Configuring the transmit checksum offload feature

Ubuntu 22.04 LTS LPAR mode z/VM guest

The qeth device driver supports offloading outbound (transmit) checksum calculations to the OSA feature.

About this task

You can enable or disable the OSA feature calculating the transmit checksums by using the ethtool command.

Issue a command of the form:

# ethtool -K <interface_name> tx <value>

where <value> is on or off.

To let the OSA feature calculate the outbound checksum for network device encf500, issue
```
# ethtool -K encf500 tx on
```
To let the host CPU calculate the outbound checksum for network device encf500, issue
```
# ethtool -K encf500 tx off
```