ASP. NET obtains the Client IP address, user name, and other information.

1. Special attributes in ASP. NET:
Get server computer name: page. server. manchinename
Get user information: page. User
Obtain the client computer name: page. Request. userhostname
Obtain the Client IP Address: page. Request. userhostaddress

2. General methods in network programming:
Get the current computer name: static system. net. DNS. gethostname ()
Retrieve all IP addresses based on the computer name: static system. net. DNS. Resolve (computer name). Addresslist
You can also obtain the computer name static system. net. DNS. Resolve (IP address). hostname Based on the IP address.

3. General attributes of the system environment:
Current computer name: static system. environment. machinename
Domain Name of the current computer: static system. environment. userdomainname
Current computer user: static system. environment. Username

4. If (request. servervariables ["http_via"]! = NULL) {string user_ip = request. servervariables ["http_x_forwarded_for"]. tostring ();
} Else {
String user_ip = request. servervariables ["remote_addr"]. tostring ();
}
5. <% = request. userhostaddress %>

6. Obtain the Client IP Address:

Private string getclientip ()
{
String result = httpcontext. Current. Request. servervariables ["http_x_forwarded_for"];
If (null = Result | result = string. Empty)
{
Result = httpcontext. Current. Request. servervariables ["remote_addr"];
}

If (null = Result | result = string. Empty)
{
Result = httpcontext. Current. Request. userhostaddress;
}
Return result;
}

Obtain the MAC address:

[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 );

Private void page_load (Object sender, system. eventargs E)
{
// Place the user here Code To initialize the page
Try
{
String userip = request. userhostaddress;
String strclientip = request. userhostaddress. tostring (). Trim ();
Int32 ldest = inet_addr (strclientip); // 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 ")
Response. Write ("accessing localhost! ");
Else
Response. Write ("Welcome to friends from" + userip +! "+" <Br> ");
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 ))
{
If (I = 10)
{
Mac_dest = mac_dest.insert (0, mac_src.substring (I, 2 ));
}
Else
{
Mac_dest = "-" + mac_dest.insert (0, mac_src.substring (I, 2 ));
}
}
}

Response. Write ("Welcome to friends from" + userip + "<br>" + "and MAC address" + mac_dest +! "

+ "
");
}< br> catch (exception ERR)
{< br> response. write (err. message);
}< BR >}< br>