This detailed set of articles will guide you through the steps of installing and configuring Snort as a Network Intrusion Detection System (NIDS), along with additional software that extends the functionality of your Snort system. These articles are based on the Snort Installation guide I wrote, and which was posted in the documents section of the Snort website. If you are instead looking for a quick install guide for Snort on Ubuntu, please see my other standalone article: Snort 2.9.9.x on Ubuntu (quick install guide). If you want to test the new alpha version of Snort, please see my articles: Installing Snort++ (Version 3.0 Alpha 4) in Ubuntu.
These articles are designed to take you step-by-step through the installation, configuration, and testing of each component of a Snort system. I will explain the design decisions and the purpose of specific commands throughout this guide, which will will help you understand how Snort is installed, configured, tested, executed, and how it interfaces with its supporting software. You can follow the steps in this guide, but choose to skim the detailed explanations if you would like, and you will still end up with a working Snort system. However, if you take the effort to understand every step you will have a much deeper understanding of Snort, be better able to troubleshoot issues, and fully customize your Snort installation.
This guide has been tested with Snort 2.9.9.0 on both the x86 and x64 architectures of Ubuntu 14, and 16. This guide will probably work on other Ubuntu-derived distributions, and I have been told that it works fairly well (with some modifications) for Debian systems including the Raspberry Pi. This guide will note VMware specific configuration options, if you want to run Snort as a virtual machine. At the time of this writing, the latest version of Snort is 2.9.9.0, and the instructions below are tailored for that version. If you want to use more recent versions of any of the software installed below (updated versions released after the publication of this guide), it should work without significant changes, but obviously you may encounter issues I can’t foresee.
On its own, Snort runs in standalone mode as a packet sniffer and logger. With a few additional applications and some configuration, a Snort system becomes much more useful as a NIDS. The supporting software components we will install in this set of articles are:
If you just want a Snort system installed and running without having to compile and install all the individual components, there are some alternatives:
If you are running Snort as a VMware ESXi virtual machine, it is recommended that you use the vmxnet 3 network adapter.
So let’s get started. First, we need to ensure that the network card does not truncate over-sized packets. From The Snort Manual:
Some network cards have features named “Large Receive Offload” (lro) and “Generic Receive Offload” (gro). With these features enabled, the network card performs packet reassembly before they’re processed by the kernel. By default, Snort will truncate packets larger than the default snaplen of 1518 bytes. In addition, LRO and GRO may cause issues with Stream5 target-based reassembly. We recommend that you turn off LRO and GRO.
Edit /etc/network/interfaces as an admin:
sudo vi /etc/network/interfaces
Append the following two lines for each network interface you will have Snort listen on, making sure to change eth0 to match your interface name (See note below for Ubuntu 16):
post-up ethtool -K eth0 gro off post-up ethtool -K eth0 lro off
Important note for people running Ubuntu 16: Begining with Ubuntu 15.10, network interfaces no longer follow the ethX standard (eth0, eth1, …). Instead, interfaces names are assigned as Predictable Network Interface Names. This means you need to check the names of your interfaces using ifconfig -a. In my case, what was originally eth0 is now ens160. If you are running Ubuntu 15.10, anywhere in this guide you see eth0, you will need to replace with your new interface name.
an example of how the /etc/network/interfaces file should look for a single interface:
# This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). source /etc/network/interfaces.d/* # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet dhcp post-up ethtool -K eth0 gro off post-up ethtool -K eth0 lro off
Next we will create a directory to save the downloaded tarball files:
mkdir ~/snort_src cd ~/snort_src
Next we need to install all the prerequisites from the Ubuntu repositories:
sudo apt-get install -y build-essential libpcap-dev libpcre3-dev libdumbnet-dev bison flex zlib1g-dev liblzma-dev openssl libssl-dev
Breakdown of the packages you are installing:
The final library that Snort requires is the development library for Nghttp2: a HTTP/2 C Library which implements the HPAC header compression algorithm.
