Q211. What is VLAN?

VLAN (Virtual LAN) is a logical network segmentation that divides one physical network into multiple isolated networks at the switch level.

🏭 Real Production Example:

In a corporate data center:

• VLAN 10 – Application servers

• VLAN 20 – Database servers

• VLAN 30 – Users

Even though all devices use the same physical switch, VLANs prevent unauthorized access and broadcast flooding, improving security and performance.

✅ Interview One-Liner:

“VLAN logically separates networks on the same switch to improve security, performance, and manageability.”