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Date:      Wed, 17 Dec 2014 17:09:36 -0800
From:      "David P. Discher" <dpd@dpdtech.com>
To:        Alan Somers <asomers@freebsd.org>
Cc:        FreeBSD Net <freebsd-net@freebsd.org>, Adam McDougall <mcdouga9@egr.msu.edu>
Subject:   Re: FreeBSD 10-stable (r274577) LACP / IEEE 802.3ad with TP-Link TL-SG2008 - not working
Message-ID:  <2BCFC9D3-3B7D-421F-9FDA-0C4E1018F8F5@dpdtech.com>
In-Reply-To: <CAOtMX2h3U-C9stM5qdix1HCqG=6rZD2GzKQw0t6Raoh6ToL3Og@mail.gmail.com>
References:  <1A44709E-7D0C-4932-8A28-383EAC3F340B@dpdtech.com> <CAOtMX2gEGxTyXjitBu=pjkteocp1pSGxnb%2BWDb_jL3f0YNOjrg@mail.gmail.com> <9AE69175-92D9-49FA-A651-119C7046A1FA@dpdtech.com> <5480D8EF.9000804@egr.msu.edu> <3D993418-E632-44BA-8FE2-2F3F34188F20@dpdtech.com> <34276C9E-CAEF-4E3F-AA2A-568F2D3099EC@dpdtech.com> <CAOtMX2h3U-C9stM5qdix1HCqG=6rZD2GzKQw0t6Raoh6ToL3Og@mail.gmail.com>

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On Dec 15, 2014, at 11:33 AM, Alan Somers <asomers@freebsd.org> wrote:

> On Sun, Dec 14, 2014 at 6:23 PM, David P. Discher <dpd@dpdtech.com> =
wrote:
>>=20
>> So, I think I=92ve identified the issue.  In =
sys/net/ieee8023ad_lacp.c, lacp_pdu_input() has a sanity check :
>>=20
>>        if (m->m_pkthdr.len !=3D sizeof(*du)) {
>>                goto bad;
>>        }
>>=20
>> I added some debugging information in if_lagg, and ran with it.  The =
lacpdu packet that being sent by the TP-Link switch is 4 bytes longer =
than the FreeBSD "struct lacpdu du=94.
>>=20
>>        em1: lacp_pdu_input-sizeof(du) bad m_pkthdr.len=3D128 =
sizeof(du)=3D124
>>=20
>> My packet captures shows the packet size differing as well.
>>=20
>> I=92m still poking around. I=92ve been trying to look for the =
official LACPDU binary/wire format =85 if someone can point me to the =
reference for that, that would be helpful (at least my own =
understanding).
>=20
> Try here:
> http://standards.ieee.org/findstds/standard/802.1AX-2008.html
>=20

Thanks - I hadn=92t seen the =93free=94 version from IEEE, and may =
looking into that later.  However, I think my time with messing around =
with this switch and lagg is just about over.=20

I did get FreeBSD to work with LACP in this Switch.  I hacked in the 4 =
extra bytes in struct lacpdu in src/sys/net/ieee8023ad_lacp.h

Index: ieee8023ad_lacp.h
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- ieee8023ad_lacp.h	(revision 275779)
+++ ieee8023ad_lacp.h	(working copy)
@@ -151,6 +151,7 @@
 	struct lacp_collectorinfo ldu_collector;
 	struct tlvhdr		ldu_tlv_term;
 	uint8_t			ldu_resv[50];
+	uint8_t			tplink[4];
 } __packed;

 /*


This work great and without any issue.  All the defaults with 10-stable =
(r275778) and recent version of -head with this one line made it work.  =
Of course, this will likely break FreeBSD with all other switches LACP.

However, what I have also discovered this this switch is unlike FreeBSD =
which lagghash includes L4, the switch only seems to hash over SRC+DST =
IP or SRC+DST MAC.  Which makes it pretty much just sends all the =
traffic down one link from the switch. So for my particular use case =
with a small set of hosts, this switch is not useful for me.

I would not recommend the TP-Link TL-SG2008 8-Port Gigabit Smart Switch =
for use with FreeBSD =85 or for any use with LACP that is expecting =
increased throughput for a small set of hosts.=20


-
David P. Discher
http://davidpdischer.com/
AIM: DavidDPD | Y!M: daviddpdz=20



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