[CentOS] Centos 6 - Networking: Some Queries -- GURUS HELP PL

Fri Jun 8 13:32:22 UTC 2012
Sanjay Arora <sanjay.k.arora at gmail.com>

On Mon, Jun 4, 2012 at 10:44 PM, Gordon Messmer <yinyang at eburg.com> wrote:

>> On a separate note however, I'd still like to know how to use a bridge to
>> route packets between two networks.....say network card having
>> address... and a kvm based virtual network say
>> to use this device for Internet access (through
>> router
>> using a bridge? How to do it?
> If your networks are on different IPv4 broadcast domains (as you
> describe), you don't want a bridge.
> If you want bridged networking with KVM, your guests will be on the same
> network as the host.  They'll use your existing DHCP services and
> routing.  They can be configured according to this document:
> http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6-Beta/html/Virtualization_Host_Configuration_and_Guest_Installation_Guide/sect-Virtualization_Host_Configuration_and_Guest_Installation_Guide-Network_Configuration-Network_Configuration-Bridged_networking_with_libvirt.html
> That configuration used to be reflected here:
> http://wiki.centos.org/HowTos/KVM
> ...but someone went and put in some really braindamaged instructions.
> That should be fixed or removed.

In case of a separate network, should it not be possible to create a
dummy bridge or something and forward packets through maybe...NAT....A
guy talks of this kind of thing here
but I don't quite understand it, because I am not familiar with
/etc/network/interfaces.....seems to be ubuntu or some other linux.

I am using /etc/sys-config/network-scripts/ifcfg-xxx files. or any
other forwarding system...but don't know how?

Any ideas of how to do it with separate IP addressing? The main
network is out of my control and I cannot use its IP addresses.