Can wireless adapters operate as client access points to make SoftAPs?

Can wireless adapters operate as client access points to make SoftAPs?

My laptop has two wireless adapters: a built-in Intel Pro/Wireless 3945BG and a Linksys Compact Wireless G-USB. Is it possible to connect one of these adapters to an access point (AP)/router and have the other adapter act as an access point?

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Most wireless adapters operate as clients that can be connected in two ways:
  • To another Ad Hoc node (peer client) directly.
  • To an upstream network, through an access point (AP).
SoftAPs in wireless attacks
To learn about the role of SoftAPs in wireless attack "evil twins," read this LiveSecurity article by Lisa Phifer.

However, some adapters can also operate as 802.11 APs, behaving as a wireless bridge or router. For this, you need support in the wireless adapter/driver and a compatible "Soft AP" program. For example, many older wireless adapters known to be compatible with the Linux HostAP driver are listed here Linux wireless LAN drivers. A few USB adapters include Win32 SoftAP programs, such as the ZyXEL AG225H and the ASUS WL-138G.

Neither of your wireless adapters ships with a Soft AP program. However, if you're willing to run Linux on your laptop (or boot your laptop from a Linux live CD like BackTrack) your 3945BG adapter can be used with the MadWiFi driver and HostAP. To learn more, consult the MadWiFi HostAP wiki. This set-up would let you connect your Linksys G-USB as a client to another AP, put your built-in 3945BG into AP mode, and route or bridge traffic between these two wireless adapters.

This was first published in September 2009