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.

Network194.2.0.0/18
Usable hosts16,382
Subnet mask255.255.192.0
Addresses16,384
Network address
194.2.0.0
Broadcast address
194.2.63.255
First usable
194.2.0.1
Last usable
194.2.63.254
Usable hosts
16,382 (16,384 less the network and broadcast addresses)
Subnet mask
255.255.192.0
Wildcard mask
0.0.63.255 (Cisco ACLs, OSPF)
Prefix length
/18
Type
Public public
Old class
C (default /24)
As numbers
Hex C2020000 · Integer 3254910976 to 3254927359
Reverse DNS zones
0.2.194.in-addr.arpa
1.2.194.in-addr.arpa
2.2.194.in-addr.arpa
3.2.194.in-addr.arpa
4.2.194.in-addr.arpa
5.2.194.in-addr.arpa
6.2.194.in-addr.arpa
7.2.194.in-addr.arpa
8.2.194.in-addr.arpa
9.2.194.in-addr.arpa
10.2.194.in-addr.arpa
11.2.194.in-addr.arpa
12.2.194.in-addr.arpa
13.2.194.in-addr.arpa
14.2.194.in-addr.arpa
15.2.194.in-addr.arpa
and 48 more
/18 is not on a 8-bit boundary, so it takes 64 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11000010.00000010.00000000.00000000194.2.0.0
Subnet mask11111111.11111111.11000000.00000000255.255.192.0
Network11000010.00000010.00000000.00000000194.2.0.0
Broadcast11000010.00000010.00111111.11111111194.2.63.255
Split into smaller subnets/27

194.2.0.0/18 makes 512 subnets of /27; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1194.2.0.0/27194.2.0.1 to 194.2.0.30194.2.0.3130
2194.2.0.32/27194.2.0.33 to 194.2.0.62194.2.0.6330
3194.2.0.64/27194.2.0.65 to 194.2.0.94194.2.0.9530
4194.2.0.96/27194.2.0.97 to 194.2.0.126194.2.0.12730
5194.2.0.128/27194.2.0.129 to 194.2.0.158194.2.0.15930
6194.2.0.160/27194.2.0.161 to 194.2.0.190194.2.0.19130
7194.2.0.192/27194.2.0.193 to 194.2.0.222194.2.0.22330
8194.2.0.224/27194.2.0.225 to 194.2.0.254194.2.0.25530
9194.2.1.0/27194.2.1.1 to 194.2.1.30194.2.1.3130
10194.2.1.32/27194.2.1.33 to 194.2.1.62194.2.1.6330
11194.2.1.64/27194.2.1.65 to 194.2.1.94194.2.1.9530
12194.2.1.96/27194.2.1.97 to 194.2.1.126194.2.1.12730
13194.2.1.128/27194.2.1.129 to 194.2.1.158194.2.1.15930
14194.2.1.160/27194.2.1.161 to 194.2.1.190194.2.1.19130
15194.2.1.192/27194.2.1.193 to 194.2.1.222194.2.1.22330
16194.2.1.224/27194.2.1.225 to 194.2.1.254194.2.1.25530
17194.2.2.0/27194.2.2.1 to 194.2.2.30194.2.2.3130
18194.2.2.32/27194.2.2.33 to 194.2.2.62194.2.2.6330
19194.2.2.64/27194.2.2.65 to 194.2.2.94194.2.2.9530
20194.2.2.96/27194.2.2.97 to 194.2.2.126194.2.2.12730
21194.2.2.128/27194.2.2.129 to 194.2.2.158194.2.2.15930
22194.2.2.160/27194.2.2.161 to 194.2.2.190194.2.2.19130
23194.2.2.192/27194.2.2.193 to 194.2.2.222194.2.2.22330
24194.2.2.224/27194.2.2.225 to 194.2.2.254194.2.2.25530
25194.2.3.0/27194.2.3.1 to 194.2.3.30194.2.3.3130
