CentOS 6

(As an alternative to this installation, you may prefer to create a FRR rpm package yourself and install that package instead. See instructions in redhat/README.rpm_build.md on how to build a rpm package)

Instructions are tested with CentOS 6.8 on x86_64 platform


CentOS 6 is very old and not fully supported by the FRR community anymore. Building FRR takes multiple manual steps to update the build system with newer packages than what’s available from the archives. However, the built packages can still be installed afterwards on a standard CentOS 6 without any special packages.

Support for CentOS 6 is now on a best-effort base by the community.

CentOS 6 restrictions:

  • PIMd is not supported on CentOS 6. Upgrade to CentOS 7 if PIMd is needed
  • MPLS is not supported on CentOS 6. MPLS requires Linux Kernel 4.5 or higher (LDP can be built, but may have limited use without MPLS)
  • Zebra is unable to detect what bridge/vrf an interface is associcated with (IFLA_INFO_SLAVE_KIND does not exist in the kernel headers, you can use a newer kernel + headers to get this functionality)
  • frr_reload.py will not work, as this requires Python 2.7, and CentOS 6 only has 2.6. You can install Python 2.7 via IUS, but it won’t work properly unless you compile and install the ipaddr package for it.
  • Building the package requires Sphinx >= 1.1. Only a non-standard package provides a newer sphinx and requires manual installation (see below)

Install required packages

Add packages:

sudo yum install git autoconf automake libtool make gawk \
   readline-devel texinfo net-snmp-devel groff pkgconfig \
   json-c-devel pam-devel flex epel-release c-ares-devel

Install newer version of bison (CentOS 6 package source is too old) from CentOS 7:

sudo yum install rpm-build
curl -O http://vault.centos.org/7.0.1406/os/Source/SPackages/bison-2.7-4.el7.src.rpm
rpmbuild --rebuild ./bison-2.7-4.el7.src.rpm
sudo yum install ./rpmbuild/RPMS/x86_64/bison-2.7-4.el6.x86_64.rpm
rm -rf rpmbuild

Install newer version of autoconf and automake (Package versions are too old):

curl -O http://ftp.gnu.org/gnu/autoconf/autoconf-2.69.tar.gz
tar xvf autoconf-2.69.tar.gz
cd autoconf-2.69
./configure --prefix=/usr
sudo make install
cd ..

curl -O http://ftp.gnu.org/gnu/automake/automake-1.15.tar.gz
tar xvf automake-1.15.tar.gz
cd automake-1.15
./configure --prefix=/usr
sudo make install
cd ..

Install Python 2.7 in parallel to default 2.6. Make sure you’ve install EPEL (epel-release as above). Then install current python27: python27-devel and pytest

sudo rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
sudo rpm -ivh https://centos6.iuscommunity.org/ius-release.rpm
sudo yum install python27 python27-pip python27-devel
sudo pip2.7 install pytest

Please note that CentOS 6 needs to keep python pointing to version 2.6 for yum to keep working, so don’t create a symlink for python2.7 to python.

Install newer Sphinx-Build based on Python 2.7.

Create a new repo /etc/yum.repos.d/puias6.repo with the following contents:

### Name: RPM Repository for RHEL 6 - PUIAS (used for Sphinx-Build)
### URL: http://springdale.math.ias.edu/data/puias/computational
name = RPM Repository for RHEL 6 - Sphinx-Build
baseurl = http://springdale.math.ias.edu/data/puias/computational/$releasever/$basearch
#mirrorlist =
enabled = 1
protect = 0
gpgkey =
gpgcheck = 0

Update rpm database & Install newer sphinx

sudo yum update
sudo yum install python27-sphinx

The libyang library can be installed from third-party packages available here.

Note: the libyang dev/devel packages need to be installed in addition to the libyang core package in order to build FRR successfully.

