Speed and call quality testMy IP addressIP subnet calculatorDNS reportWhoIs lookupRemote support

Internet and network

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.

Computers and devices

Update checkIs this computer, phone and browser up to date? With links to update.Camera and mic testCheck your webcam and microphone before a call.Test print pagePrint an A4 page to check a printer: edges, text, line art and colours.

Make and print

Clean textStrip hidden characters, smart quotes and odd spaces from pasted text.QR code makerMake a QR code for a link, contact or message. Nothing leaves your browser.Wi-Fi QR posterPrint an A4 poster that lets guests join your Wi-Fi by scanning.

Surftec support

Remote supportLet a Surftec engineer connect to your computer to help you.All workingA full-screen confirmation that everything is up and running.

Surftec

Surftec websiteServices, news and how to contact Surftec
Cloud Tools
Guest
GuestNot signed in

Surftec customers will be recognised automatically when they use these tools from their office network.

Customer sign-in is coming soon.

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.

Network117.167.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
117.167.0.0
Broadcast address
117.167.255.255
First usable
117.167.0.1
Last usable
117.167.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
A (default /8)
As numbers
Hex 75A70000 · Integer 1973878784 to 1973944319
Reverse DNS zone
167.117.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110101.10100111..00000000.00000000117.167.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01110101.10100111..00000000.00000000117.167.0.0
Broadcast01110101.10100111..11111111.11111111117.167.255.255
Split into smaller subnets/25
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

