User Guide

Chapter 3 Setting Up NetBoot Service 55
Restricting NetBoot Clients by Filtering Addresses
The filtering feature of NetBoot service lets you restrict access to the service based on
the client’s Ethernet hardware (MAC) address. A client’s hardware address is added to
the filter list the first time it starts from an image on the server and is permitted access
by default, so it is usually not necessary to enter hardware addresses manually.
To restrict client access to NetBoot service:
1 Open Server Admin and connect to the server.
2 Click the triangle to the left of the server.
The list of services appears.
3 From the expanded Servers list, select NetBoot.
4 Click Settings, then click Filters.
5 Select “Enable NetBoot/DHCP filtering.”
6 Select “Allow only clients listed below (deny others)” or “Deny only clients listed below
(allow others).”
7 Use the Add (+) and Delete (–) buttons to set up the list of client addresses.
To look up a MAC address, enter the client’s DNS name or IP address in the Host Name
field and click Search.
To find the hardware address for a computer using Mac OS X, look on the TCP/IP pane
of the computer’s Network preference or run Apple System Profiler.
Note: You can also restrict access to a NetBoot image by double-clicking the name of
the image in the Images pane of the NetBoot service settings in Server Admin and
providing the required information.
Setting Up NetBoot Service Across Subnets
A network boot starts by a client computer broadcasting for any computers that will
respond to the Boot Service Discovery Protocol (BSDP). By default, routers are usually
configured to block broadcast traffic to reduce the amount of unnecessary data
flowing to other parts of the network.
To provide NetBoot service across subnets, you must configure the router to pass on
BSDP traffic to the NetBoot server. To see if your router is capable of passing BSDP
traffic, check with your router manufacturer. Sometimes this is also referred to as using
a DHCP helper or a DHCP relay agent.