Received packets : Ignored vs Error vs Dropped
Looking at a sample from exanic-config:
RX packets: 1514936895 ignored: 20578657 error: 145683 dropped: 0
The "RX Packets" counter refers to the number of packets received to NIC hardware.
The "Ignored" counter refers to the packets that don't match the MAC address. It is incremented when the NIC receives a packet that is unicast but destined to a different address than the MAC of the
port/interface in question. This is not as a result of load of any other "problem" with the NIC/host, but that the device on the other end of the wire is sending packets not destined for this device.
The "Error" counter refers to CRC failed packets. A common cause of this type of behaviour is poor signal from the other end e.g. a bad cable or optical splitter.
These statistics have nothing to do with the speed you are reading the packets on software.
The "Dropped" counter in exanic-config is as a result of insufficient bandwidth PCIe bandwidth to transfer the packet into host memory.
The ifconfig "Dropped" counter can be a result of:
* insufficient CPU cycles to service the NIC
* if jumbo frames are coming in (the driver does not currently support jumbo frames)
* if IP6 frames are coming in when expecting IP4 only.