Installing Bro


Before installing Bro, you’ll need to ensure that some dependencies are in place.

Required Dependencies

Bro requires the following libraries and tools to be installed before you begin:

To build Bro from source, the following additional dependencies are required:

To install the required dependencies, you can use:

  • RPM/RedHat-based Linux:

    sudo yum install cmake make gcc gcc-c++ flex bison libpcap-devel openssl-devel python-devel swig zlib-devel

    In order to build Bro on Fedora 26, install compat-openssl10-devel instead of openssl-devel.

  • DEB/Debian-based Linux:

    sudo apt-get install cmake make gcc g++ flex bison libpcap-dev libssl-dev python-dev swig zlib1g-dev

    In order to build Bro on Debian 9, install libssl1.0-dev instead of libssl-dev.

  • FreeBSD:

    Most required dependencies should come with a minimal FreeBSD install except for the following.

    sudo pkg install bash cmake swig bison python py27-sqlite3

    For older versions of FreeBSD (especially FreeBSD 9.x), the system compiler is not new enough to compile Bro. For these systems, you will have to install a newer compiler using pkg; the clang34 package should work.

    You will also have to define several environment variables on these older systems to use the new compiler and headers similar to this before calling configure:

    export CC=clang34
    export CXX=clang++34
    export CXXFLAGS="-stdlib=libc++ -I${LOCALBASE}/include/c++/v1 -L${LOCALBASE}/lib"
    export LDFLAGS="-pthread"
  • Mac OS X:

    Compiling source code on Macs requires first installing either Xcode or the “Command Line Tools” (which is a much smaller download). To check if either is installed, run the xcode-select -p command. If you see an error message, then neither is installed and you can then run xcode-select --install which will prompt you to either get Xcode (by clicking “Get Xcode”) or to install the command line tools (by clicking “Install”).

    OS X comes with all required dependencies except for CMake, SWIG, and OpenSSL (OpenSSL headers were removed in OS X 10.11, therefore OpenSSL must be installed manually for OS X versions 10.11 or newer). Distributions of these dependencies can likely be obtained from your preferred Mac OS X package management system (e.g. Homebrew, MacPorts, or Fink). Specifically for Homebrew, the cmake, swig, and openssl packages provide the required dependencies. For MacPorts, the cmake, swig, swig-python, and openssl packages provide the required dependencies.

Optional Dependencies

Bro can make use of some optional libraries and tools if they are found at build time:

LibGeoIP is probably the most interesting and can be installed on most platforms by following the instructions for installing libGeoIP and the GeoIP database.

Installing Bro

Bro can be downloaded in either pre-built binary package or source code forms.

Using Pre-Built Binary Release Packages

See the bro downloads page for currently supported/targeted platforms for binary releases and for installation instructions.

  • Linux Packages

    Linux based binary installations are usually performed by adding information about the Bro packages to the respective system packaging tool. Then the usual system utilities such as apt, dnf, yum, or zypper are used to perform the installation.

The primary install prefix for binary packages is /opt/bro.

Installing from Source

Bro releases are bundled into source packages for convenience and are available on the bro downloads page.

Alternatively, the latest Bro development version can be obtained through git repositories hosted at See our git development documentation for comprehensive information on Bro’s use of git revision control, but the short story for downloading the full source code experience for Bro via git is:

git clone --recursive git://


If you choose to clone the bro repository non-recursively for a “minimal Bro experience”, be aware that compiling it depends on several of the other submodules as well.

The typical way to build and install from source is (for more options, run ./configure --help):

make install

If the configure script fails, then it is most likely because it either couldn’t find a required dependency or it couldn’t find a sufficiently new version of a dependency. Assuming that you already installed all required dependencies, then you may need to use one of the --with-* options that can be given to the configure script to help it locate a dependency.

The default installation path is /usr/local/bro, which would typically require root privileges when doing the make install. A different installation path can be chosen by specifying the configure script --prefix option. Note that /usr and /opt/bro are the standard prefixes for binary Bro packages to be installed, so those are typically not good choices unless you are creating such a package.

OpenBSD users, please see our FAQ if you are having problems installing Bro.

Depending on the Bro package you downloaded, there may be auxiliary tools and libraries available in the aux/ directory. Some of them will be automatically built and installed along with Bro. There are --disable-* options that can be given to the configure script to turn off unwanted auxiliary projects that would otherwise be installed automatically. Finally, use make install-aux to install some of the other programs that are in the aux/bro-aux directory.

Finally, if you want to build the Bro documentation (not required, because all of the documentation for the latest Bro release is available on the Bro web site), there are instructions in doc/README in the source distribution.

Configure the Run-Time Environment

You may want to adjust your PATH environment variable according to the platform/shell/package you’re using. For example:

Bourne-Shell Syntax:

export PATH=/usr/local/bro/bin:$PATH

C-Shell Syntax:

setenv PATH /usr/local/bro/bin:$PATH

Or substitute /opt/bro/bin instead if you installed from a binary package.

Copyright 2016, The Bro Project. Last updated on October 21, 2017. Created using Sphinx 1.5.2.