Ethernet port not working with a Gigabit switch

Question

Level 1

13 points

Ethernet port not working with a Gigabit switch

I have a MacMini (Early 2009). I fails to connect at gigabit ethernet speed when connected to either a netgear GS605 switch or a brand new Airport Extreme base station.

I have tried different cables, different OSs (both 10.5 and 10.6).

When I force it to 1000baseT the connection jumps between connected and not connected.

This is getting ridiculous, that Apple can't make it work properly, as there are lots of others that have the same issue.

Does anyone have any ideas?

MacBook Pro Santa Rosa 2.2GHz, Mac OS X (10.6)

Posted on Sep 21, 2009 7:13 PM

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Answer 1

rm82

Level 1

8 points

Jan 7, 2017 1:13 PM in response to mouson

FWIW, I'm having the same problem on my 2009 Early Mac Mini.

The same cable connected to my 2014 Macbook Pro shows gigabit, but on my Mac Mini it says 100mb.

Here is what I've discovered.

I was running OS X El Capitan (10.11).

I downgraded to 10.9 (boot off USB drive). Still 100mb

I downgraded to 10.8. Still 100mb

I downgraded to 10.7. Still 100mb

I downgraded to 10.6 (the original OS the Early 2009 Mac Mini ships with) and got 1Gig! Same cable, same Netgear gigabit switch.

So now I'm checking to see if the apps I use are supported by 10.6- If so, I may just keep 10.6

I wonder if there is a way to take the drivers from 10.6 and see if they'll work on a later version?

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Answer 2

rm82

Level 1

8 points

Jan 7, 2017 1:45 PM in response to rm82

Ok well after I wrote my comment above, I restarted my Mac Mini and let it boot off its local drive (running 10.11).

Now it's connecting at 1Gig!!?? I disconnected, plugged into a 100Mb switch, and it shows 100Mb. Then I connected it to a gigabit switch, and it shows 1Gig. Restarted, and same behavior. Some reason it has resolved itself for me and I have no idea why.

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Answer 3

Jul 23, 2017 7:56 AM in response to rm82

I noticed the same problem on my Mac Mini (2012) last night and upgraded to Sierra OS in the hopes it would fix the problem but no joy.

I have an office with 4 RJ45 ports connecting to a gigabit switch (which connects to my Sky Router) located in my mini data centre under the stairs (I tried multiple cables (Cat 6 & Cat 5E) and plugged directly to the router (avoiding gigabit switch) & calling Apple Support (it was suggested I bring the Mac to store for investigation) with no joy). Finally, I connected my mac directly to the gigabit switch with a Cat5E cable (extra long cable from my old house that I crimped myself) and it connected at 1GB!

The above finding led me to check all 4 RJ45 ports in my office linking back to the gigabit switch to see if any would give me a gigabit connection. 1 out of 4 gave me the gigabit connection I have been desperately troubleshooting for, HOORAH!!!!

Despite my disbelief having read the above comments, it appears to be that cabling was the problem - it certainly was for me. I now have a fully fledged 1gb connection for my 2012 Mac Mini.

Therefore, I conclude that the network cabling in my house (performed by BSP Electric) was not of a good standard, I will definately never use them for anything ever again! (Problems with ports not working and fuse box meltdown - thats another story)

Hope this helps steer the ship on this problem for anyone still having the issue...

Good Luck all!

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Answer 4

BSteely

Level 5

7,643 points

Sep 21, 2009 9:03 PM in response to Aaron Scott

What are you using for an ethernet cable? Is it rated CAT5e or CAT6?

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Answer 5

Aaron Scott Author

Level 1

13 points

Sep 21, 2009 10:15 PM in response to BSteely

I've tried both Cat5e and Cat6

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Answer 6

Sep 24, 2009 12:48 PM in response to Aaron Scott

i've had the same issue. 100 base works fine. Either thru the cabling in my wall or directly plugged into the switch. (5e in the wall, 5e to it, 5e to the switch). Try to force gig, says no cable is plugged in.

got some cat6 cable. I swear i got gig for 1 morning plugged into the wall (mini cat6 to wall, cat5e wall to router). but now neither plugged into the wall, or the cat6 to the switch it self will gig work. No issues at all with 100base though. its baffling and i have no idea how to fix.

