BGP policies from a real network
The Border Gateway Protocol is probably the most important routing protocols. It allows ISPs and enterprise networks to exchange interdomain routes, but can also used inside enterprise or ISP networks. Much of BGP’s power resides in its flexibility and ability to support various types of filters. Operates use these filters to prevent some routes over others and many other objectives.
When students learn about BGP routing policies, they often see textbook examples that describe the syntax of the BGP filters used by network operators, but rarely real routing policies. In a recent post on linkedin, Pim van Pelt who manages IPng Networks, AS8298 provides a detailed description of the BGP routing policies that are used on his network with configuration snippets using the Bird2 configuration language.