option
Use option to customize a DHCP option.
Use undo option to remove a customized DHCP option.
Syntax
option code { ascii ascii-string | hex hex-string | ip-address ip-address&<1-8> }
undo option code
Default
No DHCP option is customized.
Views
DHCP address pool view
Predefined user roles
network-admin
Parameters
code: Specifies the number of the customized option, in the range of 2 to 254, excluding 50 through 54, 56, 58, 59, 61, and 82.
ascii ascii-string: Specifies an ASCII string of 1 to 255 characters as the option content.
hex hex-string: Specifies a hexadecimal string of even numbers from 2 to 256 as the option content.
ip-address ip-address&<1-8>: Specifies the IP addresses as the option content. &<1-8> indicates that you can specify up to eight IP addresses separated by spaces.
Usage guidelines
The DHCP server fills the customized option with the specified ASCII string, hexadecimal string, or IP addresses, and sends it in a response to the client.
If you use the option command with the same code specified, the most recent configuration takes effect.
You can customize options for the following purposes:
Add newly released options.
Add options for which the vendor defines the contents, for example, Option 43.
Add options for which the CLI does not provide a dedicated configuration command. For example, you can use the option 4 ip-address 1.1.1.1 command to define the time server address 1.1.1.1 for DHCP clients.
Add all option values if the actual requirement exceeds the limit for a dedicated option configuration command. For example, the dns-list command can specify up to eight DNS servers. To specify more than eight DNS server, you must use the option 6 command to define all DNS servers.
If a DHCP option is specified by both the dedicated command and the option command, the DHCP server assigns the content specified by the dedicated command. For example, if a DNS server address is specified by the dns-list command and the option 6 command, the server uses the address specified by dns-list command.
Examples
# Configure Option 7 to specify the log server address 2.2.2.2 in address pool 0.
<Sysname> system-view [Sysname] dhcp server ip-pool 0 [Sysname-dhcp-pool-0] option 7 ip-address 2.2.2.2
Related commands
display dhcp server pool