Avoiding DNS outage is a critical mission! Downtime and losing clients because they can’t reach your website or application are unpleasant situations nobody likes to deal with. But the reality is, they can happen. Better get into the topic from now! 

​What’s a DNS outage?

DNS outage is the period a domain name can’t be accessed, meaning looking up for the domain won’t return its IP address.

Yes, users will send DNS requests to reach your domain. The DNS recursive server will ask the domain’s authoritative nameserver, but it will get an error message as an answer. 

​What causes a DNS outage?

• Authoritative name server’s maintenance. Updates or reboots are sometimes needed as a part of regular maintenance. This will stop the server from answering any DNS request.
• Configuration errors. Basically, all kinds of human mistakes while configuring DNS can cause a DNS outage. Script errors, a misspelled IP address, firewall configuration errors, etc.
• An event in the data center (authoritative name server’s location). The “cloud” is not in the sky but in a data center or different data centers. And such places are secure but not infallible. Especially when it’s about natural disasters, electricity outages, etc. Different events can shut down your authoritative name server.
• DoS and DDoS attacks. DoS and DDoS attacks’ goal is exactly to provoke a denial of service. If they succeed, you will suffer a DNS outage.

​How to avoid DNS outage?

• Add redundancy. Advantages of having a large network are many. Multiple servers instead of a few of them mean that if something goes wrong with one, two, or three servers, still many more can be in charge. So your domain or application still will be accessible. Chances for the whole network to go down are minimum. Besides, you will be able to handle high traffic loads, enhance the general performance of your domain or application, etc.
• Look for a Secondary DNS service. You already have your DNS provider (Primary DNS). Well, you can hire a different provider to use its multiple Secondary DNS servers to set them up as Secondary nameservers. These servers will hold a copy of the zone file and the DNS records. Therefore, they will be able to respond to DNS requests exactly as the Primary DNS do. If this last gets hit by downtime, you will have a backup. 
• Balance your traffic loads. High traffic loads can be a double-edged sword. They can be the growth you strongly worked for, or they can mean a DoS or DDoS attack in progress. DNS load balancing is an efficient method to distribute the traffic among all the servers of a network. You can avoid the strain on specific servers, handle sudden traffic spikes or high traffic in general.
• Monitor DNS servers professionally. Monitoring constantly is the only way to know traffic, just like the back of your hand. This way, you can identify normal and abnormal traffic. Based on traffic behavior, you can take action to prevent an attack or to handle a normal spike on time. Current solutions allow you to monitor in real-time, specific locations to determine if the issue is local, regional, or global, etc.
• Get full protection against DDoS attacks. Advanced and constant monitoring, firewalls, software, hardware, DDoS deflation for absorbing the attack, etc. 

​Conclusion.

DNS outages can really harm your domain’s reputation. Be aware and prevent them! An ounce of prevention is worth a pound of cure!