Any system can boot from the network if there is a boot server available. You might want to boot a standalone system from the network temporarily if the system cannot boot from the local disk. For information on changing or resetting the default boot device, see SPARC: How to Change the Default Boot Device.
Two network configuration boot strategies are available on sun4u systems:
RARP (Reverse Address Resolution Protocol and ONC+ RPC Bootparams Protocol)
DHCP (Dynamic Host Configuration Protocol)
The default network boot strategy is set to RARP. You can use either strategy depending on whether a RARP boot server or a DHCP boot server is available on your network.
Sun Ultra systems must have PROM version 3.25.nn or later to use the DHCP network boot strategy. For information on finding your PROM version, see SPARC: How to Find the PROM Revision for a System.
If both methods are available, you can specify which service to use in the boot command temporarily. Or, you can save the network boot strategy across system reboots at the PROM level, by setting up an NVRAM alias. The following example uses the nvalias command to set up a network device alias for booting DHCP by default on a Sun Ultra 10 system.
ok nvalias net /pci@1f,4000/network@1,1:dhcp
This alias means that when you type boot net, the system boots by using the DHCP network book strategy.
You should not use the nvalias command to modify the NVRAMRC file unless you are very familiar with the syntax of this command and the nvunalias command. For information on using these commands, see the OpenBoot 3.x Command Reference Manual.
If necessary, shut down the system.
Determine the method for booting from the network and select one of the following:
You must have already set up a RARP or DHCP boot server in your network to use either method to boot successfully.
Boot the system from the network by using the DHCP method.
ok boot net[:dhcp]
If you have changed the PROM setting to boot DHCP by default, as in the preceding nvalias example, you only have to specify boot net.
Boot the system from the network by using the RARP method.
ok boot net[:rarp]
Since RARP is the default network boot strategy, you only have to specify boot net:rarp if you have changed the PROM value to boot DHCP.