Ubuntu 22.04 LTS

This document describes installation from source. If you want to build a deb, see Packaging Debian.

Installing Dependencies

sudo apt update
sudo apt-get install \
   git autoconf automake libtool make libreadline-dev texinfo \
   pkg-config libpam0g-dev libjson-c-dev bison flex \
   libc-ares-dev python3-dev python3-sphinx \
   install-info build-essential libsnmp-dev perl \
   libcap-dev python2 libelf-dev libunwind-dev \
   libyang2 libyang2-dev


The libunwind library is optional but highly recommended, as it improves backtraces printed for crashes and debugging. However, if it is not available for some reason, it can simply be left out without any loss of functionality.

Note that Ubuntu >= 20 no longer installs python 2.x, so it must be installed explicitly. Ensure that your system has a symlink named /usr/bin/python pointing at /usr/bin/python3.

sudo ln -s /usr/bin/python3 /usr/bin/python
python --version

In addition, pip for python2 must be installed if you wish to run the FRR topotests. That version of pip is not available from the ubuntu apt repositories; in order to install it:

curl https://bootstrap.pypa.io/pip/2.7/get-pip.py --output get-pip.py
sudo python2 ./get-pip.py

# And verify the installation
pip2 --version


This is optional

sudo apt-get install protobuf-c-compiler libprotobuf-c-dev

Config Rollbacks

If config rollbacks are enabled using --enable-config-rollbacks the sqlite3 developer package also should be installed.


This is optional

sudo apt-get install libzmq5 libzmq3-dev

Building & Installing FRR

Add FRR user and groups

sudo groupadd -r -g 92 frr
sudo groupadd -r -g 85 frrvty
sudo adduser --system --ingroup frr --home /var/run/frr/ \
   --gecos "FRR suite" --shell /sbin/nologin frr
sudo usermod -a -G frrvty frr


Clone the FRR git repo and use the included configure script to configure FRR’s build time options to your liking. The full option listing can be obtained by running ./configure -h. The options shown below are examples.

git clone https://github.com/frrouting/frr.git frr
cd frr
./configure \
    --prefix=/usr \
    --includedir=\${prefix}/include \
    --bindir=\${prefix}/bin \
    --sbindir=\${prefix}/lib/frr \
    --libdir=\${prefix}/lib/frr \
    --libexecdir=\${prefix}/lib/frr \
    --localstatedir=/var/run/frr \
    --sysconfdir=/etc/frr \
    --with-moduledir=\${prefix}/lib/frr/modules \
    --enable-configfile-mask=0640 \
    --enable-logfile-mask=0640 \
    --enable-snmp=agentx \
    --enable-multipath=64 \
    --enable-user=frr \
    --enable-group=frr \
    --enable-vty-group=frrvty \
    --with-pkg-git-version \
sudo make install

Install FRR configuration files

sudo install -m 775 -o frr -g frr -d /var/log/frr
sudo install -m 775 -o frr -g frrvty -d /etc/frr
sudo install -m 640 -o frr -g frrvty tools/etc/frr/vtysh.conf /etc/frr/vtysh.conf
sudo install -m 640 -o frr -g frr tools/etc/frr/frr.conf /etc/frr/frr.conf
sudo install -m 640 -o frr -g frr tools/etc/frr/daemons.conf /etc/frr/daemons.conf
sudo install -m 640 -o frr -g frr tools/etc/frr/daemons /etc/frr/daemons

Tweak sysctls

Some sysctls need to be changed in order to enable IPv4/IPv6 forwarding and MPLS (if supported by your platform). If your platform does not support MPLS, skip the MPLS related configuration in this section.

Edit /etc/sysctl.conf and uncomment the following values (ignore the other settings):

# Uncomment the next line to enable packet forwarding for IPv4

# Uncomment the next line to enable packet forwarding for IPv6
#  Enabling this option disables Stateless Address Autoconfiguration
#  based on Router Advertisements for this host

Reboot or use sysctl -p to apply the same config to the running system.

Add MPLS kernel modules

Ubuntu 20.04 ships with kernel 5.4; MPLS modules are present by default. To enable, add the following lines to /etc/modules-load.d/modules.conf:

# Load MPLS Kernel Modules

And load the kernel modules on the running system:

sudo modprobe mpls-router mpls-iptunnel

If the above command returns an error, you may need to install the appropriate or latest linux-modules-extra-<kernel-version>-generic package. For example apt-get install linux-modules-extra-`uname -r`-generic

Enable MPLS Forwarding

Edit /etc/sysctl.conf and the following lines. Make sure to add a line equal to net.mpls.conf.eth0.input for each interface used with MPLS.

# Enable MPLS Label processing on all interfaces

Install service files

sudo install -m 644 tools/frr.service /etc/systemd/system/frr.service
sudo systemctl enable frr

Enable daemons

Open /etc/frr/daemons with your text editor of choice. Look for the section with watchfrr_enable=... and zebra=... etc. Enable the daemons as required by changing the value to yes.

Start FRR

systemctl start frr