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.

Network119.96.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
119.96.0.0
Broadcast address
119.111.255.255
First usable
119.96.0.1
Last usable
119.111.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Public public
Old class
A (default /8)
As numbers
Hex 77600000 · Integer 2002780160 to 2003828735
Reverse DNS zones
96.119.in-addr.arpa
97.119.in-addr.arpa
98.119.in-addr.arpa
99.119.in-addr.arpa
100.119.in-addr.arpa
101.119.in-addr.arpa
102.119.in-addr.arpa
103.119.in-addr.arpa
104.119.in-addr.arpa
105.119.in-addr.arpa
106.119.in-addr.arpa
107.119.in-addr.arpa
108.119.in-addr.arpa
109.119.in-addr.arpa
110.119.in-addr.arpa
111.119.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01110111.01100000.00000000.00000000119.96.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network01110111.01100000.00000000.00000000119.96.0.0
Broadcast01110111.01101111.11111111.11111111119.111.255.255
Split into smaller subnets/20
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

119.96.0.0/12 makes 256 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1119.96.0.0/20119.96.0.1 to 119.96.15.254119.96.15.2554,094
2119.96.16.0/20119.96.16.1 to 119.96.31.254119.96.31.2554,094
3119.96.32.0/20119.96.32.1 to 119.96.47.254119.96.47.2554,094
4119.96.48.0/20119.96.48.1 to 119.96.63.254119.96.63.2554,094
5119.96.64.0/20119.96.64.1 to 119.96.79.254119.96.79.2554,094
6119.96.80.0/20119.96.80.1 to 119.96.95.254119.96.95.2554,094
7119.96.96.0/20119.96.96.1 to 119.96.111.254119.96.111.2554,094
8119.96.112.0/20119.96.112.1 to 119.96.127.254119.96.127.2554,094
9119.96.128.0/20119.96.128.1 to 119.96.143.254119.96.143.2554,094
10119.96.144.0/20119.96.144.1 to 119.96.159.254119.96.159.2554,094
11119.96.160.0/20119.96.160.1 to 119.96.175.254119.96.175.2554,094
12119.96.176.0/20119.96.176.1 to 119.96.191.254119.96.191.2554,094
13119.96.192.0/20119.96.192.1 to 119.96.207.254119.96.207.2554,094
14119.96.208.0/20119.96.208.1 to 119.96.223.254119.96.223.2554,094
15119.96.224.0/20119.96.224.1 to 119.96.239.254119.96.239.2554,094
16119.96.240.0/20119.96.240.1 to 119.96.255.254119.96.255.2554,094
17119.97.0.0/20119.97.0.1 to 119.97.15.254119.97.15.2554,094
18119.97.16.0/20119.97.16.1 to 119.97.31.254119.97.31.2554,094
19119.97.32.0/20119.97.32.1 to 119.97.47.254119.97.47.2554,094
20119.97.48.0/20119.97.48.1 to 119.97.63.254119.97.63.2554,094
21119.97.64.0/20119.97.64.1 to 119.97.79.254119.97.79.2554,094
22119.97.80.0/20119.97.80.1 to 119.97.95.254119.97.95.2554,094
23119.97.96.0/20119.97.96.1 to 119.97.111.254119.97.111.2554,094
24119.97.112.0/20119.97.112.1 to 119.97.127.254119.97.127.2554,094
25119.97.128.0/20119.97.128.1 to 119.97.143.254119.97.143.2554,094
26119.97.144.0/20119.97.144.1 to 119.97.159.254119.97.159.2554,094
27119.97.160.0/20119.97.160.1 to 119.97.175.254119.97.175.2554,094
28119.97.176.0/20119.97.176.1 to 119.97.191.254119.97.191.2554,094
29119.97.192.0/20119.97.192.1 to 119.97.207.254119.97.207.2554,094
30119.97.208.0/20119.97.208.1 to 119.97.223.254119.97.223.2554,094
31119.97.224.0/20119.97.224.1 to 119.97.239.254119.97.239.2554,094
