Debian 13

Install required packages

Add packages:

sudo apt-get install git autoconf automake libtool make \
   build-essential python3-dev python3-pytest python3-sphinx \
   libjson-c-dev libelf-dev libreadline-dev cmake libcap-dev \
   bison flex pkg-config texinfo gdb

Note

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.

Debian 13 (Trixie) ships libyang-dev version 3.12, so we can install it using:

sudo apt-get install libyang-dev

For gRPC support the following packages are required:

sudo apt-get install libprotobuf-c-dev protobuf-c-compiler libgrpc-dev \
   libgrpc++-dev python3-grpc-tools libprotoc-dev protobuf-compiler \
   libprotobuf-dev protobuf-compiler-grpc

Get FRR, compile it and install it (from Git)

This assumes you want to build and install FRR from source and not using any packages

Add frr groups and user

sudo addgroup --system frr
sudo addgroup --system frrvty
sudo adduser --system --ingroup frr --home /var/opt/frr/ \
   --gecos "FRR suite" --shell /bin/false frr
sudo usermod -a -G frrvty frr

Download Source, configure and compile it

(You may prefer different options on configure statement. These are just an example.)

git clone https://github.com/frrouting/frr.git frr
cd frr
./bootstrap.sh
./configure \
    --sysconfdir=/etc \
    --localstatedir=/var \
    --sbindir=/usr/lib/frr \
    --enable-multipath=64 \
    --enable-user=frr \
    --enable-group=frr \
    --enable-vty-group=frrvty \
    --enable-configfile-mask=0640 \
    --enable-logfile-mask=0640 \
    --enable-fpm \
    --with-pkg-git-version \
    --with-pkg-extra-version=-MyOwnFRRVersion
make
make check
sudo make install

For more compile options, see ./configure --help

Create empty FRR configuration files

sudo mkdir /var/log/frr
sudo mkdir /etc/frr
sudo install -m 640 -o frr -g frr /dev/null /etc/frr/frr.conf
sudo install -m 640 -o frr -g frr tools/etc/frr/daemons /etc/frr/daemons
sudo install -m 640 -o frr -g frr tools/etc/frr/support_bundle_commands.conf /etc/frr/support_bundle_commands.conf

Edit /etc/frr/daemons and enable the FRR daemons for the protocols you need

Enable IP & IPv6 forwarding

If systemd-sysctl is used, create a /etc/sysctl.d/frr.conf file and enable the following sysctl variables:

# Uncomment the next line to enable packet forwarding for IPv4
net.ipv4.ip_forward=1

# Uncomment the next line to enable packet forwarding for IPv6
#  Enabling this option disables Stateless Address Autoconfiguration
#  based on Router Advertisements for this host
net.ipv6.conf.all.forwarding=1

Reboot or use systemctl restart systemd-sysctl to apply the same config to the running system

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

Troubleshooting

Shared library error

If you try and start any of the frrouting daemons you may see the below error due to the frrouting shared library directory not being found:

./zebra: error while loading shared libraries: libfrr.so.0: cannot open
shared object file: No such file or directory

The fix is to add the following line to /etc/ld.so.conf which will continue to reference the library directory after the system reboots. To load the library directory path immediately run the ldconfig command after adding the line to the file eg:

echo include /usr/local/lib >> /etc/ld.so.conf
ldconfig