Ignite-UX Administration Guide for HP-UX 11i (B3921-90079, October 2013)

A DHCP server or boot helper system configured to respond
to any DHCP boot request containing PXEClient will
respond to both Itanium-based servers and industry standard
servers. A PXE response suitable for an industry standard
server is unlikely to allow an Itanium-based system to boot.
lease-time How long in seconds the IP address may be used to boot a
system. The example value is 300 seconds (5 minutes) but
you may need more time if your network is a busy one.
Booting on high-traffic networks may take 10 or 15 minutes
since the install kernel and install file system must be
downloaded. The problem with increasing the lease-time
is the possibility of running out of IP addresses to use for
booting. If you increase this number, make sure you have
enough IP addresses in the pool to accommodate systems
that might boot simultaneously.
subnet-mask The subnet mask used by clients.
addr-pool-start-address The first IP address for this address pool.
addr-pool-last-address The last IP address for this address pool.
IMPORTANT: The use of the ncid option is critical because it instructs the DHCP server to exclude
the DHCP class-id in the response to the client’s boot request. If a DHCP server responds to a
PXE boot request with the DHCP class-id in the response, the booting PXE client attempts to
communicate with a PXE proxy server on the same host. Since HP-UX does not supply a PXE proxy
server, the boot fails. The ncid option resolves this issue.
With the device pool group added to the /etc/dhcptab file, your HP-UX 11i v2 or 11i v3
Ignite-UX server is now configured to respond to anonymous Itanium-based clients.
IMPORTANT: The server that sends the response to the PXE boot request is the system that the
PXE client will attempt to tftp the boot file from. If you are not using an HP-UX system to reply to
an Itanium-based PXE request, you must make the required boot files available and current with
new releases of Ignite-UX. HP does not provide support for this kind of configuration.
Isolating Ignite-UX From Noncontrollable DHCP Servers
Once Ignite-UX starts running, a DHCP request will be used to obtain an IP address used for
installation or recovery if needed. Ignite-UX can be configured to specify a class-id for this request.
For more information see Appendix B and bootpd(1M).
If you have DHCP servers on your network that you have no control over, it is possible to completely
isolate Ignite-UX from them. This is done by adding a class-id to the dhcp_class_id keyword
in the install file system. See instl_adm(1M) and instl_adm(4) for additional information.
When the network boot process completes and the install kernel is running, Ignite-UX will use DHCP
again to obtain an IP address. This is done because Ignite-UX has no way to determine the IP
address used by firmware.
If you are running HP-UX 11i v2 or 11i v3 and have configured a DHCP device group for
Itanium-based server PXE requests, you can reuse this device group for isolation purposes. If you
added the following into the install file system:
dhcp_class_id="IgniteDHCPDeviceGroup",
you can change the class-id in the DHCP device group that responds to anonymous
Itanium–based PXE boot requests to read:
class-id="PXEClient:Arch00002|IgniteDHCPDeviceGroup"
Configuring an Ignite Server to Boot Anonymous Itanium-Based Clients 45