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cf_525_pain_310's avatar
cf_525_pain_310
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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 ...
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cf_525_pain_310's avatar
cf_525_pain_310
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  1. the cipher suites are compatible. I made comparisons and even matched CFs entire list and applied it to the f5s. didn't change the error condition

     

  2. SNI isn't being used. rather, none of the checkboxes or the server name field have any data. as an FYI, there are 3 websites/domains that go to this VIP, but they share one ssl cert with all 3 domain names in it. the cert I'm using does have all 3 domain names (san) in it.

     

  3. Yes and no. I tried but the nginx proxy isn't configured to handle that ssl traffic and would require other resources to do it, which I can do if necessary.

     

  4. There are some weird logs on the f5 that I see; but they don't seem to correlate with the 525s.

     

cf_525_pain_310's avatar
cf_525_pain_310
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Feb 17, 2017
  1. I noticed it right away. we actually saw a browser display that 525 error, then had trouble repro'ing it...it happens less than 1% of requests. but I have Catchpoint, I see a few of them in those automated tests each day and many on the cloudflare dashboard. so this could simply be exposing a preexisting condition that now manifests in a browser error. but, I wasn't seeing basic websites tests fail just trying to hit an https page this like does at times.