Ethernet port not working with a Gigabit switch

Re: Mac vs kit. I've BTDT, exactly the same path you are going....

1. For whatever reason, the Mac becomes sensitive about auto-negotiation

2. Apple will tell you it's a motherboard problem & sell you a whole new machine

So, you have several choices to fix this:

1. New machine

2. New OS

3. New Cisco switch

I choose #3 as there were several critical apps that required 10.6, it was a $50 fix. http://www.newegg.com/Product/Product.aspx?Item=N82E16833124417

As for some bit of code fixing the problem, probably. I'm sure there is a kernel driver that you could compile that would fix it, I just never bothered to go that far....

OK I've returned the Netgear kit and I will order a Cisco switch but I am going to have to put this on hold for a few days as I've got behind on my work. Thanks to everyone - if ever a kernel driver surfaces....

Amazing this thread starts in 2009 and continues up till a day ago. I noticed not being able to attain gigabit speeds on my 2008 Mac Pro, 10.6.8 (snow leopard), using Cat 6 wire, and a Zoom Gateway Router/modem. As in the original posts, the ethernet port doesn't sense being connected if put in manual mode at 1000 speed. When put in auto mode, it shifts down to 100 speed and does work. I read through about half the posts, and what struck me was that a disproportionate number of folks complaining were using Snow Leopard, and many, though not all, cured their problem but upgrading out of Snow Leopard. Since I have the older 10.5.1 on another disk in the Mac Pro tower, I tried starting up in that OS. In the auto mode for ethernet, it still reverts to 100 speed; however, I can manually set it to 1000 with flow control, and it works (which didn't work in Snow Leopard). And the machine is noticeably snappier when surfing the web in that circumstance. So end result of the experiment is that only changing the operating system did make a difference in attaining gigabit speeds and the port being active.

My overall guess, not being a network expert by any means, is that the causes of the issue are multifactorial, which is why no one fix works for everybody. If I had to guess, some combo of the cable and the switch in the gateway router is generating too much noise/incompatibility/interference/whatever to make the signal optimal for gigabit, AND Snow Leopard is somehow more picky in the negotiation process such that it will not allow much noise at all before giving up on that port. The reason I say that is that OS X 10.5.1 also prefers to set the negotiated rate down to 100 if given the choice in the "auto" mode. It is sensing that 100 may be more stable, but if you insist on gigabit, it's not going to refuse you. Perhaps when they built Snow Leopard, they believed too many bad things were happening if gigabit was allowed as a choice in the manual mode in the face of a noisy line/imperfect switch, but that's just a wild guess.

Anyhow, that's my 2¢ of guesswork (from a non expert). Just food for thought. Maybe my experiment will help narrow down the problem.

I have a new dual band, ac Linksys router on order (EA6200, $69 at Best Buy on black Friday weekend) and a new Motorola modem coming as well, and I'm hoping the linksys magic will work here as it did for some others in the thread. The Zoom router was based on a Broadcom chip, and I suspect the Linksys is based on a Cisco chip. I do actually believe it may work, although the Zoom is not that old a box. I have heard that these gateway router/modems are mediocre at best in performance relative to picking highly rated independent routers and modems (although they certainly do cut down on the wiring, etc). If this doesn't work, then I'll also upgrade to Lion and perhaps Mountain Lion later to see if that helps.

Hopefully I'll remember to get back to this thread to post my findings. Will take a week to know, though.

rickkkk makes good points. I have abandoned gigabyte for the present but will borrow a switch and run a series of tests with various combinations of cable and machines and O/Ss when I can find time. It is worth noting that on the machine I am using this moment (MacBook Pro) 10.4.11 it synched at 1000. Otherwise my experience is as rickkkk's and others. The common element in the machines with problems is OSX 10.6.8 Where there have been solutions other factors are red herrings for the most part although I suspect that an occasional "cocktail" of switch and cabling (type and length) can give a result. The trouble is that there are so many components in the mix that one can never be 100% which solution is the right one. This is where the community system while hugely comforting and often helpful breaks down; the advantage is at least you learn you aren't alone in experiencing a problem (thus it isn't your own error that caused it). The disadvantage is that there is no-one from Apple ready willing and able to propose a solution. Apple kit is expensive and beautifully engineered; users deserve more than self-help especially for such problems. It seems to me that someone ought to write a new / corrected driver or drivers (I don't now if every machine has the same ethernet port) for 10.6.8 I am not mean but don't see why I should be forced to upgrade simply to address a very specific issue. I am going to visit the Apple Store and see where I I can get with a "Genius" - I am not holding my breath.

Thought I'd chip in here with what I've discovered. I have a gigabit network setup, with a Cisco/Linksys gigabit router connected to a Netgear ProSafe gigabit switch. Connections between the router and the switch are showing as gigabit and connections from the switch are showing gigabit connections (2 green lights).

