[SOLVED] 802.3ad Link Aggregation Load Balancing

TrojanMan78 · 08-30-2012, 09:44 AM

I am running SuSE with (4) 1GB NICs using LACP. I have configured the switched correctly and the bond link works properly. What baffles me is that it does not seem to balance the load to the other members. One NIC always seems to do all the heavy lifting. If i start a cp from a remote host and then do another cp at the same time from a different host it will use the same NIC. I was under the impression 802.3ad did load balancing in addition to link aggregation? What am i missing here?

Thanks
TM

benp6 · 08-30-2012, 02:14 PM

Hi,

I myself have come across this and i believe its due to fact that you can only utilize one link in a single stream. If you were to run two separate iperf tests at the same time i think you would see results more like what you are expecting...

No 100% sure on this though.

Cheers,
Ben

baldy3105 · 08-31-2012, 04:10 PM

The load balancing is done using an algorithm that looks at source and destination MAC or IP or TCP/UDP port dependent on how the system is configured. The algorithm is deterministic in that it will always make the same decision for balancing two devices, so its quite possible that you have by chance just picked two pairs of devices that use the same link.

The "load balancing" is only in aggregate, not per connection. Once you have more pairs running on it you should see both links being used.

TrojanMan78 · 09-08-2012, 11:27 AM

I switched it to round robin and is performing as expected. I read up on 802.3ad before I implemented it however it seems I failed to completely understand it.