32119.97.240.0/20119.97.240.1 to 119.97.255.254119.97.255.2554,094
33119.98.0.0/20119.98.0.1 to 119.98.15.254119.98.15.2554,094
34119.98.16.0/20119.98.16.1 to 119.98.31.254119.98.31.2554,094
35119.98.32.0/20119.98.32.1 to 119.98.47.254119.98.47.2554,094
36119.98.48.0/20119.98.48.1 to 119.98.63.254119.98.63.2554,094
37119.98.64.0/20119.98.64.1 to 119.98.79.254119.98.79.2554,094
38119.98.80.0/20119.98.80.1 to 119.98.95.254119.98.95.2554,094
39119.98.96.0/20119.98.96.1 to 119.98.111.254119.98.111.2554,094
40119.98.112.0/20119.98.112.1 to 119.98.127.254119.98.127.2554,094
41119.98.128.0/20119.98.128.1 to 119.98.143.254119.98.143.2554,094
42119.98.144.0/20119.98.144.1 to 119.98.159.254119.98.159.2554,094
43119.98.160.0/20119.98.160.1 to 119.98.175.254119.98.175.2554,094
44119.98.176.0/20119.98.176.1 to 119.98.191.254119.98.191.2554,094
45119.98.192.0/20119.98.192.1 to 119.98.207.254119.98.207.2554,094
46119.98.208.0/20119.98.208.1 to 119.98.223.254119.98.223.2554,094
47119.98.224.0/20119.98.224.1 to 119.98.239.254119.98.239.2554,094
48119.98.240.0/20119.98.240.1 to 119.98.255.254119.98.255.2554,094
49119.99.0.0/20119.99.0.1 to 119.99.15.254119.99.15.2554,094
50119.99.16.0/20119.99.16.1 to 119.99.31.254119.99.31.2554,094
51119.99.32.0/20119.99.32.1 to 119.99.47.254119.99.47.2554,094
52119.99.48.0/20119.99.48.1 to 119.99.63.254119.99.63.2554,094
53119.99.64.0/20119.99.64.1 to 119.99.79.254119.99.79.2554,094
54119.99.80.0/20119.99.80.1 to 119.99.95.254119.99.95.2554,094
55119.99.96.0/20119.99.96.1 to 119.99.111.254119.99.111.2554,094
56119.99.112.0/20119.99.112.1 to 119.99.127.254119.99.127.2554,094
57119.99.128.0/20119.99.128.1 to 119.99.143.254119.99.143.2554,094
58119.99.144.0/20119.99.144.1 to 119.99.159.254119.99.159.2554,094
59119.99.160.0/20119.99.160.1 to 119.99.175.254119.99.175.2554,094
60119.99.176.0/20119.99.176.1 to 119.99.191.254119.99.191.2554,094
61119.99.192.0/20119.99.192.1 to 119.99.207.254119.99.207.2554,094
62119.99.208.0/20119.99.208.1 to 119.99.223.254119.99.223.2554,094
63119.99.224.0/20119.99.224.1 to 119.99.239.254119.99.239.2554,094
64119.99.240.0/20119.99.240.1 to 119.99.255.254119.99.255.2554,094
65119.100.0.0/20119.100.0.1 to 119.100.15.254119.100.15.2554,094
66119.100.16.0/20119.100.16.1 to 119.100.31.254119.100.31.2554,094
67119.100.32.0/20119.100.32.1 to 119.100.47.254119.100.47.2554,094
68119.100.48.0/20119.100.48.1 to 119.100.63.254119.100.63.2554,094
69119.100.64.0/20119.100.64.1 to 119.100.79.254119.100.79.2554,094
70119.100.80.0/20119.100.80.1 to 119.100.95.254119.100.95.2554,094
71119.100.96.0/20119.100.96.1 to 119.100.111.254119.100.111.2554,094
72119.100.112.0/20119.100.112.1 to 119.100.127.254119.100.127.2554,094
73119.100.128.0/20119.100.128.1 to 119.100.143.254119.100.143.2554,094
74119.100.144.0/20119.100.144.1 to 119.100.159.254119.100.159.2554,094
75119.100.160.0/20119.100.160.1 to 119.100.175.254119.100.175.2554,094
76119.100.176.0/20119.100.176.1 to 119.100.191.254119.100.191.2554,094
77119.100.192.0/20119.100.192.1 to 119.100.207.254119.100.207.2554,094
78119.100.208.0/20119.100.208.1 to 119.100.223.254119.100.223.2554,094
