The Domain Name System (DNS) is an essential component of Internet infrastructure and digital communications, allowing users to access websites, send emails, and connect with other online resources. In today’s fast-paced world, businesses rely heavily on the Internet for their daily operations, making DNS service even more critical each year that goes by.
When it comes to managing and monitoring DNS, organizations often turn to DNS reporting, which provides valuable backward-looking insights into the performance, availability, and security of the DNS service. High-quality reporting allows businesses to track metrics, identify potential issues, and ensure the smooth operation of their online presences.
However, relying solely on DNS reporting from external providers can leave organizations with incomplete visibility into the DNS service. While these external vendors offer valuable information, they may not provide a comprehensive view of the service as a whole. This limitation means that organizations may lack crucial insights into DNS performance, reachability, and real-time record security.
That’s where DNS monitoring comes in, allowing organizations to actively monitor the speed, availability, and security of the DNS infrastructure in real time to ensure that it is operating optimally and safely. With DNS monitoring, organizations can go far beyond reporting by configuring tests to identify problems before they occur, providing a proactive approach to keeping their DNS services running smoothly.
This article will describe both the importance of DNS monitoring and the best practices for doing it effectively. We will discuss how DNS monitoring can benefit organizations in terms of performance, availability, and security, and what you should look for when implementing DNS monitoring to stay ahead of potential problems.
Summary of DNS monitoring key concepts
Here is a brief summary of what will be covered in this article.
Definition of DNS monitoring
DNS is a critical component of Internet infrastructure. Any problems with DNS can have a significant impact on how reliably and quickly users and services can connect to network resources.
DNS monitoring is the process of tracking and analyzing the availability, performance, and security of DNS servers/services, resource records, and related systems. Monitoring is a critical part of ensuring that DNS is always functioning as intended and in detecting any anomalies or suspicious activity that could indicate a cyber attack.
Why is DNS monitoring important?
DNS translates human-readable domain names into IP addresses that computers can understand, a process that involves billions of requests every day and ensures that the Internet is accessible to everyone. According to the DNS Observability Project, more than 1 trillion DNS queries were reported in a three-month period. Such a staggering volume of requests underscores the criticality of DNS and its potential to impact business operations and customer experience when problems occur.
According to the 2022 Global DNS Threat Report, 73% of organizations agree that awareness of the importance of DNS security remains high and is a concern. Despite that, however, 25% of organizations still don’t collect or analyze their DNS traffic. The report also mentioned that all DNS-based attacks increased in 2022 compared to 2021 (as shown in the image below): Seven in ten organizations have experienced application downtime due to DNS attacks.
These statistics highlight the need for proactive DNS monitoring so that organizations can ensure that DNS is functioning as intended. Monitoring DNS-based attacks can help prevent common cyber-threats such as DNS floods, DNS cache poisoning, and DNS hijacking attacks. By monitoring DNS performance, organizations can address issues related to DNS mapping, micro-outages, DNS latency, and DNS server availability.
Here is a summary of some important reasons why you should consider DNS monitoring in your organization.
- Availability: Monitoring can help ensure that DNS servers are always available, so users have access to websites and online services.
- Security: Unfortunately, DNS-based attacks are becoming increasingly common. DNS monitoring can help identify and prevent cyber attacks before they cause damage or compromise sensitive data.
- Performance: Poor DNS performance can impact the user experience, a problem that monitoring DNS can help identify and resolve, avoiding issues such as high latency and micro-outages.
- Accuracy: DNS monitoring can help ensure the accuracy of DNS record configuration. DNS configuration issues, such as incorrect or outdated DNS records, can lead to the unavailability of a site or service, impacting users.
- Visibility: DNS monitoring provides visibility into DNS traffic and usage patterns, which can help organizations optimize their DNS infrastructure. Organizations can see usage patterns, identify potential problems, and optimize DNS configuration for better performance and efficiency.
- Early Detection: DNS monitoring offers a proactive approach to identifying response time anomalies and directly observing DNS servers. It enables early detection of potential problems, such as DNS misconfigurations, server failures, and suspicious DNS activities, which facilitates fast responses and minimizes mean time to repair (MTTR). This capability ensures the timely mitigation of DNS-related incidents, reducing their impact and promoting smoother operations overall.
DNS monitoring must-haves: Configuration
Proper DNS monitoring starts with proper configuration. In this section we’ll discuss some must-haves related to configuration, including zone transfers and various facets of DNS record verification.
A DNS zone transfer is a critical process that involves copying a complete zone file from one DNS server to another. Zone transfers enable DNS servers to stay updated with the latest DNS record changes and ensure data consistency across DNS servers.
However, zone transfers can cause performance issues and be a potential point of vulnerability if not configured correctly. Monitoring DNS zone transfers updates and ensuring completion is crucial for detecting any issues that may arise during the process, including unauthorized zone transfers, zone file corruption, and transfer failure, which can lead to DNS downtime and negatively impact the user experience.
DNS record verification
DNS record verification helps ensure the authenticity of the records that support domain resolution, ensuring they have not been misconfigured or tampered with by attackers. Here are some of the aspects you should be able to check when monitoring DNS records.
- IP addresses: This type of DNS monitoring test involves verifying that the IP address returned after a DNS lookup matches the expected IP range. With a DNS monitoring solution, you can set up tests and alerts to trigger when an IP address mismatch occurs, allowing you to quickly take action to mitigate any potential security threats.
