All know the default basic trust, in addition to the local untrust and DMZ these three areas, what meaning is divided into the three area, divided the grade is based on what? Show what? The default untrust can prevent the DMZ, trust can visit to the DMZ and untrust, if I add untrust can access the strategy of trust is the firewall becomes a common fool switch or router, some anti attack in the two areas still work? Untrust access trust can do packet filtering attack traffic? The security level of each of those 5,50,85 is to verify that the default access direction? But just match a strategy can disrupt the hierarchy?