Tag: DNS

Perform an NSLookup in PowerShell to find the IP Address(es) tied to a hostname

Scenario:  You want to perform an NSLookup in PowerShell so you can use the multiple IP addresses that you are using for DNS Round Robin in another PowerShell Query.

Solution: Run the following:

#Collect the IP Addresses of the hostname into a variable
$address = [system.net.dns]::GetHostAddresses("mail.domain.com" | Select IPAddressToString)

#For Each Loop it with a command
$address | Select -expandproperty IPAddressToString | %{ Get-ADComputer $_ }

 

Determine TTL on a DNS record

Scenario:  You changed an IP address on a DNS record and you want to determine the TTL (Time to Live) value of the DNS record to figure out when this DNS record will become refreshed.

Solution: Run the following NSLookup command with the -type=soa record against the DNS name you wish to determine TTL.

nslookup -type=soa http://www.google.com

 

Determine the IP Address and check to see if a PTR record exists for each Exchange Server

Scenario:  You want to determine the IP Address and PTR record for each Exchange Server in your environment.   Below is the script I used.  This will query for DNS and put the results into a table called $final.

Script:

$servers = get-exchangeserver ex2013* | Where AdminDisplayVersion -like *15*

$final = @()

$Servers | %{ 
write-host $_.Name
$Name = ([System.Net.Dns]::GetHostEntry("$_")).HostName;
$Address = ([System.Net.Dns]::GetHostEntry("$_")).AddressList;
$PTR = ([System.Net.Dns]::GetHostByAddress($Address)).HostName

$returnobj = new-object psobject
$returnobj |Add-Member -MemberType NoteProperty -Name "ServerName" -Value $Name
$returnobj |Add-Member -MemberType NoteProperty -Name "IPAddress" -Value $Address
$returnobj |Add-Member -MemberType NoteProperty -Name "PTR" -Value $PTR
$final += $returnObj

$Name = $null
$address = $null
$ptr = $null


}

$final