Network issue KVM host centos

michaelux · 06-03-2010, 08:35 PM

Hi all.

After a lot of reading and google search about virtualization, xen, kvm And having some problem creating my first guest I finally installed asterisknow as guest in Centos, it start fine(guest asterisknow), but I have problems and doubts about the network config.

I am using my laptop with 1 ethernet connection and 1 wireless connection(compiling broadcom driver)

In the host is virbr0, eth0 (LAN) and eth1(wireless with compiled driver)..

I have read but I am a little confused about how to set up network.

I select the default option: default virtual network.

What else should I do? . How can I do if only have 1 network connection and 3 o 2 guest + host to provide connection to internet and between them? or for start of, have connection only for 1 guest ?

alli_yas · 06-04-2010, 09:42 AM

What you need to do is bridge your physical network interface - which you seem to have partially done.

Please post the output of

Code:

 ifconfig -a

Also, a quick tutorial; on my Fedora machine which acquires its IP via DHCP, the process to bridge the interface was:

1. Edit /etc/sysconfig/network-scripts/ifcfg-eth0 so that it looks like the below:

Code:

# more /etc/sysconfig/network-scripts/ifcfg-eth0 
# Intel Corporation 82567LM-3 Gigabit Network Connection
DEVICE=eth0
TYPE=Ethernet
HWADDR=00:25:B3:15:2E:00
ONBOOT=yes
BRIDGE=br0
NM_CONTROLLED=no

Note the "NM_CONTROLLED" setting is something you can probably leave out - I've only had to use it on Fedora 13 - so on CentOS you probably don't need it.

2. Create a new file /etc/sysconfig/network-scripts/ifcfg-br0 that looks similar to the below:

Code:

# more /etc/sysconfig/network-scripts/ifcfg-br0 
DEVICE=br0
TYPE=Bridge
BOOTPROTO=dhcp
HWADDR=00:25:B3:15:2E:00
ONBOOT=yes
NM_CONTROLLED=no

Note the same explanation about NM_CONTROLLED as the previous point.

3. Restart the network interface (be careful if this box is not locally accessible):

Code:

#service network restart

And that should be that. Thereafter in virt-manager, you assign br0 as the network interface for your VM - and once the VM boots up, it should dynamically receive an IP via DHCP which is different to your host IP.

If you're using a static IP/s, its just as simple; with the difference being that you manually specify the IP, NETMASK and GATEWAY in the abovementioned configuration files.

michaelux · 06-05-2010, 09:14 PM

Thanks buddy.

I removed centos 5.3 and installed fedora 13, I tested live cd and it recognize multimedia button, wireless (after some changes with b43fcutter..) and runs smooth..and can install centos as guest only to test what I need before apply changes to production servers..

I am running as guest and Backtrack 4, but it runs slow, the host use high cpu, I have amd turion x2 64...

michaelux · 06-05-2010, 11:51 PM

my next step well be to do bridge connection... I have a asterisk guest and this need to be accessed from the LAN..

But, can I do bridge connection using wlan?_ . I have kvm in my laptop with asterisk guest but just to learn and test some things. I am not sure if I can do a bridge connection with wlan..

thanks