How to remove a damaged Wired Connection

[Robert Heller]

At Sun, 28 Aug 2016 20:12:51 +0200 irons.charles at gmail.com wrote:

> 
> 
> 
> irons.charles at gmail.com
> Home   +2711 782 8623On Sun, 2016-08-28 at 11:43 -0400, Robert Heller wrote:
> > At Sun, 28 Aug 2016 16:22:10 +0200 "Ubuntu user technical
> > support,  not for general discussions" <ubuntu-users at lists.ubuntu.com
> > > wrote:
> > 
> > > 
> > > 
> > > On Sun, 28 Aug 2016 15:18:15 +0200, Chas IRONS wrote:
> > > > 
> > > > 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.
> > > Hi,
> > > 
> > > could it be, that you switched from PPPoE to DHCP, but you still
> > > connect by cable and not by wifi? There was likely an issue with
> > > the
> > > modem and not with ADSL, so the modem to dial up was replaced by
> > > the
> > > router. The router likely provides LAN and WLAN.
> > > 
> > > However, wifi unlikely is eth1, it should be wlan0, wlan1 ...
> > > wlann.
> > Hmmm... Not necessarily -- it is quite possible for wifi to be
> > eth1.  It all 
> > depends on what is in /etc/udev/rules.d/70-persistent-net.rules and 
> > /etc/network/interfaces. 
> Hi again Robert. Gedit shows /etc/network/interfaces content that I do
> not understand :
> auto lo
> iface lo inet loopback
> Could that cause eth0 to prevent eth1 from connecting?

No.

> and also /etc/udev/rules.d/70-persistent-net.rules contains:
> # PCI device 0x10ec:0x8168 (r8169)
> SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*",
> ATTR{address}=="10:c3:7b:6a:c5:ea", ATTR{dev_id}=="0x0",
> ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
> # USB device 0x:0x (cdc_ether)
> SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*",
> ATTR{address}=="3c:1e:04:96:54:05", ATTR{dev_id}=="0x0",
> ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"
> So I see eth0 is a PCI device (was the ADSL router) and eth1 is a USB
> device (the wireless router I am using now)
> Thanks for showing me the basics again.

Yes, that is correct.  The USB "Wireless" NIC is advertising itself as a 
Ethernet NIC, which is why it is showing up as eth1 and not wlan0.  I expect 
this was a choice made by the author of the kernel device driver (cdc_ether). 
I'm guessing that there is a wired version of this device somewhere out there 
(USB <=> Ethernet RJ45).

> > > 
> > > 
> > > What's the output of
> > > 
> > >   lsb_release -rc; ifconfig -a
> > > 
> > > ?
> > > 
> > > I can't help you with Network Manager and also not really with wifi in
> > > general, since I'm using a router by LAN, not by WLAN.
> > > 
> > > However, is your wifi thingy up?
> > > 
> > > If I connect a wifi thingy by USB, "ifconfig -a" shows it...
> > > 
> > > 
> > > 
> > >   $ ifconfig -a
> > >   enp3s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
> > >           [snip]
> > > 
> > >   lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
> > >           [snip]
> > > 
> > >   wlp0s19f3u1: flags=4098<BROADCAST,MULTICAST>  mtu 1500
> > >           [snip]
> > > 
> > > 
> > > 
> > > ...but it's not shown by ifconfig...
> > > 
> > > 
> > > 
> > >   $ ifconfig
> > >   enp3s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
> > >           [snip]
> > > 
> > >   lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
> > >           [snip]
> > > 
> > > 
> > > 
> > > It requires to bring the Interface up...
> > > 
> > > 
> > > 
> > >   $ sudo ip link set wlp0s19f3u1 up
> > > 
> > > 
> > > 
> > > ...then its shown:
> > > 
> > > 
> > > 
> > >   $ ifconfig
> > >   enp3s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
> > >           [snip]
> > > 
> > >   lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
> > >           [snip]
> > > 
> > >   wlp0s19f3u1: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
> > >           [snip]
> > > 
> > > 
> > > 
> > > Regards,
> > > Ralf
> > > 
> > > 
> > > 
> 
> > 
> > 
> > -- 
> > Robert Heller             -- 978-544-6933
> > Deepwoods Software        -- Custom Software Services
> > 
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> 
>                                                                                           

-- 
Robert Heller             -- 978-544-6933
Deepwoods Software        -- Custom Software Services
http://www.deepsoft.com/  -- Linux Administration Services
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