Configuring BIRD as a BGP Route Reflector
These instructions will take you through installing BIRD as a BGP route reflector, and updating your other BIRD instances to speak to your new route reflector.
These instructions are valid for both Ubuntu 14.04 and RHEL 7.
Prerequisites
Before starting this you will need the following:
- A machine running either Ubuntu 14.04 or RHEL 7 that is not already being used as a compute host.
- SSH access to the machine.
Installation
Step 1: Install BIRD
Ubuntu 14.04
Add the official BIRD PPA. This PPA contains fixes to BIRD that are not yet available in Ubuntu 14.04. To add the PPA, run:
sudo add-apt-repository ppa:cz.nic-labs/bird
Once that’s done, update your package manager and install BIRD (the
single bird
package installs both IPv4 and IPv6 BIRD):
sudo apt-get update
sudo apt-get install bird
RHEL 7
First, install EPEL. Depending on your system, the following command may be sufficient:
sudo yum install epel-release
If that fails, try the following instead:
wget https://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-9.noarch.rpm
sudo yum install epel-release-7-9.noarch.rpm
With that complete, you can now install BIRD:
yum install -y bird bird6
Step 2: Set your BIRD IPv4 configuration
Before doing this, you’ll need to take note of what BGP AS number you’ve used in your compute node install.
Open /etc/bird/bird.conf
on your route reflector system and initially
fill it with the following template, replacing <router_id>
with the
IPv4 address of your route reflector:
# Configure logging
log syslog { debug, trace, info, remote, warning, error, auth, fatal, bug };
log stderr all;
# Override router ID
router id <router_id>;
filter import_kernel {
if ( net != 0.0.0.0/0 ) then {
accept;
}
reject;
}
# Turn on global debugging of all protocols
debug protocols all;
# This pseudo-protocol watches all interface up/down events.
protocol device {
scan time 2; # Scan interfaces every 2 seconds
}
Then, at the end, for each compute node in your deployment add one of
the following blocks, replacing <node_shortname>
with a purely
alphabetical name for the host (this must be unique for each host, but
the shortname is only used within this file), <node_ip>
with the
node’s IPv4 address, and <as_number>
with the AS number you’re using:
protocol bgp <node_shortname> {
description "<node_ip>";
local as <as_number>;
neighbor <node_ip> as <as_number>;
multihop;
rr client;
graceful restart;
import all;
export all;
}
Step 3 (Optional): Set your BIRD IPv6 configuration
If you want to use IPv6 connectivity, you’ll need to repeat step 2 but
using /etc/bird/bird6.conf
. The only differences between the two
are:
- the filter needs to filter out ::/0 instead of 0.0.0.0/0
- where before you set
<node_ip>
to the compute node’s IPv4 address, this time you need to set it to the compute node’s IPv6 address
Note that <router_id>
should still be set to the route reflector’s
IPv4 address: you cannot use an IPv6 address in that field.
Step 4: Restart BIRD
Ubuntu 14.04
Restart BIRD:
sudo service bird restart
Optionally, if you configured IPv6 in step 3, also restart BIRD6:
sudo service bird6 restart
RHEL 7
Restart BIRD:
systemctl restart bird
systemctl enable bird
Optionally, if you configured IPv6 in step 3, also restart BIRD6:
systemctl restart bird6
systemctl enable bird6
Step 5: Reconfigure compute nodes
If you used the calico-gen-bird-conf.sh
script to configure your
compute hosts, and you used the route reflector IP when you did, you do
not need to do anything further.
Otherwise, on each of your compute nodes, edit /etc/bird/bird.conf
(and, if you’re using IPv6, /etc/bird/bird6.conf
) to remove all their
peer relationships (the blocks beginning with protocol bgp
) except for
one. Edit that one’s neighbor
field IP address to be the IP address of
the route reflector (either IPv4 or IPv6). Then, restart their BIRD
instances as detailed in step 4.