"Cable unplugged" after upgrade

Issues related to configuring your network
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Latenights
Posts: 10
Joined: 2018/01/25 08:51:48

"Cable unplugged" after upgrade

Post by Latenights » 2019/09/26 23:14:04

I just applied upgrades and rebooted. There is no internet connection and the Network Tool says Cable Unplugged. Also the router LED for this cable connection is off. But I rebooted with the previous kernel and all works again.

New kernel says cable is unplugged
kernel-3.10.0-1062.1.1.el7.x86_64

Previous kernel that works OK
kernel-3.10.0-957.12.2.el7.x86_64

# lspci -nn | grep -i net
03:00.0 Network controller [0280]: Ralink corp. RT3090 Wireless 802.11n 1T/1R PCIe [1814:3090]
04:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 03)

Before I upgrade to Centos 8 I need to know what the problem is in case I need to fix it in 8.

chemal
Posts: 776
Joined: 2013/12/08 19:44:49

Re: "Cable unplugged" after upgrade

Post by chemal » 2019/09/27 01:01:11

My [10ec:8168] also hehaved strangely when I updated to 7.7 (from CR). But starting with the next day everything was ok again. Try to cold start your computer. :)

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jlehtone
Posts: 4530
Joined: 2007/12/11 08:17:33
Location: Finland

Re: "Cable unplugged" after upgrade

Post by jlehtone » 2019/09/27 07:52:01

Similar with [10ec:8168] (rev 02)

Steps that I took:
1. yum update ; reboot
2. "Cable unplugged"
3. Reboot to previous kernel
4. Remove 3.10.0-1062.1.1
5. Exclude kernel from yum
... some days ...
6. Enable kernel ; reinstall 3.10.0-1062.1.1 ; reboot
7. Still "Cable unplugged"
8. Attempt "ethtool -s autoneg off" (Google: years ago that was a workaround). Result: "Not possible"
9. rmmod r8169 ; modprobe r8169 ; still down
9. Reboot
10. Miraculously the link is up

The r8169 has been updated between 7.6 and 7.7.

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TrevorH
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Location: Brighton, UK

Re: "Cable unplugged" after upgrade

Post by TrevorH » 2019/09/27 17:49:57

If you see the problem again then try modprobe realtek and then retry. If that doesn't work try removing and reloading r8169 with realtek already loaded.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

Latenights
Posts: 10
Joined: 2018/01/25 08:51:48

Re: "Cable unplugged" after upgrade

Post by Latenights » 2019/09/29 10:38:03

chemal wrote:
2019/09/27 01:01:11
My [10ec:8168] also hehaved strangely when I updated to 7.7 (from CR). But starting with the next day everything was ok again. Try to cold start your computer. :)
Solved! I shutdown, unplugged the power for 20 seconds.
Plugged it back in, rebooted into the latest kernel, networking came up no problems.

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