String host=ping_dest instanceof IpAddress? ((IpAddress)ping_dest).getIpAddress().getHostAddress() : ping_dest.toString();
String command=cmd + " " + host;
if(log.isDebugEnabled())
log.debug("executing \"" + command + "\" (own address=" + local_addr + ')');
try {
Log tmp_log=verbose? log : null;
int rc=Pinger.execute(command, tmp_log);
num_heartbeats++;
if(rc == 0) { // success
num_tries.set(0);
}