How many firewalls do you need to setup dmz?

To set up a DMZ (Demilitarized Zone), you typically need at least two firewalls. One firewall is used to separate the DMZ from the internal network, while the other secures the DMZ from the external internet. This layered approach enhances security by controlling traffic between the different zones. In some configurations, a single firewall with multiple interfaces can also be used to achieve similar results.