So you open a website and get a warning Attention
required! One more step. Please complete security check to access the website. That’s that?
A virus? Scroll the page down to see it was generated by CloudFlare. CloudFlare is a cloud
hosting, offering a very interesting feature CDN, or content delivery network. This really
helps to protect a website from DDOS attacks, so many webmasters use it. Before switching
to CloudFlare, my websites dns resolved through Freedns service by Namecheap. But they offer
an ordinary DNS, that points the website URL to a specific IP of the hosting server where
the site content is hosted. As DDOS attacks the IP, not the DNS name, hosting providers
just change the IP address of the server. If you use DNS within the hosting provider,
they also switch it, but that is obviously not true for external DNS providers like Freedns.
CloudFlare’s DNS links the website domain name URL not to the IP, but to the technical
domain name the hosting provider assigns to your site. In this case, IP change does not
affect the resolution on your website, and it can be accessed even when the server IP
address changed. Cloudflare also offers some services to speed up server load time, so
no wonder more and more webmasters use their services to speed up and protect the websites
they run. And this page is a piece of that protection. Cloudfalre obviously keeps a black
list of IP addresses, and if you happen to obtain one on connect to your provider, they
display this enter CAPTCHA screen to ensure you are not a bot or a spammer, so just enter
the captcha. After a couple correct entries, this message will stop to appear. However,
recently this page sometimes seem to be broken, and doesn’t allow you get through to website
even when you enter correct CAPTCHA. This is a bug, that should be reported to Cloudflare.