Every online interaction starts with a DNS query, and the availability and integrity of your services depend on the security of your authoritative DNS. An attack on your recursive DNS can disrupt traffic flow, impacting revenue generation and customer service.
In this blog post, we’ll discuss best practices to secure your authoritative DNS servers and ensure smooth traffic flow to the right destination.
How to secure your authoritative DNS server and domains
Use multiple redundant and diversified servers.
To reduce the impact of an outage, it’s beneficial to use multiple authoritative DNS servers from different network providers, data centers, and physical locations. This way, if any one of these components is impacted in an outage, your domain remains available.
Do capacity planning and manage utilization.
For large authoritative DNS deployments with many queries, managing capacity against current and future query loads helps you avoid cascade failure from a localized outage or maintenance period.
Separate your authoritative DNS servers from recursive/resolver servers.
If you host your own DNS servers, it’s very tempting to use the same set for both. However, doing so means that attacks on your public servers could affect your internal resources and your ability to restore service.
Separate servers for internal and external zones.
When you put your internal resource records on your authoritative servers used for zones on the public Internet, it gives attackers the opportunity to remotely enumerate your internal network.
Sign your zone with DNSSEC.
By signing your zone, you use cryptography to verify that the response originated from your authoritative server. This helps prevent various attacks like cache poisoning and aids in detecting other attacks such as network hijacking.
Isolate your DNS servers with a DMZ network.
Isolate your authoritative DNS servers and your management traffic to them from the Internet using a demilitarized zone (DMZ) and a restrictive set of firewall rules.
Harden your DNS servers.
Protect your DNS servers by disabling unnecessary services, applying patches, and regularly scanning for vulnerabilities. This helps ensure that your servers’ operating systems and application software are resilient against potential attacks.
Update your DNS software.
Keep your DNS software up to date to protect against vulnerabilities. By regularly applying security patches and bug fixes, you can mitigate the risk of them being exploited.
Lock your domain.
Locking a domain with the registrar adds a second step when you change the registrar or authoritative nameservers for the domain. This helps you to detect and block domain hijacks.
Manage zone TTLs.
Achieve a balance between query load and updated DNS records by setting appropriate Time-To-Live for the zone and its resource records. Take into consideration factors like record update frequency and the failover time to a new server for optimal performance.
Use a non-public publisher server.
By publishing zone changes to a non-public authoritative server, which then publishes to your public-facing authoritative servers, it reduces the ability of an attacker to compromise and alter your zone information.
Restrict zone transfers.
Protect your DNS zones from being copied verbatim by reconnaissance tools and other unauthorized access attempts by limiting zone transfers to authorized servers. You can do this by implementing IP access control lists and using secure zone transfer mechanisms, such as TSIG or SIG(0), to enhance security.
Log and monitor your DNS servers.
Monitor your DNS servers with a Host Intrusion Detection System (HIDS) and a log management system. Analyze logs to detect and respond to any malicious activity or security breaches promptly.
In conclusion, hardening your DNS servers and domains is a crucial aspect of an overall cybersecurity program and keeps your user traffic going to the correct destination. By implementing measures at the network, server, software, and zone, you can significantly reduce the risk of a successful interruption of your services.
Your services — always online, always available
Our globally recognized authoritative DNS service is designed to secure your online presence and provide uninterrupted access to your digital infrastructure.
Experience the peace of mind that comes with over a decade of reliable service, backed by our 100% uptime guarantee. Our high-performance network ensures rapid query responses, while our service-level redundancy adds an extra layer of reliability.
With Vercara, you get industry-leading resolution speed, scalable DDoS mitigation, and a suite of features that include health checks and instant worldwide zone propagation.
Don’t leave your DNS security to chance. Choose Vercara for authoritative DNS resolution that promises near-zero response times and 100% availability. Speak to sales today.