117.167.0.0/16 makes 512 subnets of /25; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1117.167.0.0/25117.167.0.1 to 117.167.0.126117.167.0.127126
2117.167.0.128/25117.167.0.129 to 117.167.0.254117.167.0.255126
3117.167.1.0/25117.167.1.1 to 117.167.1.126117.167.1.127126
4117.167.1.128/25117.167.1.129 to 117.167.1.254117.167.1.255126
5117.167.2.0/25117.167.2.1 to 117.167.2.126117.167.2.127126
6117.167.2.128/25117.167.2.129 to 117.167.2.254117.167.2.255126
7117.167.3.0/25117.167.3.1 to 117.167.3.126117.167.3.127126
8117.167.3.128/25117.167.3.129 to 117.167.3.254117.167.3.255126
9117.167.4.0/25117.167.4.1 to 117.167.4.126117.167.4.127126
10117.167.4.128/25117.167.4.129 to 117.167.4.254117.167.4.255126
11117.167.5.0/25117.167.5.1 to 117.167.5.126117.167.5.127126
12117.167.5.128/25117.167.5.129 to 117.167.5.254117.167.5.255126
13117.167.6.0/25117.167.6.1 to 117.167.6.126117.167.6.127126
14117.167.6.128/25117.167.6.129 to 117.167.6.254117.167.6.255126
15117.167.7.0/25117.167.7.1 to 117.167.7.126117.167.7.127126
16117.167.7.128/25117.167.7.129 to 117.167.7.254117.167.7.255126
17117.167.8.0/25117.167.8.1 to 117.167.8.126117.167.8.127126
18117.167.8.128/25117.167.8.129 to 117.167.8.254117.167.8.255126
19117.167.9.0/25117.167.9.1 to 117.167.9.126117.167.9.127126
20117.167.9.128/25117.167.9.129 to 117.167.9.254117.167.9.255126
21117.167.10.0/25117.167.10.1 to 117.167.10.126117.167.10.127126
22117.167.10.128/25117.167.10.129 to 117.167.10.254117.167.10.255126
23117.167.11.0/25117.167.11.1 to 117.167.11.126117.167.11.127126
24117.167.11.128/25117.167.11.129 to 117.167.11.254117.167.11.255126
25117.167.12.0/25117.167.12.1 to 117.167.12.126117.167.12.127126
26117.167.12.128/25117.167.12.129 to 117.167.12.254117.167.12.255126
27117.167.13.0/25117.167.13.1 to 117.167.13.126117.167.13.127126
28117.167.13.128/25117.167.13.129 to 117.167.13.254117.167.13.255126
29117.167.14.0/25117.167.14.1 to 117.167.14.126117.167.14.127126
30117.167.14.128/25117.167.14.129 to 117.167.14.254117.167.14.255126
31117.167.15.0/25117.167.15.1 to 117.167.15.126117.167.15.127126
32117.167.15.128/25117.167.15.129 to 117.167.15.254117.167.15.255126
33117.167.16.0/25117.167.16.1 to 117.167.16.126117.167.16.127126
34117.167.16.128/25117.167.16.129 to 117.167.16.254117.167.16.255126
35117.167.17.0/25117.167.17.1 to 117.167.17.126117.167.17.127126
36117.167.17.128/25117.167.17.129 to 117.167.17.254117.167.17.255126
37117.167.18.0/25117.167.18.1 to 117.167.18.126117.167.18.127126
38117.167.18.128/25117.167.18.129 to 117.167.18.254117.167.18.255126
39117.167.19.0/25117.167.19.1 to 117.167.19.126117.167.19.127126
40117.167.19.128/25117.167.19.129 to 117.167.19.254117.167.19.255126
41117.167.20.0/25117.167.20.1 to 117.167.20.126117.167.20.127126
42117.167.20.128/25117.167.20.129 to 117.167.20.254117.167.20.255126
43117.167.21.0/25117.167.21.1 to 117.167.21.126117.167.21.127126
44117.167.21.128/25117.167.21.129 to 117.167.21.254117.167.21.255126
45117.167.22.0/25117.167.22.1 to 117.167.22.126117.167.22.127126
46117.167.22.128/25117.167.22.129 to 117.167.22.254117.167.22.255126
47117.167.23.0/25117.167.23.1 to 117.167.23.126117.167.23.127126
48117.167.23.128/25117.167.23.129 to 117.167.23.254117.167.23.255126
49117.167.24.0/25117.167.24.1 to 117.167.24.126117.167.24.127126
50117.167.24.128/25117.167.24.129 to 117.167.24.254117.167.24.255126
51117.167.25.0/25117.167.25.1 to 117.167.25.126117.167.25.127126
52117.167.25.128/25117.167.25.129 to 117.167.25.254117.167.25.255126