79119.100.224.0/20119.100.224.1 to 119.100.239.254119.100.239.2554,094
80119.100.240.0/20119.100.240.1 to 119.100.255.254119.100.255.2554,094
81119.101.0.0/20119.101.0.1 to 119.101.15.254119.101.15.2554,094
82119.101.16.0/20119.101.16.1 to 119.101.31.254119.101.31.2554,094
83119.101.32.0/20119.101.32.1 to 119.101.47.254119.101.47.2554,094
84119.101.48.0/20119.101.48.1 to 119.101.63.254119.101.63.2554,094
85119.101.64.0/20119.101.64.1 to 119.101.79.254119.101.79.2554,094
86119.101.80.0/20119.101.80.1 to 119.101.95.254119.101.95.2554,094
87119.101.96.0/20119.101.96.1 to 119.101.111.254119.101.111.2554,094
88119.101.112.0/20119.101.112.1 to 119.101.127.254119.101.127.2554,094
89119.101.128.0/20119.101.128.1 to 119.101.143.254119.101.143.2554,094
90119.101.144.0/20119.101.144.1 to 119.101.159.254119.101.159.2554,094
91119.101.160.0/20119.101.160.1 to 119.101.175.254119.101.175.2554,094
92119.101.176.0/20119.101.176.1 to 119.101.191.254119.101.191.2554,094
93119.101.192.0/20119.101.192.1 to 119.101.207.254119.101.207.2554,094
94119.101.208.0/20119.101.208.1 to 119.101.223.254119.101.223.2554,094
95119.101.224.0/20119.101.224.1 to 119.101.239.254119.101.239.2554,094
96119.101.240.0/20119.101.240.1 to 119.101.255.254119.101.255.2554,094
97119.102.0.0/20119.102.0.1 to 119.102.15.254119.102.15.2554,094
98119.102.16.0/20119.102.16.1 to 119.102.31.254119.102.31.2554,094
99119.102.32.0/20119.102.32.1 to 119.102.47.254119.102.47.2554,094
100119.102.48.0/20119.102.48.1 to 119.102.63.254119.102.63.2554,094
101119.102.64.0/20119.102.64.1 to 119.102.79.254119.102.79.2554,094
102119.102.80.0/20119.102.80.1 to 119.102.95.254119.102.95.2554,094
103119.102.96.0/20119.102.96.1 to 119.102.111.254119.102.111.2554,094
104119.102.112.0/20119.102.112.1 to 119.102.127.254119.102.127.2554,094
105119.102.128.0/20119.102.128.1 to 119.102.143.254119.102.143.2554,094
106119.102.144.0/20119.102.144.1 to 119.102.159.254119.102.159.2554,094
107119.102.160.0/20119.102.160.1 to 119.102.175.254119.102.175.2554,094
108119.102.176.0/20119.102.176.1 to 119.102.191.254119.102.191.2554,094
109119.102.192.0/20119.102.192.1 to 119.102.207.254119.102.207.2554,094
110119.102.208.0/20119.102.208.1 to 119.102.223.254119.102.223.2554,094
111119.102.224.0/20119.102.224.1 to 119.102.239.254119.102.239.2554,094
112119.102.240.0/20119.102.240.1 to 119.102.255.254119.102.255.2554,094
113119.103.0.0/20119.103.0.1 to 119.103.15.254119.103.15.2554,094
114119.103.16.0/20119.103.16.1 to 119.103.31.254119.103.31.2554,094
115119.103.32.0/20119.103.32.1 to 119.103.47.254119.103.47.2554,094
116119.103.48.0/20119.103.48.1 to 119.103.63.254119.103.63.2554,094
117119.103.64.0/20119.103.64.1 to 119.103.79.254119.103.79.2554,094
118119.103.80.0/20119.103.80.1 to 119.103.95.254119.103.95.2554,094
119119.103.96.0/20119.103.96.1 to 119.103.111.254119.103.111.2554,094
120119.103.112.0/20119.103.112.1 to 119.103.127.254119.103.127.2554,094
121119.103.128.0/20119.103.128.1 to 119.103.143.254119.103.143.2554,094
122119.103.144.0/20119.103.144.1 to 119.103.159.254119.103.159.2554,094
123119.103.160.0/20119.103.160.1 to 119.103.175.254119.103.175.2554,094
