Basic recipe/expectations for VALE w/physical ports

[Nicholas Bastin]

We're continuing to have problems with VALE not forwarding packets on
physical ports, and I suspect at least some of the problem is local
configuration - we've tried to cobble together the right workflow between
fragments from various READMEs and the source code for the module and the
tools, but without much luck.  Is there a basic recipe available for
building even a 2-port VALE bridge with netmap (igb) interfaces, with
perhaps some output (log entries, etc.) to validate that the configuration
is behaving as expected?

We get lots of log messages that seem good, as well as many whose meaning
is unclear (they only appear with "verbose" set, but seem to indicate
unexpected happenings), and we see packets enter the bridge and the
learning loop executed (although unfortunately there doesn't seem to be any
way to inspect the current state of the FIB), but no packets actually
egress from the device.

Thanks,
Nick