On my iMac (whch is a mid 2011 model) with Mavericks installed, the Broadcom ethernet refuses to show as linked at gigabit speeds. Network Monitor shows 100Mb/s link speed. Also, manually changing the ethernet to 1000BaseT in the system preferences just refuses to connect.

Here's the good bit - I've installed Windows XP as a virtual machine through VMware. The network connection shows as 1Gbps.

So, for all those with this problem, convert your Apple machine to a Windows one using a VM.

I have found no way to solve the problem and can only guess that it is an Apple bug that has lasted for the best part of 4 years.

Same for me. I tried everything - eventually I bought the Lynksys SE250 for £31 and it worked perfectly (and I have three more ethernet ports). This is something that Apple should have sorted out though!

BW

Dennis

Just to shed a little bit of light on this, I just started having this issue today. My ethernet port was working like a champ, but then it wouldn't connect at all. After finding this post and doing some testing here is what I've found.

System Info:

Model Name: MacBook Pro

Model Identifier: MacBookPro8,3

Processor Name: Intel Core i7

Processor Speed: 2.2 GHz

Number of Processors: 1

Total Number of Cores: 4

L2 Cache (per Core): 256 KB

L3 Cache: 6 MB

Memory: 16 GB

Boot ROM Version: MBP81.0047.B27

SMC Version (system): 1.70f5

Ethernet card info:

Broadcom 57765-B0:

Name: ethernet

Type: Ethernet Controller

Bus: PCI

Vendor ID: 0x14e4

Device ID: 0x16b4

Subsystem Vendor ID: 0x14e4

Subsystem ID: 0x16b4

Revision ID: 0x0010

Link Width: x1

BSD name: en0

Kext name: AppleBCM5701Ethernet.kext

Firmware version: 57765-v1.37, 0x7cfcc847

Location: /System/Library/Extensions/IONetworkingFamily.kext/Contents/PlugIns/AppleB CM5701Ethernet.kext

mDNS offload capable: 70:cd:60:xx:xx:xx

Version: 3.6.9b9

The issue started when I was trying to connect to an enterprise level switch locked at 1000baseT. I got the "cable unplugged" message. After troubleshooting the normal stuff, (cable, switchport) We unlocked the switch link speed and set it to auto... I connected at 10Mbps. I then tried to place a 10/100 hub between my MacBook Pro and the 1000 switchport. I connected at 100Mbps with the slower hub in place.

Ok...

So back to the direct connection to the 1000 switch. I then manually set my MacBook Pro ethernet port to 10Mbps with full duplex. Success.

I then tried to set my ethernet speed to 100Mbps or 1000Mbps with full duplex. No dice.

To me, this proves that the physical hardware is working. This is looking to be a firmware issue with my NIC. I have checked for updates... None available. Lets see what the Apple store has to say about this as I need to have faster speeds than 10Mbps for my job (IT professional) without carrying a 10/100 switch everywhere with me.

Good info wifigeek.

If I had a firmware issue with my Broadcom then wouldn't my windows VM also show a non gigabit connection?

In the end it'll probably be just apple making us spend more money on upgrading pieces of kit again. Looks like I'll have to buy a new router at this rate etc etc, or just go buy a fast windows laptop and be done with it. Shame really.

Come on Apple. You must read these postings!!

Your Windows VM would depend on the settings. When you install a VM program (parallels or VMware) it creats a virtual switch to go between your Mac and the VM. Make sure your VM is bridged directly to your ethernet NIC to get an accurate reading. It may be showing the virtual connection between the VM and your Mac.

Ok. The issue started when you were trying to connect to a enterprise level switch locked at 1 gigabit and you got a cable unplugged message. When you set the switch port back to auto, it would only connect at 10 Mbps. Are you using a cat5e or cat6 cable between the Macbook Pro and the switch? The 10 Mbps sync says that is highly doubtful. Gigabit ethernet requires all 4 pairs (8 pins) to have connectivity. A cat 5e cable can handle gigabit ethernet over a short range but the errors will build. A cat 6 rated cable will meet the requirements for running gigabit. Apple's fault may be setting a zero tolerance for networking smoke and mirrors. To run gigabit ethernet, the path from one end to the other must be rated for that standard..period. Someone posted their transfer numbers for a "gigabit" connection and numbers didn't add up. The networking gear gave you the false assumption that you had connected at a gigabit rate but when you transferred data, the rate was closer to 100 Mbps than 1 gigabit. I set up a connection between 2 Mac mini's on my home network - mac mini, gigabit switch, mac mini. All of the cabling was rated for cat 6 (gigabit). I transferred several multi-gigabyte files using FTP. The transfer rates matched up with what can be expected for a gigabit connection. The test was to verify if the backplane of the switch was delivering the full gigabit of bandwidth. Before this test setup, I had planned on using netcps on a Windows XP VM on Parallels 7..busted. The network speed maxed at 100 mbps. I don't know if that was a configuration issue. I have not tried it again since the Parallels 9 upgrade but the point was verifying the switch networking bandwidth.

