CloudfloorDNS Blog

12-11-2023 – Significance of Secondary DNS

By: Jeff Cronstrom, CloudfloorDNS

Significance of Secondary DNS

Secondary DNS (Domain Name System) is important for several reasons, primarily related to ensuring the reliability, availability, and resilience of your domain name services. Here are some key reasons why implementing Secondary DNS is so crucial.


Redundancy and High Availability

Secondary DNS provides redundancy by having a backup DNS network to a primary DNS configuration. In the event that the primary DNS network becomes unavailable due to hardware failure, network issues, or other reasons, the secondary DNS network can take over, ensuring that your domain names remain accessible and online. This redundancy helps minimize downtime and ensures high availability for your online presence and services.

Load Distribution

Secondary DNS can also help distribute the query load evenly across multiple DNS platforms which reside on different networks, AS’s (autonomous system) and geographical regions. This is especially important for high-traffic websites or services that need to be online and available 24x7x365 with significant uptime (99.99%+). By spreading the DNS queries across multiple servers clusters, you can prevent overloading a single network or region, which can help prevent slow response times or potential service outages.

Geographic Redundancy

If you have a global audience, using a secondary DNS network in different geographic locations can help improve the performance and reliability of your domain name resolution globally. Users from various regions and countries will be directed to the nearest and most responsive DNS server, reducing latency and providing the best user experience.

Protection Against DDoS Attacks

Secondary DNS can provide extra protection against Distributed Denial of Service (DDoS) attacks. With multiple DNS servers in different locations on different networks, it becomes more challenging for attackers to overwhelm your DNS infrastructure. It adds a layer of defense by distributing the attack traffic across multiple networks.

Maintenance and Updates

A Secondary DNS network can be used to aid maintenance or updates on the primary DNS network without causing disruptions. During maintenance, you can temporarily switch to the Secondary DNS platform to continue serving DNS requests while work is performed on the primary server network.

DNS Zone Transfer

Secondary DNS servers regularly synchronize with the primary DNS server through a process called zone transfer and it’s triggered from a change to the SOA (Start of Authority) serial number on the Primary DNS Network. This ensures that they always have up-to-date DNS records, including changes to IP addresses, new or deleted records, and other DNS configuration information. This synchronization ensures accurate and consistent DNS information across all connected DNS Servers.

Business Continuity

Secondary DNS is essential for business continuity. If your primary DNS provider experiences an outage or if there are issues with your primary DNS infrastructure, having secondary DNS ensures that your online services can continue to function, minimizing the impact on your business operations and customer experience.

Fault Tolerance

Secondary DNS adds another layer of fault tolerance to your DNS infrastructure. It provides a failover mechanism that can automatically take over DNS resolution if the primary DNS network encounters problems, enhancing the overall reliability of your DNS services and your online presence.


In summary, Secondary DNS is a critical component of a robust and reliable DNS infrastructure. It helps ensure high availability, load distribution, geographic redundancy, protection against DDoS attacks, and business continuity for your online services. Implementing secondary DNS is a best practice for organizations that rely on the internet for their operations and want to provide a seamless and reliable experience to their users.


To learn more please visit our page describing our Secondary DNS Service.