In Ubuntu 16 the install is easy:
# Ubuntu 16 only: sudo apt-get install -y libnghttp2-dev
for Ubuntu 14, we need to compile from source:
# Ubuntu 14 only (not Ubuntu 16) sudo apt-get install -y autoconf libtool pkg-config cd ~/snort_src wget https://github.com/nghttp2/nghttp2/releases/download/v1.17.0/nghttp2-1.17.0.tar.gz tar -xzvf nghttp2-1.17.0.tar.gz cd nghttp2-1.17.0 autoreconf -i --force automake autoconf ./configure --enable-lib-only make sudo make install
Snort uses the Data Acquisition library (DAQ) to abstract calls to packet capture libraries. DAQ is downloaded and installed from the Snort website:
cd ~/snort_src wget https://snort.org/downloads/snort/daq-2.0.6.tar.gz tar -xvzf daq-2.0.6.tar.gz cd daq-2.0.6 ./configure make sudo make install
Now we are ready to install Snort from source. When we configure the build of Snort, we use the --enable-sourcefire flag, which enables Packet Performance Monitoring (PPM), and matches the way the sourcefire team builds Snort.
cd ~/snort_src wget https://snort.org/downloads/snort/snort-2.9.9.0.tar.gz tar -xvzf snort-2.9.9.0.tar.gz cd snort-2.9.9.0 ./configure --enable-sourcefire make sudo make install
Run the following command to update shared libraries:
sudo ldconfig
Since the Snort installation places the Snort binary at /usr/local/bin/snort, it is a good policy to create a symlink to /usr/sbin/snort:
sudo ln -s /usr/local/bin/snort /usr/sbin/snort
The last step of our Snort installation is to test that the Snort Binary runs. Execute Snort with the -V flag, which causes Snort to show the version number:
/usr/sbin/snort -V
and you should see output similar to the following:
user@snortserver:~$ snort -V
Version 2.9.9.0 GRE (Build 56)
By Martin Roesch & The Snort Team: http://www.snort.org/contact#team
Copyright (C) 2014-2016 Cisco and/or its affiliates. All rights reserved.
Copyright (C) 1998-2013 Sourcefire, Inc., et al.
Using libpcap version 1.7.4
Using PCRE version: 8.38 2015-11-23
Using ZLIB version: 1.2.8
Congratulations, if you have output similar to the above then you have successful installed Snort. Continue to the next section to Configure Snort to Run as a NIDS.
The instructions below show how to install OpenAppId in Snort 2.9.9.x on Ubuntu 14 and Ubuntu 16.
If you want a more in-depth explanation of the install steps, as well as instructions on how to configure and enhance Snort’s functionality, see my in-depth series for installing Snort on Ubuntu, or my Quick Install Guide for Snort 2.9.9.x on Ubuntu. If you want to test the new alpha version of Snort (Version 3.0 Alpha 4), please see my article: Installing Snort 3 Alpha in Ubuntu.
So let’s get started. First we need tocreate a directory to save the downloaded tarball files:
mkdir ~/snort_src cd ~/snort_src
Next we install all the Snort pre-requisites from the Ubuntu repositories:
sudo apt-get install -y build-essential libpcap-dev libpcre3-dev libdumbnet-dev bison flex zlib1g-dev liblzma-dev
Snort 2.9.9.x needs the development libraries for Nghttp2. On Ubuntu 16 this is simple:
# Ubuntu 16 only (not Ubuntu 14) sudo apt-get install -y libnghttp2-dev
On Ubuntu 14, we do this from scratch:
# Ubuntu 14 only (not Ubuntu 16) sudo apt-get install -y autoconf libtool pkg-config cd ~/snort_src wget https://github.com/nghttp2/nghttp2/releases/download/v1.17.0/nghttp2-1.17.0.tar.gz tar -xzvf nghttp2-1.17.0.tar.gz cd nghttp2-1.17.0 autoreconf -i --force automake autoconf ./configure --enable-lib-only make sudo make install
Next we want to install the pre-requisites that are specific to OpenAppID:
sudo apt-get install -y libluajit-5.1-dev pkg-config openssl libssl-dev
Download and install Data Acquisition library (DAQ) from the Snort website:
cd ~/snort_src wget https://www.snort.org/downloads/snort/daq-2.0.6.tar.gz tar -xvzf daq-2.0.6.tar.gz cd daq-2.0.6 ./configure make sudo make install
Now we are ready to install Snort from source. We use the ‑‑enable-open-appid option, which prepares Snort to be built with OpenAppID support. We also use the ‑‑enable-sourcefire option, which enables the Sourcefire-specific build options:
Now we are ready to install Snort from source:
cd ~/snort_src wget https://snort.org/downloads/snort/snort-2.9.9.0.tar.gz tar -xvzf snort-2.9.9.0.tar.gz cd snort-2.9.9.0 ./configure --enable-sourcefire --enable-open-appid make sudo make install
Run the following command to update shared libraries:
sudo ldconfig
Since the Snort installation places the Snort binary at /usr/local/bin/snort, it is common to create a symlink to /usr/sbin/snort:
sudo ln -s /usr/local/bin/snort /usr/sbin/snort
We need to a few configuration things to prepare Snort for use. More detailed information on the steps below can be found here .
