c# - Reverse IP Domain Check?

Question

There is a website which you can query with a domain and it will return a list of all the websites hosted on that IP. I remember there being a method in C# that was something like ReturnAddresses or something of that sort. Does anyone have any idea how this is done? Quering a hostname or IP and having returned a list of hostnames aka other websites hosted on the same server?

the website is: http://www.yougetsignal.com/tools/web-sites-on-web-server/

Answer 1

After reading the comments, bobince is definitely right and these 2 should be used in tandem with each other. For best results you should use the reverse DNS lookup here as well as to use the passive DNS replication.

string IpAddressString = "208.5.42.49"; //eggheadcafe

try 
{
   IPAddress hostIPAddress = IPAddress.Parse(IpAddressString);
   IPHostEntry hostInfo = Dns.GetHostByAddress(hostIPAddress);
   // 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("Host name : " + hostInfo.HostName);
   Console.WriteLine("
Aliases :");
   for(int index=0; index < alias.Length; index++) {
     Console.WriteLine(alias[index]);
   } 
   Console.WriteLine("
IP address list : ");
   for(int index=0; index < address.Length; index++) {
      Console.WriteLine(address[index]);
   }
}
catch(SocketException e) 
{
     Console.WriteLine("SocketException caught!!!");
   Console.WriteLine("Source : " + e.Source);
   Console.WriteLine("Message : " + e.Message);
}
catch(FormatException e)
{
     Console.WriteLine("FormatException caught!!!");
   Console.WriteLine("Source : " + e.Source);
   Console.WriteLine("Message : " + e.Message);
}
catch(ArgumentNullException e)
{
     Console.WriteLine("ArgumentNullException caught!!!");
   Console.WriteLine("Source : " + e.Source);
   Console.WriteLine("Message : " + e.Message);
}
catch(Exception e)
{
    Console.WriteLine("Exception caught!!!");
    Console.WriteLine("Source : " + e.Source);
    Console.WriteLine("Message : " + e.Message);
}

courtesy of http://www.eggheadcafe.com/community/aspnet/2/83624/system-dns-gethostbyaddre.aspx