• A specific communication domain, such as a network connection or a Unix Interprocess Communication (IPC) pipe


• A specific communication type, such as stream or datagram


• A specific protocol, such as TCP or UDP

Network Addresses

After the socket is created, it must be bound to a network address/port pair. UNIX offers an IP-specific address structure, sockaddr_in , which uses the following elements. Using the sockaddr_in structure requires placing the appropriate IP address and port values in the proper data element.

1. sin_family An address family, defined as a short type


2. sin_port A port number, defined as a short type


3. sin_addr An address, defined as a long type (4-byte) IP address


4. sin_data 8 bytes of padding.

.NET defines two classes in the System.Net namespace to handle various types of IP address information.The classes are IPAddress and IPEndPoint IPAddress object is used to represent a single IP address. This value can be used in the various socket methods to represent the IP address.

IPAddress Methods:-

IPEndPoint: object is used when binding sockets to local addresses, or when connecting sockets to remote addresses. The following two constructors are used to create IPEndPoint instances:

• IPEndPoint (long address , int port )


• IPEndPoint(IPAddress address , int port )

PEndPoint Methods:

Form4.cs

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Net;

namespace _CSharpApplication

{

public partial class Form4 : Form

{

public Form4()

{

InitializeComponent();

}

private void button1_Click( object sender, EventArgs e)

{ //Introduction to IP Addresses.

IPAddress _address1 = IPAddress .Parse( "192.168.1.1" );

IPAddress _address2 = IPAddress .Broadcast;

IPAddress _address3 = IPAddress .Loopback;

IPAddress _address4 = IPAddress .None;

IPAddress _address5 = IPAddress .Any;

IPHostEntry _hostName = Dns .GetHostEntry( Dns .GetHostName());

IPAddress _myMachine = _hostName.AddressList[0];

if ( IPAddress .IsLoopback(_address3))

lstAddresses.Items.Add( "Loopback address is: " + _address3.ToString());

else

lstAddresses.Items.Add( "Error obtaining the LoopbackAddress" );

lstAddresses.Items.Add( "Local IP address is: " + _myMachine.ToString());

if (_myMachine == _address3)

lstAddresses.Items.Add( "Loopback Address Is Same AsLocal Address.\n" );

else

lstAddresses.Items.Add( "The loopback address is not the local address.\n" );

lstAddresses.Items.Add( "Given Address is: " + _address1.ToString());

lstAddresses.Items.Add( "Broadcast address: " + _address2.ToString());

lstAddresses.Items.Add( "ANY address is: " + _address5.ToString());

lstAddresses.Items.Add( "NONE address is: " + _address4.ToString());

}

private void button2_Click( object sender, EventArgs e)

{ //Introduction To IPEndPoint

IPAddress test1 = IPAddress .Parse( "192.168.1.1" );

IPEndPoint _endPoint = new IPEndPoint (test1, 8000);

lstIPEndPoint.Items.Add( "IPEndPoint is ::" + _endPoint.ToString());

lstIPEndPoint.Items.Add( "AddressFamily is ::" +_endPoint.AddressFamily);

lstIPEndPoint.Items.Add( "Address is :: " + _endPoint.Address);

lstIPEndPoint.Items.Add( "Port is :: " + _endPoint.Port);

lstIPEndPoint.Items.Add( "Min port number is :: " + IPEndPoint .MinPort);

lstIPEndPoint.Items.Add( "Max port number is :: " +IPEndPoint .MaxPort);

_endPoint.Port = 80;

lstIPEndPoint.Items.Add( "Changed IPEndPoint is :: " + _endPoint.ToString());

SocketAddress _socketAddress = _endPoint.Serialize();

lstIPEndPoint.Items.Add( "SocketAddress is :: " + _socketAddress.ToString());

}

}}

Output:

Clicking on both the buttons the output will be: