Summary

Now that you’ve completed this chapter, you are able to identify the strengths of using a zone-based firewall versus a route-based one. You understand how applications can be identified even though they may all be using the same protocol and port, and you understand how deep packet inspection is achieved in single-pass parallel processing. Most importantly, you have a firm grasp of which phases a packet goes through to form a session. It’s okay if this information seems a bit overwhelming; we will see more practical applications, and implications, in the next two chapters. We will be taking a closer look at how security and NAT rules behave once you start playing with zones, and how to anticipate expected behavior by simply glancing at the rules.

If you are preparing for the PCNSE exam, this chapter covered parts of the Planning and Core Concepts and Deploy and Configure domains. Make note of Figure 1.2 regarding packet processing, remember that route lookups...