26194.2.3.32/27194.2.3.33 to 194.2.3.62194.2.3.6330
27194.2.3.64/27194.2.3.65 to 194.2.3.94194.2.3.9530
28194.2.3.96/27194.2.3.97 to 194.2.3.126194.2.3.12730
29194.2.3.128/27194.2.3.129 to 194.2.3.158194.2.3.15930
30194.2.3.160/27194.2.3.161 to 194.2.3.190194.2.3.19130
31194.2.3.192/27194.2.3.193 to 194.2.3.222194.2.3.22330
32194.2.3.224/27194.2.3.225 to 194.2.3.254194.2.3.25530
33194.2.4.0/27194.2.4.1 to 194.2.4.30194.2.4.3130
34194.2.4.32/27194.2.4.33 to 194.2.4.62194.2.4.6330
35194.2.4.64/27194.2.4.65 to 194.2.4.94194.2.4.9530
36194.2.4.96/27194.2.4.97 to 194.2.4.126194.2.4.12730
37194.2.4.128/27194.2.4.129 to 194.2.4.158194.2.4.15930
38194.2.4.160/27194.2.4.161 to 194.2.4.190194.2.4.19130
39194.2.4.192/27194.2.4.193 to 194.2.4.222194.2.4.22330
40194.2.4.224/27194.2.4.225 to 194.2.4.254194.2.4.25530
41194.2.5.0/27194.2.5.1 to 194.2.5.30194.2.5.3130
42194.2.5.32/27194.2.5.33 to 194.2.5.62194.2.5.6330
43194.2.5.64/27194.2.5.65 to 194.2.5.94194.2.5.9530
44194.2.5.96/27194.2.5.97 to 194.2.5.126194.2.5.12730
45194.2.5.128/27194.2.5.129 to 194.2.5.158194.2.5.15930
46194.2.5.160/27194.2.5.161 to 194.2.5.190194.2.5.19130
47194.2.5.192/27194.2.5.193 to 194.2.5.222194.2.5.22330
48194.2.5.224/27194.2.5.225 to 194.2.5.254194.2.5.25530
49194.2.6.0/27194.2.6.1 to 194.2.6.30194.2.6.3130
50194.2.6.32/27194.2.6.33 to 194.2.6.62194.2.6.6330
51194.2.6.64/27194.2.6.65 to 194.2.6.94194.2.6.9530
52194.2.6.96/27194.2.6.97 to 194.2.6.126194.2.6.12730
53194.2.6.128/27194.2.6.129 to 194.2.6.158194.2.6.15930
54194.2.6.160/27194.2.6.161 to 194.2.6.190194.2.6.19130
55194.2.6.192/27194.2.6.193 to 194.2.6.222194.2.6.22330
56194.2.6.224/27194.2.6.225 to 194.2.6.254194.2.6.25530
57194.2.7.0/27194.2.7.1 to 194.2.7.30194.2.7.3130
58194.2.7.32/27194.2.7.33 to 194.2.7.62194.2.7.6330
59194.2.7.64/27194.2.7.65 to 194.2.7.94194.2.7.9530
60194.2.7.96/27194.2.7.97 to 194.2.7.126194.2.7.12730
61194.2.7.128/27194.2.7.129 to 194.2.7.158194.2.7.15930
62194.2.7.160/27194.2.7.161 to 194.2.7.190194.2.7.19130
63194.2.7.192/27194.2.7.193 to 194.2.7.222194.2.7.22330
64194.2.7.224/27194.2.7.225 to 194.2.7.254194.2.7.25530
65194.2.8.0/27194.2.8.1 to 194.2.8.30194.2.8.3130
66194.2.8.32/27194.2.8.33 to 194.2.8.62194.2.8.6330
67194.2.8.64/27194.2.8.65 to 194.2.8.94194.2.8.9530
68194.2.8.96/27194.2.8.97 to 194.2.8.126194.2.8.12730
69194.2.8.128/27194.2.8.129 to 194.2.8.158194.2.8.15930
70194.2.8.160/27194.2.8.161 to 194.2.8.190194.2.8.19130
71194.2.8.192/27194.2.8.193 to 194.2.8.222194.2.8.22330
72194.2.8.224/27194.2.8.225 to 194.2.8.254194.2.8.25530
73194.2.9.0/27194.2.9.1 to 194.2.9.30194.2.9.3130
74194.2.9.32/27194.2.9.33 to 194.2.9.62194.2.9.6330
75194.2.9.64/27194.2.9.65 to 194.2.9.94194.2.9.9530
