Updating the kernel breaks 802.3ad mode Bonding

  • 7001411
  • 22-Sep-2008
  • 27-Apr-2012


Novell Open Enterprise Server 1 (OES 1) Support Pack 1 Linux


Bonding is configured for 802.3ad mode and is set up and working.
Apply all patches and reboot the server.
Bonding is now broken.  (Can't even ping the default route)


Add miimon=100 to the Bonding Driver Options line in the YaST > Network Devices > NetWork Address Setup page.
This is where you define the 802.3ad mode.  Just add a space and then miimon=100.
(Example: 802.3ad miimon=100)
Verify that the the default route is correct and is assigned to the NIC that you want it be assigned to.

Additional Information

After the kernel update the LAN drivers may take longer to load.
When the bonding driver checks the bonded interfaces to see if they are up, if it finds that they are not up bonding fails to set up the 802.3ad mode.  In this failed condition bonding switches to the default, mode 0.
The miimon setting tells the bonding driver to recheck the interfaces in whatever milliseconds you have set this miimon value to be.
That keeps the bonding driver from switching modes.
When the interfaces are finally up bonding continues to set up the 802.3ad mode and the bond completes.