[TUT] Detect and prevent DNS-Leak Win&Mac


Oct 11, 2015
DNS Leak
Once a domain is called the DNS server queries the associated IP address . Should you are behind a router , then the DNS server your ISP is set in the router and your computer , the DNS queries to your router . Do you connect in this scenario with our VPN server , then we put our DNS server in your computer , so that all requests are routed through this server .
However, it may happen that your operating system , depending on the configuration , further directed the questions to your router . This sets you up an unnecessary security risk from , because should record the request of your DNS server a page , then it is possible , if your DNS server also logs out mitschneidet , your real IP address .

Am I affected?

Connect yourself first with the VPN and call on http://www.dnsleaktest.com/ . There you can test to see if you are also affected. Click on " Check DNS leaks now!" . If the result at an IP address issued from your country and especially your ISP , then you're affected

What can I do about it?

The problem can easily be fixed , to be by looking an extra DNS server assigns your network adapter :


Google Public DNS
DNS change ( Windows / Mac OS X )

It is recommendable to use an alternate DNS server , because usually the DNS server of your Internet provider is used . This is either slow , stores the requests or block certain sites . If you use a VPN , it can also lead to a so-called DNS Leak without fixed presets .

A selection , which DNS server you use can
OpenDNS: und
ComodoDNS: und
GoogleDNS: und
UltraDNS: und
NortonDNS: und


Step 1 : Open the Control Panel and click on " View network status and tasks"
Step 2 : Click on " Change adapter settings "
Step 3 : Click with the right -click the network adapter that you connect to the Internet and click then "Properties"
Step 4 : Select " Internet Protocol Version 4 ( TCP / IPv4 ) " and click on "Properties"
Step 5 : "Use the following DNS server addresses : " Click on and carry on the two DNS server addresses , is important that a DNS server is at " Preferred DNS server " is entered . The alternative DNS server is optional , but it is recommended there should be registered also a server . In the example I have entered the Google Public DNS servers .

Mac OS X:
Step 1 : Open the System Preferences and click " Network " .
Step 2 : Choose your Ethernet adapter and click on " More options " .
Step 3 : Click on the + and add the IP addresses of the selected DNS server (for example, and ) .
Step 4 : Click on "OK " .
Step 5 : Under DNS server , the IP addresses entered should be listed .
Last edited:


Apr 27, 2015
Sorry, but I have to tell you this: You've got to rewrite this post in english. Otherwise we eventually have to delete it (I don't want to do that as it is a good tutorial.. :( )