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Chasing DNS Reverse Lookup..

VC#08

I'm trying to take an IP and do a reverse lookup to find the host name. Originally I was using GetHostByAddress, but it fails with "The requested name is valid and was found in the database, but it does not have the correct associated data being resolved for". I drop to command prompt and it works just fine. So after looking a little, I found the API deprecated, so I went to GetHostEntry, but it always returns the IP as the host name. Can someone please tell me what we are too use.

IPAddress hostIPAddress = IPAddress.Parse(address);
//IPHostEntry ipHostEntry = Dns.GetHostByAddress(hostIPAddress);
IPHostEntry ipHostEntry = Dns.GetHostEntry(hostIPAddress);
return ipHostEntry.HostName;

Chizl.com

Looks fine to me!

IPAddress ipAddress = IPAddress.Parse("66.102.9.104");

IPHostEntry ipHostEntry = Dns.GetHostEntry(ipAddress);

Console.WriteLine("{0} is {1}", ipAddress, ipHostEntry.HostName);

output:

66.102.9.104 is lm-in-f104.google.com

My local IP resolves to my machine name

output:

192.168.0.51 is NelsonMandela

However another local machine's name cannot be resolved:

192.168.0.52 is 192.168.0.52

But that other machine's name is not in my local hosts file so I shouldn't be able to determine the host name.

Marked As Answer byReymarx GeredaMSFT, OwnerFriday, September 11, 2009 2:12 PM

Wole Ogunremi

Looks fine to me!

IPAddress ipAddress = IPAddress.Parse("66.102.9.104");

IPHostEntry ipHostEntry = Dns.GetHostEntry(ipAddress);

Console.WriteLine("{0} is {1}", ipAddress, ipHostEntry.HostName);

output:

66.102.9.104 is lm-in-f104.google.com

My local IP resolves to my machine name

output:

192.168.0.51 is NelsonMandela

However another local machine's name cannot be resolved:

192.168.0.52 is 192.168.0.52

But that other machine's name is not in my local hosts file so I shouldn't be able to determine the host name.

Marked As Answer byReymarx GeredaMSFT, OwnerFriday, September 11, 2009 2:12 PM

Wole Ogunremi

I'm on sinus meds today or least that my story and I'm sticking to it.

I didn't realize my host providers DNS has www.chizl.comas the website and chizl.com pointing at my mail server. So they come back with two different IP's andthe reverse lookup on the IP for www.chizl.com comes back with nothing where the one with chizl.com comes back with my hosting provider's name, which seems backwards. I was doing the reverse lookup in the console with chizl.com and using www.chizl.com in the code. Hints the error.

Sorry for taking up your time.

Chizl.com

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