ASP.NET - Telling the difference between localhost and 127.0.0.1

Question

How can you tell the difference between a request going to 127.0.0.1 and localhost.

This line of code on Windows 7 and VS2010 built-in web server can not tell the difference.

if (Request.ServerVariables["SERVER_NAME"].ToLower() == "localhost")
{

}

try hitting your own built-in web server with: http://127.0.0.1/ and then http://localhost/

Answer 1

Does it matter? Don't you just want to know if the connection is a local connection? I would just use the IsLocal property for this.

if (Request.IsLocal)
{
}

Answer 2

You can actually specify any name as your localhost Server Name (just edit your hosts file for example, and use an arbitrary name)

You probably want to let the machine tell you if it's a local request rather than trying to figure it out for yourself.

Answer 3

Request.Headers will differentiate the requests:

if (Request.Headers["host"].ToLower() == "localhost") 
{ 
  //shouldn't be hit for 127.0.0.1
} 

Note: depending on your needs, you will have to consider clearing off the port number before your check.