Comment by tjgq

This reminds me of this (slightly old) article, wherein the authors observe that about 1 in every 30,000 TCP packets fails the TCP checksum, even though the actual errors should have been caught by the link-level CRC. They go on to speculate about possible causes, which include memory corruption at the hosts.

A good read, and it seems to be an instance of the same problem.

"When The CRC and TCP Checksum Disagree" - http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.27.7...