Mine

logging {
  channel "default_syslog" {
    syslog local6;
    severity debug;
  };

  category default { default_syslog; };
  category general { default_syslog; };
  category config { default_syslog; };
  category security { default_syslog; };
  category resolver { default_syslog; };
  category xfer-in { default_syslog; };
  category xfer-out { default_syslog; };
  category notify { default_syslog; };
  category client { default_syslog; };
  category network { default_syslog; };
  category update { default_syslog; };
  category queries { default_syslog; };
  category lame-servers { default_syslog; };
};