Kismet is a free and open Wi-Fi stumbler, packet sniffer, and intrusion detection system for Windows, Mac OS X, Linux, and BSD. It shows the AP details, including the SSID of “hidden” networks. Apart from the paid hotspot gateway, there are many open source captive portal based free solution available. WiFi is most demanding technology today and doing a certain area wifi called hotspot zone. But to make a secure and reliable hotspot zone we required some authentication gateway.

The MAC address is a basic underpinning of how most consumer networks communicate. By changing your NICs MAC address, you are essentially telling the world that the old device no longer exists and that a new device wants to make a connection. There isn't really a way to advertise one MAC address but use another. As far as making it easier, there are. That aside, let's say you want to create an ethernet packet from scratch and send it out into the wild. (While, as pointed out in the comments, wifi is not ethernet, it can be treated as ethernet when it comes to doing these kinds of things.

The documentation talking about constructing ethernet packets apply to wifi as well.) Mostly this means assembling the correct data structures and spitting them out. Doing this on Linux is. Doing this on Windows is. There are some issues with doing this on wifi as opposed to ethernet. The main one is that wifi adapters (especially cheap ones) will often overwrite the source MAC.

Even if you have an enterprise-level Wi-Fi spectrum analyzer, like or, free Wi-Fi tools can also come in handy. You might use them during the planning or installation stages of your wireless LAN, while troubleshooting, or when performing maintenance. They could even serve as your primarily tools in smaller and less-complex environments. Here are several free programs you can use to do Wi-Fi stumbling and surveying on all the popular platforms—Windows, Mac OS X, and Linux. You’ll be able see all the nearby wireless access points (APs) and their details, including channels, signal levels, and MAC address. NetStumbler NetStumbler is one of the oldest and most known Wi-Fi stumblers and runs on Windows and Windows CE/Mobile. It lists nearby APs and displays their basic details: SSID, channel, speed, MAC address, vendor, and encryption.

Unlike most other stumblers, it also shows the signal, noise, and signal-to-noise ratio (SNR) levels. Additionally, it has GPS support to record AP locations when wardriving. Keep in mind, hasn’t been updated since 2004. It may not run well on Windows Vista or 7, or even 64-bit Windows XP. How to add table in latex. Additionally, it doesn’t show the real encryption methods of APs. If an AP has encryption enabled it’s always marked as WEP, regardless if it’s WEP, WPA, or WPA2. NetStumbler can be useful when doing basic signal reading or wardriving, but the limitations I mentioned prevent it from being a go-to tool for other situations, such as when doing a security audit to look for misconfigured or rogue APs.