Thousands of sites worldwide have been experiencing connectivity issues since Tuesday morning as the Cloudflare service crashed.

Cloudflare operated as a content delivery network and distributed DNS (domain name server). Its services protect website owners from peak loads, spam, and DDoS attacks (distributed denial of service).

Cloudflare was down

It was realized yesterday that there was a global problem on the Internet, and thousands of websites crashed. The problem was fixed relatively quickly, and Cloudflare services were gradually restored.

There has been a widespread reaction from Twitter users, with official accounts also reporting connectivity issues with the hashtag “#internetdown” being famous worldwide. The official Cloudflare account said it was working to address the issue.

Problems have been reported on pages and applications such as AWS, Google, Skype, Discord, Spotify, Fitbit, JustEat, and Ladbrokes.

On a practical level, Internet users trying to visit Cloudflare-supported Websites encountered an HTTP 500 error. HTTP 500 status code is a general error response. The server encountered an unexpected condition that prevented it from fulfilling the request.

There was a Cloudflare connectivity problem where it affected the Internet.

Cloudflare is a threat protection service that improves website performance and speeds up load times using multiple data centers worldwide.

It is not the first time that Cloudflare has encountered a problem, and in early 2020, a vast connectivity issue affected thousands of websites and services.

Technical description

Networks like Cloudflare use a protocol called BGP. Based on this, operators define policies that decide which prefixes (a collection of adjacent IP addresses) are advertised to peers (the other networks to which they are connected) or accepted by peers. The result is that any given prefixes will either be advertised or not advertised.

So, it is understood that a policy change may mean that a previously advertised prefix is ​​no longer being advertised, known as “withdrawn,” and that these IP addresses will no longer be accessible on the Internet.

Essentially the Cloudflare technicians changed the standardization of BGP communities which is a subset of prefixes. Specifically, we add information communities to our local website prefixes.

These prefixes allow their metals to communicate with each other and be connected to their customers’ origin. As part of the change process in Cloudflare, a Change Request form was created, including a dry execution of the change and a gradual release process. Before being allowed out, many engineers also examined it by peers. Unfortunately, in this case, the steps were not small enough to realize the error before it hit on such a large scale.