Using Multiple Loopback Addresses for Socket Binding

127.0.0.1 is a reserved IP address that refers to the local machine. It is commonly used for testing and development purposes, allowing applications to communicate with themselves without needing an external network connection. But, the full range of loopback addresses is from 127.0.0.0 to 127.255.255.255 (127.0.0.0/8), which means you can use other addresses in this range for similar purposes.

The following code demonstrates how to bind multiple sockets to different loopback addresses:

var server1 = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
server1.Bind(IPEndPoint.Parse("127.0.0.1:8080"));

var server2 = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
server2.Bind(IPEndPoint.Parse("127.0.0.2:8080"));

var server3 = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
server3.Bind(IPEndPoint.Parse("127.1.0.3:8080"));

So, if you have 2 services that expect to run on the same port (e.g., 8080), you can bind them to different loopback addresses.

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