Technical data

Configuring the DHCP Server
7.7 Configuring DHCP Manually
The ASCII string must have the correct number of digits for the specified
hardware type; for example, twelve digits for a 48-bit Ethernet address. To
improve readability, you can:
Separate the two-digit sequences (bytes) with hyphens (-).
Separate the two-digit sequences (bytes) with periods (.).
Add a 0x prefix to each byte (or only some bytes) of the address.
Add a hyphen between some bytes and 0x prefixes before others.
Add a period between some bytes and 0x prefixes before others.
Examples of valid hexadecimal ASCII strings are:
ha=7F-FF-81-00-0A-47
ha=0X7F0XFF0X81000A47
ha=0X7F-FF0XF8-1000A47
• Booleans and switches
A boolean symbol performs a function just by its presence. A switch is the
value 0 or 1, and it associates one of two functions to those values (usually,
disable and enable, respectively).
:ms=1:\ #This is an example of switch type field
:hn:\ #This is an example of a boolean type field
7.7.2.5 DHCP Configuration Symbols
Table 7–8 describes each DHCP configuration file symbol and indicates whether
you use the symbol in DHCP configuration only or in BOOTP and DHCP
configuration.
Table 7–8 BOOTP/DHCP Configuration File Symbols
Symbol Function Value Format Description
as Maximum
datagram
reassembly size
ASCII integer Specifies the maximum size
datagram that the client should
be prepared to reassemble. The
minimum value is 576.
at ARP cache timeout ASCII integer Specifies the timeout (in seconds) for
ARP cache entries.
ba Broadcast address IP address Specifies the broadcast address in
use on the client’s subnet.
bf Boot file ASCII string Specifies the fully qualified path
name of the client’s default boot
image.
br IP forwarding Boolean Specifies whether the client should
configure its IP layer for packet
forwarding. A value of 0 means
disable IP forwarding, and a value of
1 means enable IP forwarding.
bs Boot file size ASCII integer or
auto
Specifies the length in 512-octet
blocks of the default boot image for
the client.
(continued on next page)
Configuring the DHCP Server 7–53