"PCI Configuration" terminates ethernet connection, randomly.

Mavericks 10.10.1, Macbook Pro Retina (Mid 2012), Thunderbolt Ethernet Adapter.

Found my network connection (en4) dropping randomly and found a few different reasons in console for this.

I've tried:

• setting a location in network preferences
• removing thunderbolt adapter in network settings and adding it again
• removing thunderbolt bridge
• rebooting computer
• keeping the system awake by using it - still goes down while using it (clearly not a 'sleep' issue?)
• changing thunderbolt sockets
• testing another thunderbolt ethernet adapter

Console info below. Any help would be much appreciated, this is a really frustrating problem.

Here is one event in the Console, showing the link going down due to "PCI configuration":

(i've highlighted the link going down in bold)

16/01/2015 11:26:56.000 am kernel[0]: ASP_TCP Detach: Reply queue not empty?

16/01/2015 11:26:56.610 am com.apple.backupd[1158]: Ejected Time Machine network volume.

16/01/2015 11:27:29.000 am kernel[0]: Google Chrome He (map: 0xffffff803c583780) triggered DYLD shared region unnest for map: 0xffffff803c583780, region 0x7fff92e00000->0x7fff93000000. While not abnormal for debuggers, this increases system memory footprint until the target exits.

16/01/2015 11:27:53.000 am kernel[0]: Google Chrome He (map: 0xffffff803ebd4690) triggered DYLD shared region unnest for map: 0xffffff803ebd4690, region 0x7fff92e00000->0x7fff93000000. While not abnormal for debuggers, this increases system memory footprint until the target exits.

16/01/2015 11:28:52.825 am SystemUIServer[243]: Attempt to use XPC with a MachService that has HideUntilCheckIn set. This will result in unpredictable behavior: com.apple.backupd.status.xpc

16/01/2015 11:29:36.121 am DesktopServicesHelper[877]: notify name "com.apple.filecoordination.dump_request" has been registered 40 times - this may be a leak

16/01/2015 11:29:37.000 am kernel[0]: [ PCI configuration begin ]

16/01/2015 11:29:37.000 am kernel[0]: [ PCI configuration end, bridges 12, devices 17 ]

16/01/2015 11:29:37.000 am kernel[0]: AppleBCM5701Ethernet [en4]: willTerminate - offline

16/01/2015 11:29:37.122 am configd[26]: bootp_client_bind_socket_to_if(en4, 9): setsockopt IP_BOUND_IF failed

16/01/2015 11:29:37.122 am discoveryd[51]: Basic Network GetExtendedFlags ioctl failed Device not configured

16/01/2015 11:29:37.122 am configd[26]: DHCP en4: RELEASE transmit failed

16/01/2015 11:29:37.125 am discoveryd[51]: Basic Network GetExtendedFlags ioctl failed Device not configured

16/01/2015 11:29:37.131 am networkd[127]: +[NETLedBelly stopFastFail] Clearing ledbelly failure cache

16/01/2015 11:29:37.132 am configd[26]: network changed: v4(en4-:192.168.1.198) DNS- Proxy-

16/01/2015 11:29:37.136 am discoveryd[51]: Basic WABServer NetResolverEvent no resolvers, resetting domains

16/01/2015 11:29:37.136 am discoveryd[51]: Basic Bonjour stop listening on en4

16/01/2015 11:29:37.000 am kernel[0]: smb2_smb_parse_change_notify: smb_rq_reply failed 60

16/01/2015 11:29:37.000 am kernel[0]: smb2_smb_parse_change_notify: smb_rq_reply failed 60

16/01/2015 11:29:37.000 am kernel[0]: smb2_smb_parse_change_notify: smb_rq_reply failed 60

16/01/2015 11:29:37.000 am kernel[0]: smb2_smb_read_write_async: smb_rq_reply failed 60

16/01/2015 11:29:41.833 am com.apple.iCloudHelper[1238]: objc[1238]: Class FALogging is implemented in both /System/Library/PrivateFrameworks/FamilyCircle.framework/Versions/A/FamilyCircl e and /System/Library/PrivateFrameworks/FamilyNotification.framework/Versions/A/Famil yNotification. One of the two will be used. Which one is undefined.

16/01/2015 11:29:41.839 am com.apple.xpc.launchd[1]: (com.apple.imfoundation.IMRemoteURLConnectionAgent) The _DirtyJetsamMemoryLimit key is not available on this platform.

