Add check-dns-server.ps1

Scripts/check-dns-server.ps1

@@ -0,0 +1,53 @@
+<#
+.SYNOPSIS
+	Checks DNS server
+.DESCRIPTION
+	This PowerShell script checks the performance of public DNS server.
+.EXAMPLE
+	PS> ./check-dns-server
+.LINK
+	https://github.com/fleschutz/PowerShell
+.NOTES
+	Author: Markus Fleschutz | License: CC0
+#>
+
+function CheckDNS { param($IP, $Name)
+	$StopWatch = [system.diagnostics.stopwatch]::startNew()
+	$null = (nslookup heise.de $IP)
+	[int]$Elapsed = $StopWatch.Elapsed.TotalMilliseconds
+	"                   $IP ($Name) = $Elapsed ms "
+}
+ 
+try {
+	"Checking performance of public DNS server..."
+	CheckDNS 217.237.150.188 "1&1"
+	CheckDNS 217.237.150.33 "1&1"
+	CheckDNS 217.237.150.141 "1&1"
+	CheckDNS 1.1.1.1 Cloudflare
+	CheckDNS 1.0.0.1 Cloudflare
+	CheckDNS 1.1.1.2 "Cloudflare with malware blocklist"
+	CheckDNS 1.0.0.2 "Cloudflare with malware blocklist"
+	CheckDNS 1.1.1.3 "Cloudflare with malware+adult blocklist"
+	CheckDNS 1.0.0.3 "Cloudflare with malware+adult blocklist" 
+	CheckDNS 217.5.100.185 "Deutsche Telekom AG"
+	CheckDNS 217.5.100.186 "Deutsche Telekom AG"
+	CheckDNS 8.8.8.8 Google
+	CheckDNS 8.8.4.4 Google 
+	CheckDNS 4.2.2.1 "Level3 one"
+	CheckDNS 4.2.2.2 "Level3 two"
+	CheckDNS 4.2.2.3 "Level3 three"
+	CheckDNS 4.2.2.4 "Level3 four"
+	CheckDNS 4.2.2.5 "Level3 five"
+	CheckDNS 4.2.2.6 "Level3 six"
+	CheckDNS 9.9.9.9 "Quad9 with malware blocklist, with DNSSEC"
+	CheckDNS 9.9.9.10 "Quad9, no malware blocklist, no DNSSEC"
+	CheckDNS 9.9.9.11 "Quad9, with malware blocklist, with DNSSEC, with EDNS"
+	CheckDNS 9.9.9.12 "Quad9, with malware blocklist, with DNSSEC, NXDOMAIN only"
+	CheckDNS 217.237.151.97 "Telekom München"
+	CheckDNS 217.237.151.161 "Telekom Stuttgart"
+	CheckDNS 217.237.150.141 "Telekom Ulm"
+	exit 0 # success
+} catch {
+	"⚠️ Error in line $($_.InvocationInfo.ScriptLineNumber): $($Error[0])"
+	exit 1
+}