To obtain the MAC of the client, the web server must be in the same lan network segment. Since it is already in the same network segment, the subnet mask and gateway are the same; therefore, you can only obtain the Client IP to Mac conversion process. If the lan mac has registration information, you can determine the user access record.
<% @ Page Language = "C #" DEBUG = "true" %>
<% @ Import namespace = "system. Data" %>
<% @ Import namespace = "system. Data. sqlclient" %>
<% @ Import namespace = "system. runtime. interopservices" %>
<Script language = "C #" runat = "server">
[Dllimport ("iphlpapi. dll")]
Private Static extern int sendarp (int32 DEST, int32 host, ref int64 Mac, ref int32 length );
[Dllimport ("ws2_32.dll")]
Private Static extern int32 inet_addr (string IP );
Void page_load (Object sender, eventargs E)
{
Try
{
String userip = request. userhostaddress;
Int32 ldest = inet_addr (userip); // ip address of the destination
Int32 lhost = inet_addr (""); // ip address of the local server
Int64 macinfo = new int64 ();
Int32 Len = 6;
Int res = sendarp (ldest, 0, ref macinfo, ref Len );
String mac_src = macinfo. tostring ("X ");
If (mac_src = "0 ")
{
If (userip = "127.0.0.1 ")
Userinfo. Text = "accessing localhost! ";
Else
Userinfo. Text = "Welcome to friends from" + userip +! ";
Return;
}
While (mac_src.length <12)
{
Mac_src = mac_src.insert (0, "0 ");
}
String mac_dest = "";
For (INT I = 0; I <11; I ++)
{
If (0 = (I % 2 ))
Mac_dest = mac_dest.insert (0, mac_src.substring (I, 2 ));
}
Userinfo. Text = "Welcome to friends from" + userip + "and" + mac_dest + "for MAC address! ";
}
Catch (exception ERR)
{
Response. Write (ERR. Message );
}
}
</SCRIPT>
<Htm>
<Body>
<Center>
<Asp: Label id = "userinfo" runat = Server> </ASP: Label>
</Center>
</Body>
</Htm>
