Turning inbound checksum calculations on and off

7.1 LPAR mode z/VM guest

A checksum calculation is a form of redundancy check to protect the integrity of data.

Procedure

The qeth device driver supports offloading checksum calculations on inbound packets (receive) to the OSA feature.

To enable or disable checksum calculations by the OSA feature, issue a command of this form:

# ethtool -K <interface_name> rx <value>

where <value> is on or off.

To let the OSA feature calculate the receive checksum for network device eth0, issue
```
# ethtool -K eth0 rx on
```
To let the host CPU calculate the receive checksum for network device eth0, issue
```
# ethtool -K eth0 rx off
```