Hi,
1. If you are using Internal-Authenticated, then we need to have a user account created in
internal database or use external server.
Under Authentication server , if you use Internal server we just need to create ac account by clicking on
User opton
2. if you are using Internal-Acknowledged, then we do not need any kind of user account
3. If you choose External, then your captive portal page needs to be hosted on some kind of external web server.
Make sure the ACL's are correctly configured Under Access tab so that the user is not blocked.