fhall1
Level 1 (0 points)

Q: 2012 mac mini dropping ethernet connection

2012 Mac Mini i7, 16GB RAM, 1TB SSD. Running OS X 10.10.5.


I've owned this since it was released in 2012 and have had no issues with it until a couple weeks ago. There have been no recent OS updates or other s/w or hardware additions that I could attribute to this issue.

 

I've noticed that a few times a day, a notification will pop up that my wired ethernet connection went down, then back up. Originally it happened so sporadically I just ignored it. But yesterday it happened about 50 times in a row, up down, up down, up down. Usually when it finally would reconnect, the interface would be at 100baseT instead of 1000baseT. Syspref is set to automatically configure.

 

My home network hasn't changed during this time either. My cable modem (Motorola SB6141) feeds a Cisco (Linksys) router, that feeds an Apple Airport Extreme (latest gen) and another router (I run two separate subnets, one for business, one for home). The AE feeds an 8 port switch that my Mac Mini is plugged into. I've reset the cable modem, the Linksys, the AE, and tried different ports on the switch....note that no other machines on the network exhibit any strange network anomalies.

 

I did a safe boot yesterday and that seemed to help for a while, but I noticed just now the switch lights for the MacMini port are orange instead of green, indicating 100baseT and sure enough it's verified by the syspref config.

 

Below is console output related to en0 for today:

 

2/20/16 8:19:45.000 AM kernel[0]: AppleBCM5701Ethernet [en0]: Link down (womp disabled, proxy idle)

2/20/16 8:19:45.689 AM configd[51]: network changed: v4(utun0:10.105.1.6, en0-:192.168.11.83) DNS! Proxy- SMB-

2/20/16 8:19:49.000 AM kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en0, 1-Gigabit, Full-duplex, Symmetric flow-control, Debug [796d,0301,0de1,0300,cde1,3800]

2/20/16 8:19:51.173 AM configd[51]: network changed: v4(en0+:192.168.11.83, utun0) DNS! Proxy+ SMB+

2/20/16 8:29:49.000 AM kernel[0]: AppleBCM5701Ethernet [en0]: Link down (womp disabled, proxy idle)

2/20/16 8:29:49.279 AM configd[51]: network changed: v4(utun0:10.105.1.6, en0-:192.168.11.83) DNS! Proxy- SMB-

2/20/16 8:29:53.000 AM kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en0, 1-Gigabit, Full-duplex, Symmetric flow-control, Debug [796d,0301,0de1,0300,cde1,3800]

2/20/16 8:29:55.637 AM configd[51]: network changed: v4(en0+:192.168.11.83, utun0) DNS! Proxy+ SMB+

2/20/16 9:40:19.000 AM kernel[0]: AppleBCM5701Ethernet [en0]: Link down (womp disabled, proxy idle)

2/20/16 9:40:19.961 AM configd[51]: network changed: v4(utun0:10.105.1.6, en0-:192.168.11.83) DNS! Proxy- SMB-

2/20/16 9:40:24.000 AM kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en0, 1-Gigabit, Full-duplex, Symmetric flow-control, Debug [796d,0301,0de1,0300,cde1,3800]

2/20/16 9:40:26.216 AM configd[51]: network changed: v4(en0+:192.168.11.83, utun0) DNS! Proxy+ SMB+

2/20/16 9:41:44.000 AM kernel[0]: AppleBCM5701Ethernet [en0]: Link down (womp disabled, proxy idle)

2/20/16 9:41:44.327 AM configd[51]: network changed: v4(utun0:10.105.1.6, en0-:192.168.11.83) DNS! Proxy- SMB-

2/20/16 9:41:47.000 AM kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en0, 1-Gigabit, Full-duplex, Symmetric flow-control, Debug [7949,0021,0de1,0300,0000,0000]

2/20/16 9:41:48.000 AM kernel[0]: AppleBCM5701Ethernet [en0]: Link down (womp disabled, proxy idle)

2/20/16 9:42:01.000 AM kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en0, 100-Megabit, Full-duplex, Symmetric flow-control, Debug [796d,0301,0de1,0300,4de1,0000]

2/20/16 9:42:03.324 AM configd[51]: network changed: v4(en0+:192.168.11.83, utun0) DNS! Proxy+ SMB+

 

At 9:42 the link changed from 1-Gigabit to 100-Megabit, but I don't see why. Any ideas on what's happening from the console log? Logic board issue? Other?

Posted on Feb 20, 2016 8:39 AM

by LACAllen,Apple recommended
LACAllen LACAllen
Level 5 (5,106 points)
iCloud
A:

I didn't see "swap the cable". Have you tried that? The cable between your switch and your router?

 

Cable your mini directly into your modem or main router, bypassing the rest of your network?

 

Did you have any power saving settings enabled?

 

You have lots of variables and break points in your system. Tough to isolate what is happening.

Posted on Feb 28, 2016 4:48 AM

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fhall1

Q: 2012 mac mini dropping ethernet connection

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  • Helpful answers

  • by LACAllen,Apple recommended

    LACAllen LACAllen Feb 28, 2016 4:48 AM in response to fhall1
    Level 5 (5,106 points)
    iCloud
    Feb 28, 2016 4:48 AM in response to fhall1

    I didn't see "swap the cable". Have you tried that? The cable between your switch and your router?

     

    Cable your mini directly into your modem or main router, bypassing the rest of your network?

     

    Did you have any power saving settings enabled?

     

    You have lots of variables and break points in your system. Tough to isolate what is happening.

  • by fhall1,

    fhall1 fhall1 Feb 21, 2016 9:52 AM in response to LACAllen
    Level 1 (0 points)
    Feb 21, 2016 9:52 AM in response to LACAllen

    I did not try swapping cables because I figured "how does a cable that just sits there and never gets jostled suddenly go bad after years of being fine".  But someone else on a different forum also suggested that.  This morning I had more en0 drops/connects - so I ran a new cable between the switch and the Mac.  Five hours later - probably jinxing it now - and no drops.  Hopefully is was that simple.  Time will tell.

  • by LACAllen,

    LACAllen LACAllen Feb 21, 2016 6:34 PM in response to fhall1
    Level 5 (5,106 points)
    iCloud
    Feb 21, 2016 6:34 PM in response to fhall1

    Agreed. It never makes sense, but it is the quickest and usually cheapest thing to check first.

  • by fhall1,

    fhall1 fhall1 Feb 28, 2016 4:50 AM in response to LACAllen
    Level 1 (0 points)
    Feb 28, 2016 4:50 AM in response to LACAllen

    Not trying to jinx myself, but it has been a week since I replaced the cable between my Mac Mini and the 8-port switch and I haven't had any network disconnects or speed decreases to 100baseT.  Fingers crossed the solution was that simple.  Thanks!