Getting started with BGP on Linux with Cumuls Quagga12 Jul 2016
Before we begin, I’d like to admit something: “I spent a good number of years as a Windows sysadmin.” There, I said it. Now, I’m proud of my time as a Windows guy, so that’s’ not why I bring it up. I mention my time as a Windows admin perhaps to provide a reason why it took me so long to get BGP between some Linux VMs.
What we’re building
The above figure depicts a three node, three router network that we will create in this post. Following these steps:
- Install the routers
- Configure the routers
- Configure the hosts
- Test connectivity
Install the Routers
In our setup we start with Ubuntu 14.04 boxes with two interfaces. We assume eth0 is on the 10.0.1.0/24 network, and eth1 is on the 172.x.100.0/24 network.
First download the 14.04 package from here. In the commands below wget this file from another server in the environment, you can get it there however you like.
Configure the interfaces
On each router, configure your interfaces, substituting network addresses where relevant:
# cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet static address 10.0.1.19/24 gateway 10.0.1.1 dns-nameservers 188.8.131.52 184.108.40.206 auto eth1 iface eth1 inet static address 220.127.116.11 netmask 255.255.255.0
Then, restart the interfaces:
sudo service networking restart
sudo echo "net.ipv4.ip_forward = 1" >> /etc/sysctl.conf sudo sysctl -p
As root, run the following commands:
apt-get update && apt-get -qq dist-upgrade && reboot wget http://location/of/the/download/roh-ubuntu1404.tar tar -xvf roh-ubuntu1404.tar cd ubuntu1404/ dpkg -i quagga_0.99.23.1-1+cl3u2_trusty_amd64.deb duagga-dbg_0.99.23.1-1+cl3u2_trusty_amd64.deb quagga-doc_0.99.23.1-1+cl3u2_trusty_all.deb
We then need to provide some initial start up configuration for Quagga. We do this by changing the /etc/quagga/daemons file to reflect the services we would like started. In this case, the obligatory Zebra, and BGP:
zebra=yes bgpd=yes ospfd=no ospf6d=no ripd=no ripngd=no isisd=no
Now that Quagga is installed, we need to start said service:
service quagga start
Configure the Routers
with Quagga installed and running on each Quagga host, we can configure the needed bits to get BGP operational. The commands and configuration that follow configure the 10.0.1.19/24 router from our diagram above. Note, you will want to choose Private AS numbers from here: Private BGP AS Numbers. In the example, these are 64512, 513, and 514 respectively.
# vtysh conf t hostname cab1-router password zebra enable password zebra log file /var/log/quagga/bgpd.log ! router bgp 64512 bgp router-id 10.0.1.19 network 18.104.22.168/24 neighbor 10.0.1.20 remote-as 64513 neighbor 10.0.1.21 remote-as 64514 distance bgp 150 150 150 ! exit exit wr mem
Configure the Hosts
For each host behind out of our Quagga routers, you need to set the interfaces file to an appropriate address and gateway per host:
$ cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet static address 172.30.100.100/24 gateway 172.30.100.1
Now that all three routers and all three VMs are configured, we will test connectivity. First between routers, then between VMs:
From router 1:
cab1-router# ping 172.20.100.1 PING 172.20.100.1 (172.20.100.1) 56(84) bytes of data. 64 bytes from 172.20.100.1: icmp_seq=1 ttl=64 time=0.367 ms ^C --- 172.20.100.1 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.367/0.367/0.367/0.000 ms cab1-router# ping 172.20.100.100 PING 172.20.100.100 (172.20.100.100) 56(84) bytes of data. 64 bytes from 172.20.100.100: icmp_seq=1 ttl=63 time=0.448 ms ^C --- 172.20.100.100 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1000ms rtt min/avg/max/mdev = 0.298/0.373/0.448/0.075 ms
[root@cab3-test-vm:~] [17:03:59] $ ping 172.20.100.100 PING 172.20.100.100 (172.20.100.100) 56(84) bytes of data. 64 bytes from 172.20.100.100: icmp_seq=1 ttl=62 time=0.443 ms 64 bytes from 172.20.100.100: icmp_seq=2 ttl=62 time=0.475 ms ^C --- 172.20.100.100 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1000ms rtt min/avg/max/mdev = 0.443/0.459/0.475/0.016 ms [root@cab3-test-vm:~] [17:10:06] $ ping 22.214.171.124 PING 126.96.36.199 (188.8.131.52) 56(84) bytes of data. 64 bytes from 184.108.40.206: icmp_seq=1 ttl=63 time=0.179 ms 64 bytes from 220.127.116.11: icmp_seq=2 ttl=63 time=0.410 ms ^C --- 18.104.22.168 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 999ms rtt min/avg/max/mdev = 0.179/0.294/0.410/0.116 ms
In this post we built three L3 networks, and configured BGP routing between them using Quagga on a Ubuntu 14.04 host. We then tested connectivity between these networks.