Intel 4-port ethernet adaptor link aggregation issue

[Joe Moog]

On Aug 1, 2013, at 5:36 PM, Sean Bruno <sean_bruno at yahoo.com> wrote:

>> UPDATE: After additional testing, I'm beginning to suspect the igb driver. With our setup, ifconfig identifies all the ethernet ports as igb(0-5). I configured igb0 with a single static IP address (say, 192.168.1.10), and was able to connect to the host administratively. While connected, I enabled another port as a second standalone port, again with a unique address (say, 192.168.1.20), and was able to access the host via that interface as well. The problem arises when we attempt to similarly add a third interface to the mix -- and it doesn't seem to matter what interface(s) we use, or in what order we activate them. Always on the third interface, that third interface fails to respond despite showing "active" both in ifconfig and on the switch.
>> 
>> If there is anything else I could try that would be useful to help identify where the issue may reside, please let me know.
>> 
>> Thanks
>> 
>> Joe
> 
> Your test seems to indicate that the *first* port on the quad-port card
> is causing you issues as the on-board interfaces igb0/1 are working
> fine.
> 
> Can you bring up *any* ports on the quad-port card?
> 
> Are you sure that device enumeration is correct in the host o/s and that
> port 1 on the aud-port card is really igb2, port 2 is igb3, etc ?
> 
> Sean

Sean:

It is not always the first port on the NIC. The host maps the ports the same way every time, in the same order, so this doesn't appear to be of any consequence. We can enable any one port on the host (on-board or NIC), and then enable another (again, on-board or NIC), and both appear to function as expected. The problem arises when we enable a third port -- any port, in any order. That third port always fails to respond appropriately in our setup, despite appearing to be active according to ifconfig and the interface status on the switch. Any port activated after the second one fails to respond to any sort of network activity.

Is it possible there is a sysctl option that is restricting igb from allowing more than two active ethernet ports?

Thanks

Joe