> > The classic ways this can happen are either getting so many errors
> > that one of the packets hits the 1/65535 probability of getting the
> > checksum randomly right,
> 
> Ethernet has a 32bit CRC to it is 1 in 2^32..... somehwat unlikely
> (especiallly since you aren't seeing timeouts)

The Ethernet CRC doesn't protect much, however.  It protects from
damage caused to the packet in transit on particular wires but not from
damage caused inside routers or in the media adaptors.

The TCP checksum is end-to-end, so it is what you are relying on to
protect from all the damage that media CRCs don't catch.  Its probability
of detecting random errors is 1 in 65535.  Certain errors, like data
in packets getting rearranged, it won't detect at all.

Dennis Ferguson