Peering with the outside world using BGP
In this section, we will start looking at how OpenDaylight communicates with other legacy networking products, such as routers. I would like to remind you that what we have learned until now about SDN and OpenDaylight was through a standalone, isolated SDN domain, meaning that the hosts and switches in the SDN domain were able to communicate with each other. We learned that the SDN domain is similar to a very large chassis-based switch with many line cards to connect to servers.
Now let's connect our SDN domain, which consists of many hosts and servers, to the outside world. For this, we need to first learn how to communicate with the outside world and then program the fabric in such a way that it would allow real traffic to transit from the SDN domain to the outside.
For communication with the outside world, we need to run a legacy routing protocol with legacy external routers. This is the role of OpenDaylight: to run routing protocols and establish...