53117.167.26.0/25117.167.26.1 to 117.167.26.126117.167.26.127126
54117.167.26.128/25117.167.26.129 to 117.167.26.254117.167.26.255126
55117.167.27.0/25117.167.27.1 to 117.167.27.126117.167.27.127126
56117.167.27.128/25117.167.27.129 to 117.167.27.254117.167.27.255126
57117.167.28.0/25117.167.28.1 to 117.167.28.126117.167.28.127126
58117.167.28.128/25117.167.28.129 to 117.167.28.254117.167.28.255126
59117.167.29.0/25117.167.29.1 to 117.167.29.126117.167.29.127126
60117.167.29.128/25117.167.29.129 to 117.167.29.254117.167.29.255126
61117.167.30.0/25117.167.30.1 to 117.167.30.126117.167.30.127126
62117.167.30.128/25117.167.30.129 to 117.167.30.254117.167.30.255126
63117.167.31.0/25117.167.31.1 to 117.167.31.126117.167.31.127126
64117.167.31.128/25117.167.31.129 to 117.167.31.254117.167.31.255126
65117.167.32.0/25117.167.32.1 to 117.167.32.126117.167.32.127126
66117.167.32.128/25117.167.32.129 to 117.167.32.254117.167.32.255126
67117.167.33.0/25117.167.33.1 to 117.167.33.126117.167.33.127126
68117.167.33.128/25117.167.33.129 to 117.167.33.254117.167.33.255126
69117.167.34.0/25117.167.34.1 to 117.167.34.126117.167.34.127126
70117.167.34.128/25117.167.34.129 to 117.167.34.254117.167.34.255126
71117.167.35.0/25117.167.35.1 to 117.167.35.126117.167.35.127126
72117.167.35.128/25117.167.35.129 to 117.167.35.254117.167.35.255126
73117.167.36.0/25117.167.36.1 to 117.167.36.126117.167.36.127126
74117.167.36.128/25117.167.36.129 to 117.167.36.254117.167.36.255126
75117.167.37.0/25117.167.37.1 to 117.167.37.126117.167.37.127126
76117.167.37.128/25117.167.37.129 to 117.167.37.254117.167.37.255126
77117.167.38.0/25117.167.38.1 to 117.167.38.126117.167.38.127126
78117.167.38.128/25117.167.38.129 to 117.167.38.254117.167.38.255126
79117.167.39.0/25117.167.39.1 to 117.167.39.126117.167.39.127126
80117.167.39.128/25117.167.39.129 to 117.167.39.254117.167.39.255126
81117.167.40.0/25117.167.40.1 to 117.167.40.126117.167.40.127126
82117.167.40.128/25117.167.40.129 to 117.167.40.254117.167.40.255126
83117.167.41.0/25117.167.41.1 to 117.167.41.126117.167.41.127126
84117.167.41.128/25117.167.41.129 to 117.167.41.254117.167.41.255126
85117.167.42.0/25117.167.42.1 to 117.167.42.126117.167.42.127126
86117.167.42.128/25117.167.42.129 to 117.167.42.254117.167.42.255126
87117.167.43.0/25117.167.43.1 to 117.167.43.126117.167.43.127126
88117.167.43.128/25117.167.43.129 to 117.167.43.254117.167.43.255126
89117.167.44.0/25117.167.44.1 to 117.167.44.126117.167.44.127126
90117.167.44.128/25117.167.44.129 to 117.167.44.254117.167.44.255126
91117.167.45.0/25117.167.45.1 to 117.167.45.126117.167.45.127126
92117.167.45.128/25117.167.45.129 to 117.167.45.254117.167.45.255126
93117.167.46.0/25117.167.46.1 to 117.167.46.126117.167.46.127126
94117.167.46.128/25117.167.46.129 to 117.167.46.254117.167.46.255126
95117.167.47.0/25117.167.47.1 to 117.167.47.126117.167.47.127126
96117.167.47.128/25117.167.47.129 to 117.167.47.254117.167.47.255126
97117.167.48.0/25117.167.48.1 to 117.167.48.126117.167.48.127126
98117.167.48.128/25117.167.48.129 to 117.167.48.254117.167.48.255126
99117.167.49.0/25117.167.49.1 to 117.167.49.126117.167.49.127126
100117.167.49.128/25117.167.49.129 to 117.167.49.254117.167.49.255126
101117.167.50.0/25117.167.50.1 to 117.167.50.126117.167.50.127126
102117.167.50.128/25117.167.50.129 to 117.167.50.254117.167.50.255126
103117.167.51.0/25117.167.51.1 to 117.167.51.126117.167.51.127126
104117.167.51.128/25117.167.51.129 to 117.167.51.254117.167.51.255126
105117.167.52.0/25117.167.52.1 to 117.167.52.126117.167.52.127126
