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. The qeth device driver failed to enable the required reflective relay mode on
the adjacent switch port although the switch port supports this mode.
User response
Enable reflective relay mode on the switch for the adjacent port and try again.