10G interfaces packet drops

Hello,

we are using NTOPNG to monitor our 10G link to internet.
We are using an Arista switch in Tap Aggregation mode to send traffic to NTOPNG server.

The traffic is about 2Gbps and we see several dropped packets:

  Received Traffic  157.47 GB [292,586,873 Pkts] 	Dropped Packets	25,637,433 Pkts [ 8.06 % ] 

I've configured PF_RING ZC, the interface is an Intel 82599, ixgbe driver.

ixgbe.conf configuration:    RSS=4,4,4,4

pf_fing.conf configuration:  min_num_slots=65536

ntopng.conf  configuratrion:

#
-i=ens2
#
-w=3000
#
-m=10.0.0.0/8,193.205.23.0/24
#
-n=1
#
-d=/var/lib/ntopng
#
-x=150000
#
-X=1000000
#


What do I need to setup correctly to see less dropped packets ?

Thank you very much.
Marco

-- 
Marco Pirovano
Security & Network Competence Centre
ICT - Universita' Bocconi
via Gobbi, 5 - 20136 Milano
Tel. +39 02 5836.3173