SYN Flood on AWS EC2 instance

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When you tested your domain using the [Cloudflare Diagnostic Center] what were the results?


Describe the issue you are having:
On almost daily basis we are having our website down for a specific time period. We have our server hosted on AWS and we created a support ticket on AWS to debug the issue. As per them it is SYN Flood , they said this might be a DDOS attack but not sure and said us to check the netstat when the website went down again. At that time the bandwidth and network packet in is increased to 100Mbps and the server then stop responding until restarted. We have already implemented the Cloudflare and are not sure if this is the traffic increase at that sudden time ( The chances are less because it’s not appearing on the Google Console ) or is it a DDOS and if this is a DDOS , Why Cloudflare is not handling or the server ip is exposed and there is an attack directly on the server ( Chances of this is very less as well )

What error message or number are you receiving?
SYN Flood as per AWS Support

What steps have you taken to resolve the issue?


Was the site working with SSL prior to adding it to Cloudflare?


What are the steps to reproduce the error:


Have you tried from another browser and/or incognito mode?

Yes and from multiple locations but the server is down

Please attach a screenshot of the error:

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Can you please let us know the domain name where you see the issue. Kindly create a support ticket and give the ticket number so that we can check on this further.

Done already.

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