packets per second routing tests: mismatch between switch (~4M pps) and netstat (~10M pps) scores

[Caraballo-Vega, Jordan A. (GSFC-6062)[COMPUTER SCIENCE CORP]]

Hi all,

We are currently running udp 1500 bytes pps tests through a Dell PE R530
and two Chelsio T62100-LP-CR NICs acting as a router. At the switch we
are seeing ~4M pps, while with "netstat -w1 -d -h" we are seeing ~10M
pps or ~31k in the same test. Any idea of why scores are so different?
It could be a misconfiguration of my network interfaces? Where should I
look at?

Scores from the switch are as follow:

2017-09-15 10:57:57: duration=360, nodes=24, streams=85ea/2040agg,
frame_size=1500, pps=1499977, Mbps=17999: Zone-1(in:57%, out:0%)
Zone-2(in:0%, out:14%)

Scores from netstat are as follow:

            input        (Total)           output
   packets  errs idrops      bytes    packets  errs      bytes colls drops
       17M     0     0        23G        10M     0        14G     0     0
       17M     0     0        23G        10M     0        14G     0     0
       17M     0     0        23G        10M     0        14G     0     0
       17M     0     0        23G        10M     0        14G     0     0
       17M     0     0        24G        31k  7.8M       1.9M     0  7.8M
       17M     0     0        24G        31k  7.8M       1.9M     0  7.8M
       17M     0     0        24G        31k  7.8M       1.9M     0  7.8M
       17M     0     0        24G        31k  7.8M       1.9M     0  7.8M

Interfaces are bonded as follow (/etc/rc.conf):

ifconfig_cc0="-tso -lro mtu 9000 up"
ifconfig_cc1="-tso -lro mtu 9000 up"
ifconfig_cc2="-tso -lro mtu 9000 up"
ifconfig_cc3="-tso -lro mtu 9000 up"
cloned_interfaces="lagg0 lagg1 vlan0 vlan1"
ifconfig_lagg0="laggproto lacp laggport cc0 laggport cc1"
ifconfig_lagg1="laggproto lacp laggport cc2 laggport cc3"
ifconfig_vlan0="inet 172.16.2.1/24 vlan 20 vlandev lagg0"
ifconfig_vlan1="inet 172.16.1.1/24 vlan 10 vlandev lagg1"

Thanks in advance,

- Jordan