[CentOS] disconnected NIC under CentOS 6

Tue May 1 23:03:27 UTC 2012
Boris Epstein <borepstein at gmail.com>

On Tue, May 1, 2012 at 3:12 PM, Digimer <lists at alteeve.ca> wrote:

> On 05/01/2012 02:46 PM, John R Pierce wrote:
> > On 05/01/12 11:03 AM, Boris Epstein wrote:
> >> That's precisely what I planned on doing - but I believe the network
> >> adapter needs to have an address first. Then you bridge pseudo adapters
> to
> >> it. It would all be fine but I can't take this initial step of
> assigning an
> >> IP address to the NIC in question.
> >
> >
> > no, no.  the BRIDGE pseudodevice has the IP, network adapter(s) that are
> > bridged to it don't have their own IP at all
>
> If it helps, I show how to create a bridge as part of a bigger tutorial.
> I show ethX -> bond -> bridge, but you can drop the bond and go straight
> from ethX -> bridge.
>
>
> https://alteeve.com/w/2-Node_Red_Hat_KVM_Cluster_Tutorial#Creating_Some_Network_Configuration_Files
>
> --
> Digimer
> Papers and Projects: https://alteeve.com
> _______________________________________________
>

I found a solution that seems to work best for now. If you go into
 /etc/sysconfig/network-scripts/ and edit the  ifcfg file corresponding to
the NIC in question (in my case, ifcfg-eth1) and change the ONBOOT flag to
"yes":

ONBOOT=yes

then the interface comes up with the right address regardless of whether it
is physically connected to anything via an ethernet cable. I intend to
bridge both virtual and physical devices to it but that will be the next
step.

Thanks to everyone who helped.

Boris.