Check for DNS record using PowerShell 2.0 - powershell

Question

What could be the best way to resolve a computer name apart from using:
[System.Net.DNS]::GetHostByName('MachineName').HostName
I dont want to import any specific DNS Modules.

Answer 1

You can try the GetHostEntry method:
[Net.DNS]::GetHostEntry("MachineName")
Another way would be to ping it using Test-Connection cmdlet, see this tip

Answer 2

I was in a case where I had to query a specific DNS server, which is not possible directly with .net / powershell. So I ended up with using the good old nslookup :
$client="10.110.10.10"
$ns="10.20.1.10"
(nslookup $client $ns |sls name).toString().split(":")[1].trim()

Answer 3

The following 2 ways to resolve IP's to DNS addresses are the only ones.
It's how you use it that counts.
[Net.DNS]::GetHostEntry("MachineName")
[System.Net.DNS]::GetHostByName('MachineName').HostName
Like I said, It's how you use them.
I have written a script for doing just this.
It takes a list of IP addresses and resolves there DNS.
Later in the script it converts the output to an excel sheet, showing you the results.
Based upon filters you can set the layout.
Now I know not all IP's will be resolved with these methods, that's why I included a function in my script that filters out unresolved IP's and places them to the bottom of the excel sheet.
(Giving every IP a direct link to who.is/whois/ipadress
Here's the script, íf you are interested.
#Get current date
$Date = date -format yyyy-MM-dd
$Company = "Company"
$Company2 = "Company2"
########################
#Define all Paths.
$Path = "C:\inetpub\wwwroot\BlockedIP" #This is where your file's will be saved.
md "$Path\HTML\$Date" -Force |Out-Null
$path2 = "$Path\HTML\$Date"
$PathWeb = "/ResolvedIp/HTML/$Date"
########################
#Define File's used or created in this script.
$File = "$Path\IP-$Date.txt"
$FileHtml = "$Path2\IP-$Date.htm"
$FileXML = "$Path\IP-$Date.xlsx"
$FileHTMLWeb = "$PathWeb\IP-$date.htm"
######################################
#Define error actions.
$erroractionpreference = "SilentlyContinue"
###########################################
#Since the script used COM objects it will need the following 2 folders:
#(32Bit)
MD "C:\Windows\System32\config\systemprofile\Dektop" -force
MD "C:\Windows\System32\config\systemprofile\AppData\Local\Microsoft\Windows\Temporary Internet" -force
#(64Bit)
MD "C:\Windows\SysWOW64\config\systemprofile\Desktop" -force
MD "C:\Windows\SysWOW64\config\systemprofile\AppData\Local\Microsoft\Windows\Temporary Internet" -force
#Once successfull the script will run without a problem if scheduled.
cls
(gc $File) | ? {$_.trim() -ne "" } | set-content $File
$IPCount = (gc $File)
$IPCount = $IPCount.count
write "$IPCount unique IP addresses detected."
#Define error actions.
$erroractionpreference = "SilentlyContinue"
#Get content from given IP list.
$colComputers = #(gc $File | sort |Select -unique)
$SourceCount = $colComputers.Count
write "$SourceCount IP's detected."
Function Set-KnownIPs{
Param([Object]$DNSLookupObject)
Switch($DNSLookupObject){
{$_.Source -Match "(108.162.254|141.101.(?:104|105)|199.27.128|173.245(?:53|52|51))"}{$_.HostName = "CloudFlare, Inc."}
{$_.Source -Match "(64.18.[0-18])"}{$_.HostName = "Google, Inc."}
{$_.Source -Match "(192.168|127.0.0)"}{$_.HostName = "Internal Infrastructure"}
