Ethernet port not working with a Gigabit switch

Check your cable. CAT5 will not support 100MB or 1GB speeds. You will need CAT5e or CAT6. It may seem to work with some hardware, but have a very high error rate. Some NICs are smart enough to step down the speed under those conditions. By the way, the mini is smart about how it sets network speed. It does step it down when it is in sleep mode and still listening to the network, for example. I did try to set it manually before I realized what it was doing. DIdn't work. Not sure if the mini will try to override a bad configuration. It wouldn't surprise me if it did.

Also, please clarify. Mac Minis don't have a separate network card. Are you talking about the builtin ethernet controller? My mini is a 2010 and has the Broadcom 57765-A0 ethernet controller.

Thanks: the CAT5 has been working fine at 100 for years (anyway I can't face pulling up floorboards again). We have an old house on 4 floors... We haven't noticed any error rate problems - the network has always been responsive even when playing back DVDs. The reason for wanting to up the speed is that we digitised a load of 8mm and Super8mm to a high resolution (as basic originals). Now I am trying to copy each one to my Mac to process it, add voice-over, music etc. Trouble is that these files are 11GB in size (and more) and the network just cannot cope. I bought the gigabyte switch but the Mac refuses to play! Copying up to my local machine for processing with iMovie can take 4 hours (!!!!!) for the larger files whereas with the PC that synchs with the 1000 network it just takes 20 minutes... Yes I am speaking of the built in ethernet controller.

@agent-p might be right about cabling, but if it was working in the past, it's probably that notorious bad software driver problem... I ran into this a few years ago (posted some things about it upthread), it was a difficult problem to solve.

A couple of software-related things you might try that have worked for some people:

- Apply all updates

- Delete the network connection & reinstall them

- Upgrade to a newer OSX version

- Try a better/different Cat6 cable

If you have done those things (or can't upgrade the OS), then I would look at the switch you are using. It turns out that whatever updates were done to the ethernet driver made the hardware very, very picky about auto-negotiation. It's pretty complicated, but what it boils down to is that a lot of cheaper switches were not adhering strictly to the standard and that caused auto-negotiation to fail. If you look at your kernel logs, you will see the error messages about this...

I went through six different switch brands before finding that Cisco switches don't have a problem. I also think HP units will work well, although I can't be sure as I got new hardware and can no longer test. The solution that worked was a Cisco Linksys SE2500 8-port switch. I tried switches from Trend, Dlink, Asus, Zyxel, Netgear and a couple of no-names before this fixed the issue.... I also have an HP Procurve 1810G which worked well, but wasn't fully tested before I bought a new iMac.

And also - if the Mac were working properly surely it would step down to 100 even if the switch was offering 1000 As it is it simply gives up. Puzzle - I am kind of glad there is so much written on it but depressed that there isn't a straightforward answer.

Sorry, but I think it is your cable, and you probably have a high error rate, as well. You might not notice it for DVD playback. I can stream HD to 2 appleTVs of the 10MB portion of my network and I don't notice any issues.

In any case, doing some quick math. Your 11GB file should copy over in about 2.5 hours on a 10MB network. 4 hours is excessive even at the slower speed. Has to be a significant error rate in there. I can't account for you PC working at 1GB on CAT5. It shouldn't work. I have tried it a couple of times, and it has never worked for me. Maybe you actually have CAT5e and don't know it.

What you can do, to verify it is your mini that is giving you the problem, is connect it directly to your PC. The mini should be smart enough to reverse RX and TX (there are crossover cables available if it isn't). Use a CAT5e or CAT6 cable. They are relatively inexpensive purchased online. If you mini is working you should be able to set up a 1GB peer to peer connection. If you mini's networking is broken it should show up when you try to make the connection.

Thanks everyone, I will look at this again tomorrow - meantime I will probably reinstall my 100 switch as I have a rat's nest of cables around my desk right now as I bypassed the house cabling!

It's probably not as hard as you think to replace the old Cat5 cabling. Typically, it's just loose in the wall/floor and old Cat5 makes a great pull wire... You can probably just open the wall plate and check if pulling it creates movement at the other end. I would generally suggest that you don't have to replace all the cable, just run one Cat6 to each floor, then put a switch in at that floor for your Cat5 runs. If you decide to this, make sure you get Cat6 that's designed to be in a wall and make sure your cable can't come loose when you pull it through (BTDT, not fun).

Also, given what you are doing, I would suggest you get a good quality switch. I had pretty slow speeds on my backbone until I upgraded to the HP Procurve which has significantly higher backplane speeds, thus better overall throughput.

In general, it's a good idea to have a core/backbone 'heavy duty' switch and smaller downstream switches if you have a lot of end-points and/or you are saturating the network. I use the Procurve as a backbone and several smaller/cheaper switches (Cisco/Netgear/Trend) downstream one in each room. It makes things significantly faster by segmenting the network and allows for easier future upgrades. Given how cheap you can get a 'pro' used switch, it's an easy upgrade.

Finally, you might try using wired & wifi simultaneously. Depending on how you network is setup, you might get aggregate bandwidth. If that doesn't work, there's always sneakernet. It's amazing how fast you can transfer stuff with an external hard drive....

Thanks again for the extra comment (ckm5). I'm not so sure that it will be that easy everything is very tidily out of sight...

However I better correct a couple of things - I was lazy in an earlier post.

