Secure your network

Though often overlooked, one of the most crucial security settings that should be changed to help safeguard a network is the default username and password that is used to access the router’s configuration screen. Most manufacturers ship their equipment with standard usernames and passwords, such as admin and password. As this information is freely available online, it is a clear security risk. So, be sure to log into your router and change these settings to something that is harder to guess. Generally, this will involve launching a web browser and typing in the router’s web or IP address. Our Netgear router, for example, is accessed by typing www.routerlogin.net into the browser’s Address or Location bar. If you’re not sure how to access your router’s setup screen, you’ll need to refer to the manufacturer’s instructions.

If the wireless capabilities of the router have not yet been enabled, now is the time to do so. Where this setting is found differs from one router to another, but there should be a section called ‘Wireless settings’ or something similar. If there’s an option to enable and disable the wireless feature, make sure it’s enabled and assign an SSID – this is simply a friendly name for the network. To make the network harder for others to detect, some routers provide the option of not broadcasting the SSID, which should be selected if it’s available. If you only want to use a wired network, you can disable the wireless network on this page and skip to step four.

To help protect data that is transmitted across the network wirelessly, encryption is available in three varieties – WEP, WPA and WPA2 (an even more secure version than WPA). Again the options that are available here will depend on which router is used and what features it supports. Select the level of encryption that should be used from the options displayed, then enter a password. The best security is provided by WPA/WPA2, so select one of these, if available. Do not make the password too short or easy to guess, and try to use a combination of letters and numbers.

All wirelessly networked devices from desktop and notebook computers to media streamers and games consoles have a unique address, which is known as a MAC address (not to be confused with the MAC code required to leave an internet service provider). This information can be used to limit which computers are able to connect to the network. The address of each computer can be found printed on its network card or on the case of the computer itself. Head to the MAC Address Filtering or Access Control section of the router configuration to make sure that this feature is enabled.

MAC address filtering works by allowing only those devices whose MAC addresses are listed to connect to the network. Some routers will automatically display a list of all PCs currently connected and enable you to add them to the permitted list. If this is the case, simply select each of the computers you would like to allow in turn and click on the Add or Allow button. This process may need to be repeated at a later time if other computers that are not currently available also need to be added.

You can also add computers to the permitted list manually by entering the computer name and providing its associated MAC address. Make sure the MAC addresses are entered in the correct format of six pairs of letters or numbers separated by a colon, for example: 01:23:4F:78:1C:45. If an address is entered incorrectly, it may be that one computer is not able to connect to the network until the problem is rectified. Repeat the process as many times as required and save the changes.

Many routers also make it possible to view a list of all of the computers that are connected to the network – be it wirelessly or using traditional network cables. This section of the router configuration may be labelled ‘Attached devices’, ‘Currently connected devices’ or something similar. Additionally, some routers enable you to blacklist computers that are listed as being connected. If this is the case, a Block option will be visible. This should only be used on devices that you are certain are not your own.

While many routers include an integrated firewall, these can be tricky to configure. This is because it is generally necessary to know in advance what type of internet traffic should be blocked and what should be permitted. Windows XP and Vista both include a firewall that offers an extra level of protection and you should check that yours is switched on. In either version of Windows, open the Windows Firewall option in the Control Panel. In Windows XP, select the On option. In Vista you need to click on Change Settings followed by On if it is disabled.

If you’re using the firewall supplied with Windows XP or Vista, it is not essential to install alternative firewall software. However, there are alternatives that are easier to configure. One such tool is ZoneAlarm, which can be downloaded free of charge from the Downloads section on this website. Click the Free download link and save the file to the Windows Desktop. Note that if you don’t want to install an alternative firewall program, just skip to step 12.

Double-click the installation file, select the version of Windows that is being used and click Next before choosing ‘Download and install’ and clicking Next again. There will be a short pause while the required setup files are downloaded and installation begins. Click Next, enter your name and email address, and click Next again. After agreeing to the licence terms, click Next and a few moments later ZoneAlarm will be installed – just click on Finish. Click Yes to launch the program and click No Thanks at the dialogue box that appears.

Make sure that the ‘Scan my computer’ option is selected and click on Next followed by Finish. When prompted, click on OK to restart Windows and when the Windows Desktop reloads, click on Finish to hide the tutorial message. To configure Zone Alarm, just use Windows as you normally would. Whenever a program attempts to connect to the internet or another computer attempts to communicate with yours, Zone Alarm will display a warning message. Tick the box labelled ‘Remember this setting’ and click the Allow or Deny button. In this way, it is possible to block unwanted connections.

Now that a network has been correctly configured and properly secured,you can start sharing files and folders between computers. To do this in Windows XP, right-click a folder and select Sharing and Security. In the lower half of the dialogue, click the link to enable sharing without using a wizard, select ‘Just enable file sharing’ and click OK. Tick the box labelled ‘Share this folder on the network’ and enter a suitable name. If other computers are to be allowed to edit as well as view files, tick the box labelled ‘Allow network users to change my files’ and click OK.

To share files in Vista, the process is very similar and can be achieved in one of two ways. The first option is to right-click a folder and select the Share option. The dropdown menu can then be used to select which users should be allowed access to the folder. To allow users to connect without having to enter a username and password, click the link to visit the Network and Sharing Center and turn off ‘Password-protected sharing’. Shares can also be created by right-clicking, selecting Properties and clicking Advanced Sharing on the Sharing tab. After ticking ‘Share this folder’, permission settings can be configured.

To make it easier to access shared files and folders quickly, a network icon can be added to the Windows Desktop. In Windows XP, right-click the Desktop, select Properties, move to the Desktop tab and click Customize Desktop. Tick the box labelled My Network Places and click OK. In Windows Vista, right-click on the Desktop, select Personalize and then click ‘Change desktop icons’ in the task pane to the right. Tick the Network box and click OK. Double-clicking the newly created icon will display a list of networked computers – double-clicking these icons will display a list of shared files.