How to Tell If an Outside User Is on Your Wireless...

Wireless security is very important these days. You don't want anyone stealing your bandwidth or getting into your network to perfom mallicious attacks on your computer. This is a guide to help you know when someone else is on your wireless network. Since every wireless router is different, this article will discuss the basics and use one of the most popular wireless routers, the Linksys WAP54G as an example. The steps for your router may differ. This guide assumes you are connected to your router (either through a network cable or over its wireless signal) correctly.
Steps:
1. Open your web browser and input your router's IP address. If you do not know this, refer to your documentation. Default for Linksys products is usually 192.168.1.1, Default for Netgear routers is 192.168.0.1
2. Input your router's username and password. Default for Linksys products is usually username: (blank) password: admin, Default for Netgear routers is Username: admin password: password. Other default UNs and PWs can be found using google.
3. If you are using the default username and password, go to the Administration tab to change it to something more secure.
Finding who is on your network:
1. Navigate to the Setup tab
2. Scroll down until you see 'DHCP Server' if it is enabled, continue to the next step.
3. Click on the Status tab and then on Local Network just below the main tabs.
4. Click the button that says 'DHCP Clients Table'. This list will tell you the computer name of everyone that is connected to your network on DHCP (DHCP automatically configures a computer's IP and DNS settings)
Tips:
1. If you are concerned about people connected to your network, click the Wireless tab then click on Security and enable WEP or WPA (recommended). Everyone that wants to connect will need the WEP or WPA key to connect.
2. If you want to deal with assigning your own IP address, disable the DHCP server on your router. You will have to assign your own internal IP address, but it will keep some people out that do not know your subnet (or how to do it)
3. Use a different subnet. This will keep people guessing if your DHCP server is off. To do this, just change the router's IP address (on the Setup page) to something other than default (192.168.1.1). Try 192.168.0.1 or 10.0.0.1
4. Installing a firewall will HELP prevent hacking to your computer
5. Enable MAC address filtering. Only allow MAC addresses of computers you know.
6. Once you're connected to your network, disable the broadcast option. This will stop the router from broadcasting its name. You will still be able to connect, since you know the name.
Warnings:
1. Make sure you have physical access to your router in case you need to reset it back to factory defaults.