124119.103.176.0/20119.103.176.1 to 119.103.191.254119.103.191.2554,094
125119.103.192.0/20119.103.192.1 to 119.103.207.254119.103.207.2554,094
126119.103.208.0/20119.103.208.1 to 119.103.223.254119.103.223.2554,094
127119.103.224.0/20119.103.224.1 to 119.103.239.254119.103.239.2554,094
128119.103.240.0/20119.103.240.1 to 119.103.255.254119.103.255.2554,094
129119.104.0.0/20119.104.0.1 to 119.104.15.254119.104.15.2554,094
130119.104.16.0/20119.104.16.1 to 119.104.31.254119.104.31.2554,094
131119.104.32.0/20119.104.32.1 to 119.104.47.254119.104.47.2554,094
132119.104.48.0/20119.104.48.1 to 119.104.63.254119.104.63.2554,094
133119.104.64.0/20119.104.64.1 to 119.104.79.254119.104.79.2554,094
134119.104.80.0/20119.104.80.1 to 119.104.95.254119.104.95.2554,094
135119.104.96.0/20119.104.96.1 to 119.104.111.254119.104.111.2554,094
136119.104.112.0/20119.104.112.1 to 119.104.127.254119.104.127.2554,094
137119.104.128.0/20119.104.128.1 to 119.104.143.254119.104.143.2554,094
138119.104.144.0/20119.104.144.1 to 119.104.159.254119.104.159.2554,094
139119.104.160.0/20119.104.160.1 to 119.104.175.254119.104.175.2554,094
140119.104.176.0/20119.104.176.1 to 119.104.191.254119.104.191.2554,094
141119.104.192.0/20119.104.192.1 to 119.104.207.254119.104.207.2554,094
142119.104.208.0/20119.104.208.1 to 119.104.223.254119.104.223.2554,094
143119.104.224.0/20119.104.224.1 to 119.104.239.254119.104.239.2554,094
144119.104.240.0/20119.104.240.1 to 119.104.255.254119.104.255.2554,094
145119.105.0.0/20119.105.0.1 to 119.105.15.254119.105.15.2554,094
146119.105.16.0/20119.105.16.1 to 119.105.31.254119.105.31.2554,094
147119.105.32.0/20119.105.32.1 to 119.105.47.254119.105.47.2554,094
148119.105.48.0/20119.105.48.1 to 119.105.63.254119.105.63.2554,094
149119.105.64.0/20119.105.64.1 to 119.105.79.254119.105.79.2554,094
150119.105.80.0/20119.105.80.1 to 119.105.95.254119.105.95.2554,094
151119.105.96.0/20119.105.96.1 to 119.105.111.254119.105.111.2554,094
152119.105.112.0/20119.105.112.1 to 119.105.127.254119.105.127.2554,094
153119.105.128.0/20119.105.128.1 to 119.105.143.254119.105.143.2554,094
154119.105.144.0/20119.105.144.1 to 119.105.159.254119.105.159.2554,094
155119.105.160.0/20119.105.160.1 to 119.105.175.254119.105.175.2554,094
156119.105.176.0/20119.105.176.1 to 119.105.191.254119.105.191.2554,094
157119.105.192.0/20119.105.192.1 to 119.105.207.254119.105.207.2554,094
158119.105.208.0/20119.105.208.1 to 119.105.223.254119.105.223.2554,094
159119.105.224.0/20119.105.224.1 to 119.105.239.254119.105.239.2554,094
160119.105.240.0/20119.105.240.1 to 119.105.255.254119.105.255.2554,094
161119.106.0.0/20119.106.0.1 to 119.106.15.254119.106.15.2554,094
162119.106.16.0/20119.106.16.1 to 119.106.31.254119.106.31.2554,094
163119.106.32.0/20119.106.32.1 to 119.106.47.254119.106.47.2554,094
164119.106.48.0/20119.106.48.1 to 119.106.63.254119.106.63.2554,094
165119.106.64.0/20119.106.64.1 to 119.106.79.254119.106.79.2554,094
166119.106.80.0/20119.106.80.1 to 119.106.95.254119.106.95.2554,094
167119.106.96.0/20119.106.96.1 to 119.106.111.254119.106.111.2554,094
168119.106.112.0/20119.106.112.1 to 119.106.127.254119.106.127.2554,094