- DNS propagation: DNS propagation refers to the time it takes for DNS changes or updates made to a domain’s DNS records to propagate or spread across the DNS network, ensuring that the updated information becomes globally accessible. Monitoring this process is also crucial to ensure that updated DNS records have been successfully propagated globally, as any delay or failure could leave DNS performance at risk. This type of testing should be supported by a globally distributed, multi-server monitoring infrastructure for the most accurate visibility.
- DNS delegation: One essential test for DNS monitoring is to verify DNS delegation, which ensures that the name server acting as a parent (e.g., com) has the correct zone to be delegated (e.g., catchpoint.com) and returns an accurate response. This test traces the DNS delegation process and is critical to ensuring the reliability and availability of the DNS system.
- NS records and root servers: It is vital to monitor NS records to ensure that no unauthorized changes have been made to the primary and backup name server records and to verify that they respond with the correct information. Verification of the root hints file, which contains the names and IP addresses of all root servers, is also a critical component to consider monitoring.
- DNSSEC configurations: There’s no “free lunch” in the world of technology: Using DNSSEC greatly enhances security, but it can impose a performance penalty on a system. For this reason, it is essential to have a good read on DNSSEC configurations to ensure that DNSSEC doesn’t impose any more performance burden than absolutely necessary.
DNS monitoring must-haves: Dealing with attacks
DNS attacks can significantly impact the performance and availability of DNS services. Regularly monitoring DNS can help both with preventing these attacks (by increasing awareness to enable proactive action) and more quickly responding to these attacks. This will not only ensure the availability and reliability of DNS services but also help protect the organization’s brand reputation and prevent financial losses.
During a DNS flood attack, a large volume of DNS queries is sent to the servers, overwhelming them and causing them to either stop responding or slow down the query response time. This results in end users experiencing delays in accessing the requested web resources, resulting in frustration.
It is crucial to constantly monitor DNS traffic across multiple locations and devices to quickly detect any unusual traffic patterns or any sudden spike in traffic that could indicate a potential DNS flood attack. Early detection provides organizations with a chance to take proactive measures to mitigate the impact of the attack, such as implementing failover strategies, traffic filtering, and other security measures.
DNS spoofing / cache poisoning
DNS spoofing or cache poisoning is a type of attack where attackers inject false DNS information into a DNS resolver’s cache. This will cause the resolver to return incorrect IP addresses for a domain name, thus redirecting traffic to a malicious site.
To prevent this, it’s crucial to monitor DNS transactions and verify that the DNS responses are valid and accurate. For example, by using an appropriate DNS monitoring tool, it is possible to configure tests that can set off alerts as soon as the IP address returned after the DNS lookup is not within the expected range, thereby ensuring that the website is not a victim of DNS spoofing or cache poisoning.
DNS monitoring must-haves: Performance
While having multiple name servers associated with a domain name can provide redundancy and ensure continuous website availability, it is crucial to verify that all name servers are performing optimally and delivering the expected results. For example, it would be beneficial to monitor whether the closest DNS server is being provided when querying your domain from different locations worldwide. Additionally, it is necessary to continuously monitor DNS to identify and resolve any latency issues as they arise, ultimately improving the end-user experience.
Geo-based DNS routing
Geo-based DNS routing is an essential technique used to reduce the latency involved in resolving a domain name by mapping end-users to DNS servers based on their locations. This approach helps avoid the use of distant DNS servers, which can cause increased latency.
The process of mapping end-users to DNS servers based on geolocation varies depending on your managed DNS provider. With proper DNS monitoring, you can set up tests along with alerts to ensure that this process is working correctly.
Latency in DNS is a key factor in overall response time, and it can quickly accumulate at any stage of the DNS resolution process, resulting in a negative impact on the user experience. As we mentioned earlier, DNS latency can be affected by several factors, such as the load on recursive servers, available network capacity, latency between top-level domain (TLD) and root servers, cache misses, geographic distance, DNS flood attacks, and more.
There are several approaches you can take to reduce DNS latency, including choosing a fast DNS provider, implementing DNS anycast, using CDNs to cache and deliver DNS responses closer to end users, enabling caching, and minimizing the number of CNAME records.
You should have a monitoring solution in place that allows you to set up tests to monitor the availability and performance of each of the name servers assigned to a domain. It’s also important to monitor not only the CPU and memory of the name servers but also the disk I/O and network throughput under different levels of query load.
DNS plays a critical role in maintaining the availability and accessibility of online services and will continue to be an essential service for years to come. That’s why many organizations recognize the importance of DNS and the need for continuously monitoring critical aspects of their DNS infrastructure to prevent potential security breaches and ensure service availability.
When it comes to monitoring DNS, two crucial aspects to focus on are DNS configuration and DNS attacks. In terms of configuration, monitoring DNS zone transfers is essential for ensuring regular updates, detecting unauthorized transfers, and identifying issues like zone file corruption or failed transfers. Additionally, DNS record verification plays a vital role in maintaining the accuracy and integrity of DNS records, including monitoring IP address mismatches and DNS propagation to ensure global accessibility of updated records. DNS delegation, NS records, root servers, and DNSSEC configurations are also important elements to consider monitoring.
In terms of DNS attacks, It is important to note that these are on the rise and pose a significant threat to organizations. These attacks can compromise the security of the DNS infrastructure, resulting in brand damage, financial loss, and lost productivity.
Assessing performance is also an essential part of DNS monitoring. Key considerations in this area include geo-based DNS routing, watching DNS latency, and monitoring DNS servers.
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