In message <199812201839.NAA04281@jfwhome.funhouse.com>"John F. Woods" writes
>(I *have*, however, seen a case where a bad card was corrupting packets that
>survived not only the IP header check but the UDP checksum as well!  (Yes,
>UDP checksums were enabled. ;-)  However, for each packet that snuck through,
>tens of thousands failed, as you might imagine.  But if it's a busy NFS
>server...)

Ahh, our very own Jonathon Stone is a checksum gooroo, and has
documented all sorts of interesting problems that plague the
TCP/IP checksum algorithm:

        Craig Partridge, Jim Hughes, Jonathan Stone,
        "Performance of Checksums and CRCs over Real Data",
        Proc. SIGCOMM '95

        http://www1.acm.org:81/sigcomm/sigcomm95/papers/partridge.html

Enjoy,

Kevin
kml@bnas.nasa.gov