Powershell: Display Errors from Resolve-DnsName - powershell

Question

Good morning,
so i got a bunch of IPs and wanted to get the DNS Name,
so i tried this.
Select-String -Allmatches -pattern '\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}' |% { $_.Matches }| % { $_.Value }| select -Unique| %{Resolve-Dnsname -name $_}
This works, but when i output it to a file i only get the results where he could find an Hostname.
Is there a method to also display the errors.

Answer 1

I would probably do it this way:
Select-String -AllMatches -Pattern '\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}' |
Select-Object -ExpandProperty Matches |
Select-Object -ExpandProperty Value -Unique |
ForEach-Object {
$Resolve = $null
$Resolve = Resolve-DnsName -Name $_ -ErrorAction SilentlyContinue
[PSCustomObject]#{
IP = $_
Name = $Resolve.Name
Type = $Resolve.Type
TTL = $Resolve.TTL
Section = $Resolve.Section
NameHost = $Resolve.NameHost
}
}
You can specify whatever fields you want in the custom object. I have simply included the default properties that Resolve-DnsName outputs to the screen.
In general, Select-Object -ExpandProperty <property> performs better than ForEach-Object { $_.<property> }.
I'm fairly certain the code I have above will work, but there's an outside chance that this:
Select-Object -ExpandProperty Value -Unique |
May need to be this:
Select-Object -ExpandProperty Value |
Select-Object -Unique |