Hi all, back again trying to debug causes of bad performances in my lab's network.
I tried to place two boxes behind a Cisco router (no information on model, sorry), the first with OpenBSD 4.6 and the second one with Linux Ubuntu 9.04. I used iperf to measure bandwidth, in particular the two boxes were acting as server, and a third machine (Linux Ubuntu) were used as client for iperf. This latter machine is in a local network, so packets will flow through Cisco router before reaching the two iperf servers. To make it short, TCP bandwidth between client and Ubuntu server reaches 3.4 Mbits/s, while transmission between client and OpenBSD server is bursty and hardly gets to 900 kbits/s. The strange thing is that with UDP both servers reach 36 Mbits/s, with almost no difference between each other. If I put the client on the same subnetwork as servers, Cisco router would not intervene and even with TCP I get almost full speed (like UDP). Any idea? I attach iperf log. #### me...@jimi:~$ iperf -c 192.167.132.99 -i 1 -d ####OpenBSD box from linux client ------------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 85.3 KByte (default) Client connecting to 192.167.132.99, TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 4] local 172.16.11.190 port 60482 connected with 192.167.132.99 port 5001 [ ID] Interval Transfer Bandwidth [ 4] 0.0- 1.0 sec 216 KBytes 1.77 Mbits/sec [ 4] 1.0- 2.0 sec 240 KBytes 1.97 Mbits/sec [ 4] 2.0- 3.0 sec 136 KBytes 1.11 Mbits/sec [ 4] 3.0- 4.0 sec 64.0 KBytes 524 Kbits/sec [ 4] 4.0- 5.0 sec 88.0 KBytes 721 Kbits/sec [ 4] 5.0- 6.0 sec 184 KBytes 1.51 Mbits/sec [ 4] 6.0- 7.0 sec 104 KBytes 852 Kbits/sec [ 4] 7.0- 8.0 sec 264 KBytes 2.16 Mbits/sec [ 4] 8.0- 9.0 sec 176 KBytes 1.44 Mbits/sec Waiting for server threads to complete. Interrupt again to force quit. [ 4] 9.0-10.0 sec 352 KBytes 2.88 Mbits/sec [ 4] 0.0-10.0 sec 1.79 MBytes 1.50 Mbits/sec me...@jimi:~$ iperf -c 192.167.132.96 -i 1 -d ###Ubuntu box from linux client ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 85.3 KByte (default) Client connecting to 192.167.132.96, TCP port 5001 TCP window size: 16.0 KByte (default) ------------------------------------------------------------ [ 5] local 172.16.11.190 port 48551 connected with 192.167.132.96 port 5001 [ 4] local 172.16.11.190 port 5001 connected with 192.167.132.96 port 47079 [ ID] Interval Transfer Bandwidth [ 5] 0.0- 1.0 sec 360 KBytes 2.95 Mbits/sec [ 5] 1.0- 2.0 sec 0.00 Bytes 0.00 bits/sec [ 5] 2.0- 3.0 sec 352 KBytes 2.88 Mbits/sec [ 5] 3.0- 4.0 sec 1016 KBytes 8.32 Mbits/sec [ 5] 4.0- 5.0 sec 192 KBytes 1.57 Mbits/sec [ 5] 5.0- 6.0 sec 256 KBytes 2.10 Mbits/sec [ 5] 6.0- 7.0 sec 712 KBytes 5.83 Mbits/sec [ 5] 7.0- 8.0 sec 120 KBytes 983 Kbits/sec [ 5] 8.0- 9.0 sec 360 KBytes 2.95 Mbits/sec [ 5] 9.0-10.0 sec 520 KBytes 4.26 Mbits/sec [ 5] 0.0-10.0 sec 3.80 MBytes 3.19 Mbits/sec [ 4] 0.0- 1.0 sec 0.00 Bytes 0.00 bits/sec [ 4] 1.0- 2.0 sec 0.00 Bytes 0.00 bits/sec [ 4] 2.0- 3.0 sec 0.00 Bytes 0.00 bits/sec [ 4] 3.0- 4.0 sec 0.00 Bytes 0.00 bits/sec [ 4] 4.0- 5.0 sec 0.00 Bytes 0.00 bits/sec [ 4] 5.0- 6.0 sec 0.00 Bytes 0.00 bits/sec [ 4] 6.0- 7.0 sec 0.00 Bytes 0.00 bits/sec [ 4] 7.0- 8.0 sec 0.00 Bytes 0.00 bits/sec [ 4] 8.0- 9.0 sec 0.00 Bytes 0.00 bits/sec [ 4] 9.0-10.0 sec 0.00 Bytes 0.00 bits/sec [ 4] 0.0-10.2 sec 4.15 MBytes 3.40 Mbits/sec
