/17117.18.0.1 to 117.18.127.254117.18.127.25532,766
38117.18.128.0/17117.18.128.1 to 117.18.255.254117.18.255.25532,766
39117.19.0.0/17117.19.0.1 to 117.19.127.254117.19.127.25532,766
40117.19.128.0/17117.19.128.1 to 117.19.255.254117.19.255.25532,766
41117.20.0.0/17117.20.0.1 to 117.20.127.254117.20.127.25532,766
42117.20.128.0/17117.20.128.1 to 117.20.255.254117.20.255.25532,766
43117.21.0.0/17117.21.0.1 to 117.21.127.254117.21.127.25532,766
44117.21.128.0/17117.21.128.1 to 117.21.255.254117.21.255.25532,766
45117.22.0.0/17117.22.0.1 to 117.22.127.254117.22.127.25532,766
46117.22.128.0/17117.22.128.1 to 117.22.255.254117.22.255.25532,766
47117.23.0.0/17117.23.0.1 to 117.23.127.254117.23.127.25532,766
48117.23.128.0/17117.23.128.1 to 117.23.255.254117.23.255.25532,766
49117.24.0.0/17117.24.0.1 to 117.24.127.254117.24.127.25532,766
50117.24.128.0/17117.24.128.1 to 117.24.255.254117.24.255.25532,766
51117.25.0.0/17117.25.0.1 to 117.25.127.254117.25.127.25532,766
52117.25.128.0/17117.25.128.1 to 117.25.255.254117.25.255.25532,766
53117.26.0.0/17117.26.0.1 to 117.26.127.254117.26.127.25532,766
54117.26.128.0/17117.26.128.1 to 117.26.255.254117.26.255.25532,766
55117.27.0.0/17117.27.0.1 to 117.27.127.254117.27.127.25532,766
56117.27.128.0/17117.27.128.1 to 117.27.255.254117.27.255.25532,766
57117.28.0.0/17117.28.0.1 to 117.28.127.254117.28.127.25532,766
58117.28.128.0/17117.28.128.1 to 117.28.255.254117.28.255.25532,766
59117.29.0.0/17117.29.0.1 to 117.29.127.254117.29.127.25532,766
60117.29.128.0/17117.29.128.1 to 117.29.255.254117.29.255.25532,766
61117.30.0.0/17117.30.0.1 to 117.30.127.254117.30.127.25532,766
62117.30.128.0/17117.30.128.1 to 117.30.255.254117.30.255.25532,766
63117.31.0.0/17117.31.0.1 to 117.31.127.254117.31.127.25532,766
64117.31.128.0/17117.31.128.1 to 117.31.255.254117.31.255.25532,766
65117.32.0.0/17117.32.0.1 to 117.32.127.254117.32.127.25532,766
66117.32.128.0/17117.32.128.1 to 117.32.255.254117.32.255.25532,766
67117.33.0.0/17117.33.0.1 to 117.33.127.254117.33.127.25532,766
68117.33.128.0/17117.33.128.1 to 117.33.255.254117.33.255.25532,766
69117.34.0.0/17117.34.0.1 to 117.34.127.254117.34.127.25532,766
70117.34.128.0/17117.34.128.1 to 117.34.255.254117.34.255.25532,766
71117.35.0.0/17117.35.0.1 to 117.35.127.254117.35.127.25532,766
72117.35.128.0/17117.35.128.1 to 117.35.255.254117.35.255.25532,766
73117.36.0.0/17117.36.0.1 to 117.36.127.254117.36.127.25532,766
74117.36.128.0/17117.36.128.1 to 117.36.255.254117.36.255.25532,766
75117.37.0.0/17117.37.0.1 to 117.37.127.254117.37.127.25532,766
76117.37.128.0/17117.37.128.1 to 117.37.255.254117.37.255.25532,766
77117.38.0.0/17117.38.0.1 to 117.38.127.254117.38.127.25532,766
78117.38.128.0/17117.38.128.1 to 117.38.255.254117.38.255.25532,766
79117.39.0.0/17117.39.0.1 to 117.39.127.254117.39.127.25532,766
80117.39.128.0/17117.39.128.1 to 117.39.255.254117.39.255.25532,766
81117.40.0.0/17117.40.0.1 to 117.40.127.254117.40.127.25532,766
