11.8 Chapter Summary

This chapter has introduced you to routing policy, where policy is used, and how to implement it in JUNOS. A routing policy, as was discussed, allows a network engineer to apply business considerations onto the operation of a network. Recall that the routing policy extended throughout an AS and differed depending on the routers placement within the network. The examples throughout the chapter should enable you to configure an abundance of flexible policies. Whether they are for route redistribution, route parameter modification, or for more complex applications like regular expressions, you now have the necessary tools to tackle these problems successfully.

You were introduced to the DIET policy methodology, a design model for policy deployment that can be also applied in many other areas of configuration. The chapter reviewed route redistribution and filtering and the flexibility that they provide in controlling the information that flows into and out from your routers. In the regular expressions section you also learned how to construct complex matching patterns for BGP AS path lists using operators as building blocks. Finally, remember that the secret to any good policy is simplicity. Simplicity can be clearly implemented when your goals are clearly defined.