@Override
  public boolean applyPFRules(Network network, List<PortForwardingRule> rules)
      throws ResourceUnavailableException {
    if (!canHandle(network)) {
      return false;
    }

    return _externalNetworkManager.applyFirewallRules(network, rules);
  }
  @Override
  public boolean applyFWRules(Network config, List<? extends FirewallRule> rules)
      throws ResourceUnavailableException {
    if (!canHandle(config)) {
      return false;
    }

    return _externalNetworkManager.applyFirewallRules(config, rules);
  }