private void
fallback() throws ZoneTransferException {
	if (!want_fallback)
		fail("server doesn't support IXFR");

	logxfr("falling back to AXFR");
	qtype = Type.AXFR;
	state = INITIALSOA;
}
Sets the local address to bind to when sending messages.
@param addr The local address to send messages from.
src/main/java/core/org/xbill/DNS/ZoneTransferIn.java