[OmniOS-discuss] LACP Omnios , igb and C3750

[Doug Hughes]

On 12/13/2014 4:53 PM, Paul B. Henson wrote:
> On Sat, Dec 13, 2014 at 11:12:35AM -0500, Dan McDonald wrote:
>> I thought I'd mentioned this on the thread, but does the machine
>> attempt to use one of the IGB interfaces for IPMI as well?  We do not
>> support dual-use NICs like that.  (Check your BIOS.)
> Hmm, I had thought that the "shared" IPMI port was invisible to the OS?
> That there was an internal three-port switch, with one port connected to
> the physical jack on the back of the server, and then the other two
> wired internally to the NIC on the motherboard and the NIC on the BMC?
>
> Do these boxes do something else that actually tweaks with the hardware
> on the motherboard NIC when the BIOS is set to shared?
>
That's the typical setup with IPMI NIC = shared. The OS is totally 
unaware that there's another device using the same hardware. The amazing 
thing is that while the OS is using the physical port at 1gbit the BMC 
is using it at 100mbits/sec on the same physical port, all without 
either knowing about the other. IMHO, the best way to do this is to set 
the IPMI to use a different VLAN than the host, but that's dependent on 
the features of your BMC and network hardware. (tagged to BMC, untagged 
to host).

The other options are 'dedicated' where there's a dedicated IPMI/BMC 
port, and 'failover' which has a dedicated port, but can failover to the 
motherboard/host port. (crazy: some of them even support bonding across 
the ports for the BMC; who thought this was a good idea?!)