On 7/01/2010 10:44 AM, Dmitri Girski wrote:
> Hi everybody,
>
> Many thanks to everyone replied, I think we are on the right way.
> I've used tcpdump to generate the logs and there are a lot of dropped
> packets due to the bad checksum. Network guy is currently looking at the
> problem and most likely this is hardware issue.
Hang on a sec. You need to ignore bad checksums on *outbound* packets,
because many (most?) Ethernet drivers implement some level of TCP
offloading, and this will result in packet sniffers seeing invalid
checksums for transmitted packets - the checksums haven't been generated
by the NIC yet.
Unless you know for sure that your NIC doesn't do TSO, ignore bad
checksums on outbound packets from the local interface.
--
Craig Ringer