Host name via Dns.GetHostEntry(ip);

[Victor Kulichkin]

Hi,

I have a problem with resolving a host name (via IP) for some hosts. For that operation I use the following method:

            string ip;
            try
            {
               ...
                IPHostEntry iphost = Dns.GetHostEntry(ip);
               ......
            }
            catch (Exception ex)
            {
                MessageBox.Show("Unable to process the request because " +
                    "the following problem occured:" + Environment.NewLine +
                    ex.Message,
                    "Exception for " + ip);
            }

For some hosts I get the exception: "No such host....". However if I replace Dns.GetHostEntry(ip) on Dns.Resolve(ip), then it works well. But I cannot use Resolve() because that method is obsolete.

Ideas?

[boudino]

It seems that GetHostEntry() is ready for IPv6 while Resolve() expects only IPv4. Can this be the difference? Something in net infrastructure?

[Victor Kulichkin]

it is an old problem :

http://msdn.microsoft.com/en-us/library/ms143998.aspx

IPv4 will live long time, I read that 90% of networks use Ipv4.

Perhaps Resolve() uses also the C deprecated functions: gethostbyaddress() and gethostbyname(). MS recommend to replace them on getnameinfo().