Tag: domain

Group Policy Object Processing And Precedence

by Samuel Mitchell, posted in Microsoft, windows, Windows server

This article is about the order of processing and precedence of the Group Policy Object (GPO).

There is a acronym used to remember the order of processing:

LSDOU – Local, Site, Domain, OU.

Local GPO

Site linked GPO

Domain linked GPO

Organizational Unit linked GPO

The rule of thumb with precedence for the LSDOU order of processing is that the last GPO applied takes precedence which will be the OU linked GPO. There are additional rules to consider such as when multiple GPOs are applied to an object (e.g. Domain), the GPO are process according to order from top to bottom (1 to …) and the top GPO takes precedence.

Inheriting Parent GPO

In some case there make be nested OUs or Parent and Child domains in which GPOs are inherited from the Parent automatically. The inherited GPOs has the least precedence by default on the child node which can be changed by rearranging the link order.

Enforcing GPO

The precedence of the GPO can change by Enforcing it which will allow it to move to the top (become number 1).

 

Manipulating the DHCP Server using Powershell

by Samuel Mitchell, posted in Microsoft, windows, Windows server

This article will go through the cmdlet to successfully configure DHCP services on a Windows server using Powershell.

Firstly you can start a Powershell session on the DHCP server using the following command: It will prompt for the credential using the Get-Credential command.

Enter-PSSession -ComputerName [DHCPServerName] -Credential (Get-Credential)

Create an IPv4 DHCP Scope for 10.10.10.0 name Ground Floor with range 10-200 on server DC1.domain.com

Add-DhcpServerv4Scope -StartRange “10.10.10.10” -EndRange “10.10.10.200” -SubnetMask “255.255.255.0”-Name “Ground Floor” LeaseDuration [day.hrs:mins:secs]-ComputerName “DC1.domain.com” -Description “Subnet for Data VLAN on Ground Floor” -State [Active/InActive]

Configure the Scope 10.10.10.0 DHCP server DNS, Domain, Gateway, WINS and wpad settings

Add-DhcpServerv4OptionValue -ScopeId 10.10.10.0 -Router 10.10.10.1 -DnsDomain “domain.com” -DnsServer 10.10.10.250 WinsServer 10.10.10.251 -Wpad “http://proxy.domain.com/wpad.dat” -ComputerName “DC1.domain.com”

Note: To configure the options above at the reservation level replace the parameter ReservedIP and for setting it at the server level, exclude both ReservedIP and ScopeId parameters.

Show the DHCP server IPv4 Scope

Get-DhcpServerv4Scope [-ComputerName “DC1.domain.com”] [[-ScopeId] 10.10.10.0]

Change a DHCP Server Scope Settings

Set-DhcpServerv4Scope [-Type [DHCP|Bootp|Both]] [-ScopeId] 10.10.10.0 [-Description “Scope for data vlan for 10.10.10.0“] [-LeaseDuration day.hrs:mins:secs] [-Name “Ground Floor”]  [-ComputerName “DC1.domain.com”]  -StartRange 10.10.0.20  -EndRange 10.10.10.200

Remove a DHCP server IPv4 Scope

Remove-DhcpServerv4Scope [-ScopeId] 10.10.10.0 [-Force] [-ComputerName “DC1.domain.com”]

 

Create a reservation for IP address 10.10.10.100 on DHCP server DC1.domain.com

Add-DhcpServerv4Reservation -ScopeId 10.10.10.0 -IPAddress 10.10.10.100 -ClientId [usually-MAC-address] -ComputerName DC1.domain.com -Description “Reservation for Kiosk PC”

Listing the DHCP Server Scope

Get-DhcpServerv4Scope -ComputerName [DHCPServerName] -ScopeId [IPAddress]

Get the List of DHCP Server Options

Get-DhcpServerv4OptionValue -ScopeId [IPAddress][-All -Brief] -ReservedIP [SpecificIP]

Note: Exclude the ReservedIP parameter to list the values at the scope level and exclude ScopeId parameter to list the values at the server level.

Get the interface and IP address that the DHCP server service is bound

Get-DhcpServerv4Binding -ComputerName “DC1.domain.com”

Set the interface that the DHCP server service will be bound

Set-DhcpServerv4Binding -ComputerName “DC1.domain.com” -BindingState $true -InterfaceAlias “Wired Ethernet Connection”

Set the Boot server Host Name (option id ) for the DHCP server scope of 192.168.0.0 

Set-DhcpServerv4OptionValue -OptionId 3 -Value 192.168.0.1 -ScopeId 192.168.0.0

List the DHCP server IPv4 address lease

Get-DhcpServerv4Lease -ScopeId 10.10.10.0 [-IPAddress 10.10.10.25] [–ClientId 00-00-fe-3e-b0-01] [-BadLeases] [-AllLeases] -ComputerName “DC1.domain.com”

Note: Using the IPAddress parameter return lease for specific IP address. Using the ClientId parameter returns only lease for client mac. Using the BadLeases returns only bad leases. Using the AllLeases parameter includes all leases including Offered, Declined and Expired.

 

Removing a DHCP server IPv4 address lease

Remove-DhcpServerv4Lease -ScopeId 10.10.10.0 [-IPAddress 10.10.10.25] -ClientId [00-54-fe-ed-00] [-BadLeases] [-ComputerName “DC1.domain.com”]

Note: same rule applies as the Get cmdlet for this command.

Get ten (10) Free IP Address from the DHCP server from the scope 10.10.10.0 in the range 10.10.10.50-100

Get-DhcpServerv4FreeIPAddress -ScopeId 10.10.10.0 -NumAddress 10 -StartAddress 10.10.10.50 -EndAddress 10.10.10.100

Add a DHCP Scope of IPv4 Excluded Range

Add-DhcpServerv4ExclusionRange [-ComputerName “DC1.domain.com“] [-ScopeId] 10.10.10.0 [-StartRange] 10.10.10.200 [-EndRange] 10.10.10.250

Show the DHCP Scope of IPv4 Address Excluded Range

Get-DhcpServerv4ExclusionRange [-ComputerName “DC1.domain.com“] [[-ScopeId] 10.10.10.0]

Remove an DHCP Scope of IPv4 Address Excluded Range

Remove-DhcpServerv4ExclusionRange [-ComputerName “DC1.domain.com”] [-ScopeId] 10.10.10.0 [[-StartRange] 10.10.10.200] [[-EndRange] 10.10.10.250]

 

Retrieves the DHCP server scope statistics which includes Free, In Use, Reserved, Pending and Percentage in use IP address

Get-DhcpServerv4ScopeStatistics [[-ScopeId] 10.10.10.0] [-ComputerName “DC1.domain.com”] [-Failover]