Network Hubs Versus Switches

After choosing those network cards, it’s time to start shopping for the device you’ll connect them to, namely a switch or a hub. Yes, they both look very much alike, but when it comes to performance, the two couldn’t be farther apart.

Although hubs are cheaper than switches, they suffer from a few key drawbacks – first, when multiple systems are connected to a hub, they can only communicate in half-duplex. That’s similar to a CB radio, except that in this case, a connected PC can only send or receive data at once, and not both. When PCs are connected to a hub, they are truly sharing the network, and only one system can send data over the network at a time. In other words, if one system is sending data, another can’t. If a second system tries to use the network at the same time, a collision occurs, and data needs to be retransmitted. Although this might be fine for a home network, you’re much better off moving to the next step up, namely a switch.

Unlike with a hub, multiple PCs connected to a switch can send and receive data simultaneously. When system are connected to directly to their own switch port (rather than through a hub connected a switch port), collisions don’t happen, and all systems can transmit at the maximum speed that the switch and network card allow, hopefully 1000 Mbps (1 Gbps) if you’ve planned things right. The absence of collisions and the ability for multiple systems to transmit and receive data in full duplex simultaneously are the major advantages of a switch, and that’s what you’re paying for. The good news is that a switch only costs slightly more than a hub, so spend the extra bit and do it right – trust us on this one.

How many ports does your switch need? Well, that’s up to you. A good rule of thumb is to always go for a few more ports than you think you’ll need. More switches come with a minimum of 4 ports for home users, up to hundreds for business environments. Most home users will easily get by with an 8-port model, which will also allow you to connected a home router or even a network printer later, with room to spare.

Finally, ensure that the switch you choose supports 10, 1000, and 1000 Mbps connections on every port – some will support only one or another, and that’s one mess that you want to avoid. You’ll not helping anything by choosing a lower-priced switch that only supports 100 Mbps connections. Eventually, you may have to plug in a 10 Mbps network card that will not work, so it’s better to be safe (and completely flexible) than sorry.

Network Adapter Cards

The first pieces of equipment that you’ll want to consider for your home network are the network cards. Each PC that will connect to the network will need one, and they come in different shapes and sizes. Rather than trying to save a bit of money buying used or older network cards, do yourself a favor and still to a popular name brand. Not only are most standard PCI network cards inexpensive, the good quality ones don’t cost much more than the cheapest. Regardless of which brand you choose, there are three main things to keep clear.

First, what you are shopping for is an Ethernet card – one that has an RJ-45 port on the back, runs at 10, 100, and/or 1000 Mbps, and one that provides drivers for your operating system. If any of these three don’t match, steer clear. Don’t try to save money by purchasing a 10 or 100 Mbps-only card, or get suckered into buying an older card that accepts a coaxial-cable connection – unless you’ll planning to build an antique network, that is! The dual-speed network card is a minimum requirement – a 100 Mbps-only card won’t work with a 10 Mbps-only hub, and vice versa. Almost all new network cards (and switches/hubs) are multi-speed (10/100/1000), but be sure to keep your eyes open at any rate. Lots of networking equipment is cheap for a reason.

Note: Unless your PC is ancient, it probably already includes a 10/100 or 10/100/1000 Ethernet adapter integrated on the motherboard – check the back of your PC!

Second, don’t feel limited to using an internal network card for your desktop PC. To be completely honest, it’s a hundred times easier to use an external 10/100 Mbps Ethernet card that plugs into a USB port. They may be a little more expensive that an internal PCI card, but they’re also portable – if you ever change PCs, you only need to plug the USB cable into the new system and you’re almost ready to go. We can’t explain how many times a USB-based Ethernet card has saved us reams of time – just remember that you’ll need a USB port to use it.

Finally, if you’re shopping for a PCMCIA network card for a laptop, be sure keep your eyes open for a model with a built-in port rather than one that uses a dongle. What’s a dongle? It’s the annoying little cable that plugs into the PCMCIA card and has a port on one end for the network cable. Short of using a roll of duct tape, a dongle will always come loose at the most inconvenient time. For only a few more quid, stick with a built-in port, or go with an external USB card as mentioned previously.

Sharing Files and Printers With a Network

In all operating systems since Windows 95, Microsoft has done a very good thing, and separated client and server functions. When Client for Microsoft Networks is installed, it allows your system to make requests from network servers. It does not, however, allow other systems to make requests of this same system. In other words, client for Microsoft Networks allows a system to make requests. To service requests for files or printers, another service needs to be configured – File and Print Sharing. Accessed via the Network program in Control Panel, the File and Print Sharing button allows you to configure your system to handle requests for files, print services, or both. It’s worth noting that this is potentially a very dangerous service to configure on your system, especially if your PC is not properly secured and connected to the Internet. For example, if you were connected to the Internet and has this service enabled without a firewall of some type, outsiders would potentially be able to browse through any folders you might have shared.

