MLAG bonding sub-interfaces

  • 16 January 2019
  • 3 replies


Is bonding sub-interfaces in an MLAG pair supported?
I am not able to successfully configure it.


3 replies

Userlevel 4
@noster can you show us how you're trying to configure the bonds please?

If you're talking about the subinterfaces that dual connect the MLAG pair, then it is supported. Check the requirements section of the MLAG chapter and make sure you're adhering to them. Let us know how it goes.
Well, I am trying out some configurations but I have been unsuccessful so I wanted to ask before I spend too much time on it. I have read the documentation you referenced a few times before but there is no specific configuration for sub-interface bonding.

The few ways I tried were 1). Tried bonding the identical subinterface from each switch on the pair 2). Tried bonding the parent interface on each switch on the pair (I did not think this is a right way..)

Neither worked.
Please note each sub-interface is mapped to a VRF on each switch (another point I am not sure whether it is supported..)

I will paste the config once I regain access to the environment.

Userlevel 5
@noster As far as I know this is not possible. LACP PDUs are always sent on the wire untagged, meaning that they effectively ignore sub interfaces. It is the link as a whole that is in a bond, or not.