Internet Routing Architectures, Second Edition

Route Filtering and Attribute Manipulation

The concept of route filtering is straightforward. A BGP speaker can choose what routes to send and what routes to receive from any of its BGP peers. Route filtering is essential in defining routing policies. An autonomous system can identify the inbound traffic it is willing to accept from other neighbors by specifying the list of routes it advertises to its neighbors. Conversely, an AS can control what routes its outbound traffic uses by specifying the routes it accepts from its neighbors.

Tip

See the section Route Filtering and Attribute Manipulation in Chapter 11.

Filtering is also used on the protocol level to limit routing updates flowing from one protocol to another. Earlier, this chapter ...