Create the needed directories and empty files:
# Create the Snort directories: sudo mkdir /etc/snort sudo mkdir /etc/snort/rules sudo mkdir /etc/snort/rules/iplists sudo mkdir /etc/snort/preproc_rules sudo mkdir /usr/local/lib/snort_dynamicrules sudo mkdir /etc/snort/so_rules # Create some files that stores rules and ip lists sudo touch /etc/snort/rules/iplists/black_list.rules sudo touch /etc/snort/rules/iplists/white_list.rules sudo touch /etc/snort/rules/local.rules sudo touch /etc/snort/sid-msg.map # Create our logging directories: sudo mkdir /var/log/snort sudo mkdir /var/log/snort/archived_logs # Adjust permissions: sudo chmod -R 5775 /etc/snort sudo chmod -R 5775 /var/log/snort sudo chmod -R 5775 /var/log/snort/archived_logs sudo chmod -R 5775 /etc/snort/so_rules sudo chmod -R 5775 /usr/local/lib/snort_dynamicrules
Finally copy some files:
cd ~/snort_src/snort-2.9.9.0/etc/ sudo cp *.conf* /etc/snort sudo cp *.map /etc/snort sudo cp *.dtd /etc/snort cd ~/snort_src/snort-2.9.9.0/src/dynamic-preprocessors/build/usr/local/lib/snort_dynamicpreprocessor/ sudo cp * /usr/local/lib/snort_dynamicpreprocessor/
Comment out the rule files that are automatically loaded by Snort in snort.conf (since we don’t have any rule files downloaded at this time) by running the following command:
sudo sed -i 's/include \$RULE\_PATH/#include \$RULE\_PATH/' /etc/snort/snort.conf
Next we need to edit the /etc/snort/snort.conf Snort configuration file as root.
sudo vi /etc/snort/snort.conf
Line 45 of /etc/snort/snort.conf: the variable HOME_NET should match your internal (defended) network. In the below example our HOME NET is 10.0.0.0 with a 24-bit subnet mask (255.255.255.0):
ipvar HOME_NET 10.0.0.0/24
Still editing snort.conf, next we need to modify some file paths to match the lines below, beginning at line 104:
var RULE_PATH /etc/snort/rules var SO_RULE_PATH /etc/snort/so_rules var PREPROC_RULE_PATH /etc/snort/preproc_rules var WHITE_LIST_PATH /etc/snort/rules/iplists var BLACK_LIST_PATH /etc/snort/rules/iplists
Still editing snort.conf, next we need to enable the local.rules file by un-commenting (remove the hash symbol from the beginning) line 546 so it looks like the following:
include $RULE_PATH/local.rules
Once you have saved your edits to snort.conf, you should test that snort can load this configuration file without any errors. You do this by running snort with the -T flag to tell snort to test the file, the -c flag to identify the path of the snort.conf file, and the -i flag for a network interface that Snort will listen on (Note that Ubuntu 16 can have different interface names, which you can check with the ifconfig command). This is shown below. Output has been truncated to the final few lines to show success:
user@snortserver:~$ sudo snort -T -i eth0 -c /etc/snort/snort.conf (...) Snort successfully validated the configuration! Snort exiting user@snortserver:~$
Now we need to download the Application Detector Package, which contains the rules for detecting types of traffic. You can find this file on the Snort.org download page, listed as snort-openappid.tar.gz. You should download the latest version of this package, the version below is the latest as of writing, but will probably have changed, as the Snort team is updating regularly:
cd ~/snort_src wget https://snort.org/downloads/openappid/4602 -O snort-openappid.tar.gz tar -xvzf snort-openappid.tar.gz
The result of the above command will create a odp directory which holds all the application detector files. We want to move that folder under our Snort rules folder:
sudo cp -r ~/snort_src/odp/ /etc/snort/rules/
and create one folder for third-party developed application detectors:
sudo mkdir /usr/local/lib/thirdparty
We need to enable the OpenAppID pre-processor, then we need to have Snort output the AppID data. The 2.9.9.0 release of snort doesn’t seem to create the default snort.conf correctly (which would include the necessary OpenAppID settings), so rather than enabling them by uncommeting them, we will need to add these lines manually. To enable the pre-processor, edit the snort.conf file (located at /etc/snort/snort.conf) as root, and add the following lines before the commented-out section 6 (line 513 for me):
preprocessor appid: app_stats_filename appstats-u2.log, \ app_stats_period 60, \ app_detector_dir /etc/snort/rules
This tells Snort the file name of the log to output statistics to (appstats-u2-log), how often to write to the log (every 60 seconds), and where to find the odf folder we downloaded earlier.
