Set the name of the DHCP scope.

Specify the range of IP addresses that will be issued by this DHCP scope and the subnet mask. In this example, I want to use this DHCP scope for the 192.168.100.0/24 network. Within this network, the DHCP server will assign dynamic IP addresses from the range 192.168.100.50 - 192.168.100.250. In the next window, you can add exclusions to this range (Add Exclusions and Delay).

Next, you need to specify the lease duration of the DHCP client’s IP address (by default, it is 8 days, and you don’t need to change it without special need).

Select that you want to configure additional DHCP scope options.

.

Specify the IP address of the default gateway in the network that should be assigned to clients (in our example, this is 192.168.100.1).

Then specify the domain name and DNS IP server addresses to be propagated to DHCP clients.

It remains to activate the DHCP scope (allow it to serve clients).

DHCP server can assign different settings to clients (except IP address). Scope Options are used for this.

In Windows Server DHCP, you can configure global scope settings or Scope Options for each scope.

We have previously configured three scope options:

• 003 Router
• 006 DNS Server
• 015 DNS Domain Name

Other options can be added (NTP server, PXE settings, etc.).

In the Server Options section of the DHCP server, you can configure global options that will be inherited by all scopes. However, you can override the global settings in the settings of each scope (scope options take precedence over server options).

A single DHCP server can serve hundreds of subnets and VLANs. Thus, you can create multiple scopes on it. The main thing is that a DHCP relay agent must be configured on each of the subnets that forwards broadcast DHCP requests to your DHCP server. In Cisco terms, the DHCP relay is called ip helper. You can even configure DHCP Relay on the Windows Server host.

Configuring IP Address Reservation on a DHCP Server

By default, the DCHP server leases dynamic addresses to clients. This means that the IP address of any client can change. If you want certain devices to always receive the same static IP address from the DHCP server, you can reserve it (for example, for network printers connected to users’ computers).

To create a DHCP reservation, select a scope and go to the Reservation section. Select New Reservation from the menu.

When creating a reservation, you need to specify the IP address you want to assign to the device and its unique MAC address. The MAC address in Windows can be obtained from the results of the ipconfig /all command or by using PowerShell (Get-NetAdapter | select Name, Macaddress). Optionally, you can specify the name and description of the device.

You can also reserve the current dynamic address for a device by finding it in the Address Leases section of the DHCP console. Click on the device and select Add to Reservation.

How to Configure and Manage DHCP Server with PowerShell?

You can perform all the operations for configuring and managing the DHCP server in Windows Server 2019/2016 from the PowerShell console. Let’s take a look at the basic DHCP management commands. The DHCPServer module is used for this. Import the module into the PowerShell session:

Import-Module DHCPServer

You can display a complete list of cmdlets in the DHCP module like this:

Get-Command -Module DHCPServer

Let’s display the list of authorized DHCP servers in Active Directory:

Get-DhcpServerInDC

Get the list of DHCP scopes on the specified server:

Get-DhcpServerv4Scope –ComputerName be-dhcp1

If more scope displayed fields are required (Delay, Description, Name, etc.):

Get-DhcpServerv4Scope –ComputerName be-dhcp1| FL *

If the information about IPv6 scopes has to be displayed:

Get-DHCPServerv6Scope

Get the settings of a certain DHCP scope:

Get-DhcpServerv4Scope –ComputerName be-dhcp1 –ScopeID 192.168.12.0

Let’s create a new inactive DHCP scope with the IP address range from 192.168.113.50 to 192.168.113.250:

Add-DhcpServerv4Scope -Name “NY Branch1 192.168.113.0” -StartRange 192.168.113.50 -EndRange 192.168.113.250 -SubnetMask 255.255.255.0 -State InActive

Set the following DHCP scope options: DNS server, domain, and default gateway address:

Set-DhcpServerv4OptionValue -ScopeID 192.168.113.0 -DnsDomain woshub.com -DnsServer 192.168.13.4 -Router 192.168.113.1

Add exceptions to DHCP scope:

Add-DhcpServerv4ExclusionRange -ScopeID 192.168.113.0 -StartRange 192.168.113.90 -EndRange 192.168.113.100

Activate DHCP scope:

Set-DhcpServerv4Scope -ScopeID 192.168.113.0 -State Active

For convenience, you can use the following PowerShell command when creating a new scope:
$HashArgs = @{
'Name' = 'NY Office Scope';
'Description' = 'Workstations';
'StartRange' = '192.168.120.10';
'EndRange' = '192.168.120.200';
'SubnetMask' = '255.255.255.0';
'State' = 'Active';
'LeaseDuration' = '7.00:00:00';
}
Add-DhcpServerv4Scope @HashArgs

You can add other DHCP server options (e. g., WPAD) as follows:

Add-DhcpServerv4OptionDefinition -ComputerName be-dhcp1 -Name WPAD -OptionId 252 -Type String

You can display a list of configured DHCP server options:

Get-DHCPServerv4OptionValue -ComputerName be-dhcp1 | Format-List

Display a list of configured scope options:

Get-DHCPServerv4OptionValue -ComputerName be-dhcp1 -ScopeId 192.168.12.0 | Format-List

Show the current list of leased IP addresses for the DHCP scope 192.168.12.0:

Get-DHCPServerv4Lease -ScopeId 192.168.12.0 -ComputerName be-dhcp1

Create a DHCP reservation for a client who is assigned a dynamic IP address 192.168.12.88 (convert the leased IP address to a reserved one):

Get-DhcpServerv4Lease -ComputerName be-dhcp1 -IPAddress 192.168.12.88| Add-DhcpServerv4Reservation -ComputerName be-dhcp1

You can perform a bulk reservation of IP addresses for computers listed in a CSV file. To do it, create a text file in the following format:

ScopeId,IPAddress,Name,ClientId,Description
192.168.12.0,192.168.12.88,PC-be-s1,2a-a2-1c-39-42-1f,Reservation PC-be-s1
192.168.12.0,192.168.12.89,PC-be-s2,2a-a2-1c-59-22-2f,Reservation PC-be-s2

Save the file as c:\dhcp\DHCPReservations.csv and run the following command, which will import data from the CSV file and create DHCP reservations for clients:

Import-Csv –Path c:\dhcp\DHCPReservations.csv | Add-DhcpServerv4Reservation -ComputerName be-dhcp1

Deactivate a scope on a DHCP server:

Set-DhcpServerv4Scope -ComputerName be-dhcp1 -ScopeId 192.168.12.0 -State InActive

Remove a scope from a DHCP server:

Remove-DHCPServerv4Scope -ComputerName be-dhcp1 -ScopeId 192.168.12.0 -Force

You can get DHCP server statistics (the number of scopes and reservations, the percentage of used addresses, etc.).

Get-DhcpServerv4Statistics -ComputerName be-dhcp1

The same information for a specific scope can be obtained using the Get-DhcpServerv4ScopeStatistics cmdlet.

DHCP server configuration can be exported to the XML file with the following command:

Export-DHCPServer -ComputerName be-dhcp1 -File C:\dhcp\dhcp-export.xml

Further, these DHCP server settings can be imported (transferred) to another DHCP server:

Import-DHCPServer -ComputerName be-dhcp2 -File C:\dhcp\dhcp-export.xml -BackupPath C:\dhcpbackup\