Windows 7 as WiFi Access Point

OK here is the deal: You have a wired connection to the Internet e.g. in a hotel room but your fancy new smart phone, iPad etc. just has WLAN connection. Until now you had three possibilities:

Use your 3G connection
Use Bluetooth or crappy wired connections
Stay offline, go the hotel bar and get drunk you damn geek!

Well since all modern notebooks do have a WLAN card built in, why not use this card as an access point? The average Linux guy is now really LOLing but for us Windows users this just was a dream. Now Microsoft implemented some nice command line tools to turn your WLAN card into an access point. You can find the information here:

http://blogs.technet.com/b/sieben/archive/2009/09/24/virtual-wifi-macht-windows-7-zum-access-point.aspx

To make the story short the command is:

netsh wlan set hostednetwork mode=allow ssid=”YOUR WLAN” key=”YOUR KEY” keyUsage=persistent

Followed by

netsh wlan start hostednetwork

Since a Windows User is GUI-oriented, i created a small app which does the job for you:

Windows Access Point

as always you can find the source code here:

Windows Access Point Source

The app provides you some nice (undocumented) command line options

start -> Starts the WLAN you entered last
stop -> Stops the WLAN
start route 192.168.0.0 255.255.255.0 172.16.1.0 -> Adds a route after start (e.g. for VPN-Connections)

If you want to make your own app, create two text fields and two buttons and i’ll provide you the methods

private string SetWLAN(string SSID, string key)
{
System.Diagnostics.Process p = new System.Diagnostics.Process();
p.StartInfo.FileName = "netsh.exe";
p.StartInfo.Arguments = "wlan set hostednetwork mode=allow ssid=\"" + SSID + "\" key=\""+ key +"\" keyUsage=persistent";
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.CreateNoWindow = true;
string sOutput;
p.Start();
sOutput = p.StandardOutput.ReadToEnd();
p.WaitForExit();
p.Close();
return sOutput;
}

private string StartWLAN()
{
System.Diagnostics.Process p = new System.Diagnostics.Process();
p.StartInfo.FileName = "netsh.exe";
p.StartInfo.Arguments = "wlan start hostednetwork";
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.CreateNoWindow = true;
string sOutput;
p.Start();
sOutput = p.StandardOutput.ReadToEnd();
p.WaitForExit();
p.Close();
return sOutput;
}

private string StopWLAN()
{
System.Diagnostics.Process p = new System.Diagnostics.Process();
p.StartInfo.FileName = "netsh.exe";
p.StartInfo.Arguments = "wlan stop hostednetwork";
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.CreateNoWindow = true;
string sOutput;
p.Start();
sOutput = p.StandardOutput.ReadToEnd();
p.WaitForExit();
p.Close();
return sOutput;
}

Note: This is just a simple GUI for the NETSH-tool. If you are really interested in serious Virtual Wifi programming check this one out:

http://msdn.microsoft.com/en-us/library/dd815243%28v=vs.85%29.aspx

Singer-Systems