@Test
public void testExternalIp() {

    SystemProperties.getDefault().overrideParams("peer.discovery.external.ip", "");
    long st = System.currentTimeMillis();
    String ip = SystemProperties.getDefault().externalIp();
    long t = System.currentTimeMillis() - st;
    logger.info(ip + " in " + t + " msec");
    Assert.assertTrue(t < 10 * 1000);
    Assert.assertFalse(ip.isEmpty());
}