One of the primary selling points of pfSense is that deploying pfSense routers on our network enhances the overall reliability of the network. A single network component, however – for example, a single router or a single web server – still represents a single point of failure. Even in the absence of hardware failure, a single network component may not be adequate in accommodating the level of traffic on our network. For that reason, we need to consider eliminating single points of failure from our network whenever possible. This process is two-pronged, and involves incorporating both redundancy and high availability:

• Redundancy is defined as the duplication of critical components. Redundancy can be both active and passive. With passive redundancy, we incorporate excess capacity into the network, so that when an individual component...