System > System.Net > System.Net.Dns > GetHostByAddress

GetHostByAddress Method

Resolves the host name or IP address associated with the specified IP address.

public static System.Net.IPHostEntry GetHostByAddress(string ipAddress)

Parameters

  • ipAddress: The IP address to resolve.

Returns

  • An IPHostEntry object that contains address information about the host.

Exceptions

Remarks

The GetHostByAddress method performs a DNS query to resolve the hostname associated with the provided IP address. This method is useful for obtaining detailed information about a host, including its host name and aliases, given its IP address. If the IP address cannot be resolved, a SocketException may be thrown.

Example

using System;
using System.Net;

public class DnsExample
{
    public static void Main(string[] args)
    {
        try
        {
            string ipAddress = "8.8.8.8"; // Example: Google Public DNS
            IPHostEntry hostEntry = Dns.GetHostByAddress(ipAddress);

            Console.WriteLine($"Host name for {ipAddress}: {hostEntry.HostName}");

            Console.WriteLine("Aliases:");
            foreach (string alias in hostEntry.Aliases)
            {
                Console.WriteLine($"- {alias}");
            }

            Console.WriteLine("IP Addresses:");
            foreach (IPAddress addr in hostEntry.AddressList)
            {
                Console.WriteLine($"- {addr}");
            }
        }
        catch (ArgumentNullException)
        {
            Console.WriteLine("IP address cannot be null.");
        }
        catch (UnrecognizedIPAddressException)
        {
            Console.WriteLine("The provided string is not a valid IP address.");
        }
        catch (SocketException ex)
        {
            Console.WriteLine($"Socket error occurred: {ex.Message}");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"An unexpected error occurred: {ex.Message}");
        }
    }
}