CentOS virt - Jun 2014 - Finally switching from Xen to KVM - question about networking

I had so much trouble putting Centos 6 guest VMs on a Centos 5 host that 
I finally switched to a Centos 6 host.

I've not needed more that test VMs, so I've used Virtual Machine Manager
on the old system, which worked pretty well, so I decided to create my 
first KVM guest machine. I noticed when I created it, I only had the 
options of NAT for my network interface, so I used that (obvious).

Well, after starting the VM, I find I don't have connectivity with that 
interface. Reading, I find examples where I need to create bridges 
perhaps. Xen did most of this for me, so it's a little new to me.

Can anyone throw me a clue, please?

steve campbell

On 10/06/14 10:03 AM, Steve Campbell wrote:
> I had so much trouble putting Centos 6 guest VMs on a Centos 5 host that
> I finally switched to a Centos 6 host.
>
> I've not needed more that test VMs, so I've used Virtual Machine
Manager
> on the old system, which worked pretty well, so I decided to create my
> first KVM guest machine. I noticed when I created it, I only had the
> options of NAT for my network interface, so I used that (obvious).
>
> Well, after starting the VM, I find I don't have connectivity with that
> interface. Reading, I find examples where I need to create bridges
> perhaps. Xen did most of this for me, so it's a little new to me.
>
> Can anyone throw me a clue, please?
>
> steve campbell
Setting up a bridge is not that hard, and it will give your VMs direct 
access to the outside world, and host <-> VM access just fine as well.

Here is a link showing how to setup a bridge connected to a bond device. 
Ignore the bond and pretend it is a straight ethX device:

https://alteeve.ca/w/AN!Cluster_Tutorial_2#Configuring_our_Bridge.2C_Bonds_and_Interfaces


-- 
Digimer
Papers and Projects: https://alteeve.ca/w/
What if the cure for cancer is trapped in the mind of a person without 
access to education?

Steve Campbell wrote:
> Well, after starting the VM, I find I don't have connectivity with that
> interface. Reading, I find examples where I need to create bridges
> perhaps. Xen did most of this for me, so it's a little new to me.
>
> Can anyone throw me a clue, please?
Steve, I just put up my notes for how to set up an EL6
host as well as how to create a guest.  You'll note that
it is terse and it expects you to already know what options
you want.  However if you follow it step by step by copying
and pasting the appropriate lines, you'll have your system
set up in no time.

http://wiki.centos.org/HowTos/KVM

Good luck!  And let me know if you have any problems with
any of the commands in the wiki.

c

On Tue, Jun 10, 2014 at 10:03 AM, Steve Campbell <campbell at
cnpapers.com> wrote:
> I had so much trouble putting Centos 6 guest VMs on a Centos 5 host that
> I finally switched to a Centos 6 host.
>
> I've not needed more that test VMs, so I've used Virtual Machine
Manager
> on the old system, which worked pretty well, so I decided to create my
> first KVM guest machine. I noticed when I created it, I only had the
> options of NAT for my network interface, so I used that (obvious).
>
> Well, after starting the VM, I find I don't have connectivity with that
> interface. Reading, I find examples where I need to create bridges
> perhaps. Xen did most of this for me, so it's a little new to me.
>
> Can anyone throw me a clue, please?
>
> steve campbell
> _______________________________________________
> CentOS-virt mailing list
> CentOS-virt at centos.org
> http://lists.centos.org/mailman/listinfo/centos-virt
For full-blown pair-bonding, trunked VLAN's, and KVM bridges, you want
my old notes at
https://wikis.uit.tufts.edu/confluence/display/TUSKpub/Configure+Pair+Bonding,+VLANs,+and+Bridges+for+KVM+Hypervisor.

Just dial back on any features you don't need in your environment. And
rip all NetworkManager based components kicking and screaming the !@#$
out of any KVM server, it is *NOT* your friend.

      sudo yum remove *NetworkManager*