DNS is an essential Internet function that enables computers to translate a domain name into an IP address. Without a domain name server, Internet users would have to remember the IP addresses of the websites that they want to access. For this reason, DNS outages severely affect a company’s online presence and reputation. As a result, network administrators always need to ensure that online services are available, secure, and well performing. DNS monitoring enables them to do so.
The main benefits of DNS monitoring is to proactively identify and resolve DNS outages, including security breaches and performance issues. This type of monitoring is not only required for DNS providers, but also for organizations that manage their domain names.
How DNS Works
Let’s take the example of a user who wants to access a specific website, like netbeez.net. The users’ computer queries its local domain name server to obtain the website’s IP address. To perform the resolution, the DNS server, also called DNS recursor, contacts the Root Server(s) associated with the domain netbeez.net. The root server points the recursor to the appropriate Top-Level Domain (TLD) server that manages all domains ending in .net. The TLD server then tells the recursive server to query the Authoritative Server associated with netbeez.net. The Authoritative Server will provide the IP address associated with the domain name netbeez.net. Once the recursive server gets this information from the Authoritative server, it returns the IP address to the client.
Introduction to DNS Monitoring
There are three main methods to monitor a DNS service. Each method provides a very specific set of metrics, and an operational goal. At a high level, we can divide DNS monitoring into the following groups:
- DNS server monitoring – Identify DNS server performance issues and failures with traditional network monitoring tools by monitoring the servers’ resources.
- DNS response time and availability monitoring – Execute synthetic monitoring tests to measure DNS latency, DNS response rate, and user experience.
- DNS infrastructure monitoring – Inspect incoming DNS requests and outgoing DNS responses by inspecting the traffic to the DNS servers.
Importance of DNS Monitoring
Ensuring Smooth Operations
The DNS service is so important that organizations that experience DNS outages risk getting cut off completely from the Internet. An event like this can have major repercussions on a business, negatively impacting customer retention and brand image. To minimize this risk, organizations implement DNS monitoring to ensure performance, security, and availability of DNS services. DNS monitoring tools alert administrators when the response time is high, or there are too many failed lookups. These alerts can help prevent more serious outages. This can be done via periodic DNS queries.
Enhancing Security
DNS hijacking, DNS spoofing, and DNS poisoning are some of the different security threats that afflict a DNS service. Cybercriminals that are seeking to disrupt services and steal private data lead users to malicious websites by altering the DNS records, either on the server or on the clients. A network team equipped with proper DNS monitoring tools is able to detect anomalies that may indicate security threats, allowing them to respond swiftly to protect the network and the users.
Best Practices for DNS Monitoring
Choosing the Right Monitoring Tools
Choosing the right DNS monitoring tool is important for effective DNS management. A robust tool should offer features such as real-time monitoring, alerts for availability and performance degradation, and historical data analysis. It should also support IPv6, such as verifying the existence of an AAAA record for a given domain name. It should also be able to inspect security logs to identify anomalies and unexpected changes.
As a result, DNS monitoring tools come with a range of features. When selecting a tool, network engineers should prioritize uptime monitoring and performance analysis with continuous monitoring checks. Security teams prioritize the detection of security anomalies and DNS configuration issues that could pose at risk a specific domain they manage. In both cases, it’s important to consider an organization’s specific needs, including network size, security requirements, and scalability.
For the remainder of this article, we will focus on features important to network engineers, which is uptime and performance from the end-user perspective of a DNS service.
Implementing Real-time Alerts
Real-time alerts are necessary to monitor a DNS service and enable network engineers to respond promptly to performance degradation issues. Tools like NetBeez periodically run DNS queries from dedicated cloud appliances and end-user devices. The network team configures alert profiles that notify when a DNS query response times exceeds acceptable thresholds, has high failure rates, or completely fails. With these alerts in place, engineers can quickly detect and diagnose the root cause of DNS issues, mitigating potential downtime risks.
The following table lists three different alert profiles that detect the conditions outlined above. The values included in this example are based on best practices recommended by NetBeez, and experience taught us that they are not universally applicable.
| Alert Profile Name | Alert Rule |
| DNS availability | Trigger up-down alert if DNS stops responding after 5 queries |
| DNS failure rate | Trigger performance alert if failed DNS queries is > 1% |
| DNS performance | Trigger performance alert if DNS query time > 30 ms. |
Organizations should set thresholds that match the organization’s baseline traffic patterns and performance metrics. Customizable alerting allows engineers to focus on significant anomalies rather than routine fluctuations. This ensures that the tool provides actionable information and doesn’t cause alert fatigue.
DNS Monitoring Tools
When it comes to DNS monitoring, NetBeez is a network performance monitoring solution that runs DNS synthetic monitoring tests to quickly identify issues. As a troubleshooting tool, it offers comprehensive and real-time visibility into DNS availability and performance from the end-user perspective.
Designed to help network engineers proactively detect and troubleshoot issues, NetBeez is a scalable solution. The server can be hosted in the cloud, or on-premises. Getting started with NetBeez is easy. New users can request a 14 day trial and test its DNS monitoring capabilities in a few clicks.
Step 1 – NetBeez Agents Monitor DNS
NetBeez supports DNS availability and performance checks from multiple monitoring locations including public and private clouds, branch offices, and user endpoints. There are two types of agents available: network agents and remote worker agents.
The network monitoring agents are independent units that can be deployed as Linux packages, virtual machines, docker containers, or cloud images. These agents check that DNS is available from networks where they are installed and that the service is performing properly.
The remote worker agents are lightweight software clients for Windows and Mac operating systems. With those, network administrators can gather a comprehensive set of digital experience data for remote users, including DNS. If a user is having DNS issues, the network administrator has all the contextual information necessary to identify the root cause.
Step 2 – Inspect Real-Time DNS Data and Reports
NetBeez enables network teams to track DNS response times, uptime, and error rates, ensuring that DNS services operate smoothly. This feature helps identify and resolve slow DNS resolution times or failed lookups sometimes even before they affect the end-users. NetBeez also provides insights into DNS performance trends and historical data, allowing engineers to analyze changes in baselines over time and optimize the DNS infrastructure based on usage. NetBeez reporting functionality includes a variety of DNS analytics that organizations review to maintain both performance and uptime within their DNS infrastructure.
Step 3 – Customize Alerts
With NetBeez, network engineers can proactively address DNS issues, enhance uptime, and ensure a seamless user experience. The solution supports customizable alerts profiles so that engineers can set the failure rates or response times that are unacceptable for their SLAs.
The following screenshot depicts an alert profile that triggers if 1% of DNS queries in the last 5 minutes fail. These proactive alerts allow teams to act quickly on potential issues, ensuring reliability and security of DNS services for the entire organization.
Conclusion
DNS monitoring is essential for ensuring the smooth operation and security of an organization’s online presence. By proactively monitoring DNS services, network administrators can detect and resolve performance issues, maintain high uptime, and defend against security threats like DNS hijacking and spoofing. Whether monitoring DNS server performance, response times, or the overall infrastructure, DNS monitoring tools play a crucial role in maintaining a resilient network. With a robust solution like NetBeez, network engineers have the tools needed to troubleshoot and optimize DNS services, delivering a seamless and reliable experience for users. As DNS threats and demands continue to evolve, investing in effective DNS monitoring has become a critical component of any organization’s network management strategy.
