It is a prerequisite part of network designing,to achieve the task of network availability by 24×7 with scalability and security we have to consider distribution layer network before designing the core layer network.
Distribution layer is one of the most significant layer among the three (core, access, distribution), as it aggregates the data received from access layer network before transmitting to core layer.
The significance of distribution layers can be exemplified as routers, managed switches and firewalls along with all security features including policies and access lists including NAT are configured and implemented on this network layer. Furthermore, VLAN and routing decisions between work groups are also provided here.
Technically, it is the primary point in the connecting closets. The point which can be either a router or multi layer switch used for network segmentation or for the isolation of network in any organizational network.
The distribution layer can provide
- Aggregation of LAN or WAN links.
- Policy-based security.
- Routing in-between LAN subnets and VLANs
- Routing in-between routing domains (e.g.,EIGRP to OSPF).
- Redundant networks and load balancing.
This layer controls the Broadcast domain as well, i.e. routers or multi-layer switches acts as the demarcation point between broadcast domains.
Implementing the distribution layer network with best practices, following with the guidelines provided by the leading vendors, in enterprise network design can reduce network complexities, increase consistency and accelerate the overall network performance. To shape a robust network, the distribution layer plays a key role in combining core and access layer network.
This layer delivers established network foundation, the basic distribution layer designs can be defined as for large, medium, and small organizations, depending on network size and applications which is being used, the demanding services and dealing with the cost.
As both core layer and access layer are dedicated to special-purpose functionalities, i.e. the access layer is dedicated to local and remote work group access or we can say end-device connectivity, whereas core layer is dedicated to high speed switching throughout the network. The distribution layer acts as a distinctive borderline role for services and control between these two layers.