Bridged ethernet on Late 2009 iMac (10.8.5)?

Hi guys,

I figured I’ll give this bridged ethernet a shot. I have a slightly different setup than most here, so I’ll explain that first.

Until now, I have been running Roon Core on my Late 2009 iMac which is running Mountain Lion (10.8.5). The router/modem with internet is in another room far away, while the iMac and the Bryston BDP-1 are in the same room close to each other. I don’t have ethernet running throughout the house.

The iMac is connected wirelessly to my modem/router, which access the internet and lets Roon run. I have selected wireless as the preference in top order in network setting. In order to connect the BDP-1 to the iMac, I have a spare router (with wireless disabled) and a switch (w/ LPS) that I keep in the listening room. The iMac/spare router/switch/BDP-1 are connected by ethernet. This works perfectly.


So I figured I’ll try the bridged ethernet. The iMac has an ethernet port and no thunderbolt. So I got a USB to ethernet Apple adapter. All of them show up Network devices and active. I’m connecting the BDP-1 and iMac directly with ethernet. I’m using the USB to ethernet adapter for connecting to the spare router/switch in the room, so it can assign stuff.

When I go to System Preferences -> Network -> Tools (geal symbol) drop down -> Manage Virtual Interfaces -> +…I see two options for “New Vlan” and “New Link Aggregate.” I don’t see an option for 'New Bridge". I do see this option on another Mac running Sierra.

Is there any way I can make this work and feed the BDP-1 directly by the iMac? I’m running 10.8.5 on Late 2009 iMac.

Any advice would be helpful. Thanks!

Seems like you’ve deduced the answer to your question. It doesn’t appear that 10.8.5 supports bridged Ethernet.

Maybe…perhaps there is another way to do this manually.

Anyways, I got it working on MacBook Pro running Sierra w/ a Thunderbolt-ethernet adapter for the BDP-1 and a USB-ethernet adapter for the router.

I compared:

  1. bridged direct connection
  2. Switch powered by Teradak LPS
  3. Switch powered by Teradak LPS plugged into the Torus isolation transformer.

Tried it with Cat6 UTP and Cat 6a SSTP on all three settings and did a lot of switching. I preferred #3 the most. The Torus is quite valuable. Direct bridged was last place. Still a lot better than using Powerline adapters.

Unless there is something magical about the built-in ethernet port about the iMac over what’s possible using the MacBook Pro’s thunderbolt-ethernet adapter, I think this will end my journey into bridged ethernet.

I already have the network isolated data wise on the closed ethernet system. It’s reserved for Roon.