nanog mailing list archives

Re: Capture problems with Intel quad cards?


From: "Mr. James W. Laferriere" <babydr () baby-dragons com>
Date: Mon, 16 Feb 2009 09:39:18 -0900 (AKST)

        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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| James   W.   Laferriere | System    Techniques | Give me VMS     |
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