16/01/2015 11:29:42.140 am netbiosd[1077]: network_reachability_changed : network is not reachable, netbiosd is shutting down

Here is a similar situation (ethernet going down) but a different trigger (apparently?):

16/01/2015 3:41:09.000 am kernel[0]: pci pause: SDXC

16/01/2015 3:41:36.000 am kernel[0]: PM response took 1998 ms (27, powerd)

16/01/2015 3:41:36.000 am kernel[0]: ARPT: 288540.420526: AirPort_Brcm43xx::powerChange: System Sleep

16/01/2015 3:41:36.000 am kernel[0]: ARPT: 288540.420532: wl0: powerChange: *** BONJOUR/MDNS OFFLOADS ARE NOT RUNNING.

16/01/2015 3:41:37.000 am kernel[0]: AppleBCM5701Ethernet [en4]: Link down (womp enabled, proxy 1379)

16/01/2015 3:41:37.000 am kernel[0]: AppleBCM5701Ethernet [en4]: 0 0 memWrInd fBJP_Wakeup_Timer

16/01/2015 3:41:38.000 am kernel[0]: AppleThunderboltNHIType2::waitForOk2Go2Sx - retries = 86

16/01/2015 5:04:00.000 am kernel[0]: Wake reason: RTC (Alarm)

As an overview of down/up events, this is a filtered view for "link" in the console, showing when the ethernet link going up and down last night while I was asleep:

15/01/2015 11:04:23.757 pm com.apple.backupd[14541]: Copied 186 items (12.6 MB) from volume Macintosh HD. Linked 8558.

15/01/2015 11:17:22.000 pm kernel[0]: en4: attached with 4 suspended link-layer multicast membership(s)

15/01/2015 11:17:26.000 pm kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en4, 1-Gigabit, Full-duplex, Symmetric flow-control, Debug [796d,2301,0c01,0200,c5e1,3800]

16/01/2015 12:12:58.705 am com.apple.backupd[14832]: Copied 959 items (22 MB) from volume Macintosh HD. Linked 9314.

16/01/2015 1:21:48.047 am com.apple.backupd[14954]: Copied 179 items (12.8 MB) from volume Macintosh HD. Linked 7713.

16/01/2015 2:10:19.000 am kernel[0]: AppleBCM5701Ethernet [en4]: Link down (womp enabled, proxy 1379)

16/01/2015 3:10:21.000 am kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en4, 1-Gigabit, Full-duplex, Symmetric flow-control, Debug [796d,2301,0c01,0200,c5e1,3800]

16/01/2015 3:10:32.000 am kernel[0]: AppleBCM5701Ethernet [en4]: Link down (womp enabled, proxy 1379)

16/01/2015 3:34:00.000 am kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en4, 1-Gigabit, Full-duplex, Symmetric flow-control, Debug [796d,0301,0c01,0200,c5e1,3800]

16/01/2015 3:34:00.000 am kernel[0]: AppleBCM5701Ethernet [en4]: 0 0 Linkup - sending up wakeup packet

16/01/2015 3:34:52.000 am kernel[0]: AppleBCM5701Ethernet [en4]: Link down (womp enabled, proxy 1379)

16/01/2015 3:40:32.000 am kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en4, 1-Gigabit, Full-duplex, Symmetric flow-control, Debug [796d,0301,0c01,0200,c5e1,3800]

16/01/2015 3:41:37.000 am kernel[0]: AppleBCM5701Ethernet [en4]: Link down (womp enabled, proxy 1379)

16/01/2015 5:04:07.000 am kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en4, 1-Gigabit, Full-duplex, Symmetric flow-control, Debug [796d,0301,0c01,0200,c5e1,3800]

16/01/2015 5:08:36.823 am com.apple.backupd[15061]: Copied 144 items (12.7 MB) from volume Macintosh HD. Linked 7781.

16/01/2015 5:09:52.000 am kernel[0]: AppleBCM5701Ethernet [en4]: Link down (womp enabled, proxy 1379)

16/01/2015 6:34:56.000 am kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en4, 1-Gigabit, Full-duplex, Symmetric flow-control, Debug [796d,0301,0c01,0200,c5e1,3800]

16/01/2015 6:35:59.000 am kernel[0]: AppleBCM5701Ethernet [en4]: Link down (womp enabled, proxy 1379)

16/01/2015 7:36:03.000 am kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en4, 1-Gigabit, Full-duplex, Symmetric flow-control, Debug [796d,0301,0c01,0200,c5e1,3800]

16/01/2015 7:37:01.000 am kernel[0]: AppleBCM5701Ethernet [en4]: Link down (womp enabled, proxy 1379)

16/01/2015 8:22:17.000 am kernel[0]: Ethernet [AppleBCM5701Ethernet]: Link up on en4, 1-Gigabit, Full-duplex, Symmetric flow-control, Debug [796d,0301,0c01,0200,c5e1,3800]