106117.167.52.128/25117.167.52.129 to 117.167.52.254117.167.52.255126
107117.167.53.0/25117.167.53.1 to 117.167.53.126117.167.53.127126
108117.167.53.128/25117.167.53.129 to 117.167.53.254117.167.53.255126
109117.167.54.0/25117.167.54.1 to 117.167.54.126117.167.54.127126
110117.167.54.128/25117.167.54.129 to 117.167.54.254117.167.54.255126
111117.167.55.0/25117.167.55.1 to 117.167.55.126117.167.55.127126
112117.167.55.128/25117.167.55.129 to 117.167.55.254117.167.55.255126
113117.167.56.0/25117.167.56.1 to 117.167.56.126117.167.56.127126
114117.167.56.128/25117.167.56.129 to 117.167.56.254117.167.56.255126
115117.167.57.0/25117.167.57.1 to 117.167.57.126117.167.57.127126
116117.167.57.128/25117.167.57.129 to 117.167.57.254117.167.57.255126
117117.167.58.0/25117.167.58.1 to 117.167.58.126117.167.58.127126
118117.167.58.128/25117.167.58.129 to 117.167.58.254117.167.58.255126
119117.167.59.0/25117.167.59.1 to 117.167.59.126117.167.59.127126
120117.167.59.128/25117.167.59.129 to 117.167.59.254117.167.59.255126
121117.167.60.0/25117.167.60.1 to 117.167.60.126117.167.60.127126
122117.167.60.128/25117.167.60.129 to 117.167.60.254117.167.60.255126
123117.167.61.0/25117.167.61.1 to 117.167.61.126117.167.61.127126
124117.167.61.128/25117.167.61.129 to 117.167.61.254117.167.61.255126
125117.167.62.0/25117.167.62.1 to 117.167.62.126117.167.62.127126
126117.167.62.128/25117.167.62.129 to 117.167.62.254117.167.62.255126
127117.167.63.0/25117.167.63.1 to 117.167.63.126117.167.63.127126
128117.167.63.128/25117.167.63.129 to 117.167.63.254117.167.63.255126
129117.167.64.0/25117.167.64.1 to 117.167.64.126117.167.64.127126
130117.167.64.128/25117.167.64.129 to 117.167.64.254117.167.64.255126
131117.167.65.0/25117.167.65.1 to 117.167.65.126117.167.65.127126
132117.167.65.128/25117.167.65.129 to 117.167.65.254117.167.65.255126
133117.167.66.0/25117.167.66.1 to 117.167.66.126117.167.66.127126
134117.167.66.128/25117.167.66.129 to 117.167.66.254117.167.66.255126
135117.167.67.0/25117.167.67.1 to 117.167.67.126117.167.67.127126
136117.167.67.128/25117.167.67.129 to 117.167.67.254117.167.67.255126
137117.167.68.0/25117.167.68.1 to 117.167.68.126117.167.68.127126
138117.167.68.128/25117.167.68.129 to 117.167.68.254117.167.68.255126
139117.167.69.0/25117.167.69.1 to 117.167.69.126117.167.69.127126
140117.167.69.128/25117.167.69.129 to 117.167.69.254117.167.69.255126
141117.167.70.0/25117.167.70.1 to 117.167.70.126117.167.70.127126
142117.167.70.128/25117.167.70.129 to 117.167.70.254117.167.70.255126
143117.167.71.0/25117.167.71.1 to 117.167.71.126117.167.71.127126
144117.167.71.128/25117.167.71.129 to 117.167.71.254117.167.71.255126
145117.167.72.0/25117.167.72.1 to 117.167.72.126117.167.72.127126
146117.167.72.128/25117.167.72.129 to 117.167.72.254117.167.72.255126
147117.167.73.0/25117.167.73.1 to 117.167.73.126117.167.73.127126
148117.167.73.128/25117.167.73.129 to 117.167.73.254117.167.73.255126
149117.167.74.0/25117.167.74.1 to 117.167.74.126117.167.74.127126
150117.167.74.128/25117.167.74.129 to 117.167.74.254117.167.74.255126
151117.167.75.0/25117.167.75.1 to 117.167.75.126117.167.75.127126
152117.167.75.128/25117.167.75.129 to 117.167.75.254117.167.75.255126
153117.167.76.0/25117.167.76.1 to 117.167.76.126117.167.76.127126
154117.167.76.128/25117.167.76.129 to 117.167.76.254117.167.76.255126
155117.167.77.0/25117.167.77.1 to 117.167.77.126117.167.77.127126
156117.167.77.128/25117.167.77.129 to 117.167.77.254117.167.77.255126
157117.167.78.0/25117.167.78.1 to 117.167.78.126117.167.78.127126
