dhcpdb2conf(1M)

NAME

dhcpdb2conf — convert DHCP client database to config file parameters

SYNOPSIS

dhcpdb2conf [-pac] [-hdirntwu] [-s index] [lan-interfaces]

DESCRIPTION

The dhcpdb2conf command translates a client system's DHCP database parameters (from dhcpclient) into a set of standard configuration file parameters. This is an essential step for configuring a DHCP client system, and is invoked by auto_parms upon every reboot when DHCP is active.

A DHCP client database can contain settings for such items as: hostname, IP address, and default gateway (a subset of the "initial identity parameters" managed by set_parms and geocustoms). You can list the contents of the database to the screen, create a set of configuration staging files, or execute direct edits on existing configuration files using the values contained in the client database.

Arguments: You can provide a list of lan-interfaces on which to operate, such as "lan0 lan1". If you specify no LAN interfaces, dhcpdb2conf processes all entries referenced in the client's DHCP database. The entries are each defined as a unique LAN interface and a corresponding list of attributes.

Options

The following options determine the results of DHCP parameter processing.

-p

Print results to the screen (standard output). This is the default action if neither -a nor -c is specified.

-a

Apply directly: Using the results of the specified filters (see below), directly apply the parameter definitions to the existing configuration files, for example, to /etc/rc.config.d/netconf. (This is how dhcpdb2conf is called from auto_parms.)

-c

Create copies: Create a set of staging files using the results of the selected filters (see below). Each parameter processed is applied to its corresponding copy of one configuration file [re]created by dhcpdb2conf.

For example, /etc/rc.config.d/netconf is copied to /etc/rc.config.d/netconf.dhcp. (If the file already exists and can be written, it is overwritten; otherwise the command fails.) Once this staging file is created, the parameter being processed is applied to the newly created staging file rather than the real configuration file.

The following "filter" options control which parameters are processed. The options can be combined in any manner. The default with no options is to process all attributes for each LAN interface.

-h: Hostname: Process the HOSTNAME parameter.
-d: DNS: Process the DNS parameter set (in /etc/resolv.conf): domain, nameserver.
-i: Interface: Process the INTERFACE parameter set: INTERFACE_NAME[], IP_ADDRESS[], SUBNET_MASK[], BROADCAST_MASK[], LANCONFIG_ARGS[]
-r: Route: Process the ROUTE parameter set: ROUTE_DESTINATION[], ROUTE_GATEWAY[], ROUTE_COUNT[]
-n: NIS: Process the NIS parameter set: NISDOMAIN, YPSET_ADDR
-t: Time: Process the NTPDATE_SERVER parameter.
-w: DHCP_SERVER: Prints the hostname of DHCP SERVER, which has the given IP address for the interface. Options -a or -c have no effect. Option -w will print results only to the screen (standard output).
-u: Hostname: Do not update the HOSTNAME parameter in configuration files. If the -u option is used with -a or -c, then the -h option has no effect.
-s index: Set array index for the set of related parameters for one LAN interface in the configuration files. For example, with -s0 (the default) the output would include INTERFACE_NAME[0]=lan0.

The dhcpdb2conf command can be run only by users with appropriate privileges.

Configuration Files and Parameter Names

The following files, and parameters in each file, can be processed by dhcpdb2conf:

/etc/resolv.conf: domain nameserver
/etc/rc.config.d/netconf: HOSTNAME INTERFACE_NAME[index] IP_ADDRESS[index] SUBNET_MASK[index] BROADCAST_MASK[index] LANCONFIG_ARGS[index] ROUTE_DESTINATION[index] ROUTE_GATEWAY[index] ROUTE_COUNT[index]
/etc/rc.config.d/namesvrs: NISDOMAIN YPSET_ADDR
/etc/rc.config.d/netdaemons: NTPDATE_SERVER

EXAMPLES

List the entire contents of the DHCP client database:

dhcpdb2conf 

List only the INTERFACE parameter set for lan0:

dhcpdb2conf -i lan0 

List the INTERFACE and ROUTE parameter sets for lan0 and lan1:

dhcpdb2conf -ir lan0 lan1 

Apply the INTERFACE and ROUTE parameter sets for lan0 to the existing configuration files:

dhcpdb2conf -ira lan0 

Apply all parameter sets to the existing configuration files using lan0, and set index = 1:

dhcpdb2conf -a -s 1 lan0 

WARNINGS

Using the -a option overrides any existing values which are currently set in the system's configuration files (while the -c option merely revises staging files, if any).

FILES

/usr/lbin/dhcpdb2conf: The command itself.
/etc/dhcpclient.data: Current DHCP parameters received from a DHCP server by dhcpclient.
/etc/resolv.conf[.dhcp]
/etc/rc.config.d/netconf[.dhcp]
/etc/rc.config.d/namesvrs[.dhcp]
/etc/rc.config.d/netdaemons[.dhcp]: System configuration files that can be modified by dhcpdb2conf.

dhcpdb2conf(1M)

Technical documentation

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