DHCP (Dynamic Host Configuration Protocol) is used to automatically assign IP-addresses and other network configuration options to networked computers and devices on a local area network.

To configure a Windows computer to get its IP address from a DHCP server, configure it to "Obtain an IP address automatically" in TCP/IP protocol settings (under network properties).

 

This plug-in is a basic DHCP server which provides IPv4 addresses and related settings to local computers and devices.

 

The DHCP data is also used to serve DNS requests, so when a client computer/device has an active DHCP lease, an A-record and a PTR-record (reverse DNS) are automatically provided for the client's name and IP address through DNS.

This makes it very simple to locate any local DHCP client by name on a local network.

NOTE: DNS data from plug-ins does not override existing local DNS zone data - but does take effect if the requested name does not exist in a local zone.

 

Configuration

 

To setup a new DHCP Server plug-in instance; open the Options dialog / Plug-ins section, select the "DHCP Server" component and click the "Create new instance..." button. This opens the Plug-In Instance dialog for the new DHCP Server plug-in instance.

On the Plug-In Settings tab, the following options are available:

 

 

Specify the range of IP addresses (a.k.a. "DHCP scope") to assign IP addresses to DHCP clients from.

 

Specify the Default Gateway IP address assign to DHCP clients.

 

 

 

Simple DNS Plus automatically assigns itself as the "Preferred DNS server" to DHCP clients.
Optionally use this function to assign "Alternate DNS servers" which DHCP clients should use in case this DNS server becomes unavailable.

 

Reserve IP addresses for specific computers based on computer name or hardware address (network card MAC address).
To determine a computers hardware address, on Windows 95/98/Me, run "WINIPCFG" (from Start menu -> Run), select the correct adapter (network card), and see "Adapter Address". On Windows NT4/2000 and later, run "IPCONFIG /ALL" from a command prompt, and see "Physical Address".

 

If your server computer is connected to multiple local networks, you can use multiple DHCP server plug-in instances.

 

Main window View

 

The DHCP Server plug-in also has a view in the main Simple DNS Plus window (open from View menu), where you can see current and optionally expired DHCP leases.

This shows DHCP leases with each computer's name, IP-address, Hardware address, and when its lease expires.

The columns can be sorted by clicking the column headers.

 

To manually delete a DHCP lease, right click on the lease and select "Delete" from the pop-up menu. In order to prevent IP-address conflicts (two or more computers having the same address), it is very important that the computer for the deleted lease is also rebooted or removed from the network.

Generally, it is not necessary to delete leases manually, as computers automatically release their leases when shut down properly.

 

Older Apple/Mac clients and some devices which do not supply a computer name in the DHCP request will show with their hardware address as the name.

To rename these, right click on the lease and select "Rename". The new name will be associated with the client's hardware address (MAC), and remembered as long as you run Simple DNS Plus even if the IP address changes.