Red Hat Enterprise Linux (RHEL) and AlmaLinux¶

Supported Releases¶

This chapter provides additional information for installing OMNeT++ on Red Hat Enterprise Linux (RHEL), RockyLinux and AlmaLinux distributions.

The following releases were tested, without 3D support:

AlmaLinux 9.x
AlmaLinux 10.x

RHEL, RockyLinux and CentOS Stream of the same major versions are expected to work.

Installing the Prerequisite Packages¶

To install the required packages, type in the terminal. You may need sudo privileges for these commands.

First, enable the EPEL (Extra Packages for Enterprise Linux) repository, which provides additional packages:

$ sudo dnf install -y epel-release

Then, install the core development tools and libraries:

$ sudo dnf install -y make ccache clang lld lldb gdb bison flex perl \
    python3-devel python3-pip libxml2-devel zlib-devel graphviz \
    xdg-utils elfutils-devel

Note

Doxygen is not in this list, and install.sh does not install it either: on these distributions it is available only from the CodeReady Builder (CRB) repository, which is usually not enabled. Doxygen is needed only for generating the documentation of simulation models. If you need it, enable CRB and install it: sudo dnf config-manager --set-enabled crb && sudo dnf install -y doxygen (on RHEL itself, enable codeready-builder-for-rhel-<version>-<arch>-rpms with subscription-manager instead).

Note

On RHEL/AlmaLinux/RockyLinux 9, the default Python 3.9 is too old. Install python3.12-devel python3.12-pip instead of python3-devel python3-pip, and use python3.12 in place of python3 in the commands below.

Next, install packages for the graphical environment (Qtenv and IDE). If you do not need GUI support, you can skip this step and later configure OMNeT++ with WITH_QTENV=no and WITH_OSG=no.

$ sudo dnf install -y qt6-qttools-devel qt6-qtbase-devel qt6-qtsvg qt6-qtwayland

Warning

3D Visualization (OpenSceneGraph) Support

OpenSceneGraph is generally not available or easily installable on RHEL/AlmaLinux distributions from standard repositories. Therefore, it is strongly recommended to build OMNeT++ without 3D support on these systems.

You should configure OMNeT++ with the WITH_OSG=no option. If you are using the install.sh script, it asks whether to continue without 3D support (with -y, it continues without asking); use the --no-3d flag to skip the question.

Install uv, which is used to set up the Python environment. It is not packaged for this distribution, so install it for the current user (uv will be placed in ~/.local/bin, make sure it is on your PATH):

$ python3 -m pip install --user uv

Next, set up a Python virtual environment for OMNeT++ using uv. In the root directory of your OMNeT++ download:

$ UV_PYTHON_DOWNLOADS=never uv venv --python python3 --seed --prompt "omnetpp/.venv" .venv
$ source .venv/bin/activate

Then, install the required Python packages into the virtual environment:

$ uv pip install -r python/requirements.txt

Note

If you prefer not to use uv, create the virtual environment with python3 -m venv .venv --upgrade-deps --clear --prompt "omnetpp/.venv" and install the packages with python3 -m pip install -r python/requirements.txt instead.

Note

The commands above install Clang as the C++ compiler and LLD as the linker. If you prefer to use GCC and the system’s default linker, you can adjust the package list accordingly (e.g., replace clang with g++ and omit lld) and set the PREFER_CLANG=no and PREFER_LLD=no options in the configure.user file or during the ./configure step. If you skip the GUI packages or due to the lack of OpenSceneGraph, remember to disable the corresponding features (WITH_QTENV=no, WITH_OSG=no) in configure.user or during the ./configure step.

To install additional (optional) packages for parallel simulation, type:

$ sudo dnf install -y openmpi-devel

Note that openmpi will not be available by default, it needs to be activated in every session with the

$ module load openmpi_<arch>

command, where <arch> is your architecture (usually x86_64). When in doubt, use module avail to display the list of available modules. If you need MPI in every session, you may add the module load command to your startup script (.bashrc).

SELinux¶

You may need to turn off SELinux when running certain simulations. To do so, click on System > Administration > Security Level > Firewall, go to the SELinux tab, and choose Disabled.

You can verify the SELinux status by typing the sestatus command in a terminal.

Note

From OMNeT++ 4.1 on, makefiles that build shared libraries include the chcon -t textrel_shlib_t lib<name>.so command that properly sets the security context for the library. This should prevent the SELinux-related “cannot restore segment prot after reloc: Permission denied” error from occurring, unless you have a shared library which was built using an obsolete or hand-crafted makefile that does not contain the chcon command.