@Override
  public String[] applyVpnUsers(RemoteAccessVpn vpn, List<? extends VpnUser> users)
      throws ResourceUnavailableException {
    Network config = _networksDao.findById(vpn.getNetworkId());

    if (!canHandle(config)) {
      return null;
    }

    boolean result = _externalNetworkManager.manageRemoteAccessVpnUsers(config, vpn, users);
    String[] results = new String[users.size()];
    for (int i = 0; i < results.length; i++) {
      results[i] = String.valueOf(result);
    }

    return results;
  }
  @Override
  public boolean startRemoteAccessVpn(final RemoteAccessVpn vpn, final VirtualRouter router)
      throws ResourceUnavailableException {
    if (router.getState() != State.Running) {
      s_logger.warn(
          "Unable to apply remote access VPN configuration, virtual router is not in the right state "
              + router.getState());
      throw new ResourceUnavailableException(
          "Unable to apply remote access VPN configuration,"
              + " virtual router is not in the right state",
          DataCenter.class,
          router.getDataCenterId());
    }

    final Commands cmds = new Commands(Command.OnError.Stop);
    _commandSetupHelper.createApplyVpnCommands(true, vpn, router, cmds);

    try {
      _agentMgr.send(router.getHostId(), cmds);
    } catch (final OperationTimedoutException e) {
      s_logger.debug("Failed to start remote access VPN: ", e);
      throw new AgentUnavailableException(
          "Unable to send commands to virtual router ", router.getHostId(), e);
    }
    Answer answer = cmds.getAnswer("users");
    if (!answer.getResult()) {
      s_logger.error(
          "Unable to start vpn: unable add users to vpn in zone "
              + router.getDataCenterId()
              + " for account "
              + vpn.getAccountId()
              + " on domR: "
              + router.getInstanceName()
              + " due to "
              + answer.getDetails());
      throw new ResourceUnavailableException(
          "Unable to start vpn: Unable to add users to vpn in zone "
              + router.getDataCenterId()
              + " for account "
              + vpn.getAccountId()
              + " on domR: "
              + router.getInstanceName()
              + " due to "
              + answer.getDetails(),
          DataCenter.class,
          router.getDataCenterId());
    }
    answer = cmds.getAnswer("startVpn");
    if (!answer.getResult()) {
      s_logger.error(
          "Unable to start vpn in zone "
              + router.getDataCenterId()
              + " for account "
              + vpn.getAccountId()
              + " on domR: "
              + router.getInstanceName()
              + " due to "
              + answer.getDetails());
      throw new ResourceUnavailableException(
          "Unable to start vpn in zone "
              + router.getDataCenterId()
              + " for account "
              + vpn.getAccountId()
              + " on domR: "
              + router.getInstanceName()
              + " due to "
              + answer.getDetails(),
          DataCenter.class,
          router.getDataCenterId());
    }

    return true;
  }