While still in the /etc/snort/snort.conf file, add the following lower down (below the commented-out section 6, around line 526 ):
output unified2: filename snort.u2, limit 128, appid_event_types
this directive tells Snort to output alerts in the unified2 binary format to the snort.log, the size of the log, and also to output AppID data to the same location.
Now test the Snort configuration file to verify there are no errors:
sudo /usr/local/bin/snort -T -c /etc/snort/snort.conf -i eth0
as above, you should see the text: Snort successfully validated the configuration! If not, fix the errors that are reported.
Use the below command to start collecting packets (change the interface as needed), and use ctrl-c to stop the collection:
sudo /usr/local/bin/snort -c /etc/snort/snort.conf -i eth0 ctrl-c
To generate OpenAppID data while Snort is running as above, try browsing to a website, making sure the data is visible to the interface that snort is listening on, either by passing that data directly through the Snort interface, or by ensuring that your network infrastructure copies network traffic to the Snort server (span port, port mirroring, or promiscuous mode, for example).
Once you have collected data (remember that we are writing data out every 60 seconds, so wait longer than a minute before cancelling the collection), you should see file(s) in /var/log/snort/ with the name: appstats-u2.log.nnnnnnnnnn (where the n’s are numbers). these are the OpenAppID data files. We can process them with u2openappid, which is located in /usr/local/bin.
A simple example of this processing:
noah@snort:~$ sudo u2openappid /var/log/snort/appstats-u2.log.1483841898 statTime="1449426240",appName="HTTP",txBytes="0",rxBytes="8152" statTime="1449426300",appName="HTTP",txBytes="0",rxBytes="9542" statTime="1449426240",appName="DNS",txBytes="301",rxBytes="0" statTime="1449426240",appName="__unknown",txBytes="12376",rxBytes="1118" statTime="1449426300",appName="DNS",txBytes="761",rxBytes="0"
In the above example, I used curl over the same interface snort was listening on to request www.xkcd.com. The various application detectors show the amount of traffic for each detector, DNS, HTTP, and the like.
An more complex example of this processing (from an older version of OpenAppID, but still valid):
noah@snort:~$ sudo /usr/local/bin/u2openappid /var/log/snort/appstats-u2.log.1428300780 statTime="1428300720",appName="curl",txBytes="740",rxBytes="6894" statTime="1428300720",appName="http",txBytes="1306",rxBytes="7384" statTime="1428300720",appName="ubuntu",txBytes="566",rxBytes="490" statTime="1428300720",appName="python_urllib",txBytes="566",rxBytes="490" statTime="1428300780",appName="https",txBytes="777",rxBytes="1444" statTime="1428300780",appName="https",txBytes="1040",rxBytes="2116" statTime="1428300840",appName="google",txBytes="3001",rxBytes="4684" statTime="1428300840",appName="facebook",txBytes="66705",rxBytes="1841294" statTime="1428300840",appName="firefox",txBytes="9080",rxBytes="29282" statTime="1428300840",appName="google_analytic",txBytes="2441",rxBytes="17912" statTime="1428300840",appName="http",txBytes="10591",rxBytes="49907" statTime="1428300840",appName="https",txBytes="68049",rxBytes="1846327" statTime="1428300840",appName="ssl_client",txBytes="66013",rxBytes="1840694" statTime="1428300840",appName="linux_mint",txBytes="955",rxBytes="2912" statTime="1428300840",appName="python_urllib",txBytes="1511",rxBytes="20625" statTime="1428300720",appName="dns",txBytes="380",rxBytes="538" statTime="1428300720",appName="ssh",txBytes="10487",rxBytes="24943" statTime="1428300720",appName="rtp",txBytes="592",rxBytes="0" statTime="1428300780",appName="dhcp",txBytes="1368",rxBytes="0" statTime="1428300780",appName="dns",txBytes="482",rxBytes="936" statTime="1428300780",appName="vnc",txBytes="219685",rxBytes="5131591" statTime="1428300780",appName="https",txBytes="210284",rxBytes="1373974" statTime="1428300780",appName="mdns",txBytes="8316",rxBytes="0" statTime="1428300840",appName="dns",txBytes="1754",rxBytes="5372" statTime="1428300840",appName="facebook",txBytes="3109",rxBytes="11074" statTime="1428300840",appName="https",txBytes="3109",rxBytes="11074" statTime="1428300840",appName="ssl_client",txBytes="3109",rxBytes="11074"
If you have output similar to the above, then Snort is installed and works. To generate the above output, I browsed to xkcd.com with curl on one computer, and to facebook with firefox on another computer. Looking through the output, the applications listed with the same statTime are from the same request. When I used curl to request xkcd.com, snort detected the various types of traffic defined by the various detectors.
