4.3bsd UDP generates ICMP_UNREACH_PORT for broadcast packets

[Mike Karels]

Van,

Your change to in_broadcast has the side effect of causing any packets
sent to one of the "alternate broadcast" addresses on a network (e.g.,
host 0 or all zeros) to be broadcast as well.  I'm not sure that hurts
anything, as those things don't happen much, but it doesn't seem right.
I agree that it's undesirable to send any error reply to a broadcast
UDP datagram.  However, you have worse problems if you have a network
of things that disagree as to the broadcast address.

		Mike