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

[Jagabandhu]

Dear Sbabu,

As per your previous email, I will follow the suggested steps. However, it is not feasible to communicate this workaround to all 300 users. Users are questioning why the issue is specific to Chrome while other browsers work fine.

If any changes require in your FortiGate firmware end please do as soon as possible.

Could you please provide a permanent solution for this Chrome-related issue at the earliest?

Thank you for your assistance.

Best regards,
Jagabandhu

+91-9439291306

[ebilcari]

As I know the whole point of portal detection (chrome uses http://www.gstatic.com/generate_204 ) introduced by modern browsers was to detect and silently redirect the users to the portal page before they try to reach a site that is using https. Redirecting an https page is not possible without using deep inspection (impossible for guests/unmanaged end users). I'm not sure why chrome choose to change this behavior but I guess it will be temporary.

[Jagabandhu]

Dear Firewall Technical Team,

As I understand, the purpose of portal detection (with Chrome using http://www.gstatic.com/generate_204) is to automatically redirect users to the captive portal page before they try accessing an HTTPS site. Since redirecting HTTPS is not feasible without deep inspection (which isn't practical for guests or unmanaged users), I assume Chrome's change in behavior is temporary.

However, as per your explanation, what actions should we take on our end? It is essential for your technical team to address the root cause of this issue and propose a solution, whether through a firmware upgrade or configuration adjustments. This falls within your responsibility to resolve, not ours.

Please provide a timeline for the fix.

Best Regards,
Jagabandhu

+91-9439291306

[ebilcari]

I understand your concern, but I do not think there is much that can be done from the FGT side to change this browser behaviour.

[Jagabandhu]

Dear Firewall Technical Team,

As per your response, if there is indeed not much that can be done on the FortiGate side to modify this browser behavior, I need guidance on how to communicate this effectively to our users.

Please confirm if I should inform all FortiGate firewall users not to use Google Chrome and instead switch to Microsoft Edge for accessing the captive portal. I would appreciate a clear and formal response on this matter so that we can provide consistent instructions to all users.

Best Regards,
Jagabandhu
+91-9439291306

[ebilcari]

Please create a ticket with TAC support to do a proper investigation in your network and come up with an official answer for your queries.