The 3 or 4 hrs copy time was for a 26GB file from my HP server running at 1000 to the Mac Mini (100)

The 17 min copy time was for 11GB file from the HP server @ 1000 to the PC @ 1000

Before dismantling the new switch I plugged in an even older MacBook Pro (2007 vintage) and it instantly synched at 1000 and copied a file up in an acceptable time.

I also confirm that I plugged my Mac Mini directly into the gigabyte Hub with no success.

What is puzzling is that it doesn't simply step down to 100.

It just refuses to work at all.

On the switch the light pluses very slowly - looking at the port attached to the PC the activity is as expected.

The switch I have is a Netgear but I have never had problems with their kit in the past.

My main router is a Vigor and my WiFi is served by a Netgear WAP which has worked superbly. Anyway this doesn't have a bearing on the current problem.

I agree with the principle of a heavy-duty backbone but this is only a home installation and the longest cable run is probably not more than 20m of cable (allowing for routing through floors and around doors etc).

I tried few 5e cables before trying crossover cable. Why it works? I do not know. I tried it because somebody posted that as a solution already. My post was just to confirm that it worked for me too.

Thanks for the clarification. Definiteily sounds like the mini's networking. Has the mini ever worked at 1GB?

Try wiping out the network configuration. You can find the location of the file to delete by Googling it. A restart should recreate the file with a default configuration.

If that doesn't work reload or upgrade your OS. You can try just reinstalling the network drivers. I have done it once before, and I remember it being very tedious. I don't recommned it.

If none of that works it is probably a hardware fault. I have never heard of the network controller failing the way you describe, but I expect it is possible. That leaves you with sneaker net or a refurb mini. Gainsaver.com has some pretty inexpensive refurb'd minis if you want to replace yours. I got my 2010 model from them, works great.

I don't think the Mini has ever worked at 1000 cause I never had a switch.

Will try wiping the network config - good idea.

I don't think I am in the market for a re-install - I am sure it is tedious and thanks for warning!

Might look at Gainsaver - thanks

Re: Netgear - BTDT, had several that worked fine for years, then just didn't work with the Mini anymore.... It's a problem with the router, some of them don't confirm EXACTLY to the spec. For all other systems, it's not an issue, but for the Mini with 10.6 and certain updates, it's a problem. It's even more of a problem because if you take it to an Apple store, they will plug it into their Cisco gear and tell you there is nothing wrong. The only real solution is to either do a clean install of 10.6 and never upgrade, upgrade to 10.7/8/9, or get a switch that is conforming to spec*. Wy wife has the exact same Mini as yours, had the same problems which went away with the Cisco switch install...

Based on your network description, you actually already have a backbone-based system. In this case, either your Vigor or Netgear WAP is the backbone router. I have roughly the same setup, with even shorter runs. I found my old main switch (also a WAP/router) was becoming saturated when running at full speed, causing lots of dropped packets, slowing everything on the network down. Hence my upgrade, now I have: internet modem/gateway -> WAP/router/firewall -> core switch -> local switch. All of the 'server' stuff hangs off the core switch (NAS, video server, etc) and all the 'desktops' are attached to the local switches. We have something like 15 devices on the network, wired & wireless, everything pretty much runs at full speed.

Finally if 'very tidy' means in the walls/floor, then you have it easy, you can mostly likely pull new wire with few issues as it's unlikely to be attached anywhere other than the outlets. If it means 'stapled along the baseboard', forget it.

*ps - all Gig-E 'hubs' are in fact switches. Hubs only work upto 100baseT. The main difference between cheap & more expensive switches is generally management capabilities and better hardware.

Hi ckm5 and thanks very much for the trouble you've taken. I will try changing the Netgear (it is brand new out of the box). Apple are curious they design perhaps the most elegant and robust machines but their support thereafter is really quite poor. Anyway let's not get on that. I deleted the plist files - no use. Reset PRAM NVRAM and so on - nix. The point as far as a support call is concerned is that the machine spec says 10/100/1000 - it is just that I have never had occasion to worry about that before. Hacking into town to see a so-called Genius has never really worked in the past. I've always discovered a workaround or solution. I will post again later once I have further news. Surely there must be a bit of code that can correct the issue?? All the best.

Just before paking up the netgear I plugged the Mac Mini directly into the Vigor router which has a 1000 port; same issue. I think I'd tried that yesterday but I was double-checking. So I believe the problem really lies with the Mac Mini not the kit. I don't want to buy a more expensive switch just to have the same problem. PCs work, other Macs work, it is just mine that doesn't.

On the PC that syncs at 1 Gb, if you have a 2nd PC, try running netcps. I'm not sure what I was looking for at the time but, I had some concern about the bandwidth through my gigabit switch so I devised a test. Netcps is a PC program and I found that Parallels was emulating a 100mb connection so I moved on to a 2nd test setup. My older Mac Mini (3,1) is used on my TV and it has some data files for EyeTV. I FTP'd into the machine and retrieved several large files to get an average transfer and was satisfied that the gigabit switch actually had enough bandwidth in the switching fabric. I just tried did a test retrieve. The file I transferred was 6.8 GB and it took 1 min 51 seconds. Based on the math, your 20 minute transfer would not be 1 gigabit. Since FTP is more efficient, try using it to test transferring files across your network to see what your data rate actually is. When I first did my gigabit test, it was just 2 devices on the switch. The test I just ran for this post had all my other network devices so they were tapping into my bandwidth.