public static ZoneTransferIn
newIXFR(Name zone, long serial, boolean fallback, String host, int port,
	TSIG key)
throws UnknownHostException
{
	if (port == 0)
		port = SimpleResolver.DEFAULT_PORT;
	return newIXFR(zone, serial, fallback,
		       new InetSocketAddress(host, port), key);
}
Instantiates a ZoneTransferIn object to do an IXFR (incremental zone
transfer).
@param zone The zone to transfer.
@param serial The existing serial number.
@param fallback If true, fall back to AXFR if IXFR is not supported.
@param host The host from which to transfer the zone.
@param port The port to connect to on the server, or 0 for the default.
@param key The TSIG key used to authenticate the transfer, or null.
@return The ZoneTransferIn object.
@throws UnknownHostException The host does not exist.
src/main/java/core/org/xbill/DNS/ZoneTransferIn.java