9.6 Chapter Summary

In this chapter you have learned the fundamentals of BGP. During our discussion, you should have become familiar with the various topologies, homing, and the difference between transit and nontransit.

The routing section covered details of the RIB and how BGP routes relate to the three types of RIB. In addition, we covered the various routing tables JUNOS uses and how route preference and JUNOS BGP path selection work to create active routes.

With the coverage of the FSM, we are now familiar with the six states of a BGP session:

1. Idle

2. Connect

3. Active

4. OpenSent

5. OpenConfirm

6. Established

We know the four different messages used in BGP and what they do:

1. OPEN ”negotiates and establishes a BGP session

2. UPDATE ”provides NLRI and route withdrawal information

3. NOTIFICATION ”notifies the remote system when an error condition occurs

4. KEEPALIVE ”maintains a BGP session

Lastly, we covered the minimum configuration requirements for BGP for both internal and external peering sessions. This, along with the listing of common JUNOS BGP statements, has prepared you for Chapter 10, "BGP Routing Case Studies."