[Answer ID: 14622]
How to: Create Additional Wireless LAN Interface (Professional Firmware)
The wireless virtual interface feature, in the Professional (DD-WRT for Buffalo) firmware can be used to setup more than one Wireless LAN (WLAN) Interface each with its own wireless profile : SSID and encryption method.
To support different WLAN connection security (encryptions such as WEP,and TKIP ) and/or to create an entirely separated WLAN networks for guest with limited connection access to internet only use this feature.
The following is the instruction on how to create additional WLAN virtual interface.
1- Connect PC to router and launch browser to router's management WEB UI.
2- Navigate to the Wireless | Basic Settings Tab .
3- Under, the Virtual Interfaces section click ADD .
4- Assign an SSID and click the Apply Settings button.
5- Next, set wireless security for the new interface. Navigate to the Wireless | Wireless Security Tab .
Select Security mode and select encryption method and set the encryption key.
click the Apply Settings button. Now, the new SSID is ready to be used to access the Wireless LAN network.
To restrict access and a separate Wireless LAN network from existing WLAN/LAN network see this link here.