Understanding DNS Failover: Ensuring Uninterrupted Resource Availability

DNS Failover is a vital tool that guarantees uninterrupted resource availability by automatically updating DNS records when the primary endpoint becomes unavailable. This article delves into the technical details of DNS Failover, explores key terminology, and offers implementation tips for a seamless failover management experience. Discover how DigiCert DNS Trust Manager can provide reliable and efficient DNS failover solutions for your enterprise.

DNS Terminology:

Before diving into the technical aspects, let's familiarize ourselves with some essential DNS terminology:

1. Query: The request made by an end-user to resolve a domain to an IP address or hostname.
2. Endpoint: The destination address, which can be an IP address (e.g., 172.08.260.1) or a hostname (e.g., dnsmadeeasy.com).

Understanding the Failover Process:

To comprehend how DNS Failover works, let's consider an example where a user intends to visit www.yourdomain.com. During a regular DNS lookup, the DNS provider retrieves the www record for the domain yourdomain.com and returns the IP or hostname specified in the record.

However, in the case of a failover record, multiple IP addresses are listed. The second IP address acts as a backup and is only used when the primary address becomes unavailable.

Monitoring and Automatic Failover:

DigiCert DNS employs a system of monitoring nodes that continually assess the health of endpoints within the failover record. These monitoring nodes check the availability of the primary IP at regular intervals, typically every 2-4 minutes.

If the primary IP fails to respond from multiple monitoring locations, it is considered down, triggering the failover process. The failover mechanism automatically updates the DNS record to direct traffic to the secondary IP address. These record changes are instantly propagated to all nameservers in the DNSME network, ensuring immediate redirection. Additionally, an email alert notifies the account administrator about the failover event.

The monitoring nodes persistently monitor the availability of the primary system until it comes back online. Once the primary IP is accessible again, the DNS record is updated to route traffic back to the primary endpoint.

Configuring Failover:

DNS Failover allows you to configure up to four backup IP addresses, ensuring redundancy and enhanced reliability. If the secondary IP address also becomes unavailable, traffic will be seamlessly redirected to the tertiary IP address and subsequently to the remaining backups.

Pro Tip: Lowering the TTLTo optimize failover efficiency, we recommend setting a lower Time to Live (TTL) for your failover records. While DNS record updates are instantly propagated within our network, resolving nameservers may cache the old record values. Lower TTL values ensure that these caches expire more quickly, allowing the failover to take effect promptly.

DigiCert DNS Trust Manager Failover

DNS Failover is a powerful and straightforward tool that automatically updates DNS records, guaranteeing resource availability even when the primary endpoint fails. By understanding the technical aspects, key terminology, and implementation tips, you can leverage failover mechanisms to ensure uninterrupted service for your enterprise. Implement DigiCert DNS Trust Manager for reliable and efficient DNS failover solutions, and empower your business with robust tools and solutions. :Ensure uninterrupted resource availability with DigiCert DNS Trust Manager. Explore our comprehensive DNS failover solutions, backed by industry-leading reliability and expertise. Take the next step towards seamless failover management today!

‍