如何通过特定的IP地址发送httpwebrequests

Question

昨天，我收到邮件，宣布微型亚马逊EC2实例最多可以有8个IP地址。

比方说，我正在其中一个实例上运行应用程序。我使用httpwebrequest访问网站。我如何控制，请求来自哪个IP？

Answer 1

从this question

HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://stackoverflow.com"); 

req.ServicePoint.BindIPEndPointDelegate = delegate(
ServicePoint servicePoint, 
IPEndPoint remoteEndPoint, 
int retryCount) { 

if (remoteEndPoint.AddressFamily == System.Net.Sockets.AddressFamily.InterNetworkV6) { 
    return new IPEndPoint(IPAddress.IPv6Any, 0); 
} else { 
    return new IPEndPoint(IPAddress.Any, 0); 
} 

}; 

Console.WriteLine(req.GetResponse().ResponseUri);