76194.2.9.96/27194.2.9.97 to 194.2.9.126194.2.9.12730
77194.2.9.128/27194.2.9.129 to 194.2.9.158194.2.9.15930
78194.2.9.160/27194.2.9.161 to 194.2.9.190194.2.9.19130
79194.2.9.192/27194.2.9.193 to 194.2.9.222194.2.9.22330
80194.2.9.224/27194.2.9.225 to 194.2.9.254194.2.9.25530
81194.2.10.0/27194.2.10.1 to 194.2.10.30194.2.10.3130
82194.2.10.32/27194.2.10.33 to 194.2.10.62194.2.10.6330
83194.2.10.64/27194.2.10.65 to 194.2.10.94194.2.10.9530
84194.2.10.96/27194.2.10.97 to 194.2.10.126194.2.10.12730
85194.2.10.128/27194.2.10.129 to 194.2.10.158194.2.10.15930
86194.2.10.160/27194.2.10.161 to 194.2.10.190194.2.10.19130
87194.2.10.192/27194.2.10.193 to 194.2.10.222194.2.10.22330
88194.2.10.224/27194.2.10.225 to 194.2.10.254194.2.10.25530
89194.2.11.0/27194.2.11.1 to 194.2.11.30194.2.11.3130
90194.2.11.32/27194.2.11.33 to 194.2.11.62194.2.11.6330
91194.2.11.64/27194.2.11.65 to 194.2.11.94194.2.11.9530
92194.2.11.96/27194.2.11.97 to 194.2.11.126194.2.11.12730
93194.2.11.128/27194.2.11.129 to 194.2.11.158194.2.11.15930
94194.2.11.160/27194.2.11.161 to 194.2.11.190194.2.11.19130
95194.2.11.192/27194.2.11.193 to 194.2.11.222194.2.11.22330
96194.2.11.224/27194.2.11.225 to 194.2.11.254194.2.11.25530
97194.2.12.0/27194.2.12.1 to 194.2.12.30194.2.12.3130
98194.2.12.32/27194.2.12.33 to 194.2.12.62194.2.12.6330
99194.2.12.64/27194.2.12.65 to 194.2.12.94194.2.12.9530
100194.2.12.96/27194.2.12.97 to 194.2.12.126194.2.12.12730
101194.2.12.128/27194.2.12.129 to 194.2.12.158194.2.12.15930
102194.2.12.160/27194.2.12.161 to 194.2.12.190194.2.12.19130
103194.2.12.192/27194.2.12.193 to 194.2.12.222194.2.12.22330
104194.2.12.224/27194.2.12.225 to 194.2.12.254194.2.12.25530
105194.2.13.0/27194.2.13.1 to 194.2.13.30194.2.13.3130
106194.2.13.32/27194.2.13.33 to 194.2.13.62194.2.13.6330
107194.2.13.64/27194.2.13.65 to 194.2.13.94194.2.13.9530
108194.2.13.96/27194.2.13.97 to 194.2.13.126194.2.13.12730
109194.2.13.128/27194.2.13.129 to 194.2.13.158194.2.13.15930
110194.2.13.160/27194.2.13.161 to 194.2.13.190194.2.13.19130
111194.2.13.192/27194.2.13.193 to 194.2.13.222194.2.13.22330
112194.2.13.224/27194.2.13.225 to 194.2.13.254194.2.13.25530
113194.2.14.0/27194.2.14.1 to 194.2.14.30194.2.14.3130
114194.2.14.32/27194.2.14.33 to 194.2.14.62194.2.14.6330
115194.2.14.64/27194.2.14.65 to 194.2.14.94194.2.14.9530
116194.2.14.96/27194.2.14.97 to 194.2.14.126194.2.14.12730
117194.2.14.128/27194.2.14.129 to 194.2.14.158194.2.14.15930
118194.2.14.160/27194.2.14.161 to 194.2.14.190194.2.14.19130
119194.2.14.192/27194.2.14.193 to 194.2.14.222194.2.14.22330
120194.2.14.224/27194.2.14.225 to 194.2.14.254194.2.14.25530
121194.2.15.0/27194.2.15.1 to 194.2.15.30194.2.15.3130
