DNS Monitoring: Why is it important?

The Domain Name System (DNS) is a foundational component of the internet, translating URLs into IP addresses. As internet infrastructure grows in complexity, so does the importance of robust DNS operations. DNS monitoring has become an essential component of network monitoring solutions given the need for high application and service uptime, and the rise in DNS security-related threats. Organizations that rely heavily on online platforms can’t afford to overlook the efficiency and security of their DNS systems. This article describes DNS monitoring and DNS server monitoring, DNS-related monitoring challenges

What is DNS Monitoring?

DNS monitoring is the process of constantly checking DNS servers and records to ensure that they are resolving to the proper IP addresses. This includes keeping track of the performance, availability, and overall health of the DNS infrastructure. It can notify administrators of concerns such as excessive response times, unsuccessful DNS lookups, and DNS poisoning assaults, which could signal a DNS configuration issue or an active security threat.

How does it work?

The DNS monitoring process works by sending automated requests to the desired DNS server and checking the results for a specific domain name. The most common use case is querying the DNS server with a URL and checking the returned IP address returned in the A Record or AAAA Record.

The desired response for those queries is the correct IP address corresponding to the used URL. For example, when checking the URL google.com, we are looking for a response that includes IP 172.217.23.238.

When the correct IP is received no further action is taken and the monitoring continues. When a different one is returned, the monitor starts what is called a DNS incident and starts alerting according to the on-call calendar.

Why is DNS Monitoring important?

An effective system of DNS monitoring is critical to the reliability of your website, as well as the security and trust of your users. Because the DNS is a popular target for hackers, it’s important to keep a close eye on any malicious attacks on your domains and services. Common attacks include:

• DNS Poisoning. When a hacker inserts their own false information into your DNS cache, it could be used to reroute users to a spoofed version of your website or collect their private data, such as credit card numbers.
• DDoS (Distributed Denial of Service) and DoS (Denial of Service) Attacks. When either one (DoS) or multiple (DDoS) computers attempt to crash a website or service due to excessive requests.

Without DNS monitoring, your website and its users are more susceptible to the above attacks, which can lead to significant issues like unplanned downtime, unhappy users whose private information could be compromised, and ultimately lost revenue and a bad brand reputation.

DNS monitoring is critical to maintaining the credibility of your servers and avoiding security breaches. It’s equally important to the safety of your users as it is the safety and security of your websites and services.

What are the main benefits and drawbacks of DNS monitoring?

Benefits

• Automated with regular frequency: DNS monitoring can run every minute, every hour, 24 hours a day, 7 days a week, the whole year. It’s a fully automated script and once set it needs little to no maintenance, while still providing the same valuable information.
• Simple to set up and use: DNS monitoring can be set up in minutes while providing the availability information right from the start.
• Global testing: It allows for testing from different endpoints around the world. This allows for distinguishing regional errors from incidents affecting all users and allows for optimization for a global audience.

Drawbacks

Limited incident cause reporting: DNS monitoring lacks the information that could answer why any issues happened. Since it only monitors the final output and not the actual workings of the DNS settings. To get a better idea about the root cause, application performance management (APM) or a log management tool needs to be used.

How to monitor DNS?

Monitoring DNS efficiently requires several critical activities:

• Regularly Checking DNS Resolution: Ensuring that your domain names are resolving to the correct IP addresses without undue delay.
• Tracking DNS Server Performance: Monitoring the response times and availability of your DNS servers.
• Validating DNS Records: Regularly verify that all your DNS records (such as A, AAAA, MX, and TXT records) are accurate and have not been tampered with.
• Setting Up Alerts: Configuring alerts for any anomalies or issues detected during monitoring to allow for immediate action.

Challenges in DNS Monitoring

DNS Monitoring is undeniably essential, but it isn’t without its challenges. As DNS traffic has grown exponentially, and as the types and sophistication of threats have evolved, the demands on DNS monitoring tools and methodologies have amplified. Below are some of the common challenges faced by NetOps professionals in DNS monitoring:

• Scale and Complexity: The sheer volume of DNS queries processed daily can be overwhelming. Handling and analyzing this vast amount of real-time data demands powerful tools and methodologies.
• Diverse and Evolving Threat Landscape: Modern cyber threats are continuously evolving, requiring monitoring tools to be adaptable and always up-to-date. Threats like DNS tunneling, where malicious data is encapsulated in DNS queries, are hard to detect without advanced analysis capabilities.
• Data Fragmentation: In larger organizations, DNS data can be scattered across various servers, regions, and networks. Aggregating and making sense of this data is crucial for a holistic understanding of the DNS landscape.
• False Positives and Alarm Fatigue: Not every anomaly is a genuine threat. Filtering out noise and avoiding false positives is crucial. Too many irrelevant alerts can lead to alarm fatigue, causing genuine threats to be overlooked.
• Lack of Historical Context: Without a historical view of DNS data, it’s challenging to discern patterns, understand anomalies, or plan for future capacity.

Conclusion

To sum it up, DNS monitoring should be an essential part of any organization’s security strategy. By detecting and preventing attacks, it helps protect the enterprise’s infrastructure and online presence. In addition, DNS monitoring also improves the performance and reliability of web-based applications. As such, it is an important tool that companies should consider using.