GetHostAddresses Method

Dns.GetHostAddresses Method (String)

 

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.

Exception Condition
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.

System_CAPS_noteNote

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

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);
    }
}

DnsPermission

for accessing DNS information. Associated enumeration: PermissionState.Unrestricted

.NET Framework
Available since 2.0
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