158117.167.78.128/25117.167.78.129 to 117.167.78.254117.167.78.255126
159117.167.79.0/25117.167.79.1 to 117.167.79.126117.167.79.127126
160117.167.79.128/25117.167.79.129 to 117.167.79.254117.167.79.255126
161117.167.80.0/25117.167.80.1 to 117.167.80.126117.167.80.127126
162117.167.80.128/25117.167.80.129 to 117.167.80.254117.167.80.255126
163117.167.81.0/25117.167.81.1 to 117.167.81.126117.167.81.127126
164117.167.81.128/25117.167.81.129 to 117.167.81.254117.167.81.255126
165117.167.82.0/25117.167.82.1 to 117.167.82.126117.167.82.127126
166117.167.82.128/25117.167.82.129 to 117.167.82.254117.167.82.255126
167117.167.83.0/25117.167.83.1 to 117.167.83.126117.167.83.127126
168117.167.83.128/25117.167.83.129 to 117.167.83.254117.167.83.255126
169117.167.84.0/25117.167.84.1 to 117.167.84.126117.167.84.127126
170117.167.84.128/25117.167.84.129 to 117.167.84.254117.167.84.255126
171117.167.85.0/25117.167.85.1 to 117.167.85.126117.167.85.127126
172117.167.85.128/25117.167.85.129 to 117.167.85.254117.167.85.255126
173117.167.86.0/25117.167.86.1 to 117.167.86.126117.167.86.127126
174117.167.86.128/25117.167.86.129 to 117.167.86.254117.167.86.255126
175117.167.87.0/25117.167.87.1 to 117.167.87.126117.167.87.127126
176117.167.87.128/25117.167.87.129 to 117.167.87.254117.167.87.255126
177117.167.88.0/25117.167.88.1 to 117.167.88.126117.167.88.127126
178117.167.88.128/25117.167.88.129 to 117.167.88.254117.167.88.255126
179117.167.89.0/25117.167.89.1 to 117.167.89.126117.167.89.127126
180117.167.89.128/25117.167.89.129 to 117.167.89.254117.167.89.255126
181117.167.90.0/25117.167.90.1 to 117.167.90.126117.167.90.127126
182117.167.90.128/25117.167.90.129 to 117.167.90.254117.167.90.255126
183117.167.91.0/25117.167.91.1 to 117.167.91.126117.167.91.127126
184117.167.91.128/25117.167.91.129 to 117.167.91.254117.167.91.255126
185117.167.92.0/25117.167.92.1 to 117.167.92.126117.167.92.127126
186117.167.92.128/25117.167.92.129 to 117.167.92.254117.167.92.255126
187117.167.93.0/25117.167.93.1 to 117.167.93.126117.167.93.127126
188117.167.93.128/25117.167.93.129 to 117.167.93.254117.167.93.255126
189117.167.94.0/25117.167.94.1 to 117.167.94.126117.167.94.127126
190117.167.94.128/25117.167.94.129 to 117.167.94.254117.167.94.255126
191117.167.95.0/25117.167.95.1 to 117.167.95.126117.167.95.127126
192117.167.95.128/25117.167.95.129 to 117.167.95.254117.167.95.255126
193117.167.96.0/25117.167.96.1 to 117.167.96.126117.167.96.127126
194117.167.96.128/25117.167.96.129 to 117.167.96.254117.167.96.255126
195117.167.97.0/25117.167.97.1 to 117.167.97.126117.167.97.127126
196117.167.97.128/25117.167.97.129 to 117.167.97.254117.167.97.255126
197117.167.98.0/25117.167.98.1 to 117.167.98.126117.167.98.127126
198117.167.98.128/25117.167.98.129 to 117.167.98.254117.167.98.255126
199117.167.99.0/25117.167.99.1 to 117.167.99.126117.167.99.127126
200117.167.99.128/25117.167.99.129 to 117.167.99.254117.167.99.255126
201117.167.100.0/25117.167.100.1 to 117.167.100.126117.167.100.127126
202117.167.100.128/25117.167.100.129 to 117.167.100.254117.167.100.255126
203117.167.101.0/25117.167.101.1 to 117.167.101.126117.167.101.127126
204117.167.101.128/25117.167.101.129 to 117.167.101.254117.167.101.255126
205117.167.102.0/25117.167.102.1 to 117.167.102.126117.167.102.127126
206117.167.102.128/25117.167.102.129 to 117.167.102.254117.167.102.255126
207117.167.103.0/25117.167.103.1 to 117.167.103.126117.167.103.127126
208117.167.103.128/25117.167.103.129 to 117.167.103.254117.167.103.255126
