The BGP Finite State Machine

Bgp States

The stages of a BGP connection establishment and maintenance can be described in terms of a finite state machine. Figure 2-20 and Table 2-4 show the complete BGP finite state machine and the input events that can cause a state transition. Mgure 2-20 The BGP Finite State Machine Mgure 2-20 The BGP Finite State Machine Table 2-4 The Input Events (IE) of Figure 2-20 Table 2-4 The Input Events (IE) of Figure 2-20 BGP Transport connection open failed The following sections provide a brief...

Neighbor Unreachability Detection

If a node to which another is communicating fails, it is not very beneficial to detect the failure before the upper layers do. If a router in the path to the destination fails, however, there may be an alternative router to use, and it would be extremely helpful to be able to detect that failure before the upper-layer protocol does. Neighbor reachability is verified in one of two ways from hints from the upper-layer protocols or from responses to Neighbor Solicitations. Forward-direction...