If you want to learn more about how to run Snort, and how to install additional software to enhance a Snort system, see my in-depth series on installing Snort on Ubuntu. If you have any feedback (recommendations or corrections), please let me know here.
The instructions below show how to install Snort 2.9.9.x on both the x86 and x64 architectures for Ubuntu 14 and 16. If you want a more in-depth explanation of the install steps, as well as instructions on how to configure and enhance Snort’s functionality, see my in-depth series for installing Snort on Ubuntu.
If you want to test the new alpha version of Snort (Version 3.0 Alpha 4), please see my article: Installing Snort 3 Alpha in Ubuntu
If you want to work with OpenAppID, please see my guide for OpenAppID for Snort 2.9.9.x on Ubuntu.
So let’s get started. First we will create a directory to save the downloaded tarball files:
mkdir ~/snort_src cd ~/snort_src
Next we need to install all the pre-requisites from the Ubuntu repositories:
sudo apt-get install -y build-essential libpcap-dev libpcre3-dev libdumbnet-dev bison flex zlib1g-dev liblzma-dev openssl libssl-dev
We need the development libraries for Nghttp2. On Ubuntu 16 this is simple:
# Ubuntu 16 only (not Ubuntu 14) sudo apt-get install -y libnghttp2-dev
On Ubuntu 14, we do this from scratch:
# Ubuntu 14 only (not Ubuntu 16) sudo apt-get install -y autoconf libtool pkg-config cd ~/snort_src wget https://github.com/nghttp2/nghttp2/releases/download/v1.17.0/nghttp2-1.17.0.tar.gz tar -xzvf nghttp2-1.17.0.tar.gz cd nghttp2-1.17.0 autoreconf -i --force automake autoconf ./configure --enable-lib-only make sudo make install
Disable LRO and GRO for all interfaces Snort will listen on under /etc/network/interfaces. using ethtool. An explanation of LRO and GRO are in the The Snort Manual. Use an editor to edit the network interfaces file:
sudo vi /etc/network/interfaces
and for every interface that Snort will listen on (one interface for simple setups, multiple interfaces for more complex setups), add the following two lines, changing eth0 to match the interface:
post-up ethtool -K eth0 gro off post-up ethtool -K eth0 lro off
for example, my /etc/network/interfaces file looks like this:
source /etc/network/interfaces.d/* # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet dhcp post-up ethtool -K eth0 gro off post-up ethtool -K eth0 lro off
Reboot the system and verify that LRO and GRO are off:
user@snortserver:~$ ethtool -k eth0 | grep receive-offload generic-receive-offload: off large-receive-offload: off
Download and install Data Acquisition library (DAQ) from the Snort website:
cd ~/snort_src wget https://www.snort.org/downloads/snort/daq-2.0.6.tar.gz tar -xvzf daq-2.0.6.tar.gz cd daq-2.0.6 ./configure make sudo make install
Now we are ready to install Snort from source:
cd ~/snort_src wget https://snort.org/downloads/snort/snort-2.9.9.0.tar.gz tar -xvzf snort-2.9.9.0.tar.gz cd snort-2.9.9.0 ./configure --enable-sourcefire make sudo make install
Run the following command to update shared libraries:
sudo ldconfig
Since the Snort installation places the Snort binary at /usr/local/bin/snort, it is common to create a symlink to /usr/sbin/snort:
sudo ln -s /usr/local/bin/snort /usr/sbin/snort
The last step of our Snort installation is to test that the Snort Binary runs. Execute Snort with the -V flag, which causes Snort to print the current version. You should see output similar to the following:
user@snortserver:~$ snort -V
,,_ -*> Snort! <*-
o" )~ Version 2.9.9.0 GRE (Build 56)
'''' By Martin Roesch & The Snort Team: http://www.snort.org/contact#team
Copyright (C) 2014-2016 Cisco and/or its affiliates. All rights reserved.
