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AddressFamily Enumeration

AddressFamily Enumeration

Specifies the addressing scheme that an instance of the Socket class can use.

Namespace:  System.Net.Sockets
Assembly:  System (in System.dll)

Public Enumeration AddressFamily

Member nameDescription
AppleTalkAppleTalk address.
AtmNative ATM services address.
BanyanBanyan address.
CcittAddresses for CCITT protocols, such as X.25.
ChaosAddress for MIT CHAOS protocols.
ClusterAddress for Microsoft cluster products.
DataKitAddress for Datakit protocols.
DataLinkDirect data-link interface address.
DecNetDECnet address.
EcmaEuropean Computer Manufacturers Association (ECMA) address.
FireFoxFireFox address.
HyperChannelNSC Hyperchannel address.
Ieee12844IEEE 1284.4 workgroup address.
ImpLinkARPANET IMP address.
InterNetworkAddress for IP version 4.
InterNetworkV6Address for IP version 6.
IpxIPX or SPX address.
IrdaIrDA address.
IsoAddress for ISO protocols.
LatLAT address.
MaxMAX address.
NetBiosNetBios address.
NetworkDesignersAddress for Network Designers OSI gateway-enabled protocols.
NSAddress for Xerox NS protocols.
OsiAddress for OSI protocols.
PupAddress for PUP protocols.
SnaIBM SNA address.
UnixUnix local to host address.
UnknownUnknown address family.
UnspecifiedUnspecified address family.
VoiceViewVoiceView address.

An AddressFamily member specifies the addressing scheme that a Socket will use to resolve an address. For example, InterNetwork indicates that an IP version 4 address is expected when a Socket connects to an endpoint.

The following example creates a Socket using the InterNetwork AddressFamily.

Imports System
Imports System.Text
Imports System.IO
Imports System.Net
Imports System.Net.Sockets


Public Class Sample

   Public Shared Function DoSocketGet(server As String) As String 
      'Set up variables and String to write to the server. 
    Dim ASCII As Encoding = Encoding.ASCII
    Dim [Get] As String = "GET / HTTP/1.1" + ControlChars.Lf + ControlChars.NewLine + "Host: " + server + ControlChars.Lf + ControlChars.NewLine + "Connection: Close" + ControlChars.Lf + ControlChars.NewLine + ControlChars.Lf + ControlChars.NewLine
    Dim ByteGet As [Byte]() = ASCII.GetBytes([Get])
    Dim RecvBytes(256) As [Byte]
    Dim strRetPage As [String] = Nothing 

      ' IPAddress and IPEndPoint represent the endpoint that will 
      '   receive the request. 
      ' Get first IPAddress in list return by DNS. 

         ' Define those variables to be evaluated in the next for loop and  
         ' then used to connect to the server. These variables are defined 
         ' outside the for loop to make them accessible there after. 
         Dim s As Socket = Nothing 
         Dim hostEndPoint As IPEndPoint
         Dim hostAddress As IPAddress = Nothing 
         Dim conPort As Integer = 80

         ' Get DNS host information. 
         Dim hostInfo As IPHostEntry = Dns.Resolve(server)
         ' Get the DNS IP addresses associated with the host. 
         Dim IPaddresses As IPAddress() = hostInfo.AddressList

         ' Evaluate the socket and receiving host IPAddress and IPEndPoint.  
      Dim index As Integer = 0
      For index = 0 To IPaddresses.Length - 1
        hostAddress = IPaddresses(index)
        hostEndPoint = New IPEndPoint(hostAddress, conPort)

        ' Creates the Socket to send data over a TCP connection.
        s = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)

        ' Connect to the host using its IPEndPoint.

        If Not s.Connected Then 
          ' Connection failed, try next IPaddress.
          strRetPage = "Unable to connect to host"
          s = Nothing 
          GoTo ContinueFor1
        End If 

        ' Sent the GET request to the host.
        s.Send(ByteGet, ByteGet.Length, 0)

      Next index  ' End of the for loop.

      ' Receive the host home page content and loop until all the data is received. 

      'Dim bytes As Int32 = s.Receive(RecvBytes, RecvBytes.Length, 0) 
      Dim bytes As Int32 = s.Receive(RecvBytes, RecvBytes.Length, 0)

      strRetPage = "Default HTML page on " + server + ":\r\n"
      strRetPage = "Default HTML page on " + server + ":" + ControlChars.Lf + ControlChars.NewLine

      Dim i As Integer 

      While bytes > 0

        bytes = s.Receive(RecvBytes, RecvBytes.Length, 0)

        strRetPage = strRetPage + ASCII.GetString(RecvBytes, 0, bytes)

      End While 

      ' End of the try block. 
    Catch e As SocketException
         Console.WriteLine("SocketException caught!!!")
         Console.WriteLine(("Source : " + e.Source))
         Console.WriteLine(("Message : " + e.Message))
      Catch e As ArgumentNullException
         Console.WriteLine("ArgumentNullException caught!!!")
         Console.WriteLine(("Source : " + e.Source))
         Console.WriteLine(("Message : " + e.Message))
      Catch e As NullReferenceException
         Console.WriteLine("NullReferenceException caught!!!")
         Console.WriteLine(("Source : " + e.Source))
         Console.WriteLine(("Message : " + e.Message))
      Catch e As Exception
         Console.WriteLine("Exception caught!!!")
         Console.WriteLine(("Source : " + e.Source))
         Console.WriteLine(("Message : " + e.Message))
      End Try 

      Return strRetPage
   End Function 'DoSocketGet

   Public Shared Sub Main()
   End Sub 'Main
End Class 'Sample

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8
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