How do I find the fully qualified hostname of my machine in C#? [duplicate]

Answer 1

If the above doesn't work, you can also try retrieving it from the environment:

var dnsName = new StringBuilder();
dnsName.Append(Environment.GetEnvironmentVariable("COMPUTERNAME")).Append(".");
dnsName.Append(Environment.GetEnvironmentVariable("USERDNSDOMAIN"));

Answer 2

You may be able to get the whole DNS string like this:

System.Net.Dns.GetHostEntry("").HostName

We don't have full fledged DNS names where I work, but it does give me a three level faux domain name instead of just the hostname.

Edit 2011/03/17: Incorporated changes suggested by mark below.

Answer 3

I used this very similar method:

var serverName = System.Environment.MachineName; //host name sans domain
var fqhn = System.Net.Dns.GetHostEntry(serverName).HostName; //fully qualified hostname