Part of a Network..
If you are connected to the Internet, you are part of a network. A single computer hard wired to a modem, be it analogue, DSL or cable, is connected to a WAN (Wide Area Network).
Even if you have only one computer, it is a good idea to run the Internet connection through a router. What you get is an inert device between the computer and modem which works a little like a hardware firewall. The IP address of the router will be broadcast rather than the IP address of your network interface card, making it more difficult for a hacker to directly target your computer.
A wireless network allows multiple computers in a location to connect to the Internet and to each other without the need to have trailing network cables across the floors and walls. It is undoubtedly the best way to set up a home network, and most ISPs can supply a modem with router and wireless capability. When considering a wireless network in terms of cost, allow for the installation of signal boosters if each computer on the network is widely spaced, or if you intend to operate a laptop 'al fresco'.
I have always liked to make my own choice of wireless router rather than have whatever the ISP will provide. The downside of doing this is that the ISP will not directly support equipment not supplied by them. The upside was that I got what I thought was the best product regarding performance and support.
Incidentally, when they say that they don't support user purchased equipment, what they really mean is that they don't have the first clue how to set it up.
These days, ISPs will supply a modem which doubles as a wireless router too, and I am presently using a Rogers supplied Hitron CGN2-ROG wireless modem/router. It does the job reasonably well and frees up a socket on the surge protector
Unfortunately, most wireless networks broadcast their signals beyond the confines of your home, so it is important to ensure that you use wireless encryption. The most basic encryption is WEP, and will give you no security in real terms. The best encryption is WPA2. If your present modem/router does not allow for it, you should be looking at upgrading the modem/router firmware or investing in new equipment.
Wireless networks are very popular in homes, especially with laptop users who like to be portable even within the confines of their homes. Desktop machines too can become wireless with the addition of a PCI wireless adapter.
Of course, there is more to home network security than just ensuring that access is encrypted. In order to communicate with other machines on the network, file and printer sharing has to be enabled. The last location you want to share is your C drive in its entirety or even a folder on the drive but, all too often, this is the only location available to be shared.
One way around this is to install a small cheap hard drive as a slave unit and set it as the shared resource. This action will make it more difficult for a bad guy to get in and have a good look around.
I don't want to come across as paranoiac here, but unless you can control what each operator of each machine is doing or can do, your network could be prejudiced by outside forces. Regardless of whatever security is in place, if one of the operators lets a bad guy in, you have a problem.
However, you can opt to grant Internet access to each machine without setting share privileges between machines.
MAC address filtering..
How this works..
Each network adapter, wired or wireless has an identification called a MAC address. It is possible to set up a router such that only known MAC addresses are let in.
This used to be seen as a good security measure, but it is easy to crack Mac address access if you know how.
The best protection is a strong password. This is Microsoft's take on passwords..
Don't forget to password your router too.