Lesson 23: Introduction to VLANs
A Virtual Local Area Network (VLAN) is a logical grouping of devices that share the same broadcast domain, regardless of their physical location on the network.
Why Use VLANs?
- Segmentation: Breaking up a large Layer 2 broadcast domain into smaller, more efficient domains.
- Security: Isolating user groups (e.g., Guest network isolated from Employee network).
- Flexibility: Allowing users to move physically while retaining the same network privileges.
VLAN Types
- Data VLAN: Carries user traffic.
- Default VLAN (VLAN 1): Automatically assigned to all ports on a Cisco switch by default. Used for management traffic by older protocols.
- Management VLAN: A specific VLAN designated for administrative access (SSH, Telnet) to the switch.
- Voice VLAN: Used for Voice over IP (VoIP) traffic, often prioritized.