Subject: Re: [PATCH] macvlan: Set IFF_UNICAST_FLT flag to prevent unnecessary promisc mode.

From: Vlad Yasevich <[email-masked]>
Date: Thu, 07 Mar 2013 15:32:26 -0500

On 03/07/2013 03:27 PM, Ben Greear wrote:
> On 03/07/2013 12:21 PM, Vlad Yasevich wrote:
>> Macvlan already supports hw address filters.  Set the IFF_UNICAST_FLT
>> so that it doesn't needlesly enter PROMISC mode when macvlans are
>> stacked.
>
> Out of curiosity, how can stacking mac-vlans be useful?
>
> (You are stacking more macvlans on a base mac-vlan?)

Yep, and macvlans allows, but it looks like it only tries to detect a 2 
level stack.  I am not sure what the reason is.  Might be realated to 
vlan-to-vlan communication.

-vlad

> Thanks,
> Ben