Captive portal issue

[ashik_k]

I am facing an issue with the captive portal after updating Google Chrome. I am attaching a screenshot for reference.

Help please for solving the issue.

Regards,
Ashik

[AEK]

Check if the certificate authority certificate you are signing with is installed on your browser.

Chrome > Settings > Security > Manage Certificates.

[ashik_k]

its already checked

[ebilcari]

As I know this page should use http since its function is just to check if the host has internet access. Check the browser if there is any settings or extension that force every site to use https.

[ashik_k]

After that browser update we facing the issue. To get internet access, the authentication page needs to load. But right now, the authentication page is not loading, and instead, this error is appearing

[ebilcari]

Yes, usually this page is used by chrome to detect the lack of internet access and redirect to the portal page URL (the process happens in background and is not visible by the end user). This is done through http but it seems that after the upgrade something has change on chrome configuration/behavior. Maybe check if this option is now enabled:

 

[ashik_k]

its disabled, but issue not resolved.

[pminarik]

Well.. the error is pretty self-explanatory. The browser doesn't trust the CA that issued the server-certificate being presented.

I know you wrote that "it's already checked", but with all due respect I'd trust the browser's claim over yours.

1, On that error screen, click the red triangle and check what cert chain is being presented, up to the CA.

2, Inspect those certificates in details.

3, Compare the CA shown against the CA you're expecting to be used by the FortiGate for captive portals (by default controlled by config user settings > set auth-ca-cert).