Capture problems with Intel quad cards?

Murphy, Jay, DOH Jay.Murphy at state.nm.us
Mon Feb 16 15:47:39 CST 2009


Yea cards are default for separate physicals MACs, since they are
supported by individual net chips.  The only time one would see a
"logical" Mac, is when the ports are trunked, and this is driven by
software.


Jay Murphy 
IP Network Specialist 
NM Department of Health 
ITSD - IP Network Operations 
Santa Fe, New Mexico 87502 
Bus. Ph.: 505.827.2851

"We move the information that moves your world." 






-----Original Message-----
From: Mr. James W. Laferriere [mailto:babydr at baby-dragons.com] 
Sent: Monday, February 16, 2009 11:39 AM
To: John A. Kilpatrick
Cc: nanog at nanog.org
Subject: Re: Capture problems with Intel quad cards?

 	Hello John ,

On Sun, 15 Feb 2009, John A. Kilpatrick wrote:
> Has anyone had problems with using current Intel quad ethernet cards
for 
> packet capture?  As a proof-of-concept test we bought an Intel
PWLA8494GT and 
> hooked it up to some Network Critical taps.  There was a very strange
issue 
> with corruption of the captured packets.  The *only* issue (but it's a
big 
> one) is that the source IP on some captured packets is munged.  As far
as I 
> can tell that's the *only* issue with the packet captures - no other
data is 
> corrupted.
>
> Oh, and to rule out other issues:
>
> 1.  Corruption seen both when using network taps and when using a port
> span/mirror (so it's not the taps).
> 2.  Corruption *not* seen using the on-board broadcom nics of the test
> host (so it's not the box).
>
> So I'm pretty sure we narrowed it down to the card.  We tried the card
in
> an indentical host and saw the same problems.
>
> I thought it might be a driver issue - I tried both gentoo and FreeBSD
(not 
> sure how different the drivers are) just to see if it mattered at all
and it 
> didn't.  Much googling didn't show this to be a known issue - just
wondering 
> if anyone else has seen it?  Other recommendations welcome - the next
step 
> is, I suppose, a broadcom-based PCI-X card.  (I've got some old pizza
boxes 
> I'm trying to repurpose as network probes.)
>
> Thanks,
> John
 	Does this device provide 4 unique mac-addresses ?  Reason for
the 
question is some old(I mean old) multiport cards presented a single
mac-address 
because the were driven by a single 'Switch chip' .  Just a thought .
I've been 
looking a the Intel site gandering over the overview & have not seen
anything to 
relieve my concern .  But one Hopes they have learned not to create
themselves 
such a problem .

 		Hth ,  JimL
-- 
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