Help with PEAP Authentication Setup in FreeRADIUS

[Tharka Karunanayake]

Hello everyone,
I'm trying to set up user authentication using the PEAP method in FreeRADIUS, but I'm running into some issues.
I've configured the eap module and enabled inner-tunnel, but during authentication(Cisco WLC 9800), the server keeps sending Access-Challenge responses repeatedly — even though the username and password are successfully validated against the database.(I can see this is debug logs)
I have prior experience using PAP and CHAP with databases, but I'm having trouble getting PEAP to work correctly.
Could someone kindly provide clear documentation or step-by-step guidance on how to properly configure PEAP? Specifically:

  *
What files need to be modified?
  *
Are there any common pitfalls I might be missing?

So far, I've made changes to:

  *
mods-enabled/eap
  *
sites-enabled/inner-tunnel
  *
sites-enabled/default

Any help, guidance, or even reading material would be greatly appreciated.
Thank you in advance for your support!
Best regards,
Tharka