Hi, I am using Openstack Wallaby release with OVN on Ubuntu 20.04. My environment consists of 2 compute nodes and 1 controller node. ovs_version: "2.15.0" Ubuntu Kernel Version: 5.4.0-77-generic I am observing Network performance between instances on different compute nodes is slow. The network uses geneve tunnels.The environment is using 10Gbps network interface cards. However, iperf between instances on different compute nodes attains only speeds between a few hundred Mbit/s and a few Gb/s. Both instances are in the same tenant network. Note: iperf results between both compute nodes (hypervisors) across the geneve tunnel endpoints is perfect 10 Gbps. Below are the results of iperf commands. *iperf server:* 2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 8950 qdisc fq_codel state UP group default qlen 1000 link/ether fa:16:3e:4b:1d:29 brd ff:ff:ff:ff:ff:ff inet 192.168.100.111/24 brd 192.168.100.255 scope global dynamic ens3 valid_lft 42694sec preferred_lft 42694sec inet6 fe80::f816:3eff:fe4b:1d29/64 scope link valid_lft forever preferred_lft forever root@vm-01:~# iperf3 -s Server listening on 5201 Accepted connection from 192.168.100.69, port 45542 [ 5] local 192.168.100.111 port 5201 connected to 192.168.100.69 port 45544 [ 8] local 192.168.100.111 port 5201 connected to 192.168.100.69 port 45546 [ ID][Role] Interval Transfer Bitrate Retr Cwnd [ 5][RX-S] 0.00-1.00 sec 692 MBytes 5.81 Gbits/sec [ 8][TX-S] 0.00-1.00 sec 730 MBytes 6.12 Gbits/sec 0 3.14 MBytes [ 5][RX-S] 1.00-2.00 sec 598 MBytes 5.01 Gbits/sec [ 8][TX-S] 1.00-2.00 sec 879 MBytes 7.37 Gbits/sec 0 3.14 MBytes [ 5][RX-S] 2.00-3.00 sec 793 MBytes 6.65 Gbits/sec [ 8][TX-S] 2.00-3.00 sec 756 MBytes 6.34 Gbits/sec 0 3.14 MBytes [ 5][RX-S] 3.00-4.00 sec 653 MBytes 5.48 Gbits/sec [ 8][TX-S] 3.00-4.00 sec 871 MBytes 7.31 Gbits/sec 0 3.14 MBytes [ 5][RX-S] 4.00-5.00 sec 597 MBytes 5.01 Gbits/sec [ 8][TX-S] 4.00-5.00 sec 858 MBytes 7.20 Gbits/sec 0 3.14 MBytes [ 5][RX-S] 5.00-6.00 sec 734 MBytes 6.16 Gbits/sec [ 8][TX-S] 5.00-6.00 sec 818 MBytes 6.86 Gbits/sec 0 3.14 MBytes [ 5][RX-S] 6.00-7.00 sec 724 MBytes 6.06 Gbits/sec [ 8][TX-S] 6.00-7.00 sec 789 MBytes 6.60 Gbits/sec 0 3.14 MBytes [ 5][RX-S] 7.00-8.00 sec 735 MBytes 6.18 Gbits/sec [ 8][TX-S] 7.00-8.00 sec 835 MBytes 7.02 Gbits/sec 0 3.14 MBytes [ 5][RX-S] 8.00-9.00 sec 789 MBytes 6.62 Gbits/sec [ 8][TX-S] 8.00-9.00 sec 845 MBytes 7.09 Gbits/sec 0 3.14 MBytes [ 5][RX-S] 9.00-10.00 sec 599 MBytes 5.02 Gbits/sec [ 8][TX-S] 9.00-10.00 sec 806 MBytes 6.76 Gbits/sec 0 3.14 MBytes [ ID][Role] Interval Transfer Bitrate Retr [ 5][RX-S] 0.00-10.00 sec 6.75 GBytes 5.80 Gbits/sec receiver [ 8][TX-S] 0.00-10.00 sec 7.99 GBytes 6.87 Gbits/sec 0 sender Server listening on 5201 *Client side:* root@vm-03:~# iperf3 -c 192.168.100.111 --bidir Connecting to host 192.168.100.111, port 5201 [ 5] local 192.168.100.69 port 45544 connected to 192.168.100.111 port 5201 [ 7] local 192.168.100.69 port 45546 connected to 192.168.100.111 port 5201 [ ID][Role] Interval Transfer Bitrate Retr Cwnd [ 5][TX-C] 0.00-1.00 sec 700 MBytes 5.87 Gbits/sec 0 3.13 MBytes [ 7][RX-C] 0.00-1.00 sec 722 MBytes 6.06 Gbits/sec [ 5][TX-C] 1.00-2.00 sec 594 MBytes 4.98 Gbits/sec 0 3.13 MBytes [ 7][RX-C] 1.00-2.00 sec 883 MBytes 7.41 Gbits/sec [ 5][TX-C] 2.00-3.00 sec 796 MBytes 6.67 Gbits/sec 0 3.13 MBytes [ 7][RX-C] 2.00-3.00 sec 752 MBytes 6.31 Gbits/sec [ 5][TX-C] 3.00-4.00 sec 654 MBytes 5.49 Gbits/sec 0 3.13 MBytes [ 7][RX-C] 3.00-4.00 sec 876 MBytes 7.35 Gbits/sec [ 5][TX-C] 4.00-5.00 sec 598 MBytes 5.01 Gbits/sec 0 3.13 MBytes [ 7][RX-C] 4.00-5.00 sec 853 MBytes 7.16 Gbits/sec [ 5][TX-C] 5.00-6.00 sec 