122194.2.15.32/27194.2.15.33 to 194.2.15.62194.2.15.6330
123194.2.15.64/27194.2.15.65 to 194.2.15.94194.2.15.9530
124194.2.15.96/27194.2.15.97 to 194.2.15.126194.2.15.12730
125194.2.15.128/27194.2.15.129 to 194.2.15.158194.2.15.15930
126194.2.15.160/27194.2.15.161 to 194.2.15.190194.2.15.19130
127194.2.15.192/27194.2.15.193 to 194.2.15.222194.2.15.22330
128194.2.15.224/27194.2.15.225 to 194.2.15.254194.2.15.25530
129194.2.16.0/27194.2.16.1 to 194.2.16.30194.2.16.3130
130194.2.16.32/27194.2.16.33 to 194.2.16.62194.2.16.6330
131194.2.16.64/27194.2.16.65 to 194.2.16.94194.2.16.9530
132194.2.16.96/27194.2.16.97 to 194.2.16.126194.2.16.12730
133194.2.16.128/27194.2.16.129 to 194.2.16.158194.2.16.15930
134194.2.16.160/27194.2.16.161 to 194.2.16.190194.2.16.19130
135194.2.16.192/27194.2.16.193 to 194.2.16.222194.2.16.22330
136194.2.16.224/27194.2.16.225 to 194.2.16.254194.2.16.25530
137194.2.17.0/27194.2.17.1 to 194.2.17.30194.2.17.3130
138194.2.17.32/27194.2.17.33 to 194.2.17.62194.2.17.6330
139194.2.17.64/27194.2.17.65 to 194.2.17.94194.2.17.9530
140194.2.17.96/27194.2.17.97 to 194.2.17.126194.2.17.12730
141194.2.17.128/27194.2.17.129 to 194.2.17.158194.2.17.15930
142194.2.17.160/27194.2.17.161 to 194.2.17.190194.2.17.19130
143194.2.17.192/27194.2.17.193 to 194.2.17.222194.2.17.22330
144194.2.17.224/27194.2.17.225 to 194.2.17.254194.2.17.25530
145194.2.18.0/27194.2.18.1 to 194.2.18.30194.2.18.3130
146194.2.18.32/27194.2.18.33 to 194.2.18.62194.2.18.6330
147194.2.18.64/27194.2.18.65 to 194.2.18.94194.2.18.9530
148194.2.18.96/27194.2.18.97 to 194.2.18.126194.2.18.12730
149194.2.18.128/27194.2.18.129 to 194.2.18.158194.2.18.15930
150194.2.18.160/27194.2.18.161 to 194.2.18.190194.2.18.19130
151194.2.18.192/27194.2.18.193 to 194.2.18.222194.2.18.22330
152194.2.18.224/27194.2.18.225 to 194.2.18.254194.2.18.25530
153194.2.19.0/27194.2.19.1 to 194.2.19.30194.2.19.3130
154194.2.19.32/27194.2.19.33 to 194.2.19.62194.2.19.6330
155194.2.19.64/27194.2.19.65 to 194.2.19.94194.2.19.9530
156194.2.19.96/27194.2.19.97 to 194.2.19.126194.2.19.12730
157194.2.19.128/27194.2.19.129 to 194.2.19.158194.2.19.15930
158194.2.19.160/27194.2.19.161 to 194.2.19.190194.2.19.19130
159194.2.19.192/27194.2.19.193 to 194.2.19.222194.2.19.22330
160194.2.19.224/27194.2.19.225 to 194.2.19.254194.2.19.25530
161194.2.20.0/27194.2.20.1 to 194.2.20.30194.2.20.3130
162194.2.20.32/27194.2.20.33 to 194.2.20.62194.2.20.6330
163194.2.20.64/27194.2.20.65 to 194.2.20.94194.2.20.9530
164194.2.20.96/27194.2.20.97 to 194.2.20.126194.2.20.12730
165194.2.20.128/27194.2.20.129 to 194.2.20.158194.2.20.15930
166194.2.20.160/27194.2.20.161 to 194.2.20.190194.2.20.19130
