If a network is completely isolated by an air gap from all other outside networks it is using what type of configuration?

Physical network segregation

Explanation:

Network segregation is simply a tool that is used for dividing larger networks to smaller parts called network segments. There are specific reasons, spacing, positioning, purposes, and isolation that determine the type of segregation. For example, "If a network is completely isolated by an air gap from all other outside networks it is using" the physical network segregation.