How to remove a damaged Wired Connection

[Robert Heller]

At Sun, 28 Aug 2016 15:18:15 +0200 irons.charles at gmail.com, "Ubuntu user technical support,  not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:

> 
> 
> 
> Hello all. I hope you can help.
> My terminal command skills are limited as a retired end user of Ubuntu
> (since 05.04).
> 
> My Settings/Network shows two Wired entries (because my ADSL service
> was poor so my ISP gave me a wireless router that works) but my browser
> will not connect if the router is switched on first.
> 
> The lower Wired entry for the eth0 DSL router shows "Cable unplugged"
> because it was replaced by the eth1 wireless router.
> Settings/Network/Options for the eth0 Wired entry shows "Error Editing
> connection: Did not find a connection with UUID '(null)'"
> because I did "delete" but it still appears. I cannot find a way to
> remove this entry in Ubuntu users guide.

Unless this is a desktop machine with a PCI (removable) Ethernet card that you
can remove (ie it is a *really old* computer), you cannot 'remove it' -- so
long as the NIC shows up in your hardware scan at boot time, it will be there,
maybe not configured or not connected ("Cable unplugged"), but still there.
You can *edit* it, assuming you ever find a reason to plug in an Ethernet
cable from the RJ45 jack on your computer to anther LAN at some point. Why do
you want to remove it? Is this some silly 'neat and tidyness' thing?

> 
> The upper Wired entry is working (TIAllAccess wireless eth1)
> When I click on Menu bar/Edit Connections it shows only one Ethernet
> router (TIAllAccess wireless eth1).
> Then I click on Menu bar/Edit Connections/Edit TIAllAccess and it shows
> the MAC details of the router (eth1).
> After I click on Menu bar/Connection Information it shows details of
> the router (eth1).
> 
> Please tell me how to remove the second Wired Connection. 
> Maybe that will allow my browsers to connect to eth1 (the TIAllAccess
> wireless) when it is already running; it does not switch off and on
> again easily.
> 
> Maybe the Syslog snippets below will help? (that I found when I scanned
> there for some details)
> 
> *********
> devices added (path:
> /sys/devices/pci0000:00/0000:00:1c.2/0000:03:00.0/net/eth0, iface:
> eth0)
> Aug 28 11:54:26 Charles-PC NetworkManager[2350]:
> <info>  [1472378066.2036] device added (path:
> /sys/devices/pci0000:00/0000:00:1c.2/0000:03:00.0/net/eth0, iface:
> eth0): no ifupdown configuration found.
> ********
> Aug 28 11:54:26 Charles-PC NetworkManager[2350]:
> <info>  [1472378066.2036] settings: loaded plugin ifupdown: (C) 2008
> Canonical Ltd.  To report bugs please use the NetworkManager mailing
> list. (/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-settings-plugin-
> ifupdown.so)
> ***********
> keyfile: new connection /etc/NetworkManager/system-connections/Wi-Fi
> connection 2 (83c73dc1-d951-4d72-a919-13631ee95fca,"Wi-Fi 2")
> ********
> NetworkManager[2350]: <info>  [1472378067.5006] manager: (eth0): new
> Ethernet device (/org/freedesktop/NetworkManager/Devices/1)
> Aug 28 11:54:27 Charles-PC NetworkManager[2350]:
> <info>  [1472378067.5012] device (eth0): state change: unmanaged ->
> unavailable (reason 'managed') [10 20 2]
> Aug 28 11:54:27 Charles-PC kernel: [   25.609959] IPv6:
> ADDRCONF(NETDEV_UP): eth0: link is not ready
> Aug 28 11:54:27 Charles-PC NetworkManager[2350]:
> nm_device_get_device_type: assertion 'NM_IS_DEVICE (self)' failed
> Aug 28 11:54:27 Charles-PC NetworkManager[2350]:
> <info>  [1472378067.7994] device (lo): link connected
> Aug 28 11:54:27 Charles-PC NetworkManager[2350]:
> <info>  [1472378067.7998] manager: (lo): new Generic device
> (/org/freedesktop/NetworkManager/Devices/2)
> Aug 28 11:54:27 Charles-PC kernel: [   25.907292] r8169 0000:03:00.0
> eth0: link down
> Aug 28 11:54:27 Charles-PC kernel: [   25.907351] IPv6:
> ADDRCONF(NETDEV_UP): eth0: link is not ready
> Aug 28 11:54:27 Charles-PC NetworkManager[2350]:
> <info>  [1472378067.8743] urfkill disappeared from the bus
> 

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