When most people think of cybersecurity, they think of antivirus software, VPNs, and adblockers. These are all effective security measures, but they neglect a critical aspect of any security solution – the Domain Name System (DNS) layer.

Unbeknownst to many, almost all internet queries go through the DNS layer; without it, the internet as we know it wouldn't exist. But, surprisingly, few leverage the available security measures.

This presents a massive gap for attackers to exploit, which can have nasty consequences for you and your business.

It's crucial that you not only understand what the DNS layer is but, more importantly, know how to secure it. Let's find out how.

What is the DNS layer?

In the context of the Open Systems Interconnection (OSI) model, the DNS layer works at the Application Layer (Layer 7), where all DNS queries are handled. The DNS is the unsung hero that helps users translate domain names to their corresponding IP addresses – DNS resolution – to connect to websites and apps.

Imagine if you had to remember all the phone numbers in your contact list – it would be almost impossible. It's far easier to remember the person's name and let your phone do the hard work of connecting your number to theirs, right?

DNS works in a similar fashion, making your user experience on the internet far simpler.

At a high level, to find the domain's IP address, your browser uses the DNS layer to send a DNS query. Your DNS resolver will find the IP address and return it to your device. Only then is a connection made between your device and the website, which then loads onto your browser.

As such, the DNS layer is the foundation of how the internet operates; without it, browsing on the internet would be impossible.

Why is DNS layer security important?

A DNS layer security protocol prevents users from communicating with malicious domains and networks that pose risks at the DNS level – which often do not have built-in security protocols.

When visiting a website, your device will first connect to a DNS server, meaning it's your business's first point of security. Without security measures in place, your device will be allowed to connect with any and every domain on the internet, which can expose you to attackers.

Since the DNS protocol was not designed with cybersecurity in mind, and given its importance in facilitating internet communication, the DNS layer is an attractive target for criminals looking to engage in cyber threats and DNS attacks.

Examples of such attacks include DNS hijacking, DNS spoofing, DNS tunneling, and Distributed Denial of Service (DDoS), all of which can be used to steal sensitive data, disrupt services, and other malicious activities.

DNS attacks are incredibly common. In fact, a 2021 survey found that 89% of all participants had their apps or services disrupted by an attack. Such a high number suggests that almost all businesses will be threatened at some point.

Therefore, to mitigate this as much as possible, it's important to implement adequate DNS security solutions to block harmful DNS connections from occurring in the first place, which will protect your organization.

How do you secure the DNS layer?

Using a customizable DNS resolver can maximize DNS security since it allows you to deploy many effective security measures in one place, such as implementing DNSSEC, DNS filtering, analyzing all your DNS requests, and more. Other DNS security solutions include having multiple DNS servers, updating them regularly, and having backups.

Deploy DNSSEC

Domain Name System Security Extensions (DNSSEC) is perhaps the most obvious DNS layer security solution available.

It adds cryptographic authentication to all inbound and outbound DNS queries. By authenticating all your DNS data, devices and networks are protected from attacks such as DNS spoofing and hijacking, ensuring users are directed to legitimate domains, not malicious websites.

However, this alone will not be enough. You'll also want to incorporate the following measures on this list.

DNS filtering

DNS filtering blocks inappropriate, unwanted, and malicious websites and domains from connecting to your network or device. This is typically done by utilizing blocklists.

These blocklists can be tailored to your needs via a custom DNS resolver. They enable you to block entire categories of websites, such as Social Media, Gambling, and Adult Content, as well as specific domains and platforms.

Since DNS filtering prevents malicious or unwanted domains from being resolved – i.e., communicating with your device or network – harmful or inappropriate IP addresses are blocked from the get-go, ensuring you don't put yourself in danger in the first place.

Analyze your DNS requests

Almost all internet activity goes through the DNS layer. Therefore, analyzing your DNS queries can provide valuable insight.

For instance, suspicious DNS activity and anomalies can often indicate a security breach. As such, continuously analyzing your organization's DNS data will help you quickly detect and respond to this activity.

Many customizable DNS resolvers also give you the option to set alerts that flag suspicious traffic, which can help you act in real time and minimize the impact of a potential attack.

Regular software updates

As with many things in the cybersecurity space, regular updates to the software are key to having secure DNS servers.

Patches and updates often address security concerns that attackers can use to infiltrate your networks and servers. If network protection is your goal, it's best to update them as soon as they're available – even a few days can be the difference between a successful and obstructed cyber attack.

Multiple DNS servers

Having one DNS server upon which your entire DNS is reliant can be dangerous, mainly because you have one single point of failure. If it goes down completely, your organization's entire network and devices will go down with it.

Safeguard yourself from that scenario by having one or more extra servers to fall back on.

Regular backups

It's also important to conduct regular backups to ensure minimal downtime if a server gets compromised. Daily backups are great if you have the capacity for them. However, weekly backups should suffice for most organizations.

Conclusion

The DNS layer is the backbone of the internet, connecting domain names to IP addresses, which we use to browse websites and apps. Despite its importance, it has no security measures in place, which can pose risks to users who may connect to malicious domains without knowing.

Securing your DNS layer can be done in various ways. The easiest solution is to have a customizable DNS resolver that you can personalize to your specific needs, from filtering specific unwanted content to adding cryptographic authentication via DNSSEC.

However, you should use as many security protocols as possible, including having multiple DNS servers, regularly updating them, and backing up your DNS data to ensure a smooth rollback.