Not long ago there was a problem in the network that caused a significant number of websites to go down, some of them belonging to highly relevant companies. We are going to see why this happened, for this we must know what CDNs are and what effects their fall has on the internet.

What is a CDN

A  CDN (from the English Content Delivery Network or Content Distribution Network, in its translation into Spanish) is a set of servers located in different parts of the world that have copies of the contents of the main web (images, videos, documents, music, files etc.).

The idea is that users have a server nearby   to be able to access that content effectively.

Thanks to CDNs, bottlenecks that would occur if many users wanted to enter a certain website at the same time are eliminated.

This means that when searching for a site, the server that provides that content is the closest geographically so that traffic does not have to go too far. In this way, these servers are less congested.

These CDN networks are managed by third parties, that is, specialized companies. A website can have the contents hosted on some servers and, also on others, such as the CDNs that have them in different countries where the copies of their contents are made.

What happens if a CDN is dropped

As we say, when a Spanish user connects to a website, the most normal thing is that they do not do so through the servers closest to it (for example, if they are in the United States). 

What will happen is that the connection will be to one that is closer and from it the content that you are looking for is obtained quickly.

But what if a CDN fails? It seems that the internet has gone down as if the failure occurred in the central servers of that website.

If the nearby server has crashed, all  the contents that are normally obtained are not available , so the consequence is that it seems that the web has crashed, which for that user for practical purposes is what has happened.

But things get worse because  network services  are in the hands of few companies and large websites delegate to them in such a way that when a failure occurs, it affects those with the most traffic,  giving the appearance of that the internet has collapsed