I agree that UDP is connection less. But RFC 1122, which mandates the behaviour of Linux for UDP protocol states that whenever ICMP error messages are received, they should be reported to the user application.
How do you propose this is done? Making the actual send() wait for a possible ICMP package is not practical, as you do not know whether there will come one, and you will not get a success message if the package was accepted. But if you don't wait forever, the program may have terminated before any message arrives.

In reply to Re^3: udp send not reporting host unreachable errors by JavaFan
in thread udp send not reporting host unreachable errors by saurabh.hirani

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