BGP Policies (part 1)

At the most basic level, there are only three BGP policies: pushing traffic through a specific exit point; pulling traffic through a specific entry point; preventing a remote AS (more than one AS hop away) from transiting your AS to reach a specific destination. In this series I’m going to discuss different reasons for these kinds of policies, and different ways to implement them in interdomain BGP.
In the following network—

There are many reasons an operator might want to select which neighboring AS through which to send traffic towards a given reachable destination (for instance, 100::/64). Each of these examples assumes the AS in question has learned multiple paths towards 100::/64, one from each peer, and must choose one of the two available paths to forward along.
Examining this from AS65006’s Perspective …
Assuming AS65006 is an edge operator (commonly called enterprise, but generally just originating and terminating traffic, and never transiting traffic), there are several reasons the operator may prefer one exit point (through an upstream provider), including:
- An automated system may determine AS65004 has some sort of brownout; in this case, the operator at 65006 has configured the system to prefer the exit through AS65005
- The traffic Continue reading



What is face muting ?
