Choose WebClient outgoing IP [duplicate]

Question

My .net app uses WebClient to access files on the internet and my machine has multiple IP addresses. Is there a way to programatically select which IP to use instead of the first IP when making outbound requests? (doesn't have to be WebClient)

Answer 1

One possibility to achieve this is to use the ServicePoint.BindIPEndPointDelegate event and specify which IP address to use.

Example:

var uri = new Uri("YOUR URI");
var servicePoint = ServicePointManager.FindServicePoint(uri);
servicePoint.BindIPEndPointDelegate = (sp, remoteEndPoint, retryCount) =>
{
    var address = IPAddress.Parse("PUT YOUR DESIRED IP HERE");
    return new IPEndPoint(address, 0);
};

Now try making the HTTP request to the corresponding url.

Alternatively if you are using an HttpWebrequest you could assign this per delegate per request:

var request = (HttpWebRequest)WebRequest.Create("YOUR URI");
request.ServicePoint.BindIPEndPointDelegate = (sp, remoteEndPoint, retryCount) =>
{
    var address = IPAddress.Parse("PUT YOUR DESIRED IP HERE");
    return new IPEndPoint(address, 0);
};

using (var response = request.GetResponse())
{
   ...
}