Chapter 3. Local Firewall Security

As part of our goal of covering the larger security issues before moving on to the information about how to troubleshoot your firewall problems, we feel it’s important to cover issues that affect the security of the firewall itself. Just because a system is a firewall will not imbue it with some inherent lack of susceptibility to being broken into.

A firewall is just like any other system; in fact, your firewall might be nothing more than a typical server with two or more Network Interface Cards (NICs) in it, running firewall rules, while doing double duty as your fileserver, firewall, and e-mail server. We’ve seen it done. The point here is that adding firewall rules alone will not protect your system completely. ...

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