What's New in DHCP
Applies To: Windows Server 2012 R2, Windows Server 2012
This topic describes the Dynamic Host Configuration Protocol (DHCP) functionality that is new or changed in Windows Server 2012 R2 and Windows Server 2012.
DHCP is an Internet Engineering Task Force (IETF) standard that is designed to reduce the administrative burden and complexity of configuring hosts on a TCP/IP-based network, such as a private intranet. By using the DHCP Server service, the process of configuring TCP/IP on DHCP clients is automatic.
In this topic:
What’s new in DHCP in Windows Server 2012 R2
In Windows Server 2012 R2, DHCP offers enhanced support in the following areas.
Feature/functionality |
New or improved |
Description |
|---|---|---|
New |
You can use DHCP policies to configure conditions based on the fully qualified domain name (FQDN) of DHCP clients, and to register workgroup computers using a guest DNS suffix. |
|
New |
You can enable DNS registration of address (A) and pointer (PTR) records, or just enable registration of A records. |
|
Improved |
New Windows PowerShell cmdlets are available. |
DNS registration enhancements
DHCP policies have been extended to allow users to configure conditions based on the fully qualified domain name (FQDN) of clients. DHCP policies can also be configured to register DHCP clients using a specific DNS suffix, overriding the DNS suffix that is configured on the client.
Using suitable FQDN-based conditions and a DNS suffix, DHCP policies can be configured to enable full control of DNS registration for computers and devices on the network, including workgroup computers and guest devices, or clients with a specific attribute.
DNS PTR registration options
This feature enables you to configure a DHCP server to register only address (A) resource records of DHCP clients with the DNS server. This can be helpful when a reverse lookup zone has not been configured, causing attempts to register pointer (PTR) resource records to fail. By disabling PTR registration, DHCP servers can be prevented from repeated failed attempts to register PTR records. PTR registration can be disabled for all clients of a DHCP server, or only for clients on a specified subnet or with a specified attribute.
Previously, it was possible to disable DNS registration for a specified group of DHCP clients. However, it was necessary to disable both A and PTR registration.
Windows PowerShell for DHCP server
New Windows PowerShell cmdlets are available in Windows Server 2012 R2. You can use these cmdlets to perform tasks such as creating DHCP security groups, setting DNS credentials, managing superscopes, and managing multicast scopes. Improvements have also been made in existing Windows PowerShell cmdlets for DHCP server to help perform tasks such as changing the mode of a failover relationship and configuring DNS settings for a DHCP policy.
Cmdlet name |
New or improved |
Description |
|---|---|---|
Add-DhcpServerSecurityGroup |
New |
Adds security groups to a DHCP server. |
Add-DhcpServerv4MulticastExclusionRange |
New |
Adds a range of addresses to exclude from a multicast scope. |
Add-DhcpServerv4MulticastScope |
New |
Adds a multicast scope on the DHCP server. |
Add-DhcpServerv4Policy |
Improved |
Adds a new policy either at the server level or at the scope level. This cmdlet can now be used to specify lease duration and also add FQDN-based policies. |
Get-DhcpServerDnsCredential |
New |
Gets an account that the DHCP Server service uses to register or deregister client records on a DNS server. |
Get-DhcpServerv4DnsSetting |
Improved |
This cmdlet can now be used to display DNS settings of DHCP policies. |
Get-DhcpServerv4MulticastExclusionRange |
New |
Retrieves the exclusion range for a specified multicast scope. |
Get-DhcpServerv4MulticastLease |
New |
Retrieves multicast leases for a specified scope name. |
Get-DhcpServerv4MulticastScope |
New |
Gets multicast scope objects. |
Get-DhcpServerv4MulticastScopeStatistics |
New |
Gets multicast scope statistics. |
Get-DhcpServerv4SuperscopeStatistics |
New |
Returns statistics for superscopes. |
Remove-DhcpServerDnsCredential |
New |
Removes the credential that the DHCP Server service uses to register or deregister client records on a DNS server. |
Remove-DhcpServerv4MulticastExclusionRange |
New |
Removes a range of addresses previously excluded from a multicast scope. |
Remove-DhcpServerv4MulticastLease |
New |
Removes one or more multicast scope leases for a specified multicast scope or IP address. |
Remove-DhcpServerv4MulticastScope |
New |
Removes multicast scopes. |
Rename-DhcpServerv4Superscope |
New |
Renames a superscope. |
Repair-DhcpServerv4IPRecord |
New |
Reconciles inconsistent lease records in the DHCP database. |
Set-DhcpServerDnsCredential |
New |
Sets credentials that the DHCP Server service uses to register or deregister client records on a DNS server. |
Set-DhcpServerv4DnsSetting |
Improved |
Configures how the Dynamic Host Configuration Protocol (DHCP) server service updates the DNS server with the client-related information. Ths cmdlet can now be used to set the DNS settings of policies. |
Set-DhcpServerv4Failover |
Improved |
Modifies the attributes of an existing failover relationship. This cmdlet can now be used to change the mode of a failover relationship. |
Set-DhcpServerv4MulticastScope |
New |
Modifies the properties of a multicast scope. |
Set-DhcpServerv4Policy |
Improved |
Sets the properties of an existing policy either at the server level or at the specified scope level. This cmdlet can now be used to set lease duration of a policy and also modify FQDN-based policies. |
For more information, see DHCP Server Cmdlets in Windows PowerShell.
What’s new in DHCP in Windows Server 2012
In Windows Server 2012, DHCP offers enhanced support in the following areas:
DHCP failover
This feature provides the ability to have two DHCP servers serve IP addresses and option configuration to the same subnet or scope, providing for continuous availability of DHCP service to clients. The two DHCP servers replicate lease information between them, allowing one server to assume responsibility for servicing of clients for the entire subnet when the other server is unavailable. It is also possible to configure failover in a load-balancing configuration with client requests distributed between the two servers in a failover relationship. For more information about DHCP failover, see Step-by-Step: Configure DHCP for Failover.
Policy-based assignment
With policy based assignment, the DHCP the server evaluates DHCP requests against policies that you define. Policies are applicable for a specific scope with a defined processing order. Policies applicable at a scope can be configured at the scope or inherited from server wide policies. A single client request can match multiple policies, and policies can be associated with multiple address ranges. For more information about DHCP policy based assignment, see Step-by-Step: Configure DHCP Using Policy-based Assignment.
Windows PowerShell for DHCP Server
Windows Server 2012 provides task-oriented Windows PowerShell cmdlets for DHCP server management. The DHCP server configuration operations are implemented in Windows Server 2012 as Common Information Model (CIM) based cmdlets. Windows PowerShell uses object pipelining to eliminate the need for parsing and manipulation of text output. Windows PowerShell for DHCP Server includes 103 cmdlets, covering multiple aspects of DHCP server configuration and management.