FIGURE 19-2 The Add Exclusion dialog box in .NET framework

Printer DataMatrix in .NET framework FIGURE 19-2 The Add Exclusion dialog box

Click Add to create the exclusion. Create any additional exclusions and then click Close when you re nished.

As an alternative to manually setting and managing IP addresses for xed IP devices, such as printers, you can use DHCP to assign an address and con guration settings to the device and then use a DHCP reservation to ensure that the device always gets that address and that no other device or client is assigned that address. Because reservations inherit the Scope options and can be easily modi ed from a single point, it s much better to use a reservation instead of manually setting or managing IP addresses for devices that support DHCP.

efore you can add a reservation to DHCP, you need to know the Media Access Control (MAC) address of the DHCP client you want to make a reservation for.

Although you could read the MAC address off the network device (there s a sticker somewhere on the device with the address), that s hardly easy in most cases. So, how to easily get the MAC address The two ways we know are using the getmac command (available only on Windows Server 2003 and Windows Server 2008) and the ipconfig command. To obtain the MAC address using the ipconfig command, go to the client com-

puter (or make a remote desktop connection) and type ipconfig /all at the command prompt. The MAC address is listed as the physical address. Using ipconfig / all doesn t require elevation. To obtain the MAC address using the getmac command, type the following from a command prompt: r getmac /s computer /v

r Where computer is the IP address, host name, or DNS name of the remote computer you want the MAC address for. Finally, you can obtain the MAC address of any current DHCP client by looking at the current DHCP lease for the client the MAC address is shown in the Unique ID column.

To create a DHCP reservation, complete the following steps:

1. 2. 3.

Open the DHCP console if it isn t already open. In the left pane, expand the containers until you can select Reservations. Select New Reservation from the Action menu to open the New Reservation dialog box shown in Figure 19-3. The elds are as follows:

Reservation Name Usually the DNS name for the device or client. Choose a name that conforms to DNS naming requirements for best compatibility. IP Address The IP address that you are reserving for this device or client. MAC Address The Media Access Control or hardware address of the network card for the device or client. This is a hexadecimal number that is globally unique and is generally printed directly on the device. Description A descriptive phrase that will make it easier to identify the speci c device the reservation is assigned to. Supported Types The choices are Both, DHCP Only, or BOOTP Only. BOOTP is an older protocol for automatically assigning IP addresses and con guration details that is no longer commonly used, but selecting the Both option is the best choice unless you have a speci c reason not to.

Click Add and the reservation is added. The reservation inherits the con guration options that have been set for the DHCP scope, and you can add speci c options for each reservation.

The process for setting DHCP options is essentially the same regardless of the level you set the option at. As described in the Under the Hood sidebar titled DHCP Options Scope earlier in this chapter, each level of DHCP inherits options from the higher level, but can override them. As an example of setting DHCP options, we ll set the Host Name option for the DHCP reservation for our printer. (The printer is assigned a DHCP reservation at 192.168.51.40.) To set the host name for the printer using a DHCP option, use the following steps: