I am trying to use ethtool to disable TCP checksumming by running the following cammand:
/usr/sbin/ethtool -K eth0 rx off tx off
I got :

Cannot set device rx csum settings: Operation not supported.

I then tried to show all the offload parameters by running

/usr/sbin/ethtool -k eth0

I got the following response:
Offload parameters for eth0:
Cannot get device rx csum settings: Operation not supported
Cannot get device tx csum settings: Operation not supported
Cannot get device scatter-gather settings: Operation not supported
Cannot get device tcp segmentation offload settings: Operation not supported
Cannot get device udp large send offload settings: Operation not supported
Cannot get device generic segmentation offload settings: Operation not supported
no offload info available

The RHEL kernel version is 2.6.9-67.ELsmp

I am wondering if there is a way to disable the TCP checksumming.

Thanks

Lin Chen

That would disable the hardware checksumming, if your hardware supports it. However, the "Operation not supported" messages indicates that your ethernet device does not seem to handle TCP checksumming and other offloading features.