我可以使用.NET Framework从指定的IP地址发送webrequest吗？

I have a server with multi ip addresses. Now I need to communicate with several servers with http protocol. Each server only accept the request from a specified ip address of my server. But when using WebRequest(or HttpWebRequest) in .NET , the request object will choose a ip address automatically. I can't find anyway to bind the request with a address. I have a server with multi ip addresses. Now I