Finding All DHCP and DNS servers

Question

I got a client who asked me to find all of his Dhcp and DNS servers with some additional info like DC servers and operationsystem so i decided to try sharpen my powershell skill

Answer 1

This is not too tricky. First off, you connect to a machine with the RSAT Tools installed, like an admin server, jump box, or Domain Controller, and get a list of all DHCP Servers.

$DHCPServers = Get-DhcpServerInDC

Then we use PowerShell's built in looping logic to step through each server, and check for the OS info you need.

ForEach ($DHCPServer in $DHCPServers){
   $OSInfo = Get-CIMInstance -ComputerName $DHCPServer.DnsName -ClassName Win32_OperatingSystem
}

Finally, we'll modify this above to return the info you're looking for, namely the IP Address, Name, and OS Version

ForEach ($DHCPServer in $DHCPServers){
   $OSInfo = Get-CIMInstance -ComputerName $DHCPServer.DnsName -ClassName Win32_OperatingSystem
   [pscustomobject]@{
      ServerName = $DHCPServer.DnsName;
      IPAddress=$DHCPServer.IpAddress;
      OS=$OSInfo.Caption
    }
}

ServerName IPAddress    OS                                    
---------- ---------    --                                    
dc2016     192.168.10.1 Microsoft Windows Server 2016 Standard

From there, you can store it in a variable, make it a spreadsheet, do whatever you need to do.

Hope this helps.

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