On 27Jul2021 15:22, Tom Horsley <horsley1953(a)gmail.com> wrote:
Never mind. I rebooted the router and it works now. I've noticed
a lot of weirdness with this router (Netgear Nighthawk RAX200)
and routing between wired and wireless devices on my local network.
You'd think a top of the line router could get that right :-(.
We've got a few unmanaged netgear switches here and have had some
weirdness ourselves. I have lossely discovered that having my Mac on
both ethernet and wifi at once causes the LAN to go sour.
I imagine a Linux system might do similar stuff (I know from bitter
experience that the Linux IP stack default behaviour answers on any
interface for any of its IP addresses, causing hard to debug pain if you
plugged in multiple ethernets to the wrong ports.)
My theory (unverified as yet, but supported by "did you just plug in
your ethernet? the internet's gone away!" complaints) is that the Mac
answers ARP requests on both the wifi and the LAN, suggesting to the
switches watching traffic that (say) its ethernet address is also
available on the wifi, and/or vice versa.
The local network topology is like this:
fw ---- desk-switch ----living-room-switch ---- airport-wifi
|
+--- secondary-switch ---- mac-ethernet
This might confuse the desk switch about where to send packets for the
Mac and seemed to have secondary effects for other users of the LAN
(loss of local connectivity). I'm imagining the MAC<->port tables in the
switches became insane.
Now I run my Mac in wifi only or LAN only, and the problem has gone.
Cheers,
Cameron Simpson <cs(a)cskk.id.au>