2.6 VLAN

Question 1

What does VLAN stand for?

Answer 1

Virtual Local Area Network.

Question 2

What is the purpose of VLANs?

Answer 2

To logically segment a network within the same physical infrastructure, improving security and traffic management.

Question 3

How do VLANs improve network efficiency?

Answer 3

By reducing unnecessary broadcast traffic and allowing logical grouping of devices.

Question 4

What is the default VLAN on most switches?

Answer 4

VLAN 1.

Question 5

Why are VLANs important for security?

Answer 5

They isolate sensitive traffic, preventing unauthorized access between departments or groups.

Question 6

What is VLAN trunking?

Answer 6

A method that allows multiple VLANs to share a single network link.

Question 7

What IEEE standard defines VLAN trunking?

Answer 7

IEEE 802.1q.

Question 8

How does VLAN trunking work?

Answer 8

It adds a 4-byte VLAN tag to Ethernet frames to differentiate VLAN traffic over a trunk link.

Question 9

What is the Native VLAN in 802.1q?

Answer 9

The VLAN that remains untagged on a trunk port (default is VLAN 1).

Question 10

Why is it recommended to change the Native VLAN from VLAN 1?

Answer 10

For security reasons, to prevent VLAN hopping attacks.

Question 11

What type of port is assigned to a single VLAN?

Answer 11

An access port.

Question 12

What type of port carries multiple VLANs?

Answer 12

A trunk port.

Question 13

Why is VLAN trunking beneficial?

Answer 13

It reduces the need for additional cabling and switches while maintaining VLAN separation.

Question 14

How can VLANs communicate with each other?

Answer 14

Through inter-VLAN routing using a Layer 3 switch or a router.

Question 15

What happens if VLANs are not routed?

Answer 15

Devices on different VLANs cannot communicate with each other.

Question 16

What is the difference between Access Ports and Trunk Ports?

Answer 16

Access ports carry traffic for only one VLAN, while trunk ports carry traffic for multiple VLANs.

Question 17

What protocol is commonly used for inter-VLAN routing?

Answer 17

Router-on-a-stick (ROAS) using a router with a trunk interface.

Question 18

What is a potential security risk of VLAN misconfiguration?

Answer 18

VLAN hopping, where an attacker gains unauthorized access to VLANs.

Question 19

How can VLAN hopping attacks be prevented?

Answer 19

By disabling unused switch ports and changing the Native VLAN from VLAN 1.