Forum Discussion

cf_525_pain_310's avatar
cf_525_pain_310
Icon for Nimbostratus rankNimbostratus
Feb 16, 2017

CloudFlare 525 Errors - f5 fix?

I recently started routing assets called via https through Cloudflare, a proxy service, amongst other things.   I have an interesting issue where, once i did that, i saw that around 1% of browser ...
BIG-IP
devops
iRules
security
Philippe_Page_2's avatar
Philippe_Page_2
Icon for Cirrus rankCirrus

I have an virtual server created with many websites hosted in it. It has one public IP assigned to it and is NATed to a private IP. The websites are accessible via HTTP and HTTPS. However one website uses Cloudflare, we experience an error with cloudflare (error 521). I have whitelisted the cloudflare IP addresses onto F5 via Network ›› Packet Filters : Rules

 

I am running software version 12.1.3

 

We no longer have blocking both in the F5 and the internal server. This only occurs with websites having Cloudflare configured with it. Is there anything I can check between F5 and Cloudflare?

 

I have tried applying an iRule that redirects traffic to see if the traffic from Cloudflare IPs are really reaching F5. Sometimes it does redirect but most of the times it servers error 521 immediately.

 

Philippe_Page_2's avatar
Philippe_Page_2
Icon for Cirrus rankCirrus
Jan 23, 2019

Can anyone provide an insight regarding this issue. Anything will do. Thank you.