209117.167.104.0/25117.167.104.1 to 117.167.104.126117.167.104.127126
210117.167.104.128/25117.167.104.129 to 117.167.104.254117.167.104.255126
211117.167.105.0/25117.167.105.1 to 117.167.105.126117.167.105.127126
212117.167.105.128/25117.167.105.129 to 117.167.105.254117.167.105.255126
213117.167.106.0/25117.167.106.1 to 117.167.106.126117.167.106.127126
214117.167.106.128/25117.167.106.129 to 117.167.106.254117.167.106.255126
215117.167.107.0/25117.167.107.1 to 117.167.107.126117.167.107.127126
216117.167.107.128/25117.167.107.129 to 117.167.107.254117.167.107.255126
217117.167.108.0/25117.167.108.1 to 117.167.108.126117.167.108.127126
218117.167.108.128/25117.167.108.129 to 117.167.108.254117.167.108.255126
219117.167.109.0/25117.167.109.1 to 117.167.109.126117.167.109.127126
220117.167.109.128/25117.167.109.129 to 117.167.109.254117.167.109.255126
221117.167.110.0/25117.167.110.1 to 117.167.110.126117.167.110.127126
222117.167.110.128/25117.167.110.129 to 117.167.110.254117.167.110.255126
223117.167.111.0/25117.167.111.1 to 117.167.111.126117.167.111.127126
224117.167.111.128/25117.167.111.129 to 117.167.111.254117.167.111.255126
225117.167.112.0/25117.167.112.1 to 117.167.112.126117.167.112.127126
226117.167.112.128/25117.167.112.129 to 117.167.112.254117.167.112.255126
227117.167.113.0/25117.167.113.1 to 117.167.113.126117.167.113.127126
228117.167.113.128/25117.167.113.129 to 117.167.113.254117.167.113.255126
229117.167.114.0/25117.167.114.1 to 117.167.114.126117.167.114.127126
230117.167.114.128/25117.167.114.129 to 117.167.114.254117.167.114.255126
231117.167.115.0/25117.167.115.1 to 117.167.115.126117.167.115.127126
232117.167.115.128/25117.167.115.129 to 117.167.115.254117.167.115.255126
233117.167.116.0/25117.167.116.1 to 117.167.116.126117.167.116.127126
234117.167.116.128/25117.167.116.129 to 117.167.116.254117.167.116.255126
235117.167.117.0/25117.167.117.1 to 117.167.117.126117.167.117.127126
236117.167.117.128/25117.167.117.129 to 117.167.117.254117.167.117.255126
237117.167.118.0/25117.167.118.1 to 117.167.118.126117.167.118.127126
238117.167.118.128/25117.167.118.129 to 117.167.118.254117.167.118.255126
239117.167.119.0/25117.167.119.1 to 117.167.119.126117.167.119.127126
240117.167.119.128/25117.167.119.129 to 117.167.119.254117.167.119.255126
241117.167.120.0/25117.167.120.1 to 117.167.120.126117.167.120.127126
242117.167.120.128/25117.167.120.129 to 117.167.120.254117.167.120.255126
243117.167.121.0/25117.167.121.1 to 117.167.121.126117.167.121.127126
244117.167.121.128/25117.167.121.129 to 117.167.121.254117.167.121.255126
245117.167.122.0/25117.167.122.1 to 117.167.122.126117.167.122.127126
246117.167.122.128/25117.167.122.129 to 117.167.122.254117.167.122.255126
247117.167.123.0/25117.167.123.1 to 117.167.123.126117.167.123.127126
248117.167.123.128/25117.167.123.129 to 117.167.123.254117.167.123.255126
249117.167.124.0/25117.167.124.1 to 117.167.124.126117.167.124.127126
250117.167.124.128/25117.167.124.129 to 117.167.124.254117.167.124.255126
251117.167.125.0/25117.167.125.1 to 117.167.125.126117.167.125.127126
252117.167.125.128/25117.167.125.129 to 117.167.125.254117.167.125.255126
253117.167.126.0/25117.167.126.1 to 117.167.126.126117.167.126.127126
254117.167.126.128/25117.167.126.129 to 117.167.126.254117.167.126.255126
255117.167.127.0/25117.167.127.1 to 117.167.127.126117.167.127.127126
256117.167.127.128/25117.167.127.129 to 117.167.127.254117.167.127.255126

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.