[ovirt-users] [ovirt-devel] Networking fails for VM running on Centos6.7.Works on Centos6.5

[mad Engineer]

each vm has 4 nics connected to 4 different  bridges which is
connected to 4 different physical interface in access mode VLAN.No
bonding between interfaces.I have IP assigned on "ovirtmgmt" bridge
which is used for storage,migration,console and VM internet access.All
interfaces are 10G with MTU 9000.
During my test only change i made was booting to centos6.5 kernel.

Facing another issue with PXE booting guest machines switching to old
kernel fixes this too

On Sun, Nov 29, 2015 at 1:29 PM, Dan Kenigsberg <danken at redhat.com> wrote:
> On Sat, Nov 28, 2015 at 08:10:06PM +0530, mad Engineer wrote:
>> hello all i am having strange network issue with vms that are running on
>> centos 6.7 ovirt nodes.
>>
>> I recently added one more ovirt node which is running centos6.7 and
>> upgraded from centos6.5 to centos6.7 on all other nodes.
>>
>> All VMs running on nodes with centos6.7 as host Operating system fail to
>> reach network gateway,but if i reboot that same host to centos6.5 kernel
>> everything works fine(with out changing any network configuration).
>>
>> Initially i thought it as configuration issue but its there on all nodes.if
>> i reboot to old kernel everything is working.
>>
>> I am aware about ghost vlan0 issue in centos6.6 kernel.Not aware about any
>> issue in centos6.7 Also all my servers are up to date.
>>
>>
>> All physical interfaces are in access mode VLAN connected to nexus 5k
>> switches.
>>
>>
>> working kernel- 2.6.32-431.20.3.el6.x86_64
>>
>> non working kernel- 2.6.32-573.8.1.el6.x86_64
>
> Can you provide the topology of your VM network config (vlan, bond, bond
> options, bridge options)? Do you have an IP address on the bridge?
>
> (I have not seen this happen myself)