82117.40.128.0/17117.40.128.1 to 117.40.255.254117.40.255.25532,766
83117.41.0.0/17117.41.0.1 to 117.41.127.254117.41.127.25532,766
84117.41.128.0/17117.41.128.1 to 117.41.255.254117.41.255.25532,766
85117.42.0.0/17117.42.0.1 to 117.42.127.254117.42.127.25532,766
86117.42.128.0/17117.42.128.1 to 117.42.255.254117.42.255.25532,766
87117.43.0.0/17117.43.0.1 to 117.43.127.254117.43.127.25532,766
88117.43.128.0/17117.43.128.1 to 117.43.255.254117.43.255.25532,766
89117.44.0.0/17117.44.0.1 to 117.44.127.254117.44.127.25532,766
90117.44.128.0/17117.44.128.1 to 117.44.255.254117.44.255.25532,766
91117.45.0.0/17117.45.0.1 to 117.45.127.254117.45.127.25532,766
92117.45.128.0/17117.45.128.1 to 117.45.255.254117.45.255.25532,766
93117.46.0.0/17117.46.0.1 to 117.46.127.254117.46.127.25532,766
94117.46.128.0/17117.46.128.1 to 117.46.255.254117.46.255.25532,766
95117.47.0.0/17117.47.0.1 to 117.47.127.254117.47.127.25532,766
96117.47.128.0/17117.47.128.1 to 117.47.255.254117.47.255.25532,766
97117.48.0.0/17117.48.0.1 to 117.48.127.254117.48.127.25532,766
98117.48.128.0/17117.48.128.1 to 117.48.255.254117.48.255.25532,766
99117.49.0.0/17117.49.0.1 to 117.49.127.254117.49.127.25532,766
100117.49.128.0/17117.49.128.1 to 117.49.255.254117.49.255.25532,766
101117.50.0.0/17117.50.0.1 to 117.50.127.254117.50.127.25532,766
102117.50.128.0/17117.50.128.1 to 117.50.255.254117.50.255.25532,766
103117.51.0.0/17117.51.0.1 to 117.51.127.254117.51.127.25532,766
104117.51.128.0/17117.51.128.1 to 117.51.255.254117.51.255.25532,766
105117.52.0.0/17117.52.0.1 to 117.52.127.254117.52.127.25532,766
106117.52.128.0/17117.52.128.1 to 117.52.255.254117.52.255.25532,766
107117.53.0.0/17117.53.0.1 to 117.53.127.254117.53.127.25532,766
108117.53.128.0/17117.53.128.1 to 117.53.255.254117.53.255.25532,766
109117.54.0.0/17117.54.0.1 to 117.54.127.254117.54.127.25532,766
110117.54.128.0/17117.54.128.1 to 117.54.255.254117.54.255.25532,766
111117.55.0.0/17117.55.0.1 to 117.55.127.254117.55.127.25532,766
112117.55.128.0/17117.55.128.1 to 117.55.255.254117.55.255.25532,766
113117.56.0.0/17117.56.0.1 to 117.56.127.254117.56.127.25532,766
114117.56.128.0/17117.56.128.1 to 117.56.255.254117.56.255.25532,766
115117.57.0.0/17117.57.0.1 to 117.57.127.254117.57.127.25532,766
116117.57.128.0/17117.57.128.1 to 117.57.255.254117.57.255.25532,766
117117.58.0.0/17117.58.0.1 to 117.58.127.254117.58.127.25532,766
118117.58.128.0/17117.58.128.1 to 117.58.255.254117.58.255.25532,766
119117.59.0.0/17117.59.0.1 to 117.59.127.254117.59.127.25532,766
120117.59.128.0/17117.59.128.1 to 117.59.255.254117.59.255.25532,766
121117.60.0.0/17117.60.0.1 to 117.60.127.254117.60.127.25532,766
122117.60.128.0/17117.60.128.1 to 117.60.255.254117.60.255.25532,766
123117.61.0.0/17117.61.0.1 to 117.61.127.254117.61.127.25532,766
124117.61.128.0/17117.61.128.1 to 117.61.255.254117.61.255.25532,766
125117.62.0.0/17117.62.0.1 to 117.62.127.254117.62.127.25532,766
126117.62.128.0/17117.62.128.1 to 117.62.255.254117.62.255.25532,766
