Hi, we have a PIX-515E at our customer site. The inside interface is connected to a 3750 switch and the outside is connected to a 3640 router.
When trying to ping from the 3750 to the 3640 through the PIX, 10 to 20 packets out 100 get dropped, this happens mainly with packets above 1100 bytes and it gets worse as I increase the packet size. The mtu size for the outside interface is configured as 1412 and the inside as 1500.
The duplex and speed settings of the interface for both inside and outside are ok and I don't see any errors or dropouts.