2.6 VLAN Flashcards
What does VLAN stand for?
Virtual Local Area Network.
What is the purpose of VLANs?
To logically segment a network within the same physical infrastructure, improving security and traffic management.
How do VLANs improve network efficiency?
By reducing unnecessary broadcast traffic and allowing logical grouping of devices.
What is the default VLAN on most switches?
VLAN 1.
Why are VLANs important for security?
They isolate sensitive traffic, preventing unauthorized access between departments or groups.
What is VLAN trunking?
A method that allows multiple VLANs to share a single network link.
What IEEE standard defines VLAN trunking?
IEEE 802.1q.
How does VLAN trunking work?
It adds a 4-byte VLAN tag to Ethernet frames to differentiate VLAN traffic over a trunk link.
What is the Native VLAN in 802.1q?
The VLAN that remains untagged on a trunk port (default is VLAN 1).
Why is it recommended to change the Native VLAN from VLAN 1?
For security reasons, to prevent VLAN hopping attacks.
What type of port is assigned to a single VLAN?
An access port.
What type of port carries multiple VLANs?
A trunk port.
Why is VLAN trunking beneficial?
It reduces the need for additional cabling and switches while maintaining VLAN separation.
How can VLANs communicate with each other?
Through inter-VLAN routing using a Layer 3 switch or a router.
What happens if VLANs are not routed?
Devices on different VLANs cannot communicate with each other.
What is the difference between Access Ports and Trunk Ports?
Access ports carry traffic for only one VLAN, while trunk ports carry traffic for multiple VLANs.
What protocol is commonly used for inter-VLAN routing?
Router-on-a-stick (ROAS) using a router with a trunk interface.
What is a potential security risk of VLAN misconfiguration?
VLAN hopping, where an attacker gains unauthorized access to VLANs.
How can VLAN hopping attacks be prevented?
By disabling unused switch ports and changing the Native VLAN from VLAN 1.
