Part of our management procedures should include monitoring of the IPCop firewall in order to ensure that CPU load, memory usage, network throughput, etc., maintain healthy levels. It is an extremely important role of the system administrator to establish a baseline for his or her systems in order to be able to identify abnormalities—many intrusions and hardware failures are first noticed by a drop (or rise) in network activity or CPU load.

The basic status screen allows us to view a number of basic system statistics before we inspect more detailed graphs of the statistics for the lifetime of the firewall. Services running on the IPCop box obviously have a serious impact on the ability of the box to do its job, and as a quick indicator the Services: display is useful in the event that the firewall ceases to function properly in order to ensure that the firewall thinks that the right services are running.

Many of the services, such as Secure shell...