The design of computer networks tends to be based on their size and the specific needs of different user groups for aspects such as security and performance. The design can be very complex but roughly breaks into three categories:
This is the most basic network and, as the name suggests, is totally flat meaning that all devices can see one another and there is little control on the network, which has led to them being known as ‘unmanaged’ networks. Flat networks are only used in the smallest and most basic of set-ups as they have a number of inherent issues such as potential network storms, limited security and poor traffic routing.
Managed Network / Layer 2
A managed network is a step up from an unmanaged network as it introduces VLANs (Virtual LANs) providing the capability to separate the network into a number of virtual networks offering more security and ability to shape and route traffic. Layer 2 networks are fine for medium sized networks but can still suffer from the risk of network storms or performance issues as they grow because in effect they are still one big network.
Routed Network / Layer 3
The next step up is a fully routed network or ‘layer 3’ network. This type of network uses multiple routers to create totally separate zones improving performance and offering better options for redundant paths, security and isolation. A key point is that an issue in one zone has no impact on any other zone. They are more complex to set-up but are particularly suited to scenarios where, for example, an event site wants to have a redundant optic fibre ring between all key locations for the best performance and reliability. We use layer 3 networks on all the major sites on which we operate.