fortigate Capitave portal Issue

[MahmoudH93]

when configured captive portal some sites didn't work  with error :
err1 - ERR_QUIC_PROTOCOL_ERROR
err2 - ERR_SSL_VERSION_OR_CIPHER_MISMATCH

like : YouTube , google , LinkedIn  and google search

else some sites works normally and redirect to captive portal AUTH page .

when I remove or authenticate all sites works normally 

I try it with (chrome , brave and IE browsers) 

(version 7.0.9 VM) 

FortiGate  

[mgoswami]

Hi,

Can you please try disabling QUIC in Chrome and block QUIC on the FortiGate?

BR,

Manosh

[MahmoudH93]

hello Manosh 

i do it with no hope still err and all sites didn't response 

ERR_CONNECTION_TIMED_OUT

and i configured it with 3 way and still issue exist 

[rvchande2]

Hi There,

I am also facing the same error while captive portal is enabled.

Please find attached snapshot more information.

Can someone please reply what should be done?

Regards,

Ravi

[kaman]

Hello MahmoudH93 and rvchande2,

The errors "err_quic_protocol_error" and "err_ssl_version_or_cipher_mismatch" you are encountering when accessing certain sites like YouTube, Google, LinkedIn, and Google Search while the captive portal is configured indicate issues with the SSL/TLS handshake between the client and the server. Here are some steps to troubleshoot this issue:

1. **Check SSL/TLS Settings**: Ensure that the SSL/TLS settings on the captive portal are correctly configured to support the required protocols and ciphers for these websites.

2. **Certificate Validation**: Verify that the SSL certificate used by the captive portal is valid and trusted by the client browsers.

3. **Browser Settings**: Check if there are any browser-specific settings causing the SSL errors. Clearing browser cache and cookies might help.

4. **Network Configuration**: Ensure that there are no network issues affecting SSL/TLS connections to these sites. Check for any firewall rules blocking specific protocols or ports.

5. **Update Browsers**: Make sure your browsers are up to date to support the latest SSL/TLS protocols and ciphers.

6. **Test with Different Devices**: Try accessing the sites from different devices to see if the issue is specific to a particular device.

Please refer to the below document for more information:

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Unsupported-protocol-during-HTTPS-access-E...

If you have found a solution, please like and accept it to make it easily accessible to others.