Powershell: Get FQDN Hostname

to get the fqdn corresponding to the first IpAddress, it took this command:

```
PS C:\Windows\system32> [System.Net.Dns]::GetHostByAddress([System.Net.Dns]::GetHostByName($env:computerName).AddressList[0]).HostName
WIN-1234567890.fritz.box
```

where `[System.Net.Dns]::GetHostByName($env:computerName).AddressList[0]` represents the first IpAddress-Object and `[System.Net.Dns]::GetHostByAddress` gets the dns-object out of it.

If I took the winning solution on my standalone Windows, I got only:

```
PS C:\Windows\system32> (Get-WmiObject win32_computersystem).DNSHostName+"."+(Get-WmiObject win32_computersystem).Domain
WIN-1234567890.WORKGROUP
```

that's not what I wanted.

(Get-ADComputer $(hostname)).DNSHostName

Here's the method that I've always used:
```
$fqdn= $(ping localhost -n 1)[1].split(" ")[1]
```

If you have more than one network adapter and more than one adapter is active (f.e WLAN + VPN) you need a bit more complex check. You can use this one-liner:

```powershell
[System.Net.DNS]::GetHostByAddress(([System.Net.DNS]::GetHostAddresses([System.Environment]::MachineName) | Where-Object { $_.AddressFamily -eq "InterNetwork" } | Select-Object IPAddressToString)[0].IPAddressToString).HostName.ToLower()
```

How about: `"$env:computername.$env:userdnsdomain"`

This actually *only* works if the user is logged into a domain (i.e. no local accounts), logged into the same domain as the server, and doesn't work with disjointed name space AD configurations.

Use this as referenced in another answer:

$myFQDN=(Get-WmiObject win32_computersystem).DNSHostName+"."+(Get-WmiObject win32_computersystem).Domain ; Write-Host $myFQDN

This worked in PS and PS Core on Windows (Tested on Versions 5.1 and 7.2)
```powershell
[System.Net.Dns]::Resolve($null).HostName
```

# A cleaner format FQDN remotely
[System.Net.Dns]::GetHostByName('remotehost').HostName

Using [Resolve-DNSName](

[To see links please register here]

) command this way works for **PowerShell 5.1** and **7.3** in my case.

```
(Resolve-DnsName -Name 'hostname').Name
```

## Supporting Resource

- [Resolve-DNSName](

[To see links please register here]

)


> **Description**
>
> The `Resolve-DnsName` cmdlet performs a DNS query for the specified
> name. This cmdlet is functionally similar to the nslookup tool which
> allows users to query for names.