What is Firefox request to ocsp.int-x3.letsencrypt.org and similar

Web Performance Optimization Discussions
1

When I test speed in Firefox, there are some strange requests tied with SSL certificate at the beginning of the waterfall:

[list]
[]ocsp.int-x3.letsencrypt.org when cert issuer is Let’s encrypt
[]ocsp.globalsign.com/rootr2 and ocsp.comodoca.com when issuer is Globalsign (nginx.com) WebPageTest - Running web page performance and optimization tests...
[/list]

But it isn’t always present in waterfall. For example site troyhunt.com (Comodo is cert issuer) has no such request: WebPageTest Test - WebPageTest Details

May somebody explain me what it is? Can I somehow reduce these requests? Why chrome doesn’t do such requests?

2

It’s the check as to whether a certificate has been revoked or not - Online Certificate Status Protocol or OCSP for short

Different browsers have different rules as to if and when they check them.

A technique called OCSP Stapling will remove them, which needs to be configured for the root domain on your server, third-parties need to be configured on their own servers / CDNs

3

That it was, so I have enabled OCSP Stapling on all my servers, thank you.