https://bugzilla.novell.com/show_bug.cgi?id=473948 Summary: tcp checksum errors with 2.6.27.7-9 + MCP55 (NVidia NForce chipset) Classification: openSUSE Product: openSUSE 11.1 Version: Final Platform: x86-64 OS/Version: Other Status: NEW Severity: Normal Priority: P5 - None Component: Kernel AssignedTo: bnc-team-screening@forge.provo.novell.com ReportedBy: jnelson-suse@jamponi.net QAContact: qa@suse.de Found By: --- User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.0.5) Gecko/2008121300 SUSE/3.0.5-1.1 Firefox/3.0.5 While tracking down some significant TCP performance issues with 11.1, I noted the following: 1. ethtool is UNABLE to turn OFF tcp checksumming. 2. EVERY TCP connection regardless of port shows a TCP Checksum failure in wireshark. I am unable to determine if this is real or an artifact of hardware tcp offloading. turnip:~ # ethtool -k eth1 Offload parameters for eth1: Cannot get device flags: Operation not supported rx-checksumming: off tx-checksumming: on scatter-gather: off tcp segmentation offload: off udp fragmentation offload: off generic segmentation offload: off large receive offload: off turnip:~ # ethtool -K eth1 tx off turnip:~ # ethtool -k eth1 Offload parameters for eth1: Cannot get device flags: Operation not supported rx-checksumming: off tx-checksumming: on scatter-gather: off tcp segmentation offload: off udp fragmentation offload: off generic segmentation offload: off large receive offload: off turnip:~ # This is what the interface is: 00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a2) Due to either or both of these issues, I am unable to diagnose TCP issues. Either (a) the tcp checksums are in fact wrong or (b) they are correct but wireshark does not know this (a common issue with hardware checksum offloading). Reproducible: Always Steps to Reproduce: 1. 2. 3. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.