127117.63.0.0/17117.63.0.1 to 117.63.127.254117.63.127.25532,766
128117.63.128.0/17117.63.128.1 to 117.63.255.254117.63.255.25532,766
129117.64.0.0/17117.64.0.1 to 117.64.127.254117.64.127.25532,766
130117.64.128.0/17117.64.128.1 to 117.64.255.254117.64.255.25532,766
131117.65.0.0/17117.65.0.1 to 117.65.127.254117.65.127.25532,766
132117.65.128.0/17117.65.128.1 to 117.65.255.254117.65.255.25532,766
133117.66.0.0/17117.66.0.1 to 117.66.127.254117.66.127.25532,766
134117.66.128.0/17117.66.128.1 to 117.66.255.254117.66.255.25532,766
135117.67.0.0/17117.67.0.1 to 117.67.127.254117.67.127.25532,766
136117.67.128.0/17117.67.128.1 to 117.67.255.254117.67.255.25532,766
137117.68.0.0/17117.68.0.1 to 117.68.127.254117.68.127.25532,766
138117.68.128.0/17117.68.128.1 to 117.68.255.254117.68.255.25532,766
139117.69.0.0/17117.69.0.1 to 117.69.127.254117.69.127.25532,766
140117.69.128.0/17117.69.128.1 to 117.69.255.254117.69.255.25532,766
141117.70.0.0/17117.70.0.1 to 117.70.127.254117.70.127.25532,766
142117.70.128.0/17117.70.128.1 to 117.70.255.254117.70.255.25532,766
143117.71.0.0/17117.71.0.1 to 117.71.127.254117.71.127.25532,766
144117.71.128.0/17117.71.128.1 to 117.71.255.254117.71.255.25532,766
145117.72.0.0/17117.72.0.1 to 117.72.127.254117.72.127.25532,766
146117.72.128.0/17117.72.128.1 to 117.72.255.254117.72.255.25532,766
147117.73.0.0/17117.73.0.1 to 117.73.127.254117.73.127.25532,766
148117.73.128.0/17117.73.128.1 to 117.73.255.254117.73.255.25532,766
149117.74.0.0/17117.74.0.1 to 117.74.127.254117.74.127.25532,766
150117.74.128.0/17117.74.128.1 to 117.74.255.254117.74.255.25532,766
151117.75.0.0/17117.75.0.1 to 117.75.127.254117.75.127.25532,766
152117.75.128.0/17117.75.128.1 to 117.75.255.254117.75.255.25532,766
153117.76.0.0/17117.76.0.1 to 117.76.127.254117.76.127.25532,766
154117.76.128.0/17117.76.128.1 to 117.76.255.254117.76.255.25532,766
155117.77.0.0/17117.77.0.1 to 117.77.127.254117.77.127.25532,766
156117.77.128.0/17117.77.128.1 to 117.77.255.254117.77.255.25532,766
157117.78.0.0/17117.78.0.1 to 117.78.127.254117.78.127.25532,766
158117.78.128.0/17117.78.128.1 to 117.78.255.254117.78.255.25532,766
159117.79.0.0/17117.79.0.1 to 117.79.127.254117.79.127.25532,766
160117.79.128.0/17117.79.128.1 to 117.79.255.254117.79.255.25532,766
161117.80.0.0/17117.80.0.1 to 117.80.127.254117.80.127.25532,766
162117.80.128.0/17117.80.128.1 to 117.80.255.254117.80.255.25532,766
163117.81.0.0/17117.81.0.1 to 117.81.127.254117.81.127.25532,766
164117.81.128.0/17117.81.128.1 to 117.81.255.254117.81.255.25532,766
165117.82.0.0/17117.82.0.1 to 117.82.127.254117.82.127.25532,766
166117.82.128.0/17117.82.128.1 to 117.82.255.254117.82.255.25532,766
167117.83.0.0/17117.83.0.1 to 117.83.127.254117.83.127.25532,766
168117.83.128.0/17117.83.128.1 to 117.83.255.254117.83.255.25532,766
169117.84.0.0/17117.84.0.1 to 117.84.127.254117.84.127.25532,766
170117.84.128.0/17117.84.128.1 to 117.84.255.254117.84.255.25532,766
171117.85.0.0/17117.85.0.1 to 117.85.127.254117.85.127.25532,766
