Technical data
Configuring the DHCP Server
7.7 Configuring DHCP Manually
7.7.2 Modifying the Client Configuration Parameters File
The DHCPCAP. file describes the various configuration parameters for the clients.
This file is similar to the standard
bootptab
file used by most BOOTP servers.
Each entry in the file can describe a single machine (per-node basis) or all the
machines within a subnet (per-subnet basis) or a group of machines (per-group
basis).
7.7.2.1 DHCPCAP Configuration Syntax
The DHCPCAP. configuration file uses two-character, case-sensitive symbols that
represent host parameters. Colons (:) follow and separate parameters from one
another. For example,
gw
specifies gateway. For a list of the available symbols,
see Section 7.7.2.5.
The following is the format of a configuration file entry:
entryname:symbol=value:symbol=value:symbol=value:
In this format:
• entryname is usually the name of the BOOTP or DHCP client.
• symbol is the two-character symbol that describes the parameters to be
associated with the client.
• value is a valid entry that represents the symbol. For more information, see
Section 7.7.2.4.
Example 7–8 shows a sample DHCPCAP file entry.
Example 7–8 Sample Single-Host DHCPCAP File Entry
mypc:\
:ht=ether:\
:ha=112233445566:\
:ip=143.32.3.10:\
:gw=143.32.3.1:\
:dn=acme.com:
7.7.2.2 DHCPCAP Configuration Rules
When you create the DHCPCAP file, entries must conform to the following rules:
• Start each new host entry on a new line. You can make a single entry span
multiple lines by ending each line with a backslash (\).
• Terminate each entry name and each symbol/value pair with a colon (:). For
readability, you can leave blank spaces between symbol/value pairs.
• Enter the entry name in the first field in the configuration file entry.
• Make sure that the host hardware type (
ht
) precedes the host hardware
address (
ha
).
You can delete symbol values associated with a particular client by entering an at
sign (@) immediately following the symbol. For example, gw@.
Both BOOTP and DHCP interpret lines that begin with any of the following as
comments:
• The pound sign (#)
• One or more blank spaces followed by #
Configuring the DHCP Server 7–51