Hi Han, >> GRE: 9000 bytes >> NIC: 9000 bytes >> > Where did you get NIC: 9000 bytes? What's the MTU of your physical interface?
tcpdump on the physical interface show GRE packets are segmented to ~9000 if the VMs vif has MTU 9000. The MTU on the physical NIC is 9192. > Otherwise it is normal. TSO of virtual driver of VM offload 64k > buffers to host, and host (without GRE offloading) segment the inner > packet according to VM MTU and put to transport layer (GRE). OK - I see, thanks for clearing that up. Do you know if VXLAN has the same limitation ? The Contrail vrouter seems to be able to work around it.. http://opencontrail.org/evaluating-opencontrail-virtual-router-performance/ Regards Kristoffer _______________________________________________ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
