Static validation techniques look at configurations and network topologies in order to identify security configuration errors, while dynamic verification supplements that with actual traffic logs. These techniques are commonly used to verify firewall configurations. Static validation has the advantage of being performed offline, and it can be completed prior to deploying a security configuration. It can detect errors such as shadowed rules (these are rules that will never be triggered because an earlier rule covers all of the traffic that would be covered by the shadowed rule.)