What is DNS Monitoring?
DNS monitoring involves automatically and continuously checking your domain’s address records every few minutes. It ensures that when someone types your URL, they reach the correct server.
Why is DNS monitoring important?
DNS is a foundational component of internet reliability and security, as per IETF RFC 1034 (an organisation that defines and maintains the core technical standards of the Internet). Misconfigurations or malicious changes can lead to downtime, data theft or large-scale DDoS attacks.
Additionally, effective DNS monitoring helps organisations safeguard infrastructure and comply with the following best practices defined by ICANN (Internet Corporation for Assigned Names and Numbers) and the IETF (Internet Engineering Task Force).
- Ensure availability: Prevent user-facing outages by detecting erroneous or missing records before they impact service.
- Maintain trust: Domain theft or poisoning erodes customer confidence and brand reputation.
- Enhance security posture: Spot early signs of DNS-based attacks like cache poisoning or unauthorized zone transfers.
- Meet compliance: Many regulations require strict domain control and incident logging.
Live examples of why DNS monitoring is crucial
Akamai DNS DDoS mitigation (September 21, 2023): Akamai’s DNS infrastructure absorbed a record-breaking DNS-based DDoS attack, peaking at over 500 million queries per second, without major customer impact.
Cloudflare DNS Outage (July 2024): A faulty update to Cloudflare’s DNS resolver software led to global resolution failures for 30 minutes.
How DNS monitoring works
A DNS monitor queries authoritative name servers at regular intervals, typically every 5 to 15 minutes to validate record integrity and TTL (time-to-live) consistency.
Below are the key record types to monitor and why each matters:
- A record: Maps a domain to an IPv4 address. Monitoring detects IP changes or missing records that can cause site unavailability.
- CNAME record: Aliases one domain or subdomain to another hostname. Tracking CNAMEs catches misconfigurations when alias targets change or are removed.
- MX record: Specifies mail exchange servers for a domain. Alerting on MX record changes prevents email-delivery failures and spam vulnerabilities.
- NS record: Delegates a zone to authoritative name servers. Monitoring NS records ensures delegation remains correct and guards against unauthorised transfers.
- SOA record: Defines zone metadata and serial versioning. Watching serial increments verifies that zone updates propagate properly.
- SRV record: Locates specific services (e.g., SIP, LDAP) by hostname and port. Monitoring SRV records ensures service endpoints remain reachable and correctly prioritised.
These detailed checks ensure every critical DNS component stays accurate and secure, reducing downtime and guarding against attacks.
Never miss DNS monitoring alerts with ilert
ilert connects with 130+ solutions, including DNS monitoring tools. ManageEngine Site24x7, PRTG (Paessler), HetrixTools, Catchpoint, and other platforms help you detect DNS-related issues. Here are a few other solutions and examples of how you can set up DNS monitoring with them.
Cloudflare monitors your DNS zones for changes and abnormalities, such as unexpected record edits or DDoS spikes. When an issue is detected, ilert instantly notifies your team via preferred channels so you can address problems before customers notice.
Google Cloud Monitoring collects DNS health metrics and flags resolution errors in Cloud DNS. By sending those alerts into ilert, you get on-call scheduling, ensuring DNS failures don’t slip through the cracks
Amazon CloudWatch & Amazon SNS tracks Route 53 health checks and publishes notifications to SNS. ilert subscribes to those SNS topics, turning DNS health events into actionable alerts that follow your escalation policies.
Microsoft Azure Alerts watches Azure DNS for performance or configuration issues and issues alerts in real time. With ilert, those alerts route directly to the right on-call engineer via SMS, email, or collaboration tools.
Frequently asked questions
Q: What is DNS monitoring?
Continuous validation of DNS records to ensure accurate domain resolution and prevent security or availability issues.
Q: Why is DNS monitoring important for security?
It protects against domain hijacking, cache poisoning, and DDoS amplification by detecting malicious or unauthorised record changes.
Q: Which DNS records should be monitored?
At a minimum, monitor A, CNAME, MX, NS, SOA, and SRV records for critical domains.
Q: How often should DNS records be checked?
Every 5-15 minutes for high-traffic or security-sensitive services; 30-60 minutes for lower-risk domains.
Q: Can DNS monitoring prevent domain hijacking?
Early detection of unauthorised changes reduces the window for hijacking, but comprehensive security also requires registrar locks and multi-factor authentication.