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Answer 7

LeeOwen

Level 1

4 points

Oct 26, 2009 5:21 PM in response to Aaron Scott

Same problem here. Mac Mini wont connect gigabit to an Airport Extreme. It's not my cable. If I take the cable and plug into my macbook, it connects gigabit. When I plug into my Mac Mini it connects at 100. If I force 1000, it says ethernet not connected.
I'm not sure when this started. I only recently noticed when media over the network began to get choppy and I went and checked what link speed I had.
I've upgraded to Snow Leopard and I'm current with all updates.

Help... anyone!

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Answer 8

Oct 28, 2009 8:16 AM in response to Aaron Scott

I had problems using a Linksys 4 port switch. I condemned the switch but I think its Snow leopard.
I reinstalled Snow leopard and have had no problems. Even though not everyone has had these issues and it may be connected to what hardware we use for networking. The end result is that SL does not seem to like some networks? I have given up knowing why and just use leopard until Apple addresses the issue.

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Answer 9

maido

Level 1

0 points

Nov 18, 2009 6:20 AM in response to John Scott1

Reporting same problem here, my new mac mini just arrived yesterday, tried on 2 totally different networks, initially ethernet is correctly set on 1Gbit, then after a while, randomly, it either switches to 100Mbit, 10Mbit or no connection at all.
Setting it to 1000Gbit manually just disconnects it as a whole.
I was thinking it to be a hardware failure 'til I found this thread... will have to switch to Wireless 'til someone gets a clue... so much for Gigabit networking 😟

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Answer 10

daverx7

Level 1

0 points

Nov 21, 2009 11:02 PM in response to Aaron Scott

Add another Mac Mini to the list where it will not connect in automatic or forced 1gigabit. I manually drop it to 100mbits, it connects. As the others say, I have tried known good cables and multiple switches. I am at the latest OS.

-Dave

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Answer 11

Ted_X

Level 1

0 points

Nov 23, 2009 4:14 PM in response to daverx7

For the record, my mini is doing it too. I didn't know what the problem was, but my ethernet just wouldn't connect, so I was forced to connect via wireless. When my Verizon FIOS wireless got flaky, I got more annoyed with my ethernet not connecting, which prompted my google search and led me here.

After reading the discussions, I switched to 100Mb/s half-duplex, and it connected right up. I've got a G5 and a G4 connected to the same switch at 1000Mb/s and have interchanged the cables, and the mini just will not connect at a gig.

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Answer 12

daverx7

Level 1

0 points

Nov 25, 2009 8:25 AM in response to daverx7

Hmm... anyone there? It certainly doesn't look like an isolated issue here.

^^bump^^

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Answer 13

gnwiii

Level 1

10 points

Nov 27, 2009 3:43 AM in response to daverx7

I don't think this only an issue for the mini. We have problems connecting to our Gb switch with iMac and Mac Pro machines, but the wiring is old and some drops work where others connect and disconnect or will only connect at 100 Mb. For one office we ran a new drop and that solved the problem. The ports that don't work sometimes show problems (e.g., "low signal on pin x") with a cable tester.

The old drops are in conduit, and never were reliable with SGI Octanes at 100Mb, so are clearly marginal, but booting the Mac's with Knoppix linux sometimes works when the Apple networking falls down, and windows machines don't appear to have problems (but we know from experience that windows is prone to duplex mismatches -- it is just that user expect Windows to be slow so don't notice). I have also had a case where connecting a Gb box to one drop seems to cause
disconnects on another drop -- not sure if this is a problem in the switch or maybe crosstalk between cables that share a conduit.

When we have problems, the log often has:

fuji mDNSResponder[31]: Note: Frequent transitions for interface en0 (X.X.X.X); network traffic reduction measures in effect

Once this happens you may need to delete the interface in Net Prefs and "redo from start".

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Answer 14

mooblie

Level 4

1,954 points

Nov 27, 2009 7:44 AM in response to gnwiii

FWIW: I have a Mac mini2,1 Intel Core 2 Duo 1.83 GHz connected to a NetGear 1Gbit 8-port switch via a 6ft Cat5e cable, and I've never, ever, had any problems at connecting to it automatically at 1Gbps. So it can be done.

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Answer 15

Nov 29, 2009 4:43 PM in response to mooblie

I have a new 2.5.3 Mac Mini and a 1.66 duo core. They both connect to the Airport, a five port linksys gig switch and 8 port linksys switch perfectly. Unless you are running very long runs (300ft) there is no difference between Cat 5 and Cat 6. The gig mac layers developed are so much better than previous ethernet mac layers spending money on cat 6 is a waste of money. Make sure the switches are not managed and have the ports locked down. With older switches you might need to power cycle them, also some switches have uplink ports that can behave weirdly.

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