[Snort-users] snort3 dropping frames at 200 Mbps (single core)

ziggypiggy ziggypiggy at fastmail.com
Wed Aug 15 09:39:18 EDT 2018


I installed Snort3 by according to the instructions in the Snort Setup Guide "Snort 3 on Ubuntu 14, 16, 17, 18" (https://www.snort.org/documents/snort-3-on-ubuntu-14-16-17-18).

I replay a PCAP file (avg frame size 486B) captured from a live network containing a mix of benign and malicious traffic to Snort3 running on a single CPU and afpacket DAQ:

  taskset -c 2 /opt/snort/bin/snort --daq afpacket -c /opt/snort/etc/snort/snort.lua -i "enp59s0f0" -R /opt/snort/etc/snort/rules/snort3-community.rules -A none

Results:
  - replaying the traffic at 100 Mbps, snort reports no drops. 
  - replaying at 200 Mbps, snort reports 21% packet drops. 

I was expecting closer to 1000 Mbps lossless performance.

Is this in the range of expected performance for an untuned ( "out-of-the-box") setup?

Any suggestions for where I should start looking for misconfiguration or potential tuning parameters?

CPU: Intel(R) Xeon(R) Gold 6138 CPU @ 2.00GHz
OS: Ubuntu 16.04.5

Thx,




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