How to test: Ethernet physical port

[adam9c1]

I'm working on an iMac.

I think it passes the Hardware Test (another tech did not say it failed).
I did a clean install of Lion and ML on an external USB drive.
Under both installs I do not see the icon change to green, I'm unable to get IP, the state says unplugged.

Will a physical loopback adapter test the connection if I hardcode IP?

 

[Bear]

Have you tried more than one ethernet cable? Maybe you're plugging into a bad port on the other end. Whatever you're plugging into.

 

[adam9c1]

I plugged in different cables to different ports of an unmanaged switch.
I have also plugged in a cable to a wall jack (wherever that goes).

I have also tried to force set (randomly) different speeds and duplexing (did not try all the possibilities).

 

[Bear]

I plugged in different cables to different ports of an unmanaged switch.
I have also plugged in a cable to a wall jack (wherever that goes).

I have also tried to force set (randomly) different speeds and duplexing (did not try all the possibilities).

You said the icon doesn't go green? What icon are you talking about? What color is it? Also, grab a screenshot of the window you're talking about and post it here.

 

[adam9c1]

Here is a screenshot...

 

[Bear]

Here is a screenshot...

It is possible the the iMac could have a bad ethernet port and still pass the tests.

First thing you might want to do is look at the ethernet port on the iMac and see if the wires in it appear to be in the right place and not mangled.

Second, take the problem machine and connect it to a known working port and cable that you've just tested with another Mac.

And finally if you didn't run the hardware test yourself, you might want to do so.

 

[marsmissions]

Switches and Wall ports don't always assign IP addresses using DHCP, you may need to assign that on your own to get a connection.

 

[RedReplicant]

What is the setup you're trying to do here? If you're plugged into an unmanaged switch that isn't connected to anything else then you're not really connected to anything.

 

[Bear]

Switches and Wall ports don't always assign IP addresses using DHCP, you may need to assign that on your own to get a connection.

If the iMac had a physical wire connected to another device, it would not say "Not Connected" it would say something more like no ip address assigned.

What is the setup you're trying to do here? If you're plugged into an unmanaged switch that isn't connected to anything else then you're not really connected to anything.

As said, wouyld still have the electrical connections. I suggested using a known working port and cable to eliminate everything outside the Mac.

 

[adam9c1]

I took the screenshot shortly after disconnecting the USB - Ethernet adapter.
That's probably it still says set for DHCP.

 

[Bear]

I took the screenshot shortly after disconnecting the USB - Ethernet adapter.
That's probably it still says set for DHCP.

A screenshot when it isn't connected to a network port isn't as useful as one from when it is connected as is might have been yellow or it might've had a useful status shown.

 

[RedReplicant]

As said, wouyld still have the electrical connections. I suggested using a known working port and cable to eliminate everything outside the Mac.

Try it, plug a computer into a -switch- as the only thing plugged in to it. The machine will report network cable unplugged.

 

[FreemanW]

Here's an idea . . .

1) Bring a known to be functional computer into the mix.
2) Nail down a working network and then troubleshoot the iMac.
3) Profit.