OpenDNS is a widely used tool that provides an array of services, including domain name system (DNS) services and phishing protection.

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OpenDNS is a widely used and highly regarded cybersecurity tool that provides an array of services, including domain name system (DNS) services, phishing protection, and content filtering. This glossary article will delve into the intricacies of OpenDNS, its functionalities, and its role in cybersecurity.

OpenDNS, now owned by Cisco, was initially launched in 2006 as a company that provided DNS resolution services. Over the years, it has evolved into a comprehensive cybersecurity solution that protects users from online threats and provides a safer and faster internet experience.

Understanding DNS

The Domain Name System (DNS) is a fundamental component of the internet that translates human-readable domain names into numerical IP addresses. This translation is crucial because computers and other devices connected to the internet identify and communicate with each other using these IP addresses.

When you type a URL into your web browser, a DNS server is queried to find the corresponding IP address. Once the IP address is identified, your browser can then load the requested webpage. This process is often referred to as DNS resolution.

The Role of OpenDNS in DNS Resolution

OpenDNS provides DNS resolution services, but it does so with a twist. Unlike traditional DNS servers that simply translate domain names into IP addresses, OpenDNS adds a layer of security by checking the requested domain against its database of known malicious websites.

If the requested domain is found in this database, OpenDNS will block the connection, protecting the user from potential threats such as phishing attacks or malware. This proactive approach to security is a key feature that sets OpenDNS apart from conventional DNS services.

Advantages of Using OpenDNS for DNS Resolution

One of the main advantages of using OpenDNS for DNS resolution is its speed. OpenDNS operates a network of DNS servers around the world, which allows it to provide faster and more reliable DNS resolution services than many Internet Service Providers (ISPs).

Another advantage is the added layer of security that OpenDNS provides. By blocking connections to known malicious websites, OpenDNS helps protect users from a wide range of online threats. This makes it a valuable tool for both individual users and organizations looking to enhance their cybersecurity.

Phishing Protection

Phishing is a common online scam where attackers attempt to trick users into revealing sensitive information, such as passwords or credit card numbers, by pretending to be a legitimate entity. OpenDNS offers robust protection against phishing attacks.

OpenDNS maintains a regularly updated database of known phishing websites. When a user attempts to visit one of these websites, OpenDNS blocks the connection, preventing the user from falling victim to the phishing scam.

How OpenDNS Identifies Phishing Websites

OpenDNS uses a combination of machine learning algorithms and threat intelligence feeds to identify phishing websites. These algorithms analyze various characteristics of websites, such as their domain name, hosting provider, and the content on the site, to determine if they are likely to be used for phishing.

Once a website is identified as a potential phishing site, it is added to the OpenDNS database. This database is constantly updated to ensure that users are protected from the latest phishing threats.

The Benefits of OpenDNS Phishing Protection

The primary benefit of OpenDNS's phishing protection is that it provides an additional layer of security for users. By blocking access to known phishing websites, OpenDNS helps prevent users from inadvertently revealing their sensitive information to attackers.

Another benefit is that OpenDNS's phishing protection is easy to use. Users do not need to install any additional software or hardware to benefit from this protection. All they need to do is configure their device to use OpenDNS's DNS servers, and they will automatically be protected from known phishing websites.

Content Filtering

Content filtering is another key feature of OpenDNS. This feature allows users to block access to specific types of content, such as adult content, social media sites, or video streaming services. This can be particularly useful for parents who want to control what their children can access online, or for businesses that want to limit what their employees can access during work hours.

OpenDNS's content filtering is highly customizable. Users can choose from predefined categories of content to block, or they can create their own custom categories. This flexibility allows users to tailor the content filtering to their specific needs.

How OpenDNS's Content Filtering Works

OpenDNS's content filtering works by checking the requested domain against its database of categorized websites. If the domain is found in a category that the user has chosen to block, OpenDNS will prevent the connection.

This process is transparent to the user. When a site is blocked, the user will simply see a message in their browser indicating that the site cannot be accessed. This makes OpenDNS's content filtering easy to use, even for users with little technical knowledge.

The Benefits of OpenDNS's Content Filtering

The main benefit of OpenDNS's content filtering is that it gives users control over what content can be accessed from their network. This can help protect children from inappropriate content, prevent employees from wasting time on non-work-related sites, and even help users avoid distractions when they need to focus on work or study.

Another benefit is that OpenDNS's content filtering is cloud-based, which means it can be managed from anywhere. This makes it a convenient solution for parents or businesses that need to manage content filtering for multiple devices or locations.


OpenDNS is a powerful cybersecurity tool that offers a range of features, including DNS resolution services, phishing protection, and content filtering. By adding a layer of security to the DNS resolution process, OpenDNS helps protect users from a wide range of online threats.

Whether you're an individual looking to enhance your personal cybersecurity, a parent seeking to protect your children from inappropriate content, or a business aiming to secure your network, OpenDNS offers a comprehensive solution that is both effective and easy to use.

Author Sofie Meyer

About the author

Sofie Meyer is a copywriter and phishing aficionado here at Moxso. She has a master´s degree in Danish and a great interest in cybercrime, which resulted in a master thesis project on phishing.

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