"/netbsd: arpresolv: unable to enter address for xxxxxxxx(some ethernet)"
   and
   "/netbsd: arpresolv: unable to allocate llinfo"

That should be fixed.

   and when I set the network to be down
   "/netbsd: le0: crc mismatch"
   and
   "/netbsd: le0: framing error"

This seems to be what happens when it overflows the ring buffer and
can't accept an incoming packet.  This doesn't seem to agree with the
documentation, though.