Gigabit ethernet not working, but thunderbolt adapter is

[mdelrossi]

Gigabit ethernet not working, but thunderbolt adapter is.
The internal ethernet port only connects at 100baseT, however the thunderbolt to ethernet adapter connects at 1000baseT.
Late 2014 5K iMac
Mojave 10.14.5 New install , migrated settings and docs from previous system ( it stopped working a while ago with sierra, don't recall when)

Ethernet:

MAC Address:

Media Options: Full Duplex, Flow Control

Media Subtype: 100baseTX

Proxies:

Exceptions List: *.local, 169.254/16


Any ideas?

thanks
mdr

 

[jerwin]

There's an option to configure the Ethernet Port manually or automatically.

You can select 10BaseT,100BaseTX or 1000BaseT. Gigabit is the last option. I take it that you're plugging the same cable into the thunderbolt adapter?

 

[mdelrossi]

There's an option to configure the Ethernet Port manually or automatically.

View attachment 838499

You can select 10BaseT,100BaseTX or 1000BaseT. Gigabit is the last option. I take it that you're plugging the same cable into the thunderbolt adapter?

Thanks,
I forgot to mention I tried to set it manually but it just disconnects.
And yes same cable.

thanks
mdr

 

[HDFan]

What are you connecting to?

 

[jerwin]

One troubling possibility (besides the two year old bug in the ethernet driver ) is a bad connector---1000baseT requires all 8 pins.

http://blog.biamp.com/a-few-things-you-may-not-have-known-about-ethernet-cable-construction/

 

[mdelrossi]

What are you connecting to?

Asus router, that's how I found out that I was not getting the proper speed, to Synology NAS(thats a whole 'nother ball of wax).

One troubling possibility (besides the two year old bug in the ethernet driver ) is a bad connector---1000baseT requires all 8 pins.

http://blog.biamp.com/a-few-things-you-may-not-have-known-about-ethernet-cable-construction/

Yea saw that and tried it, no help.
thanks
mdr

 

[HDFan]

Asus router, that's how I found out that I was not getting the proper speed, to Synology NAS

The internal ethernet port only connects at 100baseT, however the thunderbolt to ethernet adapter connects at 1000baseT.

Is there a way that you can run a test connecting directly to the NAS? That's exactly the problem that I had with my Cisco router/Firewall. It negotiated to 100 Mbps rather than 10 Gbps to my iMac Pro. Turns out it is a bug in the Cisco firmware so they had to create an enhancement request.

 

[mdelrossi]

Is there a way that you can run a test connecting directly to the NAS? That's exactly the problem that I had with my Cisco router/Firewall. It negotiated to 100 Mbps rather than 10 Gbps to my iMac Pro. Turns out it is a bug in the Cisco firmware so they had to create an enhancement request.

I’m getting the info directly in the router status pane and in system report, so the problem is in the iMac.

 

[HDFan]

I’m getting the info directly in the router status pane and in system report, so the problem is in the iMac.

My Cisco router did exactly the same thing. The router port status table showed that the port was 100 Mbps rather than 1000 Mbps. It is then an open question as to whether it is a Mac issue or a Cisco issue. Since Cisco support created a feature request and didn't point their finger at Apple I assume that they felt that it was their problem.

To illustrate I moved my iMac Pro ethernet cable from the 10 Gb QNAP switch to the Cisco port 2. You can see it shows as 100 Mbps. Note that the RV340 only supports 1 Gb.

but maybe I'm missing something here ...

 

[Fishrrman]

Unless you need the thunderbolt port for something else, why not just "use what works best" -- the thunderbolt/ethernet adapter...?

 

[cube]

What is the length and category of the cable?

 

[mdelrossi]

I'm getting 1000baseT speeds to the NAS ( as shown in activity monitor)with the Thunderbolt to Ethernet adapter.
I'd like to not have to use thew adapter as i might need to use the TB port soon.

 

[cube]

There could be a negotiation problem and the speed must be manually set on the switch.

Also, a router may have different kinds of ports.

 

[antonypg]

I had an iMac that refused to work at gigabit speeds when connected to a couple of gigabit switches I had, worked fine at 100MBit. I took it to the Apple Store and they confirmed the fault, they swapped out the motherboard for free (still had AppleCare).

 

[HDFan]

I'd like to not have to use thew adapter as i might need to use the TB port soon.

Have you considered getting a TB dock?

https://eshop.macsales.com/shop/doc...tYvfXE21dDVB1USXhsBoCGocQAvD_BwE&gclsrc=aw.ds