oVirt Windows guests can ping but nothing more
Give windows fans their internet :(
For the moment, i'm working on a VDI cluster based on oVirt, all of my hypervisor are linked with 2x10Gbps bond (LACP mode 4 802.3ad).
Everything is good on unix guests but with Windows guests i can't use the network, the ping pass great but eveything bigger than 500bytes fail to transfer.
At first sight i thought it was a MTU issue but nope, MTU set to 9000 didn't change anything.
Thanks to Alex Crow from ovirt-users mailing list, he showed me the good way, the issue is caused by LRO from slave interfaces.
LRO (Large Receive Offload) is a feature who reduce the CPU usage for receives but it's completely incompatible with ip forwarding and routing.The result of LRO enabled and bridging could result in a low throughput or worse, a kernel panic.
To disable LRO simply use ethtool on all slave interfaces who is used in your bridges/bonds.
ethtool -K eno1 lro off # For a permanent fix, edit the interface configuration file vim /etc/sysconfig/network-scripts/ifcfg-eno1 ETHTOOL_OPTIONS='-K eno1 lro off'