DHCP options can be used to send additional configuration parameters to the clients. The vendor class ID (DHCP option 60) shows e. g. the type of device. This table allows additional options for DHCP operations to be defined.
LANconfig: TCP/IP / DHCP / DHCP-Options
WEBconfig: LCOS menu tree / Setup / DHCP / Additional options
- Option number
Number of the option that should be sent to the DHCP client. The option
number describes the transmitted information. For example "17" (root
path) is the path to a boot image that a PC without its own hard disk
uses to obtain its operating system via BOOTP.
Possible values:
- Maximum 3 characters.
- Blank
Note: You can find a list of all DHCP options in RFC 2132 – "DHCP Options and BOOTP Vendor Extensions" of the Internet Engineering Task Force (IETF). - Network name
Name of the IP network where this DHCP option is to be used.
Possible values:
- Selection from the list of IP networks defined in the device; max. 16 characters
- Blank
- Type
Entry type. This value depends on the respective option. For option
"35" according to RFC 1232, e.g. the ARP cache time is defined as follows:
ARP cache timeout option
This option specifies the timeout in seconds for ARP cache
entries.
The time is specified as a 32-bit unsigned integer.
The code for this option is 35, and its length is 4.
Code Len Time
+-----+-----+-----+-----+-----+-----+
| 35 | 4 | t1 | t2 | t3 | t4 |
+-----+-----+-----+-----+-----+-----+
This description tells you that this the type "32-bit integer" is
used for this option.
Possible values:
- String, Integer8, Integer16, Integer32, IP address
- String
Note: You can find out the type of the option either from the corresponding RFC or from the manufacturer's documentation of their DHCP options. - Value
This field defines the contents of the DHCP option.
IP addresses are specified with the usual notation for IPv4 addresses,
e.g. as "123.123.123.100", integer types are entered as normal decimal
numbers, and strings as simple text.
Multiple values in a single field are separated with commas, e.g. "123.123.123.100,
123.123.123.200".
Possible values:
- Maximum 128 characters.
- Blank
Note: You can find out the possible length of the option value either from the corresponding RFC or from the manufacturer's documentation of their DHCP options.