What is a DNS firewall?

DNS attacks are on the rise. According to a global 2021 DNS security survey conducted by the International Data Corporation (IDC), 87 percent of organizations disclosed having their apps and services disrupted by DNS attacks in the past year. Nearly all malware (91 percent) uses DNS services to build attacks. Whether you’re an enterprise organization, small business, or home internet user, these findings form a clear picture: traditional cybersecurity measures no longer offer the protection you need. DNS security is an essential tool.

We’ve written extensively on the importance of protective DNS measures. Today, we’ll explore a critical element of DNS security—the DNS firewall.

What is a DNS firewall?

In short, a DNS firewall is a protective barrier that monitors and filters network traffic, preventing a user from accessing malicious web content. It sits at the application layer and applies intelligence threat feeds to the DNS protocol. Unlike traditional firewalls, a DNS firewall is better suited to protect users in end-to-end encryption communication. As with other protective DNS measures, this feature is used to block access to dangerous sites and defend a user’s private data from malicious actors.

How does a DNS firewall work?

A DNS firewall works by filtering network traffic through DNS endpoint services. Each DNS query is directed through the nameservers of your firewall provider, where the request is measured against a list of acceptable and unacceptable locations. If a site is suspected to be a danger, the query is denied and the user will be rerouted to safety. If a site is clean, the user’s request is granted. 

Many DNS security providers use static threat feeds that must be updated frequently, though to protect against zero-day threats, artificial intelligence tools are highly recommended. DNSFilter prioritizes AI threat protection for real-time domain analysis to ensure that a user’s DNS firewall stops threats as early as 6 days ahead of competitor feeds. Considering that nearly 4 million new domains are registered each day, a DNS firewall is only as secure as the threat feed it checks is up-to-date.

What features does a DNS firewall offer?

DNS firewalls have many advantageous features, from DNS filtering to operational speeds that won’t slow your network. Let’s take a look at a few properties of DNS firewalls:

DNS Caching

DNS responses are cached, thereby conserving bandwidth. Users will be able to receive more data thanks to more bandwidth, making their network more efficient. 

In addition to bandwidth savings, DNS caching provides query resolution in the blink of an eye. Thanks to the DNS firewall, lookups can be completed more quickly.

Response Rate Limiting (RRL)

DNS firewalls offer strong protection against Distributed Denial-of-Service (DDoS) attacks through rate limiting. Since DDoS attacks are designed to overwhelm a network, rate limits set by the DNS firewall prevent too many queries from hitting your DNS server at any given moment. As a result, you’re protected against unwanted downtime at the hands of cyber criminals.

Serving Stale Content

Avoid latency and unplanned outages in the event that an authoritative nameserver can’t be reached. By using stale DNS data, you continue to serve content as opposed to waiting for a synchronous backend revalidation. This feature ensures that your DNS is always online. High availability and reliability are no-brainers.

Why does my organization need a DNS firewall?

In addition to bandwidth savings, downtime protection, and availability, DNS firewalls provide other benefits. They block advanced threats like malware, ransomware, phishing, and zero-day threats by using robust threat intelligence. They also offer greater network visibility, which in turn will help your team better manage threats and isolate infected devices in the event of a breach. Even if your DNS servers go down, for any reason, your DNS firewall will ensure that your website will remain online by serving stale content until the situation is resolved. You have greater control over the traffic that hits your site, and your organization can even hide your origin IP addresses behind those of your DNS firewall provider’s so that attackers don’t know to target you.

How do I implement a DNS firewall?

While the details surrounding the purpose and performance of DNS firewalls can sound tricky, this part is easy! Coding isn’t necessary to implement a DNS firewall, and the utility can be set up in minutes. Simply ask your DNS security provider to deploy your DNS firewall. Don’t have a provider? Try us out!