Hi,

On Fri, Feb 26, 2021 at 05:01:38PM +0100, Claudio Luck wrote:
> Checksum errors are rather common to originate in virtualization 
> platforms. It is one of the things to check for when deploying new 
> infrastructure. Even some bigger resellers hand out VMs with these 
> problems: I occasionally have to add a "ethtool -K $IFACE rx off tx off" 
> command to the boot process.

These are not true checksum "errors".

It's just that the kernel knows it does not need to bother, because 
hardware will take care of it, so spends your CPU cycles for more useful
work.

*tcpdump* does not know.  All tcpdump can see is "I see a packet handed 
towards the NIC, and the checksum does not match" - which is reported.

Tcpdump does not see how the packet will end up on the wire.

Gert Doering
        -- NetMaster
-- 
have you enabled IPv6 on something today...?

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