Thanks for the additional info. Definitely the relation to MTU size sounds quite plausible. The checking is on traffic from the guest out and that I would expect to be affected by MTU together with GSO support. And yes, preferably we find a reproducer that does not require a production system to suffer. And ideally for me if I could do so on a local test system to understand the host side.
I will try to figure out more details from a stock c3.large if that is possible and maybe whether something like iperf can trigger it there.
Thanks for the additional info. Definitely the relation to MTU size sounds quite plausible. The checking is on traffic from the guest out and that I would expect to be affected by MTU together with GSO support. And yes, preferably we find a reproducer that does not require a production system to suffer. And ideally for me if I could do so on a local test system to understand the host side.
I will try to figure out more details from a stock c3.large if that is possible and maybe whether something like iperf can trigger it there.