* @param auth client pass phrase (only if server is working in secure mode);
* @throws IOException if connection breaks, client authentication error or other error occurs
*/
public void hello(String hostname, String auth) throws IOException {
send(ZICO_HELLO, ZicoCommonUtil.pack(
new HelloRequest(System.currentTimeMillis(), hostname, auth)));
ZicoPacket pkt = recv();
switch (pkt.getStatus()) {
case ZICO_OK:
return;
case ZICO_AUTH_ERROR: