Posted Aug 18, 2012 0:00 UTC (Sat) by intgr (subscriber, #39733)
In reply to: TCP friends by BenHutchings
Parent article: TCP friends
> tcpdump hasn't reliably shown 'packets on the wire', even for physical devices, since checksum offload was implemented
The lack of checksums is a very trivial issue. The lack of segmentation is also irrelevant -- it appears as an interface with an infinitely large MTU. The packets captured on "lo" are still basically valid TCP packets.
Not seeing any packets and being unable to debug network interactions *at all* is a huge deal compared to these.