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

> On Sun, Dec 14, 2014 at 6:23 PM, David P. Discher <d...@dpdtech.com> wrote:
>> 
>> So, I think I’ve identified the issue.  In sys/net/ieee8023ad_lacp.c, 
>> lacp_pdu_input() has a sanity check :
>> 
>>        if (m->m_pkthdr.len != sizeof(*du)) {
>>                goto bad;
>>        }
>> 
>> 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”.
>> 
>>        em1: lacp_pdu_input-sizeof(du) bad m_pkthdr.len=128 sizeof(du)=124
>> 
>> My packet captures shows the packet size differing as well.
>> 
>> I’m still poking around. I’ve been trying to look for the official LACPDU 
>> binary/wire format … if someone can point me to the reference for that, that 
>> would be helpful (at least my own understanding).
> 
> Try here:
> http://standards.ieee.org/findstds/standard/802.1AX-2008.html
> 

Thanks - I hadn’t seen the “free” 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. 

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
===================================================================
--- 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 … or for any use with LACP that is expecting increased throughput 
for a small set of hosts. 


-
David P. Discher
http://davidpdischer.com/
AIM: DavidDPD | Y!M: daviddpdz 
_______________________________________________
freebsd-net@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-net
To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"

Reply via email to