General Network Types

There are basically two types of networks in use, the Flat Network and the Hierarchical Network. We will compare and contrast the two here.

Flat Networks

Flat Network

A flat network is one network segment and each network ID is represented individually in the routing table. The network IDs have no network or subnet structure and they cannot be summarized. In flat networks, RIP based IPX internetworks, for example, use flat network addressing and have a flat routing infrastructure.

Flat networks are usually deployed in SOHOs, (Small Office Home Office.) This is because the network requirements are low and do not require greater security or separation of departments. These environments usually don’t require multiple switches for departmental separation. Flat networks are also easier to administer and maintain because of the lack of complexity.

The Disadvantages of a Flat Network

Though Flat Networks are easier to maintain, this ease of administration does have its drawbacks. These drawbacks include:

  • Redundancy – Since only one switch is used, if this device fails there is no alternate path for the data and therefore the network will fail and become inaccessible causing loss of connectivity.
  • Low Security – Again, because of only one switch or router is used, segmentation of networks is not possible and does not prevent users from accessing all parts of the network. This makes unauthorized access much easier.
  • Speed – By connecting all devices to only one switch will reduce the data transfer rate, or speed.
  • Scalability – Flat Networks scale poorly and makes it possible for network failure easier.

Hierarchical Networks

Hierarchical Network

In hierarchical routing infrastructures, the internetwork can be divided into routing domains (also known as regions or areas). A routing domain is a collection of contiguous networks connected by routers that share the routing information for the routes within the domain. Routing domains are connected by a common routing domain called the backbone. Intra-domain routing is performed by the routers within the domain. Inter-domain routing is performed by domain routers connected to the backbone.

The Disadvantages of a Hierarchial Network

Though Hierarchical Networks are by far more secure, this security as well as complexity does have drawbacks as well. These drawbacks include:

  • Maintenance and Administration – The maintenance and administration of Hierarchical Networks by their own design are harder to control and troubleshooting these types of networks is more complex.
  • Device Communication – This type of network is not usually homogeneous in nature and not all devices will communicate readily without special configuration.
  • Extravagant Design – This type of network would be somewhat overkill for a small business where segregation of networks is not needed. Moreover, the use of a collapsed core structure, where the core and distribution layers are combined, is a much more feasible approach.

Enterprise Networks

The backbone that connects computers and related devices across departments in a company or other organization is known as an Enterprise Network. This network reduces communication protocols and facilitates system and device interoperability along with the improved internal and external Enterprise Data Management.

The purpose of an Enterprise Network, (actually all networks in general) is the elimination of isolated users. All users and systems should be able to communicate, provide and to retrieve information. Enterprise computing models assure that physical systems and devices are able to maintain and provide performance, reliability and security.

An Enterprise Network can include both local, (LAN) and wide area networks, (WAN). An enterprise network can integrate all systems, including Windows and Apple computers and operating systems (OS), Unix systems, mainframes and related devices like smartphones and tablets. If the Enterprise Network is tightly integrated, it will combine and use different device and system communications protocols.

The Challenge For The I.T. Professional

The growth of IT demands place an ever growing challenge to the IT professional. Access to new applications and services are being demanded by users. Unfortunately, they want these services immediately giving the I.T. Professional minimal time to plan and make these applications operational. Making these challenges greater, users are wanting access to these services and applications available on any device that they chose to use during business hours as well as after hours. This demand forces I.T. to have to consider how these services will be delivered securely.

Setting Up A Computer Network

There are basically four steps that must be completed to set-up and maintain a computer network.

Phase 1: The Network Design

The Network Design is the first phase in the life cycle of a network. This involves creating its design, but if you are a new Network Admin, this task will probably not be assigned to you. As the design of a network involves making decisions about the type of network that best suits the needs of your organization, it will most likely be assigned to a senior network architect who is familiar with both the network software and hardware.

Phase 2: Setting Up The Network

Here is when your role as the Network Administrator gets involved and where your responsibilities lay. You will be expected to perform these tasks unless your organization is large, with an adequate network structure already in place and with the assistance of perhaps a Junior Network Administrator.

Phase 3: Maintaining The Network

The third phase of network administration consists of ongoing tasks. These responsibilities are your primary duties to maintain the network. Your responsibilities can include, but not be exclusive to:

  • Adding new host machines.
  • Administering network security.
  • Administering network services, maintaining and/or configuring servers, Group Policy management and maintaining email services.
  • Troubleshooting and solving network problems.

Phase 4: Expanding The Network

If properly designed, a network will have allowances for its expansion. To begin, you can increase network size by adding new hosts and expanding network services by providing additional shared software, however a single network will expand to the point where it can no longer operate efficiently. This is when you have no alternative but to expand the network. You have a few options at this point. You can:

  • Set up a new network and connecting it to the existing network using a machine functioning as a router.
  • Configuring machines in your users' homes or in remote office sites and enabling these machines to connect via VPN.
  • Connecting your network to the Internet, thus enabling users on your network to retrieve information from other systems throughout the world again via VPN.
  • Configuring UUCP communications, enabling users to exchange files and electronic mail with remote machines.