How does DNS Failover work? 

Maintenance, updates of software, security measures… Websites owners try everything, and even so, bugs, hardware breakdowns, clustered connections, etc., could get their sites in trouble.

What about having a 24/7 monitoring that can be so aware to notify you about an upcoming problem? Or even better, this “vigilant” reacting on time to protect your site and pocket. 

What is DNS Failover?

DNS Failover is a useful and simple tool for making automatic updates of your DNS records in case of a failure. It is a convenient “B” plan for supporting your DNS, if “A” doesn’t work. 

Think about a common DNS record pointing a domain to a hostname or IP address but with the big advantage that you can define an endpoint, hostname, or IP address as a backup. This backup you create will be used only if the main is not available.

How does DNS Failover work?

DNS Failover monitors your traffic and reacts if it detects an event. For instance, a server goes down, so DNS Failover gets triggered and automatically will switch to the backup’s DNS records, so users can obtain a new IP address of a working server. 

Thereby, using an additional IP address of an alternative DNS server, your domain will keep been available, and you won’t lose traffic. Users will have an alternative route to reach it. 

You can set up passive reactions, too, for the DNS Failover not to react automatically but to notify you about the event. DNS record could also be configured just to be disabled. 

The most attractive option is the replacement of IP addresses. If you have international traffic, with a server in every continent, downtime problems could be avoided with you can continue your online business uninterrupted. 

It is possible to configure the DNS Failover to update your DNS records for the down server as soon as it is working again.

Another useful feature is that you can define types of monitoring (HTTP, HTTPS, ping, UDP, or TCP) and if you want it to work on a specific region.

DNS Failover pros

· It’s useful to control web traffic.

· DNS Failover is easy to install, following simple steps and requiring basic tech knowledge. 

· It keeps your website constantly available and your network (servers) auto-updated.

· DNS 24/7 monitored. 

· It’s relatively inexpensive.

DNS Failover cons

· To visit a website makes its DNS records be saved in the browser cache the time the TTL (Time To Live) value points. Failover works, but the users still need those TTL values to expire. The lower TTL values are, the better the DNS failover is to update the records faster. 

Although the updated records get propagated quickly to the network, there is a chance that due to this TTL factor, visitors’ DNS records will still direct to the down server during some time. It is a short time, a few minutes, but exactly how long will depend on those TTL values. 

Who can use DNS Failover?

DNS Failover functionality is good for every web-based business, app, or service.

· All kind of remote desktop services (VMWare Horizon, RDP, etc.).

· File transfer servers. FTP/SFTP and more.

· Mail servers.

· Web servers.

· Voice Over IP (VoIP) infrastructure.

· Streaming media servers.

· Web services or application programming interfaces (APIs).

· Redundante web servers. 

· Web apps and services that are accessible through multiple IP addresses.

We recommend you take a look at the following article – Why use a Managed DNS provider?


DNS Failover will increase your regular DNS plan’s cost, but its benefits can be really helpful for pretty much anything that can be accessed through DNS and has an IP for this purpose. Try it and enjoy its advantages. 

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