167194.2.20.192/27194.2.20.193 to 194.2.20.222194.2.20.22330
168194.2.20.224/27194.2.20.225 to 194.2.20.254194.2.20.25530
169194.2.21.0/27194.2.21.1 to 194.2.21.30194.2.21.3130
170194.2.21.32/27194.2.21.33 to 194.2.21.62194.2.21.6330
171194.2.21.64/27194.2.21.65 to 194.2.21.94194.2.21.9530
172194.2.21.96/27194.2.21.97 to 194.2.21.126194.2.21.12730
173194.2.21.128/27194.2.21.129 to 194.2.21.158194.2.21.15930
174194.2.21.160/27194.2.21.161 to 194.2.21.190194.2.21.19130
175194.2.21.192/27194.2.21.193 to 194.2.21.222194.2.21.22330
176194.2.21.224/27194.2.21.225 to 194.2.21.254194.2.21.25530
177194.2.22.0/27194.2.22.1 to 194.2.22.30194.2.22.3130
178194.2.22.32/27194.2.22.33 to 194.2.22.62194.2.22.6330
179194.2.22.64/27194.2.22.65 to 194.2.22.94194.2.22.9530
180194.2.22.96/27194.2.22.97 to 194.2.22.126194.2.22.12730
181194.2.22.128/27194.2.22.129 to 194.2.22.158194.2.22.15930
182194.2.22.160/27194.2.22.161 to 194.2.22.190194.2.22.19130
183194.2.22.192/27194.2.22.193 to 194.2.22.222194.2.22.22330
184194.2.22.224/27194.2.22.225 to 194.2.22.254194.2.22.25530
185194.2.23.0/27194.2.23.1 to 194.2.23.30194.2.23.3130
186194.2.23.32/27194.2.23.33 to 194.2.23.62194.2.23.6330
187194.2.23.64/27194.2.23.65 to 194.2.23.94194.2.23.9530
188194.2.23.96/27194.2.23.97 to 194.2.23.126194.2.23.12730
189194.2.23.128/27194.2.23.129 to 194.2.23.158194.2.23.15930
190194.2.23.160/27194.2.23.161 to 194.2.23.190194.2.23.19130
191194.2.23.192/27194.2.23.193 to 194.2.23.222194.2.23.22330
192194.2.23.224/27194.2.23.225 to 194.2.23.254194.2.23.25530
193194.2.24.0/27194.2.24.1 to 194.2.24.30194.2.24.3130
194194.2.24.32/27194.2.24.33 to 194.2.24.62194.2.24.6330
195194.2.24.64/27194.2.24.65 to 194.2.24.94194.2.24.9530
196194.2.24.96/27194.2.24.97 to 194.2.24.126194.2.24.12730
197194.2.24.128/27194.2.24.129 to 194.2.24.158194.2.24.15930
198194.2.24.160/27194.2.24.161 to 194.2.24.190194.2.24.19130
199194.2.24.192/27194.2.24.193 to 194.2.24.222194.2.24.22330
200194.2.24.224/27194.2.24.225 to 194.2.24.254194.2.24.25530
201194.2.25.0/27194.2.25.1 to 194.2.25.30194.2.25.3130
202194.2.25.32/27194.2.25.33 to 194.2.25.62194.2.25.6330
203194.2.25.64/27194.2.25.65 to 194.2.25.94194.2.25.9530
204194.2.25.96/27194.2.25.97 to 194.2.25.126194.2.25.12730
205194.2.25.128/27194.2.25.129 to 194.2.25.158194.2.25.15930
206194.2.25.160/27194.2.25.161 to 194.2.25.190194.2.25.19130
207194.2.25.192/27194.2.25.193 to 194.2.25.222194.2.25.22330
208194.2.25.224/27194.2.25.225 to 194.2.25.254194.2.25.25530
209194.2.26.0/27194.2.26.1 to 194.2.26.30194.2.26.3130
210194.2.26.32/27194.2.26.33 to 194.2.26.62194.2.26.6330
211194.2.26.64/27194.2.26.65 to 194.2.26.94194.2.26.9530
212194.2.26.96/27194.2.26.97 to 194.2.26.126194.2.26.12730
