qeth.531375<bus ID of the qeth device>: Hardware checksumming is performed only if <network interface name> and its peer use different OSA Express 3 ports
Offloaded checksum calculations apply only to packets that go out to the
LAN or come in from the LAN. Linux instances that share an OSA Express 3
port exchange packets directly.
Packets transmitted through a shared port, and for which you have turned
on hardware checksumming, are neither checksummed by the OSA adapter nor by
Linux.
User response
To use hardware checksumming, ensure that the peers use separate ports.
To use software checksumming in Linux instead, turn off hardware
checksumming.
If you can risk running without checksumming for your connection,
ignore this message.