Of course, file and printer sharing is a big part of having a home network, and once your Internet connection is properly secured, will not be a worry. Once enabled, file sharing gives you the ability to share folders, making them available to other clients on the network. The same goes for printer sharing. Anything that you do not explicitly share will not be available over the network, but anything that you do share will be there for the whole network to see – and potentially connect to, assuming you haven’t restricted resources with permissions.

Network Logons

If you’ve ever installed Windows 98, you might remember the little Windows Logon dialog box presented to you when you first booted the PC. The main purpose of that logon box was to allow multiple users to share the same machine, with each given their own unique desktop environment if correctly configured. While the standard Windows Logon will allow you to connect to the Internet, it will not allow you to connect to shared folders or printers that may exist on another machine on your home network. In order to do that, your system will need the Client for Microsoft Networks Installed.

Without getting too detailed at this point, the Client for Microsoft Networks is the “client-side” of what makes Windows networking possible. In other words, this software allows a system like Windows 98 or XP to connect a shared folder on another PC. If it is not installed, the client will simple not be able to connect to those resources. Your system may already have the Client for Microsoft Networks installed, especially if your PC included a network card when you purchased it.

Network Protocols

Much like people, computers need to be speaking a common language to communicate. If you were speaking Spanish and we only spoke English, we would certainly hear each you talking, but we wouldn’t really understand what you were saying. In the same way, computers need to
be running a common “protocol” in order to share information. A protocol is essentially like a language, a formal set of communication standards that network devices follow in order to exchange information. A variety of network protocols exist, but four are far more common than others – TCP/IP, IPX/SPX, NetBEUI, and AppleTalk.

The Transmission Control Protocol/Internet Protocol is actually a suite of different protocols that make communications between systems possible. As the “protocol of the Internet”, TCP/IP has become the defacto standard for networks worldwide. Where companies previously ran a whole slew of different protocols on their networks, almost all have now moved to TCP/IP only, or are moving in that direction. On your home network, TCP/IP is almost certainly the only protocol you’ll ever need to run, with very few exceptions.

The other three protocols mentioned all have (or at least had) their time and place. IPX/SPX is a protocol that was developed by Novell for use on NetWare networks – in other words, for networks that included NetWare servers. Even NetWare uses TCP/IP as its standard protocol today, so the chances of you needing to install it are very slim indeed. NetBEUI (NetBios Extended User Interface) is a very simple protocol that was used extensively on networks until the early 90s, mainly because it was easy to configure – simply install it, and two computers will chat away. Unfortunately, NetBEUI is limited to local networks, and won’t get you onto the Internet. Given that most home networks are implemented to share Internet access, NetBEUI is unlikely to be in your future either. Finally, AppleTalk was a protocol developed by Apple for use on their Macintosh systems. Although a solid protocol in it’s own right, Macs now run TCP/IP, and even Apple (the company) runs TCP/IP on their internal network.

At the end of the day, the message should be clear – 99.9% of the time, the only protocol that home networkers will need is TCP/IP. In future articles, this subject will be looked at in much more detail.

Types of Networks

The next time you talk to your postman, ask him about his network. If he’s installed one in his home, chances are good that he now considers himself an expert. The truth of the matter is that there’s a good deal more to correctly implementing a network that installing some network cards and running some cable. Indeed it might work, but that doesn’t mean that it’s done right. An understanding of fundamental concepts is just as important as crimping your cables correctly.

Two main types of networks exist. The first is a traditional client/server network, and the second is referred to as a peer-to-peer network or workgroup. A client/server network is one in which computers have clearly defined roles. For example, a PC running Windows XP would generally be considered a client, and would request resources or services from a server. In the purest sense, a client doesn’t provide any server-type functions. This is usually the case on business networks.

Conversely, a server does what its name suggests – it “serves” resources to network clients. On most business networks, the server function is carried out by a network operating system (NOS) like Windows 2000 Server, or Novell NetWare. In this type of environment, nobody really sits in front of a server to do work. Instead, the server provides network access to data, applications, printers, and the like in the background. On bigger networks, the server may also be responsible for providing user authentication – using a central database to ensure that users provided the correct username and password to access the network and use network resources. For example, you may be familiar with the term “domain”. A domain is simply a network that includes at least one Windows 2000 Server configured to handle user authentication. Although some users choose to configure their home network as a domain, the vast majority do not.

