Linux Commands

OpenDNS vs GoogleDNS

Google Domain Name System (Google DNS) and Open Domain Name System (Open DNS) are free and publicly available servers that you can use to browse securely online. The main feature of a DNS is an increase in browsing speed. A DNS also safeguards web browsing via a fast, wide network of DNS servers. The use of a DNS (Domain Name Server) is essential for accessing the Internet. When you connect to the Internet, the DNS that is being used is that of your Internet Service Provider (ISP), which could be slow, increase your surfing time, and affect your browsing. The reason for this is that your ISP might not have the fastest DNS servers.

Importance of a DNS

A DNS is a fundamental feature for Internet users. Having a bad DNS can prove unsecure and dangerous, and you should always do your research before getting a DNS server. Sometimes, you might be sent to another website instead of the one you wanted to go to because of the DNS. Translating domain names to their respective IP Addresses is the main job of a DNS. After you have connected to the Internet, your browser will send a request to the DNS servers. The DNS servers will send back the IP addresses by getting the domain names. So, when you search for a domain name (like your browser asks your DNS the related numerical IP address (like

DNS and Caches

A domain needs to be authorized on at least one name server to be valid. There are a lot of different name servers spread across the Internet that help the Internet to function. The Domain Name System encourages DNS cache servers for increased reliability and higher regulation. The duty of a DNS cache server is to store the requests related to DNS queries for a very long time. A DNS cache server’s main job is to store DNS query requests for the time-to-live period. The domain name record contains the time-to-live record. The primary purpose is to tell the domain name for a unique time period. The caches of these DNS servers use looping programs and calculations to improve query performance.

Restrictions of ISP Name Servers

The DNS servers of your ISP are located near to your computer’s location. In this case, the network routes from the server to your system are short, which means that the response time from these DNS servers will be faster than third-party servers. A drawback in using these DNS servers is that ISPs normally have some DNS-blocked requests. When this happens, they just redirect the traffic to other warning pages. This usually happens when you open sites that are either Torrent sites, other suspicious sites, or banned sites. This may feel like you are being censored or limited. However, using a public DNS, Open DNS, Google DNS, and other DNS servers can show you a way around these restrictions so that you can eventually open and access these sites.

Options for DNS Servers

This article is about the difference between Google DNS and Open DNS, so we will only talk about the preferred and alternate IP addresses of these DNS services.

Google DNS

  • Preferred:
  • Alternate:

Open DNS

  • Preferred:
  • Alternate:

Testing the Resolution Speed

If you are operating in a Linux Operating System, you will need to use dig to check the query time of the search results to determine the speed of the DNS server response. I tested the Google DNS and Open DNS for the results of Here are the results that I got, which show the query time, as well:

$ time dig @

$ time dig @

The following result shows the query time and how much time it took for the DNS to respond. The lower number for Google DNS shows that it is a faster DNS and will show the results faster.

You can see the query times for yourself and decide which DNS you would like to use, depending on your location. Another method is to use Google DNS server ads for your primary server and Open DNS server ads for your secondary server. This can be achieved if you update your /etc/resolv.conf file to the following:

People also often think that the DNS will affect their Internet speed. However, this is wrong, as a DNS has no say in your Internet speed. The speed of your Internet connection is only determined by your ISP. However, using the Google DNS and Open DNS may provide a slight advantage in name resolution and will avoid domains that contain malware and would expose your data to phishing and pharming. This will also help with websites that have multiple images and advertising pictures, scripts, etc., that need to load quickly to solve multiple domains.

DNS Flushing

Another important task you must know to do is flushing your DNS cache. It is highly recommended that whenever you change the name of your server, you also immediately flush your DNS cache. To do so, first, restart the network manager using Linux.

$ service NetworkManager restart


Namebench is a software program that hunts down the fastest DNS servers that your computer can use. It is a complete software program that uses information from your web results and browser history to show you the best DNS servers available for your computer. Namebench is free to use for Windows, Apple, Linux, and other operating systems. The Namebench software is free of cost and does not cause damage or introduce malware to your system.


Google DNS and Open DNS are both free sources that will improve your Internet security and browsing speeds. You must check out both resources to determine the effect that each DNS service has on your browsing speeds, as well as how each service improves your browsing experience.

About the author

Younis Said

I am a freelancing software project developer, a software engineering graduate and a content writer. I love working with Linux and open-source software.