configure vlan dhcp-options

configure {vlan} vlan