[prev in list] [next in list] [prev in thread] [next in thread] 

List:       ilug
Subject:    Re: [ILUG] Cheap Linux server hardware?
From:       paul () clubi ! ie
Date:       2009-09-28 7:51:38
Message-ID: alpine.LFD.2.00.0909280847330.24758 () stoner ! jakma ! org
[Download RAW message or body]

On Mon, 28 Sep 2009, Lance Dryden wrote:

> Its own full IP stack.  I believe the SuperMicro on board provides 
> a special connector for the BMC card, which provides access to the 
> shared PHY in use for this.

Excellent.

>> (The shared-IP IPMI stuff, with the NIC hardware colluding to divert 
>> packets to a certain port to the BMC, seems creepy somehow - and fragile as 
>> it relies on host to handle ARP usually).
>
> It's not that scary: think "internal ethernet switch" in behavior, although 
> it's a little different: 1 PHY, 2 MIIs, one of them on the BMC.

Oh, shared-PHY is fine. The problem is the IPMI stuff can also be 
deployed as shared-IP (and hence PHY and MAC too obv). Basically the 
NIC diverts packets to the IPPMI port to the BMC - the OS doesn't get 
to see these packets. The BMC basically piggybacks on the OS doing 
ARP, etc.. It can break if the OS is shutdown and the BMC doesn't 
detect this and take over ARP itself. Very icky all together.

Shared-PHY, separate MAC+IP sounds fine though.

regards,
-- 
Paul Jakma	paul@jakma.org	Key ID: 64A2FF6A
Fortune:
If the aborigine drafted an IQ test, all of Western civilization would
presumably flunk it.
 		-- Stanley Garn
-- 
Irish Linux Users' Group mailing list
About this list : http://mail.linux.ie/mailman/listinfo/ilug
Who we are : http://www.linux.ie/
Where we are : http://www.linux.ie/map/
[prev in list] [next in list] [prev in thread] [next in thread]