FreeBSD 10-stable (r274577) LACP / IEEE 802.3ad with TP-Link TL-SG2008 - not working

[Alan Somers]

On Wed, Dec 17, 2014 at 10:11 PM, Craig Rodrigues <rodrigc at freebsd.org> wrote:
> On Wed, Dec 17, 2014 at 9:08 PM, Craig Rodrigues <rodrigc at freebsd.org>
> wrote:
>>
>>
>>
>> On Wed, Dec 17, 2014 at 5:36 PM, David P. Discher <dpd at dpdtech.com> wrote:
>>>
>>>
>>> Yeah, Alan - will do ... if I decided to look into more.  That is why I was
>>> looking for spec on LACP.  One side is doing it wrong.  FreeBSD is looking
>>> for a LACPDU of exactly sizeof ( struct lacpdu ) which is 124 bytes. The
>>> TP-Link is sending a PDU of 128 bytes. I was hoping someone would know off
>>> hand what the spec says, if the PDU "should be" or "must be".
>>>
>>
>>
>> I think you have stumbled across a valid problem in the FreeBSD code.  I
>> don't have access
>> to 802.3ad-2000, but this might give you some clues:
>> http://kb.juniper.net/InfoCenter/index?page=content&id=KB17674
>>
>> I would also look at the source code of wireshark to be sure.  wireshark
>> has a sample capture of LACP packets here:
>>
>> http://wiki.wireshark.org/LinkAggregationControlProtocol
>>
>>
> And here:
>
> http://www-01.ibm.com/support/docview.wss?uid=isg1VM64842

Good find, Craig.  Also, I found the full LACPDU definition.  It's in
section 5.4.2.2, page 33, of the 802.1ax-2008 spec that I linked to.
You can see the 4-byte FCS field at the end.  Does your tp_link[4]
field look like an FCS?  If so, you need to figure out why it's
propagating all the way up to the LACP level.

-Alan