Security is the key point of a networks either it is wired network or wireless network, you have to secure your network so that the miscellaneous user’s does not get into your network.
The importance of the data is not the hidden truth, now a days wireless networks are in market and a normal user(s) also uses a WiFi on their home.
Manufacturer provides a router or a Access Point(AP) to get connected into a network, normally when manufacturer makes these devices they stores a default user-name and password on these devices. When you log-in into your device web page by using user-name and password you can change the over all setting of your router. So it is important to change the default user-name and password. You can access your router setting page by typing the gateway IP or router IP normally 192.168.1.1.
MAC Address Filters
MAC (Media Access Control) is the physical or hardware address of the machine (router,computer etc). Access point or router keep track the MAC address of devices, this unique identifier help router to determine which device connect it via wireless. Many manufacturer provides an option to the user to filter out the MAC addresses means restrict other MAC address and allow only few(may be a single) MAC address.