In the world of home networks, the line between a client and a server is slightly more blurred. Even though they are usually considered clients, PCs running operating systems like Windows 98 or XP are also capable of sharing files, printers, and Internet connections with other machines – traditional server functions. While they may not be capable of handling the huge server workloads that one might find in a corporate environment, they tend to be able to handle all of the basic required functions on a home network, and are typically much less expensive. The base version of Windows 2000 Server costs many times what you would pay for Windows XP, for example.

A peer-to-peer or workgroup network is much closer to what a home network usually is. In this model, the network generally does not include a dedicated server system like Windows 2000 Server. Instead, it is made up different client machines that share resources with each other as necessary – in effect, every PC is both a client and a server at any point in time. When you configure a PC to be part of a Windows workgroup, what you are really doing is telling the system that no centralized security system exists, and that you want this PC to be part of the same logical group as the rest of your PCs for sharing functions.

Why Do You Need a Home Network?

Although it may seem elementary to some people, this question is perhaps the most important for all home users. First and foremost, just because the whole world seems to be talking about installing a network in their home, it doesn’t necessarily mean that you need one. Before you run out to buy all types of equipment and cabling, be sure to take the time to consider whether you really have the need. In most cases, the answer is generally pretty simple.

In the most basic sense, a network consists of two or more computers that wish to share resources. This begs the obvious question – what is a resource? In the world of computer networks, a resource is something that someone on one PC might want to gain access to on another. Most commonly, this is access to data files, such as spreadsheets or documents, for example. In the old days, people used a wonderfully elementary system called “sneakernet” – saving data to a floppy disk, and then walking it over to their machine. Although simple, the system obviously has some flaws, namely the fact that it is incredible time consuming if it needs to be done often. Another commonly shared resource is a printer – why purchase two printers to connect to two machines, when both could share one printer? One thing that a network provides in the longer term is savings, both in terms of time and money. Finally we come to what is perhaps the biggest resource why people consider installing a home network – in order to share access to a single very large resource, the Internet, through a single connection.

Going back to the original question, a home that could use a network is one in which you want to share resources between two or more PCs easily. If you only have one PC, and only ever plan on having one, then a network probably isn’t right for you – in the most basic sense, you really don’t have anyone else to talk to. This is not to say that networks consisting of a single PC do not exist – they sometimes do, as you’ll see later in the series.

Introduction to Home Networking

Over the course of the past two years, it may seem like everyone’s neighbour, cousin, or barkeep has just installed a network at home. While previously almost the exclusive domain or companies and the seriously tech-savvy, more and more home users are recognizing the advantages of installing networks in their homes.

Microsoft operating systems since Windows 95 have provided networking capabilities built-in. However, the explosive growth of the Internet, the availability of inexpensive high-speed connections, and a variety of do-it-yourself home networking hardware are the key factors that have driven networks into the home. Although simple in principle (and often equally easy in practice), installing and configuring a network correctly involves a solid foundation of knowledge in order to be done correctly. It’s simply too easy to overlook some important element that will leave you stuck later, such an improper cabling or some serious security holes. In this series we’re going to concentrate on doing things correctly, building your knowledge base issue-by-issue.

This series begins with a look at the concept of a network and some of the basics. As the series progresses we’ll delve into important concepts like cabling, wireless networks, configuring servers, sharing Internet connections, properly securing a network, and more. Instead of providing an overview, this series aims to provide you with practical real-world advice on installing and configuring your network correctly – the first time.

MAC Address Cloning

While typically not an issue for DSL subscribers, many cable operators have their systems set up such that your PC is identified by the MAC address of its network card. Your PC’s MAC address is used to uniquely identify you as a subscriber, and without the correct MAC address, your system may not be allocated an IP address. While this is fine in cases where you intend to keep your cable modem connected to your PC, it introduces issues when you attempt to install a hardware router since its MAC address will be different.

Many broadband routers include a feature to “clone” your MAC address such that your router’s external interface takes on the MAC address of your PC’s network card. When enabled, your service provider sees the “correct” address that they have on file, and you’re typically allocated an IP address without issue. To find your PC’s MAC address, use the ipconfig /all command and then configure it on the MAC address clone (or similar) tab on your router.

Home Networking Routers and DMZ Hosts

Finally, most home routers also support the ability to configure one internal system as a DMZ Host. In simple terms, a DMZ Host is a computer on your internal network that is completely and fully exposed to and accessible from the Internet. This option is typically used to make it simpler for a system to access multi-player online games or other services where configuring forwarding rules is confusing or cumbersome.

While configuring an internal PC on your network as a DMZ Host will immediately put an end to any port-related connectivity issues, you should also understand that you are effectively “unprotecting” this PC on your network. In other words, the router’s built-in firewall will not protect this system, leaving it susceptible to any and all of the sometimes-harsh dangers of Internet connectivity!