Capture problems with Intel quad cards?

Andreas Ott andreas at
Tue Feb 17 05:46:09 UTC 2009

On Sun, Feb 15, 2009 at 09:35:30PM -0800, 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.
> 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.

About three years back we had an issue with a dual-port E1000 NIC
in Intel 7230NH based 1U servers. Together with the knowledgeable
folks at iXsystems we tracked that down to a PCI riser card issue. The
'default' riser was the standard PCB 1U with perpendicular female PCI
connector. Using these we saw checksum mismatches on many packets using
FreeBSD. After replacing this riser with another one that has a flat
ribbon cable to draw more power from an adjacent PCI slot all works well.

We did similar elimination troubleshooting: the board worked fine, the
card worked fine, the card worked fine when sticking it into the slot
while the case was open. Just when using the riser we had trouble.

Andreas Ott      K6OTT               andreas at

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