[Jack-Devel] Failures in connecting mac OSX Sierra and an embedded board with linux via netjack2

[Chris Caudle]

> How could I verify that multicast is actually working? If it was not
> working then how the two machines could see each other?

When I first attempted to connect two machines with netjack I found that
one machine could transmit and receive multicast, one machine could
transmit but not receive, so the status messages were confusing, e.g. one
machine would report that the connection was working, but then report
errors when it got no responses later.

I found these links which may be useful.  I don't have a mac, so I can't
say how useful.
This seems like the most likely to be useful, an implementation of
multicast ping similar to omping but for Mac:
http://bdunagan.com/2010/03/31/multicast-ping-on-a-mac/

Since you mentioned that your machine has two interfaces (I think you said
wired and wireless) you may want to turn off the wireless interface and
check with just the wired interface first.  On a unicast connection there
is a default route that your operating system uses to know where to send
packets with an address that is not known to be on the local network. 
Usually an interface, and the address of a router.  For multicast the
operating system needs something similar, it needs to know which interface
to use when given a multicast packet to send.  I think with only one
interface enabled that should occur with no intervention, but with two
interfaces enabled you will probably have to configure the default route
to use for multicast addresses.

I think this link explains how to do that from a terminal.  There may be
some network configuration GUI program which can do the same thing, but I
don't know.
http://blogs.agilefaqs.com/2009/11/08/enabling-multicast-on-your-macos-unix/


-- 
Chris Caudle