Hi everyone, I'm using Openstack Train and Openvswitch for ML2 driver and GRE for tunnel type. I tested our network performance between two VMs and suffer packet loss as below. VM1: IP: 10.20.1.206 VM2: IP: 10.20.1.154 <https://10.20.1.154/24> VM3: IP: 10.20.1.72 Using iperf3 to testing performance between VM1 and VM2. Run iperf3 client and server on both VMs. On VM2: iperf3 -t 10000 -b 130M -l 442 -P 6 -u -c 10.20.1.206 On VM1: iperf3 -t 10000 -b 130M -l 442 -P 6 -u -c 10.20.1.154 <https://10.20.1.154/24> Using VM3 ping into VM1, then the packet is lost and the latency is quite high. ping -i 0.1 10.20.1.206 PING 10.20.1.206 (10.20.1.206) 56(84) bytes of data. 64 bytes from 10.20.1.206: icmp_seq=1 ttl=64 time=7.70 ms 64 bytes from 10.20.1.206: icmp_seq=2 ttl=64 time=6.90 ms 64 bytes from 10.20.1.206: icmp_seq=3 ttl=64 time=7.71 ms 64 bytes from 10.20.1.206: icmp_seq=4 ttl=64 time=7.98 ms 64 bytes from 10.20.1.206: icmp_seq=6 ttl=64 time=8.58 ms 64 bytes from 10.20.1.206: icmp_seq=7 ttl=64 time=8.34 ms 64 bytes from 10.20.1.206: icmp_seq=8 ttl=64 time=8.09 ms 64 bytes from 10.20.1.206: icmp_seq=10 ttl=64 time=4.57 ms 64 bytes from 10.20.1.206: icmp_seq=11 ttl=64 time=8.74 ms 64 bytes from 10.20.1.206: icmp_seq=12 ttl=64 time=9.37 ms 64 bytes from 10.20.1.206: icmp_seq=14 ttl=64 time=9.59 ms 64 bytes from 10.20.1.206: icmp_seq=15 ttl=64 time=7.97 ms 64 bytes from 10.20.1.206: icmp_seq=16 ttl=64 time=8.72 ms 64 bytes from 10.20.1.206: icmp_seq=17 ttl=64 time=9.23 ms ^C --- 10.20.1.206 ping statistics --- 34 packets transmitted, 28 received, 17.6471% packet loss, time 3328ms rtt min/avg/max/mdev = 1.396/6.266/9.590/2.805 ms Does any one get this issue ? Please help me. Thanks