In ASP

ipaddress = Request.ServerVariables("REMOTE_ADDR")

In PHP

$ipaddress = getenv(REMOTE_ADDR);

In ASP.NET

Dim strClientIP As String
strClientIP = Request.UserHostAddress()
Response.Write(strClientIP)

In ColdFussion

<CFCOMPONENT>
<CFSET ipaddress="#CGI.Remote_Addr#">
</CFCOMPONENT>

.NET (C Sharp)

public string IpAddress()
{
return Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
}

.NET (C Sharp)

public string IpAddress()
{
return Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
}

.NET (VB)

Public Function IpAddress()
IpAddress = Request.ServerVariables("HTTP_X_FORWARDED_FOR")
End Function