Re: PROBLEM: 3.11.0-rc2+ lost of connectivity

On Thu, 01 Aug 2013 at 14:34 GMT, Sebastiano Spicuglia [off-list ref] wrote:

The machine suddenly stops to be connected to the network.
Running "ifdown eth0" "ifup eth0" the network starts to work
again for few minutes and then the failure happens again.
It is not even possible to ping the machine.
/var/log/messages does not report anything wrong.

I instrumented the kernel with SystemTap to see what happens when the
machine is in the failure state.

the function ip_rcv is invoked.
the function ip_rcv_finish is invoked.
the function ip_local_deliver is invoked
the function ip_local_deliver_finish is invoked
the function tcp_v4_rcv is NOT invoked

When the network works the function tcp_v4_rcv is invoked.

Please turn off your firewall and run dropwatch to see where the
packets are dropped.