}
$DNSLookupObject
}
#Get DNS Results
$Progress=1
$DNSResults = $colComputers | %{
Write-Progress -Activity "Creating a usable 'Blocked IP' list ($Progress/$sourcecount)" -PercentComplete ($Progress/$sourceCount*100) -Status "Please stand by"
try {
($dnsresult = [System.Net.DNS]::GetHostEntry($_))
}
catch {
$dnsresult = "Fail"
}
Set-KnownIPs -DNSLookupObject ([PSCustomObject][Ordered]#{
Source=$_.ToUpper()
HostName=$(if(!([string]::IsNullOrEmpty($dnsresult.HostName))){$dnsresult.HostName})
IPAddress=$(if(!([string]::IsNullOrEmpty($dnsresult.AddressList))){$dnsresult.AddressList[0].ToString()})
})
$Progress++
}
$Keywords = #("Google","Cloudflare","Cloud","Ping",
"Easy-Voyage","McAfee","Pingdom","Panopta","Scoot","Uniglobe",
"Internal")
$Filter = "($(($Keywords|%{[RegEx]::Escape($_)}) -join "|"))"
$DNSLookupFailed = $DNSResults |
?{[string]::IsNullOrEmpty($_.HostName) -and !($_ -match $filter)}
$DNSWithKeyword = $DNSResults |
?{$_ -match $Filter}
$DNSNoKeyword = $DNSResults |
?{!($_.HostName -match $Filter) -and !([string]::IsNullOrEmpty($_.IPAddress))}
#$count = ($DNSResults|?{$_ -match $filter}).count
$count = $SourceCount
#####################
#start Excel.
$a = New-Object -comobject Excel.Application
# set interactive to false so nothing from excel is shown.
$a.DisplayAlerts = $False
$a.ScreenUpdating = $True
$a.Visible = $True
$a.UserControl = $True
$a.Interactive = $True
###########################
#Create sheets in Excel.
$b = $a.Workbooks.Add()
$c = $b.Worksheets.Item(1)
$c.Activate() | Out-Null
#Create a Title for the first worksheet and adjust the font
$c.Cells.Item(1,1)= "Blocked IP's $Date"
$c.Cells.Item(1,1).Font.ColorIndex = 55
$c.Cells.Item(1,1).Font.Color = 8210719
$c.Cells.Item((3+$DNSWithKeyword.Count+1),1) = "IP's not in whitelist"
$c.Cells.Item((3+$DNSWithKeyword.Count+1),1).Font.ColorIndex = 55
$c.Cells.Item((3+$DNSWithKeyword.Count+1),1).Font.Color = 8210719
$c.Cells.Item((3+$DNSWithKeyword.Count+$DNSNoKeyword.Count+3),1)= "IP's without DNS return"
$c.Cells.Item((3+$DNSWithKeyword.Count+$DNSNoKeyword.Count+3),1).Font.ColorIndex = 55
$c.Cells.Item((3+$DNSWithKeyword.Count+$DNSNoKeyword.Count+3),1).Font.Color = 8210719
#######################################
$range = $c.Range("a1","e1")
$range.Style = 'Title'
$range.Select()
$range.MergeCells = $true
$range.VerticalAlignment = -4108
################################
$Linkedin = "https://www.linkedin.com/profile/view?id=96981180" #Look me up! :D
#Define row to be used for linkedin link.
$CounterRow = $Count+5
######################
#Define subjects.
$c.Name = "Blocked IP's ($Date)"
$c.Cells.Item(2,1) = "Given IP"
$c.Cells.Item(2,2) = "Resolved DNS"
$c.Cells.Item(2,3) = "Returned IP"
$c.Cells.Item(2,5) = "$Company"
$c.Cells.Item((3+$DNSWithKeyword.Count+$DNSNoKeyword.Count+$DNSLookupFailed.Count+5),1) = "Created by"
########################################
$link = "http://www.$Company"
$link2 = "$Linkedin"
$r = $c.Range("E2")
[void]$c.Hyperlinks.Add($r, $link)
$r = $c.Range("A$(3+$DNSWithKeyword.Count+$DNSNoKeyword.Count+$DNSLookupFailed.Count+5)")
[void]$c.Hyperlinks.Add($r, $link2)
###################################
#Define cell formatting from subjects.
$c.Range("A2:E2").Interior.ColorIndex = 6
$c.Range("A2:E2").font.size = 13
$c.Range("A2:E2").Font.ColorIndex = 1
