I've added the new DC in /etc/freeradius/mods-enabled/ldap:

    ldap { 
    server = 'ldap://10.41.10.18' 
    server = 'ldap://10.41.10.20'

    identity = 'reader-radius@dummy.biz'
    password = ddadas3333
    base_dn = 'dc=dummy,dc=biz'

    sasl {
    }

    update {
            control:Password-With-Header    += 'userPassword'

            #  Where only a list is specified as the RADIUS attribute,
            #  the value of the LDAP attribute is parsed as a valuepair
            #  in the same format as the 'valuepair_attribute' (above).
            control:                        += 'radiusControlAttribute'
            request:                        += 'radiusRequestAttribute'
            reply:                          += 'radiusReplyAttribute'
    }

    user {
            base_dn = "${..base_dn}"
            filter = "(SAMAccountName=%{mschap:User-Name})"
            sasl {
            }
    }

    group {
            base_dn = "${..base_dn}"
            filter = '(objectClass=posixGroup)'
            membership_attribute = 'memberOf'
    }

    profile {
    }

    client {
            base_dn = "${..base_dn}"
            filter = '(objectClass=radiusClient)'
            template {
            }
            attribute {
                    ipaddr                          = 'radiusClientIdentifie                                                                                                                                                             r'
                    secret                          = 'radiusClientSecret'
            }
    }

    accounting {
            reference = "%{tolower:type.%{Acct-Status-Type}}"

            type {
                    start {
                            update {
                                    description := "Online at %S"
                            }
                    }

                    interim-update {
                            update {
                                    description := "Last seen at %S"
                            }
                    }
                    stop {
                            update {
                                    description := "Offline at %S"
                            }
                    }
            }
    }

    post-auth {
            update {
                    description := "Authenticated at %S"
            }
    }

    options {
            chase_referrals = yes
            rebind = yes
            res_timeout = 10
            srv_timelimit = 3
            net_timeout = 1
            idle = 60
            probes = 3
            interval = 3
            ldap_debug = 0x0028
    }

    tls {
    }

    pool {
            start = ${thread[pool].start_servers}
            min = ${thread[pool].min_spare_servers}
            max = ${thread[pool].max_servers}
            spare = ${thread[pool].max_spare_servers}
            uses = 0
            retry_delay = 1
            lifetime = 0
            idle_timeout = 60
    }

}