On Wed, Nov 28, 2018 at 4:07 PM Eric Dumazet <eduma...@google.com> wrote: > > A NIC is supposed to deliver frames, even the ones that 'seem' bad.
A quick test shows this is not the case for mlx5. With the trafgen script you gave to me, with tot_len==40, the dest host could receive all the packets. Changing tot_len to 80, tcpdump could no longer see any packet. (Both sender and receiver are mlx5.) So, packets with tot_len > skb->len are clearly dropped before tcpdump could see it, that is likely by mlx5 hardware.