213194.2.26.128/27194.2.26.129 to 194.2.26.158194.2.26.15930
214194.2.26.160/27194.2.26.161 to 194.2.26.190194.2.26.19130
215194.2.26.192/27194.2.26.193 to 194.2.26.222194.2.26.22330
216194.2.26.224/27194.2.26.225 to 194.2.26.254194.2.26.25530
217194.2.27.0/27194.2.27.1 to 194.2.27.30194.2.27.3130
218194.2.27.32/27194.2.27.33 to 194.2.27.62194.2.27.6330
219194.2.27.64/27194.2.27.65 to 194.2.27.94194.2.27.9530
220194.2.27.96/27194.2.27.97 to 194.2.27.126194.2.27.12730
221194.2.27.128/27194.2.27.129 to 194.2.27.158194.2.27.15930
222194.2.27.160/27194.2.27.161 to 194.2.27.190194.2.27.19130
223194.2.27.192/27194.2.27.193 to 194.2.27.222194.2.27.22330
224194.2.27.224/27194.2.27.225 to 194.2.27.254194.2.27.25530
225194.2.28.0/27194.2.28.1 to 194.2.28.30194.2.28.3130
226194.2.28.32/27194.2.28.33 to 194.2.28.62194.2.28.6330
227194.2.28.64/27194.2.28.65 to 194.2.28.94194.2.28.9530
228194.2.28.96/27194.2.28.97 to 194.2.28.126194.2.28.12730
229194.2.28.128/27194.2.28.129 to 194.2.28.158194.2.28.15930
230194.2.28.160/27194.2.28.161 to 194.2.28.190194.2.28.19130
231194.2.28.192/27194.2.28.193 to 194.2.28.222194.2.28.22330
232194.2.28.224/27194.2.28.225 to 194.2.28.254194.2.28.25530
233194.2.29.0/27194.2.29.1 to 194.2.29.30194.2.29.3130
234194.2.29.32/27194.2.29.33 to 194.2.29.62194.2.29.6330
235194.2.29.64/27194.2.29.65 to 194.2.29.94194.2.29.9530
236194.2.29.96/27194.2.29.97 to 194.2.29.126194.2.29.12730
237194.2.29.128/27194.2.29.129 to 194.2.29.158194.2.29.15930
238194.2.29.160/27194.2.29.161 to 194.2.29.190194.2.29.19130
239194.2.29.192/27194.2.29.193 to 194.2.29.222194.2.29.22330
240194.2.29.224/27194.2.29.225 to 194.2.29.254194.2.29.25530
241194.2.30.0/27194.2.30.1 to 194.2.30.30194.2.30.3130
242194.2.30.32/27194.2.30.33 to 194.2.30.62194.2.30.6330
243194.2.30.64/27194.2.30.65 to 194.2.30.94194.2.30.9530
244194.2.30.96/27194.2.30.97 to 194.2.30.126194.2.30.12730
245194.2.30.128/27194.2.30.129 to 194.2.30.158194.2.30.15930
246194.2.30.160/27194.2.30.161 to 194.2.30.190194.2.30.19130
247194.2.30.192/27194.2.30.193 to 194.2.30.222194.2.30.22330
248194.2.30.224/27194.2.30.225 to 194.2.30.254194.2.30.25530
249194.2.31.0/27194.2.31.1 to 194.2.31.30194.2.31.3130
250194.2.31.32/27194.2.31.33 to 194.2.31.62194.2.31.6330
251194.2.31.64/27194.2.31.65 to 194.2.31.94194.2.31.9530
252194.2.31.96/27194.2.31.97 to 194.2.31.126194.2.31.12730
253194.2.31.128/27194.2.31.129 to 194.2.31.158194.2.31.15930
254194.2.31.160/27194.2.31.161 to 194.2.31.190194.2.31.19130
255194.2.31.192/27194.2.31.193 to 194.2.31.222194.2.31.22330
256194.2.31.224/27194.2.31.225 to 194.2.31.254194.2.31.25530

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