There are times when all of sudden we receive a vague error code on our screen while surfing any site. Thus, one of those pop-up that a lot of people encounter in such a case is “error code 521”. The core server refuses to respond to Cloudflare’s demands, which associates it with server issues. Hence, to know everything about its meaning, causes, solutions, and tips, read the complete blog till the end.
What is error code 521?
So, error 521 is a technical issue that symbolizes the “connection denial” situation. Thus, in this cloudflare (deals with website services) become unable to retrieve or connect with the server. Therefore, error code 521 eventually results in unavailability of your site or inconvenience to the visitors.
Furthermore, there are various reasons for this problem, including everything running from disruption in the chain to server downtime. Apart from this, there are various other variants of error code 521 that visitors encounter depending on their devices or operating systems. Hence, they are as follows:
- HTTP Error 521
- Error 521: The web server is not responding
- Error 521: Web Server is Down
- Cloudflare Error 521
- Web server Down: Error 521
- 521 Error: Server Unreachable
Why does error code 521 happen?
There are various reasons and causes that lead to error code 521. Therefore, to learn about some of the most common ones, read the below-shared points:
- Server downtime: In this the cloudflare tries to make a connection with the server but due to the server being offline, it fails and results in error.
- Interruption by security software: Another reason for this technical issue may happen due to blocking or flagging of cloudflare IP addresses from the server itself.
- Connectivity issues: Plus, bad network, malfunctioning routers, routing issues, or network congestion can also disturb the connection between cloudflare and server which result in the error.
- Failure of domain name resolution: Any type of incorrectness in domain name, reverse DNS, or A record can also take you to error 521.
How to fix error code 521?
There are multiple ways to fix and resolve the issues error code 521. However, below, we are sharing only the easiest, quickest, and most trustworthy ones so that the website starts smooth operations in no time.
Check the condition of your web server
The proper functioning of your web server is a must to run your website appropriately. Thus, you need to cross-verify that the web server is active and working in the right condition. Here are the steps for it:
- First of all, go to your server’s official website.
- Once done, log in with the right credentials.
- Next, try to access and run local services present in the dashboard.
- If everything works well, then your server will be in optimal condition.
- And if not then you need to reboot the system, troubleshoot software, or restart the service so that everything gets refreshed and glitches or bugs vanish.
Take a look at Cloudflare settings
There might be a chance that you are witnessing error 521 due to some wrong settings in the Cloudflare itself. Thus, to check and fix it, you need to follow the below-shared points:
- Begin with opening the Cloudflare account settings.
- Once done, check whether the cloudflare is activated for your desired domain or not. If not then enable it immediately.
- After this, search for the proxy status, and if it is pre-default set to “DNS Only,” then switch it to “Proxied.”
- Finally, look for the IP address and check whether it is correct or there are some minor errors in it. Plus, you are advised to delete and re-fill the IP address.
Review the security policies
Old versions of security firewalls or inappropriate settings can also lead to error code 521. Thus, to resolve it, you need to follow the below-shared points:
- Firstly, make sure that all the security software is updated.
- In addition to this, you need to cross verify that the settings of firewall and web server configs are allowing the traffic to pass from cloudflare to the server and vice versa.
- Besides this, you also need to scan the entire server logs so that you get to see whether the access requests are being received or not.
- Lastly, you are also advised to update the WAF settings so that access is permitted every time.
Test the issue from another location
There are times when the access is denied in certain geographical areas only. Thus, in such a case, you need to test Cloudflare and the servers functioning from different regions or use a proxy or VPN. The steps for the same are mentioned below:
- First of all, install a trustworthy VPN in your system.
- Once done, give it the selected accesses and run it over. Make sure to change the current location in the VPN’s settings.
- Finally, test the website’s functioning from different locations. Thus, if it works from another region then contact your hosting provider for fixing it. But, if it doesn’t, then move to another method.
Check the capability of resources
The server may be overloaded, and your system may not be capable of handling it. Thus, conditions like this also lead to error code 521. Hence, the ways to resolve it are as follows:
- Begin with checking the server’s workload and your current software capabilities.
- If you find any lack, then upgrade to more RAM storage and CPU cores.
- Apart from this, you can also switch to larger server instance size so that the files, formats, or data is supported by your system.
Valuable tips to avoid error code 521
Apart from the fixing methods, there are some tips and tricks that can help you avoid similar errors in the future. So, to get a glimpse of that, read the below-shared points:
- Activate advanced Cloudflare features such as waiting rooms and load balancing.
- Enable server health-checking software.
- While making the config changes, make sure to validate the firewall, proxy, and DNS settings.
- Keep track of server workloads.
Conclusion
In this blog post, we talked about error code 521. Hence, ranging from its meaning to causes, we talked about everything. Not only this, but we also highlighted various ways to check and fix it. In addition to this, we also discussed some tips that can help you avoid such technical errors in the future. Overall, if none of the methods work for you, contact the web servers’ customer support team and ask for their assistance. I hope the article helped you and shared valuable content according to your technical issue.
FAQs
What is Cloudflare?
So, cloudflare is basically a cloud service which helps in improving the internet services of a website. Therefore, from better security and faster load time to boosted reliability and so on, everything related to website performance falls under this.
What are the reasons behind the web server’s down error code 521?
Server down, traffic in the route of cloudflare and server, connectivity issues, failure of domain name resolution, and interruption by security software are some of the most common causes of error code 521.
How do you check server downtime?
To check it, you just need to log into your server’s official website and take local actions. If they function appropriately, then your server is active, and if they do not respond well, then it is down.
