Imagine this. You are an owner of a large e-commerce site. It is Black Friday, the biggest online promotion that you have, and you are eager to see how the site is going on. You type your domain name into your browser and… “Oh no!” “It is not opening. This is a disaster!” What is going on! You are experiencing a DNS outage that might completely devastate your promotion!
So, what is this DNS outage?
DNS outage is the time when your DNS is not functioning for some reason (your nameservers were attacked, or they were saturated with too strong traffic, etc.), and that does not allow the domain resolution of your domain name to its IP address. The DNS resolution is the first step to enter a site. The browser won’t know where your website is hosted without it, and it can’t find its content.
All the visitors trying to resolve your domain will get an error message and won’t be able to access your site.
In a simple term:
The DNS outage is when your potential visitors enter your site name (domain name) into their browser and don’t get redirected to its IP address.
Why is it bad?
If the DNS is down, nobody will be able to visit your site, and all the services related to the domain name, like emails, won’t function correctly. You will need to get it up and running again to get back all the temporary lost functionality.
During this time, you can:
- Miss potential visitors.
- Lose potential sales.
- Have problems with services like email, FTP, VoIP, etc.
- And more.
What causes DNS outage?
- Human error. Don’t be surprised. Most of the mistakes in Tech are human errors. For example, somebody didn’t configure the DNS records properly. Another performed a DNS migration badly, and so on. There are plenty of problems that could cause it.
- Hardware problems. If you are using your own server for DNS, any hardware failure could bring your server down and all the services that it provides. That is the risk of having your own server.
- DDoS attack. A Distributed Denial of Service attack is targeted traffic going your way with the purpose of taking out of service your server or servers. There are plenty of DDoS attacks in the last years, and their popularity is just increasing. They are getting stronger too, so the future does not look very pinkish in this aspect.
Could I have prevented the DNS outage?
Of course, you could have prevented the DNS outage, and there are different measures that you can take to prevent future DNS downtime:
- Secondary DNS. The easiest solution that could save you in most cases is to use a secondary DNS service. Preferably with another DNS provider. The secondary DNS will allow you to have other authoritative DNS servers that could still respond to queries, even if the Primary DNS is down. The more, the better.
- DDoS protection. Many of the times that you are experiencing a problem with your domain name, the reason is a DDoS attack. Unfortunately, those traffic attacks have become cheap, and it is common that cybercriminals, sometimes paid by your competitors, are bringing down your domain. Get DDoS protection for your DNS servers that can resist strong traffic.
- Load Balancing. You can organize your nameservers to use a load balancing method and redirect the traffic between them. That way, you can be sure that the weight is not falling on one of them. Spreading heavy traffic will improve the performance and the resilience of your DNS network.
Suggested article: What is a Smurf DDoS Attack?