Cisco three layer hierarchical model: Networks can be extremely complex with multiple protocols and diverse technologies. Hence, Cisco has developed a three layer hierarchical model for designing a reliable network infrastructure. This three-layer model helps you design, implement, and maintain a scalable, reliable, and cost-effective network. Also, each of these layers have its own features and functionality, which also reduces network complexity.
Cisco three layer hierarchical model
- Access – controls user and workgroup access to the resources on the network. This layer usually incorporates Layer 2 switches. It also incorporates access points that provide connectivity between workstations and servers. You can also manage access control and policy, create separate collision domains. You can also implement port security at this layer.
- Distribution – serves as the communication point between the access layer and the core. Its primary functions are to provide routing, filtering, and WAN access. It also helps to determine how packets can access the core. This layer determines the fastest way to access the network service requests. For example, how a file request is forwarded to a server. Also, if necessary, forwards the request to the core layer. This layer usually consists of routers and multilayer switches.
- Core – also referred to as the network backbone, this layer is responsible for transporting large amounts of traffic quickly. The core layer provides interconnectivity between distribution layer devices it usually consists of high speed devices, like high end routers and switches with redundant links.