I wrote: > I have a Fedora 20 machine which is receiving UDP broadcast packets at > regular intervals on a high port. No program is presently listening > for these packets. If I run, "tcpdump -iany port 29531", I see each > of the packets arriving just as I expect. > > But if I then use Ncat as a surrogate for an application, "nc -lup > 29531", I sometimes don't see anything! Why not? (More details > below.) What obvious thing am I missing? > ... I now understand what is happening on this machine. It's not a bug and it's not unique to Fedora. Fedora is enforcing the networking RFC rule that general broadcast messages (those to 255.255.255.255) should not reach networks other than the one their sender is on. Smaller netmasks allowed the machine to be on the sender's network; larger netmasks meant that it was not on that network. Issue closed. -- Dave Close -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
