“:::How to configure Layer 2 Virtual Local Area Network (VLAN) on a Cisco Switch Catalyst 3560:::”

Switching ideasnet



The VLAN is defined as:
A virtual local area network, virtual LAN or VLAN, is a group of hosts with a common set of requirements that communicate as if they were attached to the same broadcast domain, regardless of their physical location. A VLAN has the same attributes as a physical local area network (LAN), but it allows for end stations to be grouped together even if they are not located on the same network switch. VLAN membership can be configured through software instead of physically relocating devices or connections. However unlike a physically separate network, VLANs must share bandwidth; two separate one-gigabit VLANs using a single one-gigabit interconnection can suffer both reduced throughput and congestion.
By wikipedia.
We know that a Layer 2 VLAN is an isolated Broadcast Domain and for communicating between VLANs a Layer 3 Device is required for inter-VLAN Routing. You can assign each switch port to a VLAN. Ports in a VLAN share broadcast traffic. Ports that do not belong to that VLAN do not share the broadcast traffic. By default, only VLAN 1 is configured on the switch. On the LAN network above, we have three VLANs. VLAN 10,20, and 30. VLAN 30 belongs both to SWITCH1 and SWITCH2, therefore we need a Trunk Port between the two switches in order for hosts in VLAN30 in SWICTH1 to be able to communicate with hosts in VLAN30 in SWITCH2. Trunking means “VLAN multiplexing” – carrying multiple VLANs through a single link through the use of a “trunking protocol”. To allow for multiple VLANs on one link, frames of the VLANs must be identified. The most common method is IEEE 802.1Q.

SWITCH-1

vlan 10

 name Accounting

!

vlan 30

 name Engineering

!

interface range fa0/1-2

 description *** LINKS TO VLAN10 ***

 switchport mode access

 switchport access vlan 10

!

interface range fa0/10-11

 description *** LINKS TO VLAN30 ***

 switchport mode access

 switchport access vlan 30

!

interface fastethernet0/24

 description *** TRUNK LINK TO SW2 ***

 switchport mode trunk

 switchport trunk encapsulation dot1q

 end

SWITCH-2

vlan 20

 name Management

!

vlan 30

 name Engineering

!

interface range fa0/1-2

 description *** LINKS TO VLAN20 ***

 switchport mode access

 switchport access vlan 20

!

interface range fa0/10-11

 description *** LINKS TO VLAN30 ***

 switchport mode access

 switchport access vlan 30

!

interface fastethernet0/24

 description *** TRUNK LINK TO SW1 ***

 switchport mode trunk

 switchport trunk encapsulation dot1q