[ovs-discuss] Packet drop after openvswitch bond interface toggles

[Ian Stokes]

On 4/2/2019 8:11 AM, Inakoti, Satish (Nokia - HU/Budapest) wrote:
> Hi,
> *Problem statement:*
> If a ovs-bond is configured with LACP active-active mode (SLB-balancing) 
> and the one of the links go down and come back up again, we observe a 
> packet drop for few seconds.
> *Environment:*
> Openvswitch version - ovs-vsctl (Open vSwitch) 2.9.3
>                                           DB Schema 7.15.1
> DPDK version - dpdk-17.11.4
> Physical nics: Intel Corporation 82599ES 10-Gigabit SFI/SFP+ Network 
> Connection
> Bond mode – LACP active-active, SLB balanced.
> *Steps to reproduce:*
> 
>  1. If one of the links go down (make it down from the ToR switch) – the
>     other takes over and traffic flows smooth as expected.
>  2. When this link becomes active again, then the VM connected to this
>     bond interface observes packets(UDP) drop for few seconds.
> 
> *Expected behavior:*
> The traffic should flow without any drop, even after the interface comes up.
> BR,

Hi,

this sounds similar to the issue described in

https://mail.openvswitch.org/pipermail/ovs-dev/2019-March/356956.html

There are 2 patches under review to help address the issue (although as 
you are using an 82599ES I would think patch 1 below should resolve the 
issue for you, the second patch is aimed at i40e devices).

https://patchwork.ozlabs.org/patch/1051724/
https://patchwork.ozlabs.org/patch/1051725/

Could you check if they resolve the issue you are seeing?

Regards
Ian