What is a LAN?
LAN stands for “Local Area Network.” Basically, it is a communications link between two or more computers to share information with each other. Although “Local Area” seemingly implies that LANs are always small, this is not always the case. A LAN could possibly consist of thousands of computers provided that they are all connected through the same network connection and are directly linked through hubs and switches. However, once a router becomes involved, the definition of LAN no longer truly applies and you may call a computer connected to another through a router a member of an Internetwork, or if it is part of the main Internetwork, the Internet, and a computer connected to the Internet. The Internet in general can be thought of as a great LAN with all of its members indirectly connected in a giant mesh with each other.
It is important to understand a bit about Networking in order to actually “build” or put together a Local Area Network. Every member of a network possesses an IP address, or a unique identifier of that computer which no other computer or node of the network can use. When a dial-up user connects to the Internet, he or she is either in use of or is dynamically assigned an IP address, which follows the following structure:
xxx.xxx.xxx.xxx
…Where each “xxx” is a three digit number from 0 to 254. For example, 163.56.52.199 is a valid IP address, while 53.275.41.3 is not, because 275 is above 254, which is the range of an IP address.
This number is used on the Internet to specifically identify your computer. However, within a network, you use a special type of IP address. Although this is certainly not the correct terminology, I will refer to this as the “Internal IP” in this guide. I call it this because the Internal IP uses a special format:
192.168.xxx.xxx [most common in LAN's]
or
10.xxx.xxx.xxx [common in large LAN's]
or
172.16.xxx.xxx – 172.31.xxx.xxx [uncommon]
Each of these Internal IP blocks, or groups of addresses, is specifically reserved for Internal IP addresses. What exactly is an Internal IP address? An Internal IP address is the IP address that a computer uses to communicate with other computers or nodes in a network. Think of it as the Office of the President. In the White House, there are many personel that operate inside of it. However, there is only one true outlet – the President and his PR team. In this metaphor, each of the computers in the network is a member of the personel of the White House. Amongst each other, they are free to communicate and all have (somewhat) of their own identity and voice. To the rest of the world (the Internet), however, your computer and all of the others in your network are represented through your WAN Address, or the IP address assigned to you by your Internet Service Provider. In other words, Juan, Joe, and Mike may have the Internal IP addresses 192.168.1.5, 192.168.1.77. and 192.168.1.83; however, when they surf the Internet, they are always represented as their WAN Address 24.54.51.146. To make this point clearer, observe the diagram below.
What equipment is necessary for a LAN?
There are some basic equipment needs for a Local Area Network. These include the communication cards to connect the network plugs into (known as Network Interface Cards, or NICs), the cables to connect between nodes (known as CAT5 cables), the switch to connect all of the nodes to, and the router to connect the switch to the Internet (therefore, indirectly connecting each of the nodes to the Internet). Note that the switch and router are often combined in to a single unit these days.
For the most part, choosing a NIC is rather simple. In many cases your computer or motherboard may already possess one. However, in the case that you need to purchase a NIC, buy a cheap 10/100 NIC (you can find one at many retail outlets for under $20.00) or a nicer 10/100/1000 NIC. The only reason you would possibly want a 10/100/1000 NIC is if you planned on buying one to keep for more than a year or so, and are anticipating your own purchase of a gigabit switch. I would recommend buying a 10/100/1000 NIC if you can, but 10/100 would of course suffice in most circumstances.
Cabling is never a serious issue these days. Just be smart enough to buy one that you know is right for your location (i.e. a five-foot cord won’t suffice in most circumstances, whereas a 1000-foot monster may not be such a great idea for your home LAN).
The main issue at hand is the switch/router. I say this because there are many switch-router combinations each with their own merits. However, for the value, I would highly reccommend the Gigafast or Netgear line of products appropriate for your network size. Something that you must understand is that networks have very little to do in physical configuration and almost everything to do with software and settings. Every switch/router has its own configuration software that is usually based off of the HTTP protocol (or in other words, accessed through a web browser). So, depending on the switch/router you choose, the configuration software for that switch/router will vary.
Physical Setup
Install the NIC in its proper place. If it is a PCI card (which it probably will be), make sure it is in snug.
Make sure that you place the switch/router in a central location such that each of your nodes has easy access to the switch/router. If the RJ-45 plug is connected on both ends, the light on the switch/router should light up under which port you are using. Do NOT place anything in the uplink port.
Power up the switch/router and get ready to rumble.
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