private void isReachable(final String remoteInetAddr) {

		Thread thead = new Thread(new Runnable() {

			boolean singleColor = false;

			@Override
			public void run() {
				isReachable = false;
				try {
					String line = "";
					logger.info("start to ping server...");
					pingCmd = Runtime.getRuntime().exec(
							"ping " + remoteInetAddr + " -t");
					BufferedReader buf = new BufferedReader(
							new InputStreamReader(pingCmd.getInputStream(),
									"utf-8"));
					int i = 0;
					while ((line = buf.readLine()) != null) {
						if (line.contains("TTL=")) {
							isReachable = true;
							if (!singleColor) {
								jLabelConnFlag
										.setForeground(new java.awt.Color(187,
												255, 209));
								singleColor = true;
							} else {
								jLabelConnFlag
										.setForeground(new java.awt.Color(0,
												153, 51));
								singleColor = false;
							}
							i = 0;
						} else {
							if (isReachable) {
								i++;
								if (i > 5) {
									isReachable = false;
								}
							}

						}
						logger.debug(line);
					}

				} catch (Exception e) {
					logger.error(e);
				}
			}
		});
		thead.start();
	}