After creating VLANs 2, 3, and 4 and assigning ports, how should unused switch ports be handled?

Unused switch ports should be configured in a "black hole" VLAN. This is a dedicated VLAN with no active interfaces and no routing, effectively isolating any device connected to these ports. This prevents unauthorized access or accidental network loops. Configuring ports in a nondefault native VLAN or the native VLAN itself is less secure, as the native VLAN is often used for management traffic or can be exploited in VLAN hopping attacks. Configuring ports as access ports without assigning them to a specific, isolated VLAN leaves them vulnerable to unauthorized device connections and potential network disruptions.