Copyright (C) 1998-2013 Sourcefire, Inc., et al.
Using libpcap version 1.7.4
Using PCRE version: 8.38 2015-11-23
Using ZLIB version: 1.2.8
user@snortserver:~$
If you have output similar to the above, then Snort is installed and works. If you want to learn more about how to run Snort, and how to install additional software to enhance a Snort system, see my in-depth series for installing Snort on Ubuntu.
If you have any questions or recommendations, please contact me. I can’t always answer questions right away, but I will do my best to get back to you. I welcome all recommendations and corrections.
NOTE: this article is out of date and has been replaced with a newer article: Installing Snort++ (Snort 3 Alpha 4 build 239) in Ubuntu.
The instructions below show how to install Snort 3 alpha 4 build 223 on Ubuntu. This install has been tested on Ubuntu 14 and 16, for both the x86 and x64 architectures. For an outdated Ubuntu 12 version of these instructions, please go here. Note that Snort 3 is Alpha software, and therefore has bugs and issues, and should be installed for testing purposes only (not on production systems).
Snort 3 Alpha 4 Build 233 was released on December 22, 2016, and this guide has been tested with that version (releases after this specific release may not follow the same steps). Generic build instructions, prerequisites, and detailed notes are available in the manual.
If you want a more in-depth explanation of the install steps, which are very similar to the 2.9.9.x version of Snort, as well as instructions on how to configure and enhance Snort’s functionality, see my series on installing Snort 2.9.9.x on Ubuntu.
So let’s get started. First we need to install all the Snort pre-requisites from the Ubuntu repositories:
sudo apt-get install -y build-essential autotools-dev libdumbnet-dev libluajit-5.1-dev libpcap-dev libpcre3-dev zlib1g-dev pkg-config libhwloc-dev cmake
Install the optional (recommended) software:
sudo apt-get install -y liblzma-dev openssl libssl-dev cpputest cmake
Install tools required for compiling the source from github:
sudo apt-get install -y libtool git autoconf
Install the DAQ pre-requisites:
sudo apt-get install -y bison flex
If you want to build the documentation as well (not really needed, unless you want it, usually about 700 MB of libraries):
sudo apt-get install -y asciidoc dblatex source-highlight
Next we will create a directory to save the downloaded tarball files:
mkdir ~/snort_src cd ~/snort_src
First and install safec for runtime bounds checks on certain legacy C-library calls (this is optional but recommended):
cd ~/snort_src wget http://downloads.sourceforge.net/project/safeclib/libsafec-10052013.tar.gz tar -xzvf libsafec-10052013.tar.gz cd libsafec-10052013 ./configure make sudo make install
One of the Snort recommended prerequisites is Hyperscan 4.2.0. From their webpage: “Hyperscan is a regular expression engine designed to offer high performance, the ability to match multiple expressions simultaneously and flexibility in scanning operation.” Hyperscan needs Ragel 6.9 and the Boost header libraries.
Install Ragel 6.9 from source:
cd ~/snort_src wget http://www.colm.net/files/ragel/ragel-6.9.tar.gz tar -xzvf ragel-6.9.tar.gz cd ragel-6.9 ./configure make sudo make install
Download the Boost 1.63 libraries, but do not install:
cd ~/snort_src wget http://downloads.sourceforge.net/project/boost/boost/1.63.0/boost_1_63_0.tar.gz tar -xvzf boost_1_63_0.tar.gz
Install Hyperscan 4.2.0 from source, referencing the location of the Boost source directory:
cd ~/snort_src wget https://github.com/01org/hyperscan/archive/v4.2.0.tar.gz tar -xvzf v4.2.0.tar.gz mkdir ~/snort_src/hyperscan-4.2.0-build cd hyperscan-4.2.0-build/ cmake -DCMAKE_INSTALL_PREFIX=/usr/local -DBOOST_ROOT=~/snort_src/boost_1_63_0/ ../hyperscan-4.2.0 make sudo make install
If you want to test that Hyperscan works, from the build directory, run:
cd ~/snort_src/hyperscan-4.2.0-build/ ./bin/unit-hyperscan
The unit tests will run (this takes a few minutes).
