1. LAN Segmentation
Virtual LAN (VLAN)

2. Network Segmentation
Segmenting is the process of separating certain portions of network traffic, either for
Performance,
Security,
Reliability
Logical or geographical organisation
Devices used for network segmentation
Switch
Router

3. Segmenting using Routers
We have seen the use of routers for
Segmenting local networks
Dividing an enterprise network into different departments
Limitations :
All devices on that subnet must be connected to the same switch and that switch must be connected to a port on the router.
What if users on a network are connected to different switches?

4. Switches
Switches are data link layer devices that enable multiple physical LAN segments to be interconnected into a single larger network
switches forward and flood traffic based on MAC addresses. 
MAC addresses are mapped to switch ports
Because switching is performed in hardware instead of in software, however, it is significantly faster. 

5. Segmentation using switches
LAN switching employs micro-segmentation within switch hardware, which segments the LAN
Switches usually allows multiple conversations (traffic between two ports) to occur simultaneously.

6. Limitation with switches
Switches do not break up broadcast domains, meaning that if a device sends a broadcast, all devices connected to that switch must listen.
Remind: To break up broadcast domains, we've traditionally used routers
Virtual LANs are a way to break up broadcast domains in a Layer 2 switched networks

7. VLANs
VLANs logically segment switched networks based on an organization's functions, project teams, or applications as opposed to a physical or geographical basis.

8. VLAN VLAN is a broadcast domain
Grouped based on logical function, department or application
20% to 40% of work force moves every year
Recabling / readdressing and reconfiguration
Traffic can be switched between VLANS with a router

9. LAN VS. VLAN

10. When should you need a VLAN?
You have more than 200 devices on your LAN
You have a lot of broadcast traffic on your LAN
Groups of users need more security or are being slowed down by too many broadcasts?
Groups of users need to be on the same broadcast domain because they are running the same applications..

11. VLAN Configuration

12. Static VLANs Assign ports to VLAN 2
Enter the following commands to add ports 0/7 to 0/9 to VLAN 2:
Switch_B#configure terminal
Switch_B# Vlan 2 name Sales
Switch_B(config)#interface fastethernet 0/7
Switch_B(config-if)#switchport mode access
Switch_B(config-if)#switchport access vlan 2
Assign ports on VLAN 3
Switch_B#configure terminal
Switch_B# vlan 3 name Admin
Switch_B(config)#interface fastethernet 0/10
Switch_B(config-if)#switchport mode access
Switch_B(config-if)#switchport access vlan 3

13. Configure VLANs on the Switches in a Converged Network Topology
Graphic

14. Role of Trunking VLANs in a Converged Network
How to communicate between hosts on a VLAN spread over different switches?
Trunk ports are created between switches to enable inter-switch communication
Basic Ethernet frame is modified to include VLAN ID to which it belongs
Frames are encapsulated
ISL (inter switch link) - Cisco proprietary
802.1Q – IEEE standard
Use graphic

15. Test VLAN configuration
Ping users on different VLANs
Ping should not work
Ping users on same VLAN
Ping should work