Hi all, I am currently running a network speed evaluation with two different kernels booting on the same base system (Debian Sid). The machine that acts as the server has a 3 GHz Core 2 Duo and an Intel Pro 1000 NIC. The two kernels are a 2.6.18.8 vanilla from kernel.org, and a 2.6.29 from the Debian sources. On the client side i have a MacBook Pro 4.1, so both machines should have more than enough power to run a gigabit ethernet UDP test.
The iperf command i am running on the server-side is a simple "iperf - s -u", on the client side i am using "iperf -c <IP> -u -f m -t 10 -b 1000M -l 1472". With the 2.6.29 kernel, the results are: [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.0 sec 967 MBytes 811 Mbits/sec [ 3] Sent 688670 datagrams [ 3] Server Report: [ 3] 0.0-10.1 sec 963 MBytes 803 Mbits/sec 0.018 ms 1674/688669 (0.24%) [ 3] 0.0-10.1 sec 1 datagrams received out-of-order Nothing to be worried about. On the older 2.6.18.8 Kernel, i always see results like: [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.0 sec 967 MBytes 811 Mbits/sec [ 3] Sent 688653 datagrams [ 3] Server Report: [ 3] 0.0-10.1 sec 329 MBytes 274 Mbits/sec 0.152 ms 454306/688652 (66%) [ 3] 0.0-10.1 sec 1 datagrams received out-of-order There is an immense packet loss. But why? Looking at ifconfig after a test, i always get 990 MB on RX bytes, and about 687000 RX packets. Regardless of which kernel was booted. These figures seem to be realistic on a gigabit UDP test. I just cant't figure out why iperf is reporting of 66% packet loss (and lower bandwidth) on the older kernel. I always get these numbers, varying from 50% till 69%. The ifconfig stats make me believe that iperf gets something wrong with counting the lost UDP packets. On both machines i use the Debian patched versions of iperf-2.0.4. Therefore i have no high CPU load problems whatsoever. Any suggestions? Cheers, Andre ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Iperf-users mailing list Iperf-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/iperf-users
