Understanding Network Segmentation and Devices

Network segmentation is a key concept in the field of networking that involves dividing a computer network into smaller parts or segments. Each of these segments behaves as an independent network allowing for increased network performance and security. Segmentation typically utilizes devices such as routers, bridges, and switches. But, not all devices segment the network. Let’s take an in-depth look at the devices and their role in network segmentation.

Hubs

The primary device that does not segment the network is a hub. A network hub is a node that broadcasts packets it receives from a source device to all connected devices in a network. Hubs are unable to discriminate between the devices on the network, hence they cannot segment the network. Hubs were primarily used in the past when networks were smaller and less complex. But, as network size and complexity grew, inefficiencies of hubs in handling network traffic led to their replacement with intelligent devices such as switches that are capable of directing packets only to intended recipients, thus segmenting the network.

Why don’t Hubs segment the network?

The main reason for this is that hubs operate on the first layer of the OSI Model – the Physical Layer. This layer conveys the bit stream through the network at the physical level. It provides only the hardware means of sending and receiving data on a carrier. Since hubs only move packets around within their respective networks without discretion, they don’t have an understanding of the network’s structure. As a result, they are not aware of the different segments and cannot manage them, unlike devices that operate in higher layers, like switches and routers.

Role of other Devices

Routers and switches, unlike hubs, do perform network segmentation. A switch works at the Data Link layer of the OSI model to create a separate collision domain for each switch port. It learns the MAC addresses of each device on each port, thereby enabling it to send frames destined for a particular device directly to the port where the device is connected. This reduces unnecessary network traffic, thereby enhancing network performance.

Routers work at Layer 3 (the Network Layer) of the OSI model. Each router interface belongs to a different network and hence, splits the broadcast domain. This allows routers to break a network into multiple smaller networks, each forming a broadcast domain.

While discussing network devices and their roles, it’s beneficial to refer to a meraki sizing guide that offers comprehensive information about the capacity and functionality of various network devices including routers, switches, and hubs. Such guides help network administrators understand the specifications of these devices and make an informed decision when setting up a network infrastructure.

Conclusion

As we have seen, various devices participate in the design and function of a network. While many do segment the network and improve its performance, others, like hubs do not. They take a more indiscriminate, broadcast approach to data transmission, making them suitable for smaller, less complex network configurations. Understanding the capabilities and limitations of these devices, through resources such as a meraki sizing guide, is crucial in the effective and efficient implementation of network infrastructure.