Create your own NSM devices with Suricata using Dualcomm’s ETAP-PI, network tap appliance
as well as Raspbery Pi with power redundant, graceful shutdown, user defined push buttons and leds.

Youtube movie here

Dualcomm社ETAP-PIで作成するSuricata NSMアプライアンス(日本語・Youtube)
Download PDF,%20network%20tap%20appliance.pdf

Dualcomm’s ETAP-PI is a network tap appliance, there are two gigabit port for inline connection, and 1 monitor gigabit port that aggregate the traffic. Not only network tap, ETAP-PI has a raspberry Pi 4 inside the box. We can create our own NSM ( network security monitoring ), NIDS devices using Suricata, Snort and so on. This TAP appliance has dual redundant power supply and graceful shutdown button, as well as user-defined two LEDs and a push button for enterprise use.
I refer the useful websites below:

Step1: Install Suricata for Raspberry Pi4 Install required packages
apt-get install python-pip libnss3-dev liblz4-dev libnspr4-dev libcap-ng-dev git
Install packages for build Suricata
apt install libpcre3 libpcre3-dbg libpcre3-dev build-essential libpcap-dev libyaml-0-2 libyaml-dev pkg-config
zlib1g zlib1g-dev make libmagic-dev libjansson-dev rustc cargo python-yaml python3-yaml liblua5.1-dev Get Suricata source file
wget Extract source file and change directory for source file
tar -xvf suricata-6.0.3.tar.gz
cd suricata-6.0.3
Execute configure script with some option
./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var --enable-nfqueue --enable-lua Compile and install Suricata
sudo make install Setup rules
cd suricata-update
sudo python build sudo python install
cd ..
sudo make install-full
Step2: Suricata Configuration Update Suricata rules
sudo suricata-update Edit configuration file
Nano /etc/suricata/suricata.yaml
Check #ring-size: 2048 section
And uncomment and change ring buffer size to 30000 ring-size: 30000

Step3: Execute Suricata and Test detection
Execute suricata in background ( -c config file -i interface -S rule file)
sudo suricata -c /etc/suricata/suricata.yaml -i eth0 -S /var/lib/suricata/rules/suricata.rules & Check the latest log file
sudo tail -f /var/log/suricata/fast.log Access malware specific website
wget 3wzn5p2yiumh7akj.onio
and you can find alert event like that
ET MALWARE Cryptowall .onion Proxy Domain [**] [Classification: A Network Trojan was detected] [Priority: 1] ps aux | grep suricata to find process ID and kill the process after testing

Step4: Set Suricata as a service Edit service script
nano /etc/systemd/system/suricata.service Copy and Paste a sample
Description=Suricata Intrusion Detection Service
ExecStart=/usr/bin/suricata -c /etc/suricata/suricata.yaml -i eth0 -S /var/lib/suricata/rules/suricata.rules ExecReload=/bin/kill -HUP $MAINPID
ExecStop=/bin/kill $MAINPID
Start/Stop/Restart/Check Suricata as a service sudo service suricata [start/stop/restart/status]
Step5: Check log and Log rotate
Suricata creates log files at /var/log/suricata
eve.json : huge json file for analysing with Erastic Search and Kibana or Sprunk, etc. fast.log : suspicious event log ( it is useful to just check event )
stats.log : network statistics log
suricata.log : Suricata’s service log
Check the latest suspicious events
sudo tail -n 100 -f /var/log/suricata/fast.log
Suricata may create huge size of log file, so you may configure log rotate setting, so edit log rotate setting file nano /etc/logrotate.d/suricata
/var/log/suricata/*.log /var/log/suricata/*.json {
maxsize 1G
rotate 30
systemctl restart suricata.service endscript
It means each daily log file limit to 1GB and holds the latest 30 files (for a month) Change logrotate configuration
Sudo logrotate -f /etc/logratate.conf

Step6: Automatically update Suricata rules at midnight
Edit crontab to update and restart suricata at 3:33 am
33 3 * * * sudo suricata-update && sudo service suricata restart
It is a typical setting of maintain Suricata by Raspberry Pi but works best with ETAP-PI
Create and customize your own stable NSM device and be ready for cyber security.
I recommend to connect other packet capturing devices at external port of ETAP-PI.
We can check actual pcap/pcapng file with Wireshark, if you find some important security event!!
Megumi Takeshita, ikeriri network service co., ltd. (Twitter@ikeriri /