VLANs, or Virtual Local Area Networks, are a fundamental concept in networking that allow you to segment a physical network into multiple logical networks. This segmentation provides various benefits such as improved security, better network performance, and simplified management.

Here's a breakdown of some key points about VLANs:

• Logical Segmentation: VLANs enable you to logically segment a network, regardless of the physical layout. Devices within the same VLAN can communicate with each other as if they were on the same physical network, even if they are physically located in different parts of the network.
• Broadcast Domain Isolation: By dividing a network into VLANs, you can limit the scope of broadcast traffic. Broadcast traffic is confined within the VLAN, reducing the amount of unnecessary traffic on the network.
• Enhanced Security: VLANs provide a level of security by separating sensitive or critical network traffic from other less critical traffic. This segregation helps in implementing security policies and access controls more effectively.
• Improved Performance: VLANs can improve network performance by reducing congestion. By logically dividing the network into smaller segments, you can limit the amount of traffic each segment carries, thus reducing congestion and improving overall performance.
• Flexibility and Scalability: VLANs offer flexibility and scalability in network design. You can easily add, remove, or modify VLANs without needing to physically reconfigure the network infrastructure. This makes it easier to adapt the network to changing requirements.
• Inter-VLAN Routing: While VLANs isolate traffic within their own network, sometimes it's necessary for communication between VLANs. Inter-VLAN routing allows communication between different VLANs while still maintaining logical separation.
• Management and Administration: VLANs simplify network management by allowing administrators to group devices logically rather than physically. This simplifies tasks such as applying network policies, managing access controls, and troubleshooting network issues.

Overall, VLANs are a powerful tool for network administrators to design efficient, secure, and scalable networks. They are widely used in enterprise environments to improve network performance, security, and management.

L2 redundancy and load balancing

Since spanning tree protocol ensures a loop-free topology is necessary to think about a way that allows us to create redundancy between interconnected L2 devices. To accomplish this goal was developed EtherChannel, also known as link aggregation or port channel, which is a method used in networking to bundle multiple physical Ethernet links into a single logical link. This aggregated link increases bandwidth, enhances redundancy, and enables load balancing. It's achieved through protocols like LACP (Link Aggregation Control Protocol) for dynamic configuration or statically by manually grouping links, and PAgP (Port Aggregation Protocol) which is specific to Cisco networking equipment and is used primarily in Cisco environments. It's not standardized like LACP, which is supported by a broader range of networking vendors. EtherChannel is widely used in enterprise networks, data centers, and campus environments to improve network performance, resilience, and scalability.

Inter VLAN Routing

Once we know what VLANs and Etherchannel are and what they are used for, we need to interconnect VLANs to provide access between them. Since they belong to different subnets, we will need an L3 device to facilitate packet routing.

There are three known ways to do this, which will be explained in depth in another project focused solely on Inter VLAN Routing:

• Router with separate interfaces
• L3 Switches
• Router on a stick

On this occasion, we implemented Router on a Stick, a networking setup used for inter-VLAN routing when only one physical connection exists between a router and a switch. In this configuration, the router interface connected to the switch acts as a gateway for multiple VLANs. Traffic from different VLANs is tagged and sent through this single router interface, where it's routed between VLANs. This setup simplifies network design and reduces hardware costs but may introduce performance limitations in high-traffic environments.