Re: ethernet connection possible with no carrier

[Dan Williams <dcbw redhat com>]

On Wed, 2016-06-29 at 16:14 +0200, Michael Hirmke wrote:
> Hi *,
>
> I'm using NetworkManager-1.2.2-341.1.x86_64 on openSuSE Leap 42.1.
> In the NM applet I can connect to my ethernet without having a
> carrier
> signal, i.e. no cable plugged in. The connection has static settings
> for
> IP address, nameserver and so on.

This is intentional for static configuration when you manually activate
the connection.  Since static configuration doesn't require any
information from the network (like DHCP or IPv6 SLAAC does), it doesn't
need a carrier.  But it still requires manual activation on your part
unless you set "ignore-carrier" in NetworkManager.conf.

Specifically, it's useful to make sure the interface is configured on
startup, even without a carrier, when other services (apache, bind,
whatever) may depend on that address being present and these services
are not smart enough to start themselves when the carrier eventually
shows up.

Dan

> In the log I see
> "eth0: link is not ready"
> and
> "device (eth0): state change: unmanaged -> unavailable (reason
> 'managed') [10 20 2]"
> With former versions of nm the connection was not available in this
> case.
> Is this a known bug or am I doing something wrong?
> Even an explicit setting of "carrier-ignore=" doasen't help.
>
> TIA.
>
> Bye.
> Michael.