Chapter 4. BGP and Routing Policies
No other IP routing protocol has the range of tools and attributes for imposing routing policies that BGP has. It is these policy capabilities that make BGP so powerful. You can also do great damage to your network, and even other peoples’ networks, if you use these capabilities incorrectly. This chapter takes an in-depth tour of BGP policy tools, how to use them correctly, and how to troubleshoot them when things go wrong.
Webster’s dictionary defines policy as a “...course or method of action selected from among alternatives and in light of given conditions to guide and determine present and future decisions.” That general definition serves us well in defining routing policy. A routing policy is
A set of ...