On Jan 29, 9:54 am, Gordon wrote:
... His friend has the same issues on his. Two faulty talkers? ...

That wouldn't surprise me, but bad cables are more common. It is
super easy to make a bad cable and the installer will probably have
had to make up several in each network. Of course, Raymarine could
have screwed-up the cables, too. In my experience, now very dated,
faulty cables made up the majority of problems on LANs followed by bad
NICs. We occasionally got whole lots of faulty NICs... Switch
failure was pretty rare.

-- Tom.