$c.Range("A2:E2").Font.Bold = $True
###################################
#Define the usedrange, excluding header and footer rows
$KeyRange = $c.Range("A3:c$(3+$DNSWithKeyword.Count)")
$NoKeyRange = $c.Range("A$(3+$DNSWithKeyword.Count+2):c$(3+$DNSWithKeyword.Count+$DNSNoKeyword.Count+2)")
$NoDNSRange = $c.Range("A$(3+$DNSWithKeyword.Count+$DNSNoKeyword.Count+4):c$(3+$DNSWithKeyword.Count+$DNSNoKeyword.Count+$DNSLookupFailed.Count+4)")
$SheetRange = $c.Range("A3:e$(4+$DNSWithKeyword.Count+$DNSNoKeyword.Count+$DNSLookupFailed.Count+4)")
$Investigate = $c.Range("c$(3+$DNSWithKeyword.Count+$DNSNoKeyword.Count+4):c$(3+$DNSWithKeyword.Count+$DNSNoKeyword.Count+$DNSLookupFailed.Count+4)")
################################
#Set background color for the IP list.
$SheetRange.interior.colorindex = 6
$KeyRange.interior.colorindex = 4
$NoKeyRange.interior.colorindex = 15
$NoDNSRange.interior.colorindex = 8
####################################
#Populate data into spreadsheet
$DNSWithKeyword | Select Source, HostName, IPAddress | Sort HostName -Descending |
ConvertTo-Csv -Delimiter "`t" -NoTypeInformation |
Select -Skip 1 | Clip
$c.Paste($KeyRange,$false)
$DNSNoKeyword | Select Source, HostName, IPAddress | Sort HostName -Descending |
ConvertTo-Csv -Delimiter "`t" -NoTypeInformation |
Select -Skip 1 | Clip
$c.Paste($NoKeyRange,$false)
$DNSLookupFailed | Select Source, HostName, IPAddress | sort Source -Descending|
ConvertTo-Csv -Delimiter "`t" -NoTypeInformation |
Select -Skip 1 | Clip
$c.Paste($NoDNSRange,$false)
############################
ForEach($Cell in $Investigate){
If([String]::IsNullOrWhitespace($Cell.value2)){
$Cell.Item($_) = "N/A"
[void]$cell.Hyperlinks.Add($Cell)
}
}
###########################################################################
#Define borders here.
$xlOpenXMLWorkbook = 51
$xlAutomatic=-4105
$xlBottom = -4107
$xlCenter = -4108
$xlRight = -4152
$xlContext = -5002
$xlContinuous=1
$xlDiagonalDown=5
$xlDiagonalUp=6
$xlEdgeBottom=9
$xlEdgeLeft=7
$xlEdgeRight=10
$xlEdgeTop=8
$xlInsideHorizontal=12
$xlInsideVertical=11
$xlNone=-4142
$xlThin=2
#########
$selection = $c.range("A2:C$(1+$DNSResults.Count-9)")
$selection.select() |out-null
$selection.HorizontalAlignment = $xlRight
$selection.VerticalAlignment = $xlBottom
$selection.WrapText = $false
$selection.Orientation = 0
$selection.AddIndent = $false
$selection.IndentLevel = 0
$selection.ShrinkToFit = $false
$selection.ReadingOrder = $xlContext
$selection.MergeCells = $false
$selection.Borders.Item($xlInsideHorizontal).Weight = $xlThin
#############################################################
#Define the usedrange for autofitting.
$d = $c.UsedRange
#################
#Make everything fit in it's cell.
$d.EntireColumn.AutoFit() | Out-Null
####################################
$c.usedrange | Where{$_.Value2 -match "(\b(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b)"} |
ForEach{$IPLink = "http://who.is/whois-ip/ip-address/$($Matches[1])";[void]$c.Hyperlinks.Add($_, $IPLink)}
#Define html code for Excel save to .htm.
$xlExcelHTML = 44
#################
#Save final result as an .xlsx file.
$b.SaveAs("$FileXML")
#####################
#Save final result as a .htm file
$b.SaveAs("$FileHTML",$xlExcelHTML)
###################################

Answer 4

In powershell 5.1 you can use
Resolve-DnsName