169119.106.128.0/20119.106.128.1 to 119.106.143.254119.106.143.2554,094
170119.106.144.0/20119.106.144.1 to 119.106.159.254119.106.159.2554,094
171119.106.160.0/20119.106.160.1 to 119.106.175.254119.106.175.2554,094
172119.106.176.0/20119.106.176.1 to 119.106.191.254119.106.191.2554,094
173119.106.192.0/20119.106.192.1 to 119.106.207.254119.106.207.2554,094
174119.106.208.0/20119.106.208.1 to 119.106.223.254119.106.223.2554,094
175119.106.224.0/20119.106.224.1 to 119.106.239.254119.106.239.2554,094
176119.106.240.0/20119.106.240.1 to 119.106.255.254119.106.255.2554,094
177119.107.0.0/20119.107.0.1 to 119.107.15.254119.107.15.2554,094
178119.107.16.0/20119.107.16.1 to 119.107.31.254119.107.31.2554,094
179119.107.32.0/20119.107.32.1 to 119.107.47.254119.107.47.2554,094
180119.107.48.0/20119.107.48.1 to 119.107.63.254119.107.63.2554,094
181119.107.64.0/20119.107.64.1 to 119.107.79.254119.107.79.2554,094
182119.107.80.0/20119.107.80.1 to 119.107.95.254119.107.95.2554,094
183119.107.96.0/20119.107.96.1 to 119.107.111.254119.107.111.2554,094
184119.107.112.0/20119.107.112.1 to 119.107.127.254119.107.127.2554,094
185119.107.128.0/20119.107.128.1 to 119.107.143.254119.107.143.2554,094
186119.107.144.0/20119.107.144.1 to 119.107.159.254119.107.159.2554,094
187119.107.160.0/20119.107.160.1 to 119.107.175.254119.107.175.2554,094
188119.107.176.0/20119.107.176.1 to 119.107.191.254119.107.191.2554,094
189119.107.192.0/20119.107.192.1 to 119.107.207.254119.107.207.2554,094
190119.107.208.0/20119.107.208.1 to 119.107.223.254119.107.223.2554,094
191119.107.224.0/20119.107.224.1 to 119.107.239.254119.107.239.2554,094
192119.107.240.0/20119.107.240.1 to 119.107.255.254119.107.255.2554,094
193119.108.0.0/20119.108.0.1 to 119.108.15.254119.108.15.2554,094
194119.108.16.0/20119.108.16.1 to 119.108.31.254119.108.31.2554,094
195119.108.32.0/20119.108.32.1 to 119.108.47.254119.108.47.2554,094
196119.108.48.0/20119.108.48.1 to 119.108.63.254119.108.63.2554,094
197119.108.64.0/20119.108.64.1 to 119.108.79.254119.108.79.2554,094
198119.108.80.0/20119.108.80.1 to 119.108.95.254119.108.95.2554,094
199119.108.96.0/20119.108.96.1 to 119.108.111.254119.108.111.2554,094
200119.108.112.0/20119.108.112.1 to 119.108.127.254119.108.127.2554,094
201119.108.128.0/20119.108.128.1 to 119.108.143.254119.108.143.2554,094
202119.108.144.0/20119.108.144.1 to 119.108.159.254119.108.159.2554,094
203119.108.160.0/20119.108.160.1 to 119.108.175.254119.108.175.2554,094
204119.108.176.0/20119.108.176.1 to 119.108.191.254119.108.191.2554,094
205119.108.192.0/20119.108.192.1 to 119.108.207.254119.108.207.2554,094
206119.108.208.0/20119.108.208.1 to 119.108.223.254119.108.223.2554,094
207119.108.224.0/20119.108.224.1 to 119.108.239.254119.108.239.2554,094
208119.108.240.0/20119.108.240.1 to 119.108.255.254119.108.255.2554,094
209119.109.0.0/20119.109.0.1 to 119.109.15.254119.109.15.2554,094
210119.109.16.0/20119.109.16.1 to 119.109.31.254119.109.31.2554,094
211119.109.32.0/20119.109.32.1 to 119.109.47.254119.109.47.2554,094
212119.109.48.0/20119.109.48.1 to 119.109.63.254119.109.63.2554,094
