Hello to all I'm using Arch Linux in a SuperMicro A1SAi-2750F motherboard and I'm having performance issues while bridging 3 Ethernet Gigabit network interfaces. The 4th network interface of that motherboard, is used to connect to the ISP. This setup is my Router/server and I use the 3 bridged interfaces to connect my home network. But now, I'm noticing severe performance issues. I conducted a small iperf3 test. The scenario was: PC A (100Mbps) <---> Server Ether 1(1Gbps) <---> Linux Bridge (br0) <---> Server Ether 2 (1Gbps) <---> PC B (1Gbps) The result: Connecting to host 192.168.123.136, port 5201 [ 4] local 192.168.123.4 port 55462 connected to 192.168.123.136 port 5201 [ ID] Interval Transfer Bandwidth Retr Cwnd [ 4] 0.00-1.00 sec 1.47 MBytes 12.3 Mbits/sec 56 9.90 KBytes [ 4] 1.00-2.00 sec 1.16 MBytes 9.70 Mbits/sec 50 8.48 KBytes [ 4] 2.00-3.00 sec 1.10 MBytes 9.25 Mbits/sec 30 12.7 KBytes [ 4] 3.00-4.00 sec 1.14 MBytes 9.52 Mbits/sec 40 5.66 KBytes [ 4] 4.00-5.00 sec 1.04 MBytes 8.76 Mbits/sec 37 8.48 KBytes [ 4] 5.00-6.00 sec 1.19 MBytes 9.96 Mbits/sec 40 12.7 KBytes [ 4] 6.00-7.00 sec 1.14 MBytes 9.55 Mbits/sec 46 7.07 KBytes [ 4] 7.00-8.00 sec 1.02 MBytes 8.55 Mbits/sec 39 14.1 KBytes [ 4] 8.00-9.00 sec 1.14 MBytes 9.52 Mbits/sec 47 12.7 KBytes [ 4] 9.00-10.00 sec 1.04 MBytes 8.72 Mbits/sec 35 11.3 KBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bandwidth Retr [ 4] 0.00-10.00 sec 11.4 MBytes 9.58 Mbits/sec 420 sender [ 4] 0.00-10.00 sec 11.4 MBytes 9.57 Mbits/sec receiver Then i conducted another iperf3 test with a different scenario: PC A (100Mbps) <---> Server Ether 1 (1Gbps) <---> Linux Bridge (br0) The result: Connecting to host 192.168.123.1, port 5201 [ 4] local 192.168.123.4 port 58982 connected to 192.168.123.1 port 5201 [ ID] Interval Transfer Bandwidth Retr Cwnd [ 4] 0.00-1.00 sec 11.3 MBytes 94.5 Mbits/sec 0 24.0 KBytes [ 4] 1.00-2.00 sec 11.2 MBytes 94.1 Mbits/sec 0 24.0 KBytes [ 4] 2.00-3.00 sec 11.2 MBytes 94.1 Mbits/sec 0 24.0 KBytes [ 4] 3.00-4.00 sec 11.2 MBytes 94.1 Mbits/sec 0 24.0 KBytes [ 4] 4.00-5.00 sec 11.2 MBytes 94.2 Mbits/sec 0 24.0 KBytes [ 4] 5.00-6.00 sec 11.2 MBytes 94.3 Mbits/sec 0 24.0 KBytes [ 4] 6.00-7.00 sec 11.2 MBytes 94.1 Mbits/sec 0 24.0 KBytes [ 4] 7.00-8.00 sec 11.2 MBytes 94.1 Mbits/sec 0 24.0 KBytes [ 4] 8.00-9.00 sec 11.2 MBytes 94.1 Mbits/sec 0 24.0 KBytes [ 4] 9.00-10.00 sec 11.2 MBytes 94.2 Mbits/sec 0 24.0 KBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bandwidth Retr [ 4] 0.00-10.00 sec 112 MBytes 94.2 Mbits/sec 0 sender [ 4] 0.00-10.00 sec 112 MBytes 94.1 Mbits/sec receiver iperf Done. Does anyone know if this low performance behaviour by a Linux bridge is "normal" or, if it is a configuration problem? I disabled iptables. Despite gaining a little improvement, I still have severe performance issues. Can anyone provide some light in this case? Thank you! Carlos Miguel Ferreira