<br><br><div class="gmail_quote">On Sat, Jan 14, 2012 at 8:41 AM, Radek Bursztynowski <span dir="ltr"><<a href="mailto:radek@bursztynowski.waw.pl">radek@bursztynowski.waw.pl</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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Dnia 2012-01-14, sob o godzinie 15:08 +0100, Dennis Jacobfeuerborn pisze:
<div><div class="h5"><blockquote type="CITE">
<pre>On 01/14/2012 02:59 PM, Radek Bursztynowski wrote:
> Hi,
>
> I have installed CentOS 6.2 x86_64 and KVM/Qemu and I have some troubles
> with network.
>
> The first case:
> -----------------
>
> The configuration is:
> - CentOS 6.2 (hardware machine) has one Ethernet interface with static IP
> address (eth0).
> - Virtual machine has bridge network interface with eth0 interface on
> CentOS 6.2. This bridge is created using wizard integrated with virt-manager.
> - Bridge interface on virtual machine receives IP addres from DHCP server.
> IP address is received well.
> - All firewalls and SELinux are closed.
>
> Virtual machine has no any connection with CentOS 6.2 hardware machine, and
> CentOS 6.2 has no any connection with virtual machine. But every others
> machines have all connection with both virtual and CentOS 6.2 machine.
>
> The question: Why?
>
> The second case:
> ----------------------
>
> The configuration is:
> - On CentOS 6.2 (hardware machine) I created bridhe (br0) with eth0
> hardware interface. Two situations:
> + I force two different IP addresses for eth0 and br0 interfaces - there no
> any connection with this server. So I don't test this case.
> + I forced one IP addres for both eth0 and br0 interfaces. ifconfig shows
> that eth0 has no IP address, br0 has IP address. So, I test this case.
> - I use Red Hat documentation:
> <a href="http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html-single/Virtualization/index.html#sect-Virtualization-Network_Configuration-Bridged_networking_with_libvirt" target="_blank">http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html-single/Virtualization/index.html#sect-Virtualization-Network_Configuration-Bridged_networking_with_libvirt</a>)
> - On virtual machine I created bridge connection with br0 interface on
> CentOS 6.2.
> - All machines have all connections.
> - All firewalls and SELinux are closed.
>
> NFS server on CentOS 6.2 (hardware machine) doesn't serve exported file system.
>
> The questions:
> 1. Is it proper that eth0 has no IP addres and bridge (br0) interface has?
> 2. What about my NFS? NFS server worked well before starting virtualization.
>
> Who can me help with my troubles?
You say you create bridge interfaces in your virtual machines. Why? Usually
you don't do that you create a bridge only on the host.
You also say you "forced" one IP address for both eth0 and br0. There is no
need to force anything. eth0 shouldn't have an IP but br0 should have this
IP instead.
Regards,
Dennis
_______________________________________________
</pre>
</blockquote></div></div>
Dennis,<br>
<br>
Thanks for interesting. Few words explanation. <br>
I have one network segment, and I try to joint virtual machines to this segment. So my hardvare machine has 192.168.0.1 address, gateway is 192.168.0.254, netmask = 255.255.255.0.<br>
<br>
Regarding bridge on my virtual machine. When I started virtualization I had NAT only in another network segment. So, I look for solution adding virtual machines to my base network segment. Previously I used VMware Server, and it was proper solution.<br>
<br>
Regarding my force one IP addres for both interface. I used this solution because eth0 has no any IP addres and I couldn't find CentOS 6.2 server in the network. Using exactly Red Hat configuration I have:<br>
<br>
# more ifcfg-eth0<br>
DEVICE=eth0<br>
TYPE=Ethernet<br>
BOOTPROTO=none<br>
IPADDR=192.168.0.1<br>
NETMASK=255.255.255.0<br>
PREFIX=24<br>
GATEWAY=192.168.0.254<br>
DNS1=192.168.0.199<br>
DNS2=194.204.159.1<br>
DNS3=194.204.152.34<br>
DEFROUTE=yes<br>
IPV4_FAILURE_FATAL=yes<br>
IPV6INIT=no<br>
NAME=eth0<br>
ONBOOT=yes<br>
BRIDGE=br0<br>
MTU=9000<br>
DOMAIN=<a href="http://bursztynowski.waw.pl" target="_blank">bursztynowski.waw.pl</a><br>
UUID=5fb06bd0-0bb0-7ffb-45f1-d6edd65f3e03<br>
<br>
# more ifcfg-br0<br>
DEVICE=br0<br>
TYPE=Bridge<br>
BOOTPROTO=dhcp<br>
#IPADDR=192.168.0.1<br>
#NETMASK=255.255.255.0<br>
#PREFIX=24<br>
#GATEWAY=192.168.0.254<br>
#DNS1=192.168.0.199<br>
#DNS2=194.204.159.1<br>
#DNS3=194.204.152.34<br>
ONBOOT=yes<br>
DELAY=0<br>
<br>
(previous configuration br0 was: <br>
BOOTPRO=static<br>
and with no '#' characters. Then all worked excluding NFS.<br>
<br>
<br>
# ifconfig <br>
br0 Link encap:Ethernet HWaddr 00:50:8D:94:2F:B7 <br>
inet addr:192.168.0.92 Bcast:192.168.0.255 Mask:255.255.255.0<br>
inet6 addr: fe80::250:8dff:fe94:2fb7/64 Scope:Link <br>
UP BROADCAST RUNNING MULTICAST MTU:9000 Metric:1 <br>
RX packets:16 errors:0 dropped:0 overruns:0 frame:0 <br>
TX packets:26 errors:0 dropped:0 overruns:0 carrier:0 <br>
collisions:0 txqueuelen:0 <br>
RX bytes:3034 (2.9 KiB) TX bytes:4313 (4.2 KiB) <br>
<br>
eth0 Link encap:Ethernet HWaddr 00:50:8D:94:2F:B7 <br>
inet6 addr: fe80::250:8dff:fe94:2fb7/64 Scope:Link<br>
UP BROADCAST RUNNING PROMISC MULTICAST MTU:9000 Metric:1<br>
RX packets:57255 errors:0 dropped:0 overruns:0 frame:0<br>
TX packets:60263 errors:0 dropped:0 overruns:0 carrier:0<br>
collisions:0 txqueuelen:1000<br>
RX bytes:21481457 (20.4 MiB) TX bytes:15768417 (15.0 MiB)<br>
Interrupt:23 Base address:0x8000<br>
<br>
lo Link encap:Local Loopback<br>
inet addr:127.0.0.1 Mask:255.0.0.0<br>
inet6 addr: ::1/128 Scope:Host<br>
UP LOOPBACK RUNNING MTU:16436 Metric:1<br>
RX packets:30723 errors:0 dropped:0 overruns:0 frame:0<br>
TX packets:30723 errors:0 dropped:0 overruns:0 carrier:0<br>
collisions:0 txqueuelen:0<br>
RX bytes:92725098 (88.4 MiB) TX bytes:92725098 (88.4 MiB)<br>
<br>
Should I replace static and dhcp addresses between eth0 and br0 interface?<br>
<br>
Regards,<br>
Radek<br>
<br>
<br>
<br>
<br>
<br>
<br>
</div>
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<br></blockquote></div><br><div>To use bridging on the virtual host you have to assign the IPs to br0 and then add "Bridge=br0" to ifcfg-eth0. I have working examples here, <a href="http://itscblog.tamu.edu/startup-guide-for-kvm-on-centos-6/">http://itscblog.tamu.edu/startup-guide-for-kvm-on-centos-6/</a>.</div>