Linux on IBM Z - VLAN device created on top of a bond reports only one slave present

Solution Verified - Updated -


A VLAN device on a two-slave active/backup bond intermittently reports only one slave present.

When the problem shows up intermittently after a reboot, there is a console message for the slave interface that subsequently fails to show up as a slave in the bond, like:

bondeth10g: Couldn't add bond vlan ids to encf300


  • Red Hat Enterprise Linux 8
  • kernel 4.18.0-147.3.1.el8_1.s390x but other kernel versions are likely to show the same problem
  • IBM Z (mainframe) or IBM LinuxONE hardware

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