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etpoole60 10-26-2014 05:23 PM

Loss Of Network Connection After Power Loss
Not sure if this is a Virtualization question or a Network question.

My primary machine is running CentOS 5.11 x86_64. I am running KVM on this machine. This machine has 4 physical NICs and eth2 is the one being used as the bridge. I am using as the bridge IP address.

I am running 2 virtual machines and they are using the following IP addresses:
JPD3VM01 (CentOS 6.5 x86_64) -
JPDSYS1 (CentOS 6.5 x86_64) -

I can no longer access either of these virtual machines using Putty from my Windows machine or SSH from my other Linux machine.

What should I look for to solve this problem?


zhjim 10-28-2014 03:23 AM


Make sure the devices from the guest are within the bridge. Check on the settings of the bridge. Some settings can make the actual bridging of the interfaces slow.

But before this. Check if you can access the host machine on the bridge ip. Try to ping the guest machine from inside the host. Check if the connection betweeen the two guest machines work.

etpoole60 10-28-2014 11:29 AM

I posted this issue to both networking and to Virtualizaton and the post to Vrtualization was closed by the moderator.

I was asked if 'virsh' was installed and it is.

As far as accessing the host machine via the br0 IP address, the answer is yes. From another CentOS machine I entered ssh and was allowed to log in. Is this correct?

Also, I am not using Network Manager on the host or the virtual machines.

I can access both virtual machines using virt-manager.


etpoole60 10-29-2014 05:28 AM

You said 'Make sure the devices from the guest are within the bridge.' How do I do that? Also, this was all working prior to the power loss.


etpoole60 11-02-2014 07:55 PM

OK, I think I have narrowed the issue down to the host system. Specifically the br0 definition (though I can't seem to pin it down to a specific line in the configuration).

Since the host has 4 physical NICs I picked one and following the directions on HowToForge, I created a br1 definition and spun up a new VM and all is working just fine using the br1 bridge.

Now it's off the the Virtualization forum to ask how I can move an existing VM from one bridge network to another - that is unless someone here can tell me how to fix or at least find where the issue is with my br0 bridge.


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