Turn on (Compatible) WPA/WEP Encryption
All Wi-Fi equipment supports some form of encryption. Encryption technology scrambles messages sent over wireless networks so that they cannot be easily read by humans. Several encryption technologies exist for Wi-Fi today. WEP is not exactly good encryption.

Change the Default SSID
Access points and routers all use a network name called the SSID. Manufacturers normally ship their products with the same SSID set. True, knowing the SSID does not by itself allow your neighbors to break into your network, but it is a start. More importantly, when someone finds a default SSID, they see it is a poorly configured network and are much more likely to attack it. n Enable MAC Address Filtering

Each piece of Wi-Fi gear possesses a unique identifier called the physical address or MAC address. Access points and routers keep track of the MAC addresses of all devices that connect to them. Many such products offer the owner an option to key in the MAC addresses of their home equipment that restricts the network to only allow connections from those devices. Do this, but also know that the feature is not as powerful as it may seem. Hackers and their software programs can fake MAC addresses easily.

Disable SSID Broadcast
In Wi-Fi networking, the wireless access point or router typically broadcasts the network name (SSID) over the air at regular intervals. This feature was designed for businesses and mobile hotspots where Wi-Fi clients may roam in and out of range. In the home, this roaming feature is unnecessary, and it increases the likelihood that someone will try to log in to your home network. Fortunately, most Wi-Fi access points allow the SSID broadcast feature to be disabled by the network administrator.

Do Not Auto-Connect to Open Wi-Fi Networks
Connecting to an open Wi-Fi network such as a free wireless hotspot or your neighbors router exposes your computer to security risks. Although not normally enabled, most computers have a setting available allowing these connections to happen automatically without notifying you (the user).

Assign Static IP Addresses to Devices
Most home networkers gravitate toward using dynamic IP addresses. DHCP technology is indeed easy to set up. Unfortunately, this convenience also works to the advantage of network attackers, who can easily obtain valid IP addresses from your networks DHCP pool. Turn off DHCP on the router or access point, set a fixed IP address range instead, and then configure each connected device to match.

Enable Firewalls on Each Computer and the Router
Modern network routers contain built-in firewall capability, but the option also exists to disable them. Ensure that your routers firewall is turned on. For extra protection, consider installing and running personal firewall software on each computer connected to the router.

Position the Router or Access Point Safely
Wi-Fi signals normally reach to the exterior of a home. A small amount of signal leakage outdoors is not a problem, but the further this signal reaches, the easier it is for others to detect and exploit. Wi-Fi signals often reach through neighboring homes and into streets, for example.

Turn Off the Network During Extended Periods of Non-Use
The ultimate in wireless security measures, shutting down your network will most certainly prevent outside hackers from breaking in! While impractical to turn off and on the devices frequently, at least consider doing so during travel or extended periods offline. Computer disk drives have been known to suffer from power cycle wear-and-tear, but this is a secondary concern for broadband modems and routers.

Source: BSNL Kolkata