> On a typical Ethernet, you should see approximately 0 of either of these
> errors.  You're getting corrupted packets.  (And intriguingly, some of those
> corrupted packets actually pass the IP header checksum!  This is not
> surprising, though; the IP checksum is disturbingly weak.)

The corruptions which I saw in the trace all appeared to be the result
of insertion of an extra 16 bits of zeros.  The header checksum is
only over the header (duh), so if the corruption occurred later in the
packet it wouldn't be picked up.

						- Bill