Download and install Data AcQuisition library (DAQ) from the Snort website (note that DAQ for Snort 3 is a different DAQ than for the 2.9.9.x series of Snort):
cd ~/snort_src wget https://www.snort.org/downloads/snortplus/daq-2.2.1.tar.gz tar -xvzf daq-2.2.1.tar.gz cd daq-2.2.1 ./configure make sudo make install
Run the following command to update shared libraries:
sudo ldconfig
Now we are ready to install Snort from source. This command downloads and installs the latest version of Snort 3 (currently 3.0.0 Alpha 4, build 223). If you want to install all the snort directories under a single directory, see the section at the bottom of this document titled Changing the install location of Snort. Here we choose to install the entire Snort directory structure to a single folder under /opt/:
cd ~/snort_src wget https://github.com/snortadmin/snort3/archive/master.tar.gz tar -xvzf master.tar.gz cd snort3-master/ autoreconf -isvf ./configure --prefix=/opt/snort make sudo make install
Since the Snort installation places the Snort binary at /opt/snort/bin/snort, it is common to create a symlink to /usr/sbin/snort:
sudo ln -s /opt/snort/bin/snort /usr/sbin/snort
Snort 3 requires a few environmental variables, we store them temporarily in the current session so we can continue working, and save them permanently to the ~/.bashrc file (you’ll need to do this for every user profile):
export LUA_PATH=/opt/snort/include/snort/lua/\?.lua\;\; export SNORT_LUA_PATH=/opt/snort/etc/snort sh -c "echo 'export LUA_PATH=/opt/snort/include/snort/lua/\?.lua\;\;' >> ~/.bashrc" sh -c "echo 'export SNORT_LUA_PATH=/opt/snort/etc/snort' >> ~/.bashrc"
to ensure that these two environmental variables are available when using sudo, we need to add them to the /etc/sudoers file:
sudo visudo
in the editor, add the following to to the bottom of the file:
Defaults env_keep += "LUA_PATH SNORT_LUA_PATH"
use ctrl-x to exit, save when prompted by pressing y, then press enter to save the file to /etc/sudoers.tmp (which will get copied automatically to /etc/sudoers).
The last step of our Snort installation is to test that the Snort Binary runs. Execute Snort with the -V flag, which causes Snort to print the current version. You should see output similar to the following:
user@snort3:~$ snort -V
,,_ -*> Snort++ <*-
o" )~ Version 3.0.0-a4 (Build 223) from 2.9.8-383
'''' By Martin Roesch & The Snort Team
http://snort.org/contact#team
Copyright (C) 2014-2016 Cisco and/or its affiliates. All rights reserved.
Copyright (C) 1998-2013 Sourcefire, Inc., et al.
Using DAQ version 2.2.1
Using libpcap version 1.5.3
Using LuaJIT version 2.0.2
Using PCRE version 8.31 2012-07-06
Using ZLIB version 1.2.8
Using LZMA version 5.1.0alpha
Using OpenSSL 1.0.1f 6 Jan 2014
Using Hyperscan version 4.2.0 2017-01-07
user@snort3:~$
Now let’s test snort with the default configuration file and ruleset:
user@snort3:~$ /opt/snort/bin/snort -c /opt/snort/etc/snort/snort.lua -R /opt/snort/etc/snort/sample.rules
--------------------------------------------------
o")~ Snort++ 3.0.0-a4-223
--------------------------------------------------
Loading /opt/snort/etc/snort/snort.lua:
ssh
rpc_decode
pop
stream_user
stream_tcp
smtp
ssl
gtp_inspect
stream_ip
appid
stream_icmp
reputation
stream_udp
file_id
back_orifice
classifications
port_scan
dnp3
ftp_data
ftp_server
telnet
ftp_client
http_inspect
stream
references
arp_spoof
sip
wizard
dns
imap
stream_file
Finished /opt/snort/etc/snort/snort.lua.
