lagg/lacp poor traffic distribution

[Eugene Grosbein]

On 26.12.2010 23:53, Gleb Kurtsou wrote:

>> I've loaded router using two lagg interfaces in LACP mode.
>> lagg0 has IP address and two ports (em0 and em1) and carry untagged frames.
>> lagg1 has no IP address and has two ports (igb0 and igb1) and carry
>> about 1000 dot-q vlans with lots of hosts in each vlan.
>>
>> For lagg1, lagg distributes outgoing traffic over two ports just fine.
>> For lagg0 (untagged ethernet segment with only 2 MAC addresses)
>> less than 0.07% (54Mbit/s max) of traffic goes to em0
>> and over 99.92% goes to em1, that's bad.
>>
>> That's general traffic of several thousands of customers surfing the web,
>> using torrents etc.  I've glanced over lagg/lacp sources if src/sys/net/
>> and found nothing suspicious, it should extract and use srcIP/dstIP for hash.
>>
>> How do I debug this problem?
> Could you try the patch attached. It changes hash function for
> distributing traffic.

I've already found source of this problem.
That's not hash function problem (it works just fine when called),
that's lagg(4) driver not using hashes for some workflows.
Details can be found in this thread, as well as solution.

Eugene Grosbein