Technical data

Appendix B 101
Configuring for a DHCP Server
Setting Up a DHCP Server
INTERFACE_NAME[2]=lan1
IP_ADDRESS[2]=15.1.50.89
SUBNET_MASK[2]=255.255.248.0
BROADCAST_ADDRESS[2]=""
The contents of /etc/rc.config.d/netconf for this definition
block should now look like the following:
INTERFACE_NAME[2]=lan1
IP_ADDRESS[2]=15.1.50.89
SUBNET_MASK[2]=255.255.248.0
BROADCAST_ADDRESS[2]=""
DHCP_ENABLE[2]=1
Correspondingly, you could disable DHCP over a particular interface
by setting the variable to "0".
Again, as in the first method, the system will only begin using DHCP
after the next reboot.
Background
Information on DHCP
Design
The DHCP protocol is implemented as extensions to the BOOTP
protocol, and in fact the HP-UX DHCP server daemon and the BOOTP
daemon are the same (bootpd(1M)). This daemon reads two configuration
files: /etc/bootptab and /etc/dhcptab.
The mapping of systems to IP addresses and lease time information is
kept in the DHCP database file /etc/dhcpdb. Some amount of
management of this database is provided by the dhcptools(1M)
command.
On the client side, a command called /usr/lbin/dhcpclient is used
to contact the server to get an IP address lease. This command has the
ability to broadcast out onto the network prior to the network interface
being enabled.
The dhcpclient also serves as a daemon process that sleeps until the
time that it needs to renew the IP address lease, at which time it will
re-contact the server where it got the original lease in order to extend it.
The dhcpclient command is not intended to be run by users directly,
and is called by other tools during system bootup and installation.