Different authentication servers like TACACS+, Radius are part of access layer. Access layer includes shared LAN, switched LAN and VLAN to workstations and servers, provide access to PSTN, WAN, DSL etc.
#Cisco switch models series
Normally here we are running with low end devices like 2900 series switches. This is our local and remote workgroup-access that is providing access to different services like workgroups, WAN connectivity.
The distribution layer is the isolation point between the network’s access layer and core layers. In a Network the number of router hops from edge to edge is called the diameter, it is considered good practice to design for a consistent diameter within a hierarchical network.
Quality of service (QoS) classification, or other processes.Fast transport and large amount of data.
Some of key characteristics of core-layer are as following: Cisco recommends that Core layer should have mesh topology and there should be no stuff like ACL, packet handling etc. Since core layer is the backbone of any network and providing services to other layers therefore this layer is reliable and have availability, also must be Redundant and have load balancing between its different links. This layer has high Speed devices like high end routers and switches with large modules with layer-2 and layer-3 functionality. Allow us the lower cost in implementation.Ĭore layer is the backbone layer of network running with high speed switching and transfers larger amount of data, also handle the requests of distribution layer.3 layer model is easy to troubleshoot because of its logical distribution into layer, as each layer has its own functionality.3 layer model is easier to understand and easy to grow your network.Provide the flexibility in our network with three layers distribution, each layer is mapped with physical implementation and each of layers has its own features and functionality.
So for designing large networks we need to have such hierarchical model for designing our network. Today’s networks are complex and large, wide variety of technology, running multiple services and also having challenges with functionality, increasing demand of bandwidth and compatibility with other businesses and venders. Using this we can design a hierarchical network with dividing the network into 3 different layers which also help us in reducing the network complexity. This three layered model is the basic foundation for creating small and larger Networks. Cisco has three layer hierarchical network model that consist of following layers: