This documentation is archived and is not being maintained.

Dns.GetHostByName Method

NOTE: This API is now obsolete.

Gets the DNS information for the specified DNS host name.

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

'Declaration
<ObsoleteAttribute("GetHostByName is obsoleted for this type, please use GetHostEntry instead. http://go.microsoft.com/fwlink/?linkid=14202")> _
Public Shared Function GetHostByName ( _
	hostName As String _
) As IPHostEntry
'Usage
Dim hostName As String 
Dim returnValue As IPHostEntry 

returnValue = Dns.GetHostByName(hostName)

Parameters

hostName
Type: System.String

The DNS name of the host.

Return Value

Type: System.Net.IPHostEntry
An IPHostEntry object that contains host information for the address specified in hostName.

ExceptionCondition
ArgumentNullException

hostName is Nothing.

ArgumentOutOfRangeException

The length of hostName is greater than 126 characters.

SocketException

An error is encountered when resolving hostName.

The GetHostByName method queries the Internet DNS server for host information. If you pass an empty string as the host name, this method retrieves the standard host name for the local computer.

For asynchronous access to DNS information, use the BeginGetHostByName and EndGetHostByName methods.

NoteNote:

This member emits trace information when you enable network tracing in your application. For more information, see Network Tracing.

The following example uses the GetHostByName method to get the DNS information for the specified DNS host name.

Public Sub DisplayHostName(hostName As [String])
    Try 
        ' Call the GetHostByName method, passing a DNS style host name(for example, 
        ' "www.contoso.com") as an argument to obtain an IPHostEntry instance, that  
        ' contains information for the specified host. 

        Dim hostInfo As IPHostEntry = Dns.GetHostByName(hostName)
        ' Get the IP address list that resolves to the host names contained in  
        ' the Alias property. 
        Dim address As IPAddress() = hostInfo.AddressList
        ' Get the alias names of the the addresses in the IP address list. 
        Dim [alias] As [String]() = hostInfo.Aliases

        Console.WriteLine(("Host name : " + hostInfo.HostName))
        Console.WriteLine(ControlChars.Cr + "Aliases : ")
        Dim index As Integer 
        For index = 0 To [alias].Length - 1
            Console.WriteLine([alias](index))
        Next index
        Console.WriteLine(ControlChars.Cr + "IP address list : ")

        For index = 0 To address.Length - 1
            Console.WriteLine(address(index))
        Next index
    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 Exception
        Console.WriteLine("Exception caught!!!")
        Console.WriteLine(("Source : " + e.Source))
        Console.WriteLine(("Message : " + e.Message))
    End Try
try {
   IPHostEntry* hostInfo = Dns::GetHostByName(hostName);
   // Get the IP address list that resolves to the host names contained in the
   // Alias property.
   IPAddress* address[] = hostInfo->AddressList;
   // Get the alias names of the addresses in the IP address list.
   String*  alias[] = hostInfo->Aliases;

   Console::WriteLine(S"Host name : {0}", hostInfo->HostName);
   Console::WriteLine(S"\nAliases : ");
   for (int index=0; index < alias->Length; index++)
      Console::WriteLine(alias->Item[index]);

   Console::WriteLine(S"\nIP address list : ");
   for (int index=0; index < address->Length; index++)
      Console::WriteLine(address->Item[index]);

} catch (SocketException* e) {
   Console::WriteLine(S"SocketException caught!!!");
   Console::WriteLine(S"Source : {0}", e->Source);
   Console::WriteLine(S"Message : {0}", e->Message);
} catch (ArgumentNullException* e) {
   Console::WriteLine(S"ArgumentNullException caught!!!");
   Console::WriteLine(S"Source : {0}", e->Source);
   Console::WriteLine(S"Message : {0}", e->Message);
} catch (Exception* e) {
   Console::WriteLine(S"Exception caught!!!");
   Console::WriteLine(S"Source : {0}", e->Source);
   Console::WriteLine(S"Message : {0}", e->Message);
}

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 1.1, 1.0
Obsolete (compiler warning) in 3.5
Obsolete (compiler warning) in 3.5 SP1
Obsolete (compiler warning) in 3.0
Obsolete (compiler warning) in 3.0 SP1
Obsolete (compiler warning) in 3.0 SP2
Obsolete (compiler warning) in 2.0
Obsolete (compiler warning) in 2.0 SP1
Obsolete (compiler warning) in 2.0 SP2

.NET Compact Framework

Supported in: 1.0
Obsolete (compiler warning) in 3.5
Obsolete (compiler warning) in 2.0
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