The VLAN features include the following
- VLAN is a function to divide a network by layer2 switch.
- Improves network flexibility and scalability
- Improves security by limiting the extent to which data is transferred.
- Networks divided by VLANs are interconnected by routers/Layer 3 switches.
The VLAN is a feature of the Layer 2 switch that divides the network. How it is divided depends on the configuration. The network can be divided without changing the physical wiring or layout. This has the advantage of increasing the flexibility and scalability of the network configuration.
The following article explains how networks are divided by VLANs.
Note that VLAN only divides a network. The divided networks are not interconnected. Therefore, if the VLANs are different, no data will be transferred and no communication will be possible. This means that VLAN improves security.
The word “security” has so many different meanings, and each person who hears the word “security” will have a very different image of it.。
Security in VLAN is not about encrypting data or authenticating users. By limiting the range in which data is transmitted, VLAN improves security by limiting the impact of any unauthorized communication.
And it would be inconvenient to have no communication between different VLANs (networks). If the network is divided into VLANs for each department, communication between departments will be impossible. Therefore, the networks divided by VLANs are interconnected using routers/Layer 3 switches. In most cases, a layer 3 switch is used.
- The need to divide the network
- Details of dividing the network
- VLAN Overview
- VLAN behavior
- Access port : Port assigned to only one VLAN
- Trunk port : Port assigned to multiple VLANs
- Summary of Trunk Protocols – IEEE802.1Q and ISL
- Native VLAN
- Specific example of native VLAN mismatch
- Cisco DTP
- Cisco Configuring and Verifying VLAN
- Cisco VLAN Detailed Configuration Example
- Notes on deleting VLANs
- Voice VLAN – VLAN for connecting IP phones
- VTP :Synchronize VLAN configuration
- VTP pruning – Stopping unnecessary flooding of trunk links
- Configuring and Verifying Cisco VTP
- Inter VLAN routing overview
- Inter-VLAN routing by router
- Inter-VLAN routing by Layer 3 switch
- Configuring and Verifying Inter-VLAN Routing by Cisco Router
- Cisco Configuring Inter-VLAN routing by Layer3 switch : SVI/routed port
- Cisco Layer3 Switch Basic Configuration Example
- Summary of Layer 3 Switch Port Concepts – Access Port/Trunk Port/SVI/Routed Port
- LAN Design pattern : 2-tier and 3-tier