172117.85.128.0/17117.85.128.1 to 117.85.255.254117.85.255.25532,766
173117.86.0.0/17117.86.0.1 to 117.86.127.254117.86.127.25532,766
174117.86.128.0/17117.86.128.1 to 117.86.255.254117.86.255.25532,766
175117.87.0.0/17117.87.0.1 to 117.87.127.254117.87.127.25532,766
176117.87.128.0/17117.87.128.1 to 117.87.255.254117.87.255.25532,766
177117.88.0.0/17117.88.0.1 to 117.88.127.254117.88.127.25532,766
178117.88.128.0/17117.88.128.1 to 117.88.255.254117.88.255.25532,766
179117.89.0.0/17117.89.0.1 to 117.89.127.254117.89.127.25532,766
180117.89.128.0/17117.89.128.1 to 117.89.255.254117.89.255.25532,766
181117.90.0.0/17117.90.0.1 to 117.90.127.254117.90.127.25532,766
182117.90.128.0/17117.90.128.1 to 117.90.255.254117.90.255.25532,766
183117.91.0.0/17117.91.0.1 to 117.91.127.254117.91.127.25532,766
184117.91.128.0/17117.91.128.1 to 117.91.255.254117.91.255.25532,766
185117.92.0.0/17117.92.0.1 to 117.92.127.254117.92.127.25532,766
186117.92.128.0/17117.92.128.1 to 117.92.255.254117.92.255.25532,766
187117.93.0.0/17117.93.0.1 to 117.93.127.254117.93.127.25532,766
188117.93.128.0/17117.93.128.1 to 117.93.255.254117.93.255.25532,766
189117.94.0.0/17117.94.0.1 to 117.94.127.254117.94.127.25532,766
190117.94.128.0/17117.94.128.1 to 117.94.255.254117.94.255.25532,766
191117.95.0.0/17117.95.0.1 to 117.95.127.254117.95.127.25532,766
192117.95.128.0/17117.95.128.1 to 117.95.255.254117.95.255.25532,766
193117.96.0.0/17117.96.0.1 to 117.96.127.254117.96.127.25532,766
194117.96.128.0/17117.96.128.1 to 117.96.255.254117.96.255.25532,766
195117.97.0.0/17117.97.0.1 to 117.97.127.254117.97.127.25532,766
196117.97.128.0/17117.97.128.1 to 117.97.255.254117.97.255.25532,766
197117.98.0.0/17117.98.0.1 to 117.98.127.254117.98.127.25532,766
198117.98.128.0/17117.98.128.1 to 117.98.255.254117.98.255.25532,766
199117.99.0.0/17117.99.0.1 to 117.99.127.254117.99.127.25532,766
200117.99.128.0/17117.99.128.1 to 117.99.255.254117.99.255.25532,766
201117.100.0.0/17117.100.0.1 to 117.100.127.254117.100.127.25532,766
202117.100.128.0/17117.100.128.1 to 117.100.255.254117.100.255.25532,766
203117.101.0.0/17117.101.0.1 to 117.101.127.254117.101.127.25532,766
204117.101.128.0/17117.101.128.1 to 117.101.255.254117.101.255.25532,766
205117.102.0.0/17117.102.0.1 to 117.102.127.254117.102.127.25532,766
206117.102.128.0/17117.102.128.1 to 117.102.255.254117.102.255.25532,766
207117.103.0.0/17117.103.0.1 to 117.103.127.254117.103.127.25532,766
208117.103.128.0/17117.103.128.1 to 117.103.255.254117.103.255.25532,766
209117.104.0.0/17117.104.0.1 to 117.104.127.254117.104.127.25532,766
210117.104.128.0/17117.104.128.1 to 117.104.255.254117.104.255.25532,766
211117.105.0.0/17117.105.0.1 to 117.105.127.254117.105.127.25532,766
212117.105.128.0/17117.105.128.1 to 117.105.255.254117.105.255.25532,766
213117.106.0.0/17117.106.0.1 to 117.106.127.254117.106.127.25532,766
214117.106.128.0/17117.106.128.1 to 117.106.255.254117.106.255.25532,766
215117.107.0.0/17117.107.0.1 to 117.107.127.254117.107.127.25532,766
