what is the source of packet loss using pfsend

Question

I'm using pfsend to send traffic at very high speed from a host1 to a host2.

At host2 side, I'm using pfcount to get some statistics regarding packet dropped and number of packets received.

Some details: 

The NICs used are Mellanox Connectx-3. 

pf_ring module is loaded at host2 side

I'm running pfsend from host1 like this : pfsend -z -n 0 -i eth2 -m MAC@

The output result of pfsend is as follows :

Sending packets on eth2
Using PF_RING v.6.1.1
Dumping statistics on /proc/net/pf_ring/stats/10047-eth2.143
TX rate: [current 1'263'756.00 pps/0.85 Gbps][average 1'263'756.00 pps/0.85 Gbps][total 1'263'756.00 pkts]
TX rate: [current 1'248'427.54 pps/0.84 Gbps][average 1'256'091.65 pps/0.84 Gbps][total 2'512'221.00 pkts]
TX rate: [current 1'264'407.18 pps/0.85 Gbps][average 1'258'863.51 pps/0.85 Gbps][total 3'776'656.00 pkts]
TX rate: [current 1'241'021.73 pps/0.83 Gbps][average 1'254'403.03 pps/0.84 Gbps][total 5'017'710.00 pkts]

At host2 side, the output of pfcount is as follows :

=========================
Absolute Stats: [2605633 pkts rcvd][687723 pkts dropped]
Total Pkts=3293356/Dropped=20.9 %
2'605'633 pkts - 218'874'205 bytes [1'301'036.68 pkt/sec - 874.30 Mbit/sec]
=========================
Actual Stats: 870113 pkts [1'000.10 ms][870'019.03 pps/0.58 Gbps]
=========================

=========================
Absolute Stats: [3480356 pkts rcvd][910603 pkts dropped]
Total Pkts=4390959/Dropped=20.7 %
3'480'356 pkts - 292'351'364 bytes [1'158'905.29 pkt/sec - 778.79 Mbit/sec]
=========================
Actual Stats: 874723 pkts [1'000.40 ms][874'368.88 pps/0.59 Gbps]
=========================

=========================
Absolute Stats: [4354304 pkts rcvd][1134899 pkts dropped]
Total Pkts=5489203/Dropped=20.7 %
4'354'304 pkts - 365'763'428 bytes [1'087'622.15 pkt/sec - 730.89 Mbit/sec]
=========================
Actual Stats: 873948 pkts [1'000.36 ms][873'627.37 pps/0.59 Gbps]
=========================

=========================
Absolute Stats: [4930161 pkts rcvd][1287203 pkts dropped]
Total Pkts=6217364/Dropped=20.7 %
4'930'161 pkts - 414'135'907 bytes [985'321.78 pkt/sec - 662.14 Mbit/sec]
=========================
Actual Stats: 575857 pkts [1'000.09 ms][575'801.14 pps/0.39 Gbps]
=========================

Any one might provide me with some insights ? Is it related to the switch that connects the two hosts ? or something related to Linux Networking Kernel ? Regards.

Answer 1

The first and easiest solution i have in mind is using **-a** options with pfcount on host2.