Re: [PATCH net-next 2/2] bonding: support QinQ for bond arp interval

[Ding Tianhong <dingtianhong@huawei.com>]

On 2014/3/20 17:40, Michal Kubecek wrote:
> On Thu, Mar 20, 2014 at 05:29:39PM +0800, Ding Tianhong wrote:
>> On 2014/3/20 16:24, Michal Kubecek wrote:
>>> On Mon, Mar 17, 2014 at 10:46:04AM -0700, Jay Vosburgh wrote:
>>>> Ding Tianhong <dingtianhong@huawei.com> wrote:
>>>>>
>>>>> ip link add link bond0  bond0.20 type vlan proto 802.1ad id 20
>>>>> ip link add link bond0.20  bond0.20.200 type vlan proto 802.1q id 200
>>>>
>>>> 	Is this nesting backwards?  The way I read it (and the way I
>>>> recall that VLANs nest), "bond0.20" is the "regular" VLAN, i.e., if we
>>>> just have bond0.20 it would be a standard 802.1q (ethertype 0x8100)
>>>> VLAN.  Adding the second VLAN, .200 in this example, would be the second
>>>> (outer) tag, and would be the 802.1ad (ethertype 0x88a8) tag.
>>>>
>>>> 	In other words, adding a VLAN to an already existing VLAN makes
>>>> the newly added VLAN the "outer" and the already existing VLAN the
>>>> "inner."  Am I confused?
>>>
>>> I don't think so. My understanding is that when sending a packet to
>>> a vlan device, it is tagged (according to its "proto") and passed to its
>>> underlying device.
>>>
>>> So in the case above, sending a packet to bond0.20.200 would add an
>>> 802.1q tag and pass the result to bond0.20 which would add an 802.1ad
>>> tag and pass the result to bond0. Which is the way it should work.
>>
>> I agree with your analysis of QinQ for vlan in common usage, but I think you miss
>> something for how the arp interval works, the bonding need to create a new
>> arp request with vlan tag to confirm that the slave should be active or unactive,  
>> the skb could not be passed to bond0.20.200, we have to build QinQ skb ourselves.
> 
> My comment referred only to the way stacked interfaces are set up in the
> quoted example, not to the original issue.
> 
>                                                          Michal Kubecek
> 

Sorry for that, I misunderstood.:)

Ding

> 
> .
>