For example, for CentOS 7.x:

wget https://ci1.netdef.org/artifact/LIBYANG-YANGRELEASE/shared/build-1/CentOS-7-x86_64-Packages/libyang-0.16.46-0.x86_64.rpm
wget https://ci1.netdef.org/artifact/LIBYANG-YANGRELEASE/shared/build-1/CentOS-7-x86_64-Packages/libyang-devel-0.16.46-0.x86_64.rpm
sudo rpm -i libyang-0.16.46-0.x86_64.rpm libyang-devel-0.16.46-0.x86_64.rpm

or Ubuntu 18.04:

wget https://ci1.netdef.org/artifact/LIBYANG-YANGRELEASE/shared/build-1/Ubuntu-18.04-x86_64-Packages/libyang-dev_0.16.46_amd64.deb
wget https://ci1.netdef.org/artifact/LIBYANG-YANGRELEASE/shared/build-1/Ubuntu-18.04-x86_64-Packages/libyang_0.16.46_amd64.deb
sudo apt install libpcre3-dev
sudo dpkg -i libyang-dev_0.16.46_amd64.deb libyang_0.16.46_amd64.deb

Alternatively, libyang can be built and installed manually by following the steps below:

git clone https://github.com/opensourcerouting/libyang
cd libyang
git checkout -b tmp origin/tmp
mkdir build; cd build
sudo make install

When building libyang on CentOS 6, it’s also necessary to pass the -DENABLE_CACHE=OFF parameter to cmake.

Note: please check the libyang build requirements first.

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 groupadd -g 92 frr
sudo groupadd -r -g 85 frrvty
sudo useradd -u 92 -g 92 -M -r -G frrvty -s /sbin/nologin \
   -c "FRR FRRouting suite" -d /var/run/frr 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
./configure \
    --bindir=/usr/bin \
    --sbindir=/usr/lib/frr \
    --sysconfdir=/etc/frr \
    --libdir=/usr/lib/frr \
    --libexecdir=/usr/lib/frr \
    --localstatedir=/var/run/frr \
    --with-moduledir=/usr/lib/frr/modules \
    --disable-pimd \
    --enable-snmp=agentx \
    --enable-multipath=64 \
    --enable-user=frr \
    --enable-group=frr \
    --enable-vty-group=frrvty \
    --disable-exampledir \
    --disable-ldpd \
    --enable-fpm \
    --with-pkg-git-version \
    --with-pkg-extra-version=-MyOwnFRRVersion \
make check PYTHON=/usr/bin/python2.7
sudo make install

Create empty FRR configuration files

sudo mkdir /var/log/frr
sudo mkdir /etc/frr

For integrated config file:

sudo touch /etc/frr/frr.conf

For individual config files:


Integrated config is preferred to individual config.

sudo touch /etc/frr/babeld.conf
sudo touch /etc/frr/bfdd.conf
sudo touch /etc/frr/bgpd.conf
sudo touch /etc/frr/eigrpd.conf
sudo touch /etc/frr/isisd.conf
sudo touch /etc/frr/ldpd.conf
sudo touch /etc/frr/nhrpd.conf
sudo touch /etc/frr/ospf6d.conf
sudo touch /etc/frr/ospfd.conf
sudo touch /etc/frr/pbrd.conf
sudo touch /etc/frr/pimd.conf
sudo touch /etc/frr/ripd.conf
sudo touch /etc/frr/ripngd.conf
sudo touch /etc/frr/staticd.conf
sudo touch /etc/frr/zebra.conf
sudo chown -R frr:frr /etc/frr/
sudo touch /etc/frr/vtysh.conf
sudo chown frr:frrvty /etc/frr/vtysh.conf
sudo chmod 640 /etc/frr/*.conf

Install daemon config file

sudo install -p -m 644 redhat/daemons /etc/frr/
sudo chown frr:frr /etc/frr/daemons

Edit /etc/frr/daemons as needed to select the required daemons

Look for the section with watchfrr_enable=... and zebra=... etc. Enable the daemons as required by changing the value to yes

Enable IP & IPv6 forwarding

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

# Controls IP packet forwarding
net.ipv4.ip_forward = 1

# Controls source route verification
net.ipv4.conf.default.rp_filter = 0

Load the modifed sysctl’s on the system:

sudo sysctl -p /etc/sysctl.d/90-routing-sysctl.conf

Add init.d startup files

sudo install -p -m 755 redhat/frr.init /etc/init.d/frr
sudo chkconfig --add frr

Enable FRR daemon at startup

sudo chkconfig frr on

Start FRR manually (or reboot)

sudo /etc/init.d/frr start