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Dns.GetHostAddresses Method

Returns the Internet Protocol (IP) addresses for the specified host.

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

public static IPAddress[] GetHostAddresses(
	string hostNameOrAddress
)

Parameters

hostNameOrAddress
Type: System.String
The host name or IP address to resolve.

Return Value

Type: System.Net.IPAddress[]
An array of type IPAddress that holds the IP addresses for the host that is specified by the hostNameOrAddress parameter.

ExceptionCondition
ArgumentNullException

hostNameOrAddress is null.

ArgumentOutOfRangeException

The length of hostNameOrAddress is greater than 255 characters.

SocketException

An error is encountered when resolving hostNameOrAddress.

ArgumentException

hostNameOrAddress is an invalid IP address.

The GetHostAddresses method queries a DNS server for the IP addresses associated with a host name. If hostNameOrAddress is an IP address, this address is returned without querying the DNS server.

When an empty string is passed as the host name, this method returns the IPv4 addresses of the local host for all operating systems except Windows Server 2003; for Windows Server 2003, both IPv4 and IPv6 addresses for the local host are returned.

IPv6 addresses are filtered from the results of the GetHostAddresses method if the local computer does not have IPv6 installed. As a result, it is possible to get back an empty IPAddress instance if only IPv6 results where available for the hostNameOrAddress.parameter.

NoteNote

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

The following code example uses the GetHostAddresses method to resolve an IP address to an array of type IPAddress.


public static void DoGetHostAddresses(string hostname)
{
    IPAddress[] ips;

    ips = Dns.GetHostAddresses(hostname);

    Console.WriteLine("GetHostAddresses({0}) returns:", hostname);

    foreach (IPAddress ip in ips)
    {
        Console.WriteLine("    {0}", ip);
    }
}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

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