734 MBytes 6.15 Gbits/sec 0 3.13 MBytes [ 7][RX-C] 5.00-6.00 sec 818 MBytes 6.86 Gbits/sec [ 5][TX-C] 6.00-7.00 sec 726 MBytes 6.09 Gbits/sec 0 3.13 MBytes [ 7][RX-C] 6.00-7.00 sec 793 MBytes 6.65 Gbits/sec [ 5][TX-C] 7.00-8.00 sec 734 MBytes 6.15 Gbits/sec 0 3.13 MBytes [ 7][RX-C] 7.00-8.00 sec 831 MBytes 6.97 Gbits/sec [ 5][TX-C] 8.00-9.00 sec 788 MBytes 6.61 Gbits/sec 0 3.13 MBytes [ 7][RX-C] 8.00-9.00 sec 845 MBytes 7.09 Gbits/sec [ 5][TX-C] 9.00-10.00 sec 600 MBytes 5.03 Gbits/sec 0 3.13 MBytes [ 7][RX-C] 9.00-10.00 sec 805 MBytes 6.76 Gbits/sec [ ID][Role] Interval Transfer Bitrate Retr [ 5][TX-C] 0.00-10.00 sec 6.76 GBytes 5.81 Gbits/sec 0 sender [ 5][TX-C] 0.00-10.00 sec 6.75 GBytes 5.80 Gbits/sec receiver [ 7][RX-C] 0.00-10.00 sec 7.99 GBytes 6.87 Gbits/sec 0 sender [ 7][RX-C] 0.00-10.00 sec 7.99 GBytes 6.86 Gbits/sec receiver iperf Done. --------------------------------------------------------------------------------------------------------- *ovs-vsctl show on compute node1:* root@kvm01-a1-khi01:~# ovs-vsctl show 88e6b984-44dc-4f74-8a9a-891742dbbdbd Bridge br-eth1 Port ens224 Interface ens224 Port patch-provnet-440be99a-c347-4458-b7c1-6c0e6155eee9-to-br-int Interface patch-provnet-440be99a-c347-4458-b7c1-6c0e6155eee9-to-br-int type: patch options: {peer=patch-br-int-to-provnet-440be99a-c347-4458-b7c1-6c0e6155eee9} Port br-eth1 Interface br-eth1 type: internal Bridge br-int fail_mode: secure datapath_type: system Port tapde98b2d4-a0 Interface tapde98b2d4-a0 Port ovn-f51ef9-0 Interface ovn-f51ef9-0 type: vxlan options: {csum="true", key=flow, remote_ip="172.16.30.3"} bfd_status: {diagnostic="No Diagnostic", flap_count="1", forwarding="true", remote_diagnostic="No Diagnostic", remote_state=up, state=up} Port tap348fc6dc-3a Interface tap348fc6dc-3a Port br-int Interface br-int type: internal Port tap6d4d8e02-c0 Interface tap6d4d8e02-c0 error: "could not open network device tap6d4d8e02-c0 (No such device)" Port patch-br-int-to-provnet-440be99a-c347-4458-b7c1-6c0e6155eee9 Interface patch-br-int-to-provnet-440be99a-c347-4458-b7c1-6c0e6155eee9 type: patch options: {peer=patch-provnet-440be99a-c347-4458-b7c1-6c0e6155eee9-to-br-int} Port tap247fe5b2-ff Interface tap247fe5b2-ff ------------------------------------------------------------------------------------------------------ *ovs-vsctl show on compute node2:* root@kvm03-a1-khi01:~# ovs-vsctl show 24ce6475-89bb-4df5-a5ff-4ce58f2c2f68 Bridge br-eth1 Port patch-provnet-440be99a-c347-4458-b7c1-6c0e6155eee9-to-br-int Interface patch-provnet-440be99a-c347-4458-b7c1-6c0e6155eee9-to-br-int type: patch options: {peer=patch-br-int-to-provnet-440be99a-c347-4458-b7c1-6c0e6155eee9} Port br-eth1 Interface br-eth1 type: internal Port ens224 Interface ens224 Bridge br-int fail_mode: secure datapath_type: system Port patch-br-int-to-provnet-440be99a-c347-4458-b7c1-6c0e6155eee9 Interface patch-br-int-to-provnet-440be99a-c347-4458-b7c1-6c0e6155eee9 type: patch options: {peer=patch-provnet-440be99a-c347-4458-b7c1-6c0e6155eee9-to-br-int} Port tap2b0bbf7b-59 Interface tap2b0bbf7b-59 Port ovn-650be8-0 Interface ovn-650be8-0 type: vxlan options: {csum="true", key=flow, remote_ip="172.16.30.1"} bfd_status: {diagnostic="No Diagnostic", flap_count="1", forwarding="true", remote_diagnostic="No Diagnostic", remote_state=up, state=up} Port tap867d2174-83 Interface tap867d2174-83 Port tapde98b2d4-a0 Interface tapde98b2d4-a0 Port br-int Interface br-int type: internal -------------------------------------------------------------------------------------------------------- I would really appreciate any input in this regard. Thank you. Regards, Malik Obaid