Chapter 3. Into the Real World

Into the Real World

The previous chapter demonstrated the configuration for basic packet filtering on a single machine. In this chapter, we’ll build on that basic setup but move into more conventional territory: the packet-filtering gateway. Although most of the items in this chapter are potentially useful in a single-machine setup, our main focus is to set up a gateway that forwards a selection of network traffic and handles common network services for a basic local network.

A Simple Gateway

We’ll start with building what you probably associate with the term firewall: a machine that acts as a gateway for at least one other machine. In ...

Get The Book of PF, 3rd Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.