New to this thread but figured I'd chime in. Bought my wife a new iMac 21.5" (16G RAM, 1TB HDD, 2.9G Quad-Core CPU) for Christmas and she loves it. Was using it with wireless broadcasting from my Dual-Band Airport Extreme Model A1143 which is supposedly gigabit capable so I decided that a Cat6 cable would be better now that she's decided where its home will be. Bought a 50' 24 AWG UTP Ethernet Bare Copper Cat6 cable and ran it. Its connected to my new Netgear ProSafe 8-port Gigabit Switch (GS108v3). Showing 100MPs (one LED not two), but _ALL_ my other connections are showing two (2) LEDs which means gigabit connections.

Curious about whether there's a reliable way to double-check our iMacs and see if there's some settings I need to change to make sure the brand-new iMac is using Gigabit. My imac is an older late 2007, early 2008 24" running Mavericks OS X v10.9.1 in 64-bit, has 6G RAM, Intel 2.8GHz Core 2 Duo with a 500GB HDD. I ordered a new Apple Airport Extreme (AC capable) and should have it tomorrow or Tuesday. Wanted better wireless coverage for the iPads, and my MBP around the house and in the garage... hoping the 6 antennas are a big improvement over my old AE.

Still... I'm a bit baffled as to why the new iMac isn't showing 1000 on the Netgear, and I even tried swapping ports on the switch... no dice.

Mike

I have kind of the same problem with my mac mini early 2009

It wasn't working in OSX (status cycling between no cable and connected.)

BUT is was working fine in Windows 7 32bits for months.

Until suddently it didn't work any more.

I then uninstalled and reinstalled the drivers and it would work until I put the computer to sleep. but even that doesn't work anymore.

I have tried A LOT.and spend A LOT of time on trying to get this to work.

I have tried:

crossover cable

multiple cat 6 and 5e cables

different routers/computers

different drivers

flow control

multiple drivers in windows.

I can only get a connection if I set it manually to 10Mbps. Otherwise the leds in router or other laptop doesn't even light up.

10Mbps kind of defeats the purpose of LAN when I have a 300Mbps internet connection.

Is it possible to somehow manually reset network settings, update firmaware or drivers in OSX? (I'm a Windows guy)

Come on Apple send out a fix, A LOT of people are having trouble with their NICs

I am sorry for you but I am afraid that no one in Apple is even remotely interested. I have just spend nearly 8 hours wading through knowledgebase articles, white papers green papers forums and so on to find out how to update AV on our servers (nothing to do with Apple - this is just an example of the disconnect). I eventually got there but only thanks to guys on the last forum I logged into. It is the same here. Someone somewhere may have solved this problem but unhappily they haven't shared their solution - or maybe it cannot be solved.

You might be able to write a driver but presumably you've better things to do!

With millions of lines of code and economic pressures to sell new versions (sometimes not as good) of the software there is simply no-one interested other than people like us who are stuck and might have found a possible solution.

Luckily I was able to return my gigabyte router... I am on 100 and it works fine for most things - we can stream video to our movie projector, we can do everything we need to do, just a little hesitation from time to time.

Large files (17 GB) have to be copied to a local drive which is a pain.

All the best.

I have lots of different kinds of Macs: iMacs, minis, laptops, even a MacBook Air, and I have never seen the kind of thing you guys are describing. I was a little troubled at first when my mini would reduce speed spontaneously. It was a bit of a puzzle until I realized that it did that behavior everytime it went to sleep, a power saving feature I am guessing. It goes right back to 1GB as soon as it wakes up. The behavior is consistent with a number of routers: TimeCapsule (two of them), Linksys 8-port GB switch, and DLink 24-port GB switch. I can't account for it working with Windows 7 which I assume is being run in a VM and not the host Mac OS. Sort of eliminates the Mac's hardware, though.

I suppose that whatever switch or hub that is being used could be defective or incompatible with the Mac driver. By the way, have you guys that are having problems checked to see if the switches you are using are managed, and if there are some settings that are non-optimal for the Mac? Only thing that could really be causing it if your Mac hardware and driver are okay, and the switch isn't defective, of course.

Also, if you want to reset the netrwork settings for your Mac, you can simply delete the configuration file. I forget where it is and what its name is, but a simple Google search should get that for you. I have had to do it a couple of times when I was playing with Wake On Lan. Resets it just fine.

I don't use the 8-port switch any longer, but for those who are interested. All of my Macs (even my old Titanium Laptop) are working at top speed with a DLink DGS-1024D 24-port GB switch. Runs cool, quiet, and fast. I have had it running continuously for about 9 months. No complaints, so far.

Sorry, you guys are having a tough time with this. Hope this helps a little.

Thanks thangkho, that really worked for me with an Imac8,1!!!