A VPN establishes an encrypted association (usually called a ‘tunnel’) between your PC and the VPN server, and the VPN server sends your request to the necessary website. Given the VPN is working correctly, all your ISP will see is that you are connecting to a VPN – it can’t see where the VPN connects you. Web snoopers (government or criminal) can’t see any content because it is encrypted.
A DNS leak occurs when something accidental happens, and the VPN server is bypassed or ignored. In this case, the DNS server operator (frequently your ISP) will see where you are going on the web while you accept he can’t.
This is awful news since it defeats the purpose of using a VPN. The content of your web traffic is still covered up (by the VPN’s encryption), however, the most important parts for anonymity – your location and browsing data – are left unprotected and most likely logged by your ISP.
DNS Leaks Problems
- Inappropriately configured network
This is perhaps the most well-known cause of DNS leakage for users who associate with the web through various networks; for instance, someone who frequently switches between their home router, a coffeehouse’s WiFi, and public hotspots. Before you associate with your VPN’s encrypted tunnel, your gadget must first interface with the local network.
Without the legitimate settings set up, you can be leaving yourself open to data leaks. When connecting to any new network, the DHCP settings (the protocol that determines your machine’s IP address inside the network) can consequently assign a DNS server to deal with your query requests – one which may have a place with the ISP or one that may not be as expected secured. Regardless of whether you interface with your VPN on this network, your DNS requests will bypass the encrypted tunnel, causing a DNS leak.
- Exposed DNS Proxies
Some ISPs have received a policy of forcing their DNS server into the image if a user changes their settings to use an outsider server. On the off chance that changes to the DNS settings are distinguished, the ISP will use a transparent proxy – a separate server that intercepts and redirects web traffic – to ensure your DNS request is sent to their DNS server. This is adequately the ISP ‘forcing’ a DNS leak and attempting to disguise it from the user. Most DNS-leak location tools will want to recognize an exposed DNS proxy similarly to a standard leak.
- Windows 8, 8.1, or 10’s insecure “features”
Windows operating systems from 8 ahead have presented the “Smart Multi-Homed Name Resolution” highlight, proposed to improve web browsing speeds. This sends out all DNS requests to all accessible DNS servers. Originally, this would possibly acknowledge responses from non-standard DNS servers if the favorites (usually the ISP’s servers or those set by the user) neglected to respond. This is terrible enough for VPN users as it enormously increases the occurrence of DNS leaks, however as of Windows 10 this element, naturally, will acknowledge the response from whichever DNS server is fastest to respond. This not just has the same issue of DNS leakage yet, in addition, leaves users powerless against DNS spoofing attacks.
Teredo is Microsoft’s innovation to improve similarity somewhere in the range of IPv4 and IPv6 and is an in-assembled highlight of Windows operating systems. For some, it’s an essential transitional innovation that allows IPv4 and IPv6 to coexist without issues, empowering v6 addresses to be sent, gotten, and understood on v4 connections. For VPN users, it’s, more importantly, a glaring security hole. Since Teredo is a tunneling protocol, it can regularly overshadow your VPN’s encrypted tunnel, bypassing it and thus causing DNS leaks.
You need the greatest possible privacy. The ideal VPN will have underlying DNS leak security, full IPv6 similarity, support for the latest versions of OpenVPN or your preferred protocol, and have usefulness set up to neutralize exposed DNS proxies.