CCNA · LAB 02

VLANS

Objectives

• Configuring VLAN
• Understanding Access port, Native VLAN , Trunk port and Vlan numbers

Theory / Background

• VLANS are used to logically segment a network at Layer 2, even when everything is connected to the same physical switch infrastructure. The goal is control—over traffic, security, and scalability.
• VLAN ID identifies and separates VLANs on a switch (0 and 4095 is reserved, 1 is default, 1006-4096 is extended VLANS.
  
• Trunking port(tagged port) : it carries multiple VLANS over the same physical connection. It uses 802.1q or ISL
• Access port(untagged port): it carries a single VLAN on a single physical interface Native VLAN: The native VLAN is the VLAN on a trunk port whose traffic is sent without VLAN tagging (untagged).

Network Topology

Fig 1 — Network topology

Configuration Commands

Switch_1

interface FastEthernet0/1                                                                      
switchport mode trunk
interface FastEthernet0/2
switchport mode trunk
interface FastEthernet0/3
switchport access vlan 20
switchport mode access
interface FastEthernet0/4
switchport access vlan 20
switchport mode access
interface FastEthernet0/5
switchport access vlan 30
switchport mode access
interface FastEthernet0/6
switchport mode trunk

Switch_2

interface FastEthernet0/1
 switchport mode trunk
interface FastEthernet0/2
 switchport access vlan 10
 switchport mode access
interface FastEthernet0/3
 switchport access vlan 30
 switchport mode access
interface FastEthernet0/4
 switchport access vlan 30
 switchport mode access

Switch_3

interface FastEthernet0/1
switchport mode trunk
interface FastEthernet0/2
switchport access vlan 10
switchport mode access
interface FastEthernet0/3
switchport access vlan 10
switchport mode access
interface FastEthernet0/4
switchport access vlan 20
switchport mode access

Verification Commands & Outputs

Show vlan Show interface status

Notice that PCS in same vlan can communicate with each pther but PCS in different vlans cannot communicate with each other

Learning Outcomes

Understood the basic configuration of vlans

Understood access and trunk ports, native vlans