- when the Layer 2 switch is using a routed port
- when the Layer 2 switch needs to be remotely managed
- when the Layer 2 switch is the default gateway of user traffic
- when the Layer 2 switch needs to forward user traffic to another device
Layer 2 switches can be configured with an IP address so that they can be remotely managed by an administrator. Layer 3 switches can use an IP address on routed ports. Layer 2 switches do not need a configured IP address to forward user traffic or act as a default gateway.