FreeBSD® Unleashed

Routing

We've already talked a little bit about how IP routing works, but we'll now cover it in a little bit more detail. Configuring routes properly is one of the great skills one can develop in networking, and it pays to be able to do it correctly—or at least to have a working understanding of it so that you can do administrative tasks that require interfacing with the routing table, such as portsentry (which we will discuss in Chapter 29, “Network Security”).

Any router—by which we mean any device configured to act as a router, which includes actual routers or regular servers that will do their job in a pinch—works by maintaining a routing table, a set of rules that says where packets that match certain IP address criteria should be sent. ...