In RHEL 6.3 a VLAN on a bond does not work anymore

Solution Verified - Updated

Environment

  • Red Hat Enterprise Linux 6.3
  • kernel-2.6.32-279.el6
  • Interfaces configured into a bond with VLAN subinterfaces

Issue

  • Following a yum update from Red Hat Enterprise Linux 6.2 to 6.3 the network no longer functions though it is showing as up.
  • Although all nic messages indicate everything should be up, the system is unreachable.
Jun 23 09:54:47 HOSTNAME kernel: 802.1Q VLAN Support v1.8 Ben Greear <greearb@candelatech.com>
...
Jun 23 09:54:47 HOSTNAME kernel: 8021q: adding VLAN 0 to HW filter on device bond0
...
Jun 23 09:54:48 HOSTNAME kernel: bonding: bond0: Removing slave eth3
Jun 23 09:54:48 HOSTNAME kernel: bonding: bond0: releasing active interface eth3
Jun 23 09:54:50 HOSTNAME kernel: bonding: bond0: Removing slave eth2
Jun 23 09:54:50 HOSTNAME kernel: bonding: bond0: releasing active interface eth2
Jun 23 09:54:53 HOSTNAME kernel: bonding: bond0: Removing slave eth1
Jun 23 09:54:53 HOSTNAME kernel: bonding: bond0: releasing active interface eth1
Jun 23 09:54:57 HOSTNAME kernel: bonding: bond0: Removing slave eth0
Jun 23 09:54:57 HOSTNAME kernel: bonding: bond0: Warning: the permanent HWaddr of eth0 - aa:aa:aa:aa:aa:aa - is still in use by bond0. Set the HWaddr of eth0 to a different address to avoid conflicts.
Jun 23 09:54:57 HOSTNAME kernel: bonding: bond0: releasing active interface eth0

Resolution

Workarounds

  • Reboot using previous kernel
  • Change /etc/grub.conf to point to old kernel

Root Cause

  • The bonding method for adding VLAN Identifiers (VIDs) did not always add the VID to a slave VLAN group. When the NETIF_F_HW_VLAN_FILTER flag was not set on a slave, the bonding module could not add new VIDs to it. This could cause networking problems and the system to be unreachable even if NIC messages did not indicate any problems. Updated kernel kernel-2.6.32-279.2.1.el6 has a fix that changes the bond VID add path to always add a new VID to the slaves (if the VID does not exist). This ensures that networking problems no longer occur in this scenario.

Diagnostic Steps

  1. Configure a bond with multiple devices, and vlan interfaces on top of it.

  2. Boot the 6.3 kernel.

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