The 'isolation' sysfs attribute of the qeth device could not be set to 'forward'.
This setting selects the ISOLATION_FORWARD policy for the QDIO data connection
isolation. The ISOLATION_FORWARD policy requires a network adapter in Virtual
Ethernet Port Aggregator (VEPA) mode with an adjacent switch port in reflective
relay mode.
User response
Use a switch port that supports reflective relay mode if you want to use the
ISOLATION_FORWARD policy for the qeth device.