System Administration Guide, Volume 1

SPARC: How to Boot a System Over the Network

Any system can boot over the network if there is a boot server available. You might want to boot a standalone system over the network temporarily if it cannot boot from the local disk. See "SPARC: How to Change the Default Boot Device" for information on changing or resetting the default boot device.

There are two network configuration boot strategies to choose from on sun4u systems: RARP (Reverse Address Resolution Protocol and ONC+ RPC Bootparams Protocol) or DHCP (Dynamic Host Configuration Protocol). The default network boot strategy is set to RARP. You can use either one depending on whether a RARP or DHCP boot server is available in your network.


Note -

Sun Ultra systems must have PROM version 3.25 or later to use the DHCP network boot strategy.


If both methods are available, you can specify which service to use in the boot command temporarily, or save the network boot strategy across system reboots at the PROM level, by setting up an NVRAM alias. The following nvalias command example sets 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 will boot using DHCP.


Caution - Caution -

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. See the OpenBoot 3.x Command Reference Manual for information on using these commands.


  1. Determine the method for booting over the network and select one of the following.

    There must be a RARP or DHCP boot server already set up in your network for either of these methods to boot successfully.

    1. Boot the system over the network by using the DHCP method.


      ok boot net[:dhcp]

      If you have changed the PROM setting to boot DHCP by default, like in the nvalias example above, you only have to specify boot net to boot using the DHCP method.

    2. Boot the system over 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.