PowerShell/scripts/list-dns-servers.ps1
2024-03-24 12:23:40 +01:00

42 lines
1.4 KiB
PowerShell
Executable File

<#
.SYNOPSIS
Lists DNS servers
.DESCRIPTION
This PowerShell script measures the latency of public and free DNS servers and lists it.
.EXAMPLE
PS> ./list-dns-servers.ps1
Provider IPv4 Latency
-------- ---- -------
AdGuard DNS (Cyprus) 94.140.14.14 / 94.140.15.15 222 / 205 ms
...
.LINK
https://github.com/fleschutz/PowerShell
.NOTES
Author: Markus Fleschutz | License: CC0
#>
function CheckDNSServer { param($Provider, $IPv4Pri, $IPv4Sec)
$SW=[system.diagnostics.stopwatch]::startNew();$null=(nslookup fleschutz.de $IPv4Pri 2>$null);[int]$Lat1=$SW.Elapsed.TotalMilliseconds
$SW=[system.diagnostics.stopwatch]::startNew();$null=(nslookup fleschutz.de $IPv4Sec 2>$null);[int]$Lat2=$SW.Elapsed.TotalMilliseconds
New-Object PSObject -Property @{ Provider=$Provider; IPv4="$IPv4Pri / $IPv4Sec"; Latency="$Lat1 / $Lat2 ms" }
}
function List-DNS-Servers {
Write-Progress "Loading data/public-dns-servers.csv..."
$table = Import-CSV "$PSScriptRoot/../data/public-dns-servers.csv"
Write-Progress -completed "Done."
foreach($row in $table) { CheckDNSServer $row.PROVIDER $row.IPv4_PRI $row.IPv4_SEC }
}
try {
List-DNS-Servers | Format-Table -property @{e='Provider';width=50},@{e='IPv4';width=32},@{e='Latency';width=15}
exit 0 # success
} catch {
"⚠️ Error in line $($_.InvocationInfo.ScriptLineNumber): $($Error[0])"
exit 1
}