What is the name of the domain?
vmware.systempro.ge, opc.systempro.ge
What is the error number?
What is the error message?
timeout while trying to connect to the host
What is the issue you’re encountering
Can not connect to web applications behind cloudflare proxy during 6AM-9AM CET
What steps have you taken to resolve the issue?
We have several applications behind cloudflare proxy in our infrastructure. Lately some(if not all) of those applications have been experiencing some strange issues, which we initially thought to be an ISP issue - I’ll explain why. Applications seem to be reachable by any ISP except Magticom(Georgia). And another strange part is, for some reason, problem only appears during 6AM-9AM CET. The other huge ISP alongside Magticom is Silknet. Silknet users seem to Access the applications with no problem. Although 522 error seemed strange in this scenario. So we did a little bit more testing, we added a second proxy(DigitalOcean) just like cloudflare and now it works from Magticom also. So the situation is like this:
Magticom users->Cloudflare->Application: doesn’t work during morning hours, displays 522 error.
Silknet users->Cloudflare->Application: always works
Magticom->Cloudflare->DigitalOcean->Application: always works
The firewall rules are out of question. we have problems on all types of platforms and their respective firewalls. We even added several test applications for which we opened full internet access, with no success. And of all things we don’t make time based rules when something is being blocked in specific period of the day.
We contacted Magticom, but they don’t seem to think it’s their problem, because the issue isn’t global. other companies have Magticom too but they don’t experience this type of issues. But because we have BGP with provider, we think some traffic destined from Cloudflare to our BGP prefixes is being blackholed. It’s probably their issue but we can’t provide any evidence that’s something is happening on their side.
The worst of all, we have no means to troubleshoot - because Cloudflare uses random IP addresses, we can’t figure out from which specific IP addresses is traffic being lost. Although we did some filtering for the traffic logs, no interesting information was fetched from it, because traffic always seems to flow without being blocked(probably that’s the traffic coming only from silknet users).
We would like to know if there is any troubleshooting tools in Cloudflare for this type of cases - like:
is traffic is being handled differenly for different ISPs?
Can we see the traffic logs on cloudflare side(where we will be able to see the source IP of cloudflare to destination ip of our app, sent/received bytes, etc…)
Or if anyone knows is there something happening in Cloudflare during 6AM-9AM CET?
What feature, service or problem is this related to?
DNS records