216117.107.128.0/17117.107.128.1 to 117.107.255.254117.107.255.25532,766
217117.108.0.0/17117.108.0.1 to 117.108.127.254117.108.127.25532,766
218117.108.128.0/17117.108.128.1 to 117.108.255.254117.108.255.25532,766
219117.109.0.0/17117.109.0.1 to 117.109.127.254117.109.127.25532,766
220117.109.128.0/17117.109.128.1 to 117.109.255.254117.109.255.25532,766
221117.110.0.0/17117.110.0.1 to 117.110.127.254117.110.127.25532,766
222117.110.128.0/17117.110.128.1 to 117.110.255.254117.110.255.25532,766
223117.111.0.0/17117.111.0.1 to 117.111.127.254117.111.127.25532,766
224117.111.128.0/17117.111.128.1 to 117.111.255.254117.111.255.25532,766
225117.112.0.0/17117.112.0.1 to 117.112.127.254117.112.127.25532,766
226117.112.128.0/17117.112.128.1 to 117.112.255.254117.112.255.25532,766
227117.113.0.0/17117.113.0.1 to 117.113.127.254117.113.127.25532,766
228117.113.128.0/17117.113.128.1 to 117.113.255.254117.113.255.25532,766
229117.114.0.0/17117.114.0.1 to 117.114.127.254117.114.127.25532,766
230117.114.128.0/17117.114.128.1 to 117.114.255.254117.114.255.25532,766
231117.115.0.0/17117.115.0.1 to 117.115.127.254117.115.127.25532,766
232117.115.128.0/17117.115.128.1 to 117.115.255.254117.115.255.25532,766
233117.116.0.0/17117.116.0.1 to 117.116.127.254117.116.127.25532,766
234117.116.128.0/17117.116.128.1 to 117.116.255.254117.116.255.25532,766
235117.117.0.0/17117.117.0.1 to 117.117.127.254117.117.127.25532,766
236117.117.128.0/17117.117.128.1 to 117.117.255.254117.117.255.25532,766
237117.118.0.0/17117.118.0.1 to 117.118.127.254117.118.127.25532,766
238117.118.128.0/17117.118.128.1 to 117.118.255.254117.118.255.25532,766
239117.119.0.0/17117.119.0.1 to 117.119.127.254117.119.127.25532,766
240117.119.128.0/17117.119.128.1 to 117.119.255.254117.119.255.25532,766
241117.120.0.0/17117.120.0.1 to 117.120.127.254117.120.127.25532,766
242117.120.128.0/17117.120.128.1 to 117.120.255.254117.120.255.25532,766
243117.121.0.0/17117.121.0.1 to 117.121.127.254117.121.127.25532,766
244117.121.128.0/17117.121.128.1 to 117.121.255.254117.121.255.25532,766
245117.122.0.0/17117.122.0.1 to 117.122.127.254117.122.127.25532,766
246117.122.128.0/17117.122.128.1 to 117.122.255.254117.122.255.25532,766
247117.123.0.0/17117.123.0.1 to 117.123.127.254117.123.127.25532,766
248117.123.128.0/17117.123.128.1 to 117.123.255.254117.123.255.25532,766
249117.124.0.0/17117.124.0.1 to 117.124.127.254117.124.127.25532,766
250117.124.128.0/17117.124.128.1 to 117.124.255.254117.124.255.25532,766
251117.125.0.0/17117.125.0.1 to 117.125.127.254117.125.127.25532,766
252117.125.128.0/17117.125.128.1 to 117.125.255.254117.125.255.25532,766
253117.126.0.0/17117.126.0.1 to 117.126.127.254117.126.127.25532,766
254117.126.128.0/17117.126.128.1 to 117.126.255.254117.126.255.25532,766
255117.127.0.0/17117.127.0.1 to 117.127.127.254117.127.127.25532,766
256117.127.128.0/17117.127.128.1 to 117.127.255.254117.127.255.25532,766

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.