213119.109.64.0/20119.109.64.1 to 119.109.79.254119.109.79.2554,094
214119.109.80.0/20119.109.80.1 to 119.109.95.254119.109.95.2554,094
215119.109.96.0/20119.109.96.1 to 119.109.111.254119.109.111.2554,094
216119.109.112.0/20119.109.112.1 to 119.109.127.254119.109.127.2554,094
217119.109.128.0/20119.109.128.1 to 119.109.143.254119.109.143.2554,094
218119.109.144.0/20119.109.144.1 to 119.109.159.254119.109.159.2554,094
219119.109.160.0/20119.109.160.1 to 119.109.175.254119.109.175.2554,094
220119.109.176.0/20119.109.176.1 to 119.109.191.254119.109.191.2554,094
221119.109.192.0/20119.109.192.1 to 119.109.207.254119.109.207.2554,094
222119.109.208.0/20119.109.208.1 to 119.109.223.254119.109.223.2554,094
223119.109.224.0/20119.109.224.1 to 119.109.239.254119.109.239.2554,094
224119.109.240.0/20119.109.240.1 to 119.109.255.254119.109.255.2554,094
225119.110.0.0/20119.110.0.1 to 119.110.15.254119.110.15.2554,094
226119.110.16.0/20119.110.16.1 to 119.110.31.254119.110.31.2554,094
227119.110.32.0/20119.110.32.1 to 119.110.47.254119.110.47.2554,094
228119.110.48.0/20119.110.48.1 to 119.110.63.254119.110.63.2554,094
229119.110.64.0/20119.110.64.1 to 119.110.79.254119.110.79.2554,094
230119.110.80.0/20119.110.80.1 to 119.110.95.254119.110.95.2554,094
231119.110.96.0/20119.110.96.1 to 119.110.111.254119.110.111.2554,094
232119.110.112.0/20119.110.112.1 to 119.110.127.254119.110.127.2554,094
233119.110.128.0/20119.110.128.1 to 119.110.143.254119.110.143.2554,094
234119.110.144.0/20119.110.144.1 to 119.110.159.254119.110.159.2554,094
235119.110.160.0/20119.110.160.1 to 119.110.175.254119.110.175.2554,094
236119.110.176.0/20119.110.176.1 to 119.110.191.254119.110.191.2554,094
237119.110.192.0/20119.110.192.1 to 119.110.207.254119.110.207.2554,094
238119.110.208.0/20119.110.208.1 to 119.110.223.254119.110.223.2554,094
239119.110.224.0/20119.110.224.1 to 119.110.239.254119.110.239.2554,094
240119.110.240.0/20119.110.240.1 to 119.110.255.254119.110.255.2554,094
241119.111.0.0/20119.111.0.1 to 119.111.15.254119.111.15.2554,094
242119.111.16.0/20119.111.16.1 to 119.111.31.254119.111.31.2554,094
243119.111.32.0/20119.111.32.1 to 119.111.47.254119.111.47.2554,094
244119.111.48.0/20119.111.48.1 to 119.111.63.254119.111.63.2554,094
245119.111.64.0/20119.111.64.1 to 119.111.79.254119.111.79.2554,094
246119.111.80.0/20119.111.80.1 to 119.111.95.254119.111.95.2554,094
247119.111.96.0/20119.111.96.1 to 119.111.111.254119.111.111.2554,094
248119.111.112.0/20119.111.112.1 to 119.111.127.254119.111.127.2554,094
249119.111.128.0/20119.111.128.1 to 119.111.143.254119.111.143.2554,094
250119.111.144.0/20119.111.144.1 to 119.111.159.254119.111.159.2554,094
251119.111.160.0/20119.111.160.1 to 119.111.175.254119.111.175.2554,094
252119.111.176.0/20119.111.176.1 to 119.111.191.254119.111.191.2554,094
253119.111.192.0/20119.111.192.1 to 119.111.207.254119.111.207.2554,094
254119.111.208.0/20119.111.208.1 to 119.111.223.254119.111.223.2554,094
255119.111.224.0/20119.111.224.1 to 119.111.239.254119.111.239.2554,094
256119.111.240.0/20119.111.240.1 to 119.111.255.254119.111.255.2554,094

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.