DNS outage explained.

DNS outage represents the time in which your DNS is not working. There are various reasons why this happen. For example, the incoming traffic is a lot, or your server is attacked. That does not allow the DNS resolution of your domain name to its IP address. All the users trying to connect with your domain are going to receive an error message and won’t be capable of exploring your website.

What are the consequences of a DNS outage?

Briefly:

The DNS outage occurs when users type your domain name into their browser but are not redirected to its IP address.

What causes it?

Only one authoritative name server.

Companies for sure are able to operate normally with one authoritative server. Usually, small businesses and medium-sized ones take this approach. However, the absence of redundancy could lead to DNS downtimes when the server requires maintenance, some updates, fixes, or is under attack. 

Human mistakes. 

DNS outage can be a result of mistakes in the configuration. For instance, one misspelling while entering the domain name’s IP address or a script error can be a reason for the DNS to stop operating. 

DDoS attacks.

DDoS attacks are, unfortunately, a possible reason for occurring DNS outages. These attacks aim to make your domain name unavailable by flooding your DNS servers with a lot of traffic. For that reason, DDoS prevention is essential.

Propagation of updates or changes. 

You probably have to make adjustments and add or delete DNS records for your company frequently, which is just a part of normal operations. It is important to note that such actions could take a little longer time to propagate to all of the machines on a network. 

At the same time, a part of the visitors could receive the previous IP address (IPv4 or IPv6) from the cache memory of the Recursive DNS server. So, that means it has not received the update yet.

That actually is not a DNS outage or a DNS failure. Yet, it is perceived that way by the visitors who cannot connect with your domain name.

Difficulties with data centers.

Your authoritative DNS server is functioning in a data center. Unfortunately, those locations can experience accidents, technical failures, and harsh weather. For that reason, redundancy is the alternative to avoid a DNS outage. 

How to avoid DNS outage?

For the purpose of avoiding and protecting your domain name from a DNS outage, you could implement several measures. 

• Secondary DNS. In most scenarios, one simple way to save your domain name is to implement a secondary DNS service. It is best to be with a distinct DNS provider. The secondary DNS is going to provide you with additional authoritative DNS servers. That server is going to be able to reply to queries in cases when your Primary DNS is down. 
• DDoS protection. Oftentimes, the reason behind your experience of difficulty with your domain name is a DDoS attack. In recent years, such types of attacks have become very popular, and it is common for cybercriminals to bring down your domain. The reason for initiating a DDoS attack varies, so it’s best to keep yourself protected. Thanks to DDoS protection for your DNS servers, your business is going to resist heavy traffic.
• Load Balancing technique. You can arrange your nameservers and redirect the traffic between them by a load balancing mechanism. You are going to spread the heavy incoming traffic and improve the performance and the strength of your DNS network.