Loading rules:
Loading /opt/snort/etc/snort/sample.rules:
Finished /opt/snort/etc/snort/sample.rules.
Finished rules.
--------------------------------------------------
rule counts
total rules loaded: 3974
text rules: 3974
option chains: 3974
chain headers: 187
--------------------------------------------------
port rule counts
tcp udp icmp ip
any 119 31 29 26
src 1685 4 0 0
dst 1927 232 0 0
both 0 1 0 0
total 3731 268 29 26
--------------------------------------------------
flowbits
defined: 124
not checked: 9
not set: 2
--------------------------------------------------
service rule counts - tcp to-srv to-cli
dcerpc: 3 0
drda: 3 0
ftp: 8 2
http: 1161 1553
ident: 1 0
imap: 29 1044
ircd: 1 1
ldap: 5 0
mysql: 29 1
netbios-ns: 4 0
netbios-ssn: 25 7
pop3: 12 1043
rtsp: 2 0
smtp: 550 3
ssl: 5 1
sunrpc: 9 0
telnet: 5 1
vnc-server: 1 3
total: 1853 3659
--------------------------------------------------
service rule counts - udp to-srv to-cli
dcerpc: 2 0
dns: 170 2
kerberos: 4 4
netbios-dgm: 7 7
netbios-ns: 1 1
netbios-ssn: 1 1
ntp: 1 0
snmp: 1 1
ssdp: 8 0
sunrpc: 7 3
tftp: 1 0
total: 203 19
--------------------------------------------------
fast pattern port groups src dst any
packet: 27 125 4
key: 23 107 1
header: 23 107 1
body: 0 2 0
file: 23 107 1
--------------------------------------------------
fast pattern service groups to-srv to-cli
packet: 29 17
key: 3 0
header: 1 3
body: 1 0
file: 1 4
--------------------------------------------------
search engine
instances: 566
patterns: 24676
pattern chars: 515657
num states: 409159
num match states: 23816
memory scale: MB
total memory: 8.27426
pattern memory: 1.05602
match list memory: 1.96014
transition memory: 5.20412
--------------------------------------------------
pcap DAQ configured to passive.
Snort successfully validated the configuration.
o")~ Snort exiting
user@snort3:~$
If you have output similar to the above, then Snort 3.0.0 Alpha 4 is installed and works.
When you install snort to /opt/snort, you get the following folder structure:
user@snort3x86:/opt/snort$ tree /opt/snort -L 3
/opt/snort
├── bin
│ ├── snort
│ ├── snort2lua
│ ├── u2boat
│ └── u2spewfoo
├── etc
│ └── snort
│ ├── file_magic.lua
│ ├── sample.rules
│ ├── snort_defaults.lua
│ └── snort.lua
├── include
│ └── snort
│ ├── actions
│ ├── codecs
│ ├── daqs
│ ├── decompress
│ ├── detection
│ ├── events
│ ├── file_api
│ ├── filters
│ ├── flow
│ ├── framework
│ ├── hash
│ ├── latency
│ ├── log
│ ├── lua
│ ├── main
│ ├── managers
│ ├── mime
│ ├── profiler
│ ├── protocols
│ ├── search_engines
│ ├── sfip
│ ├── sfrt
│ ├── stream
│ ├── time
│ └── utils
├── lib
│ ├── pkgconfig
│ │ └── snort.pc
│ └── snort
│ └── daqs
└── share
└── doc
└── snort
37 directories, 9 files
The /opt/snort/bin folder contains the following Snort binaries:
Additionally, the following folders are created / used:
If you would rather have all these folders install to a more normal location (/usr/local) , add ‑‑prefix=/usr/local/ to the ./configure command when preparing to build Snort. This will install all these folders under the path you choose. You also need to modify some of the other paths detailed above, so if you decide to install in that manner, you should follow the install instructions detailed in the Snort blog.
If you want to learn more about how to run the 2.9.9.x version of Snort, and how to install additional software to enhance a Snort system, see my series on installing Snort on Ubuntu. If you want to work with protocol (layer 7) detection, please see my article on OpenAppID.
I would love to get feedback from you about this guide. Recommendations, issues, or ideas, please contact me here.