yum install freeradius-ldap freeradius-utils freeradius

cd /etc/raddb/mods-enabled/
ln -s ../mods-available/ldap

vi ldap

In the ldap section change the following fields. In my example I stall radius on the same machine as the ldap server so I am going to connect to localhost. The following config is not the complete config, only the changed part!

ldap {
        server = "localhost"
        port = 389
        identity = "cn=manager,dc=helux,dc=nl"
        password = mypass
        base_dn = "dc=helux,dc=nl"

        update {
                control:Password-With-Header    += 'userPassword'
                control:NT-Password             := 'SambaNTPassword'
        }
        user {
                access_attribute = "dialupAccess"
                access_positive = yes
        }
}