Glenn07,

Hi, thanks for reaching out.  The C5400 and C5400X have an optional guest network portal authentication option.  I believe this is what you are referring to.   If so, HTTPS authenication would not be on the rotuer but it still possible.  You could add a optional URL which would redirrect the users listed site to complete the authentication.  This site could be encrypted with HTTPS, however that would be up to the domain owner.  The C5400 and C5400X would not generate HTTPS encryption itself. 

Best Regards 

Carl | TP-Link support 

Hi Carl,

The C5400 and C5400X have an optional guest network portal authentication option.  I believe this is what you are referring to.

I am not referring to the guest network portal authentication option. I am talking about the Web GUI for the device itself where you configure the WiFi settings and other options for the wireless router. This is the password protected page that is accessible via the admin username.

Regards,

Glenn