option

Specifies Dynamic Host Configuration Protocol (DHCP) options to be exchanged between the server and the client.
Syntax
option option-number { ascii | hex | ip } option-value
Parameters
option-number
Specifies the DHCP generic option number to be exchanged between server and client.
ascii
Specifies the option-value is an ASCII string (up to 128 characters).
hex
Specifies the option-value is a hexadecimal value (64-byte hex sequence, up to 128 characters).
ip
Specifies the option-value is an IP address. You can configure up to a maximum of three IP addresses separated by a space.
option-value
The value of the option; for example, an IP address or vendor-specific information.
Modes

DHCP server pool configuration mode

Usage Guidelines

This command is used to specify DHCP options that the DHCP server passes to clients.

For example, you can configure option 3, so the DHCP server passes the IP address of the default routers to the client.

Only one default router can be specified. Do not enter multiple router addresses.

Another example is option 43, allowing the DHCP server to pass vendor-specific information, in the form of a hex string or an ASCII string, to the clients that receive the DHCP ACK. With this example, configuring DHCP option 60 helps in identifying the incoming DHCP client. If the vendor class identifier (VCI) advertised by the DHCP client matches with the DHCP server, the server makes a decision to exchange the vendor-specific information configured as part of DHCP option 43.

Examples

The following example configures option 3, using the IP address format, to specify the default router available to the client. 

device# configure terminal
device(config)# ip dhcp-server pool ruckus
device(ip dhcp-server pool ruckus)# option 3 ip 10.10.10.1

The following example configures option 12, using the ASCII format, to specify the hostname server available to the client. 

device# configure terminal
device(config)# ip dhcp-server pool ruckus
device(ip dhcp-server pool ruckus)# option 12 ascii myhostname

The following example configures option 43, using the hex option for comma-separated Ruckus AP IP addresses configuration. 

device# configure terminal
device(config)# ip dhcp-server pool ruckus
device(ip dhcp-server pool ruckus)# option 43 hex 0x061731302e31302e31302e31302c31322e31322e31322e3132

The following example configures option 67, specifying both the image type and flash location. 

device# configure terminal
device(config)# ip dhcp-server pool ruckus
device(ip dhcp-server pool ruckus)# option 67 ascii “fi8080_manifest.txt router primary”
History
Release version Command history
08.0.30mb This command was introduced.
08.0.70 This command was expanded to support DHCP generic server options.
08.0.80 This command was modified to specify both the image type and flash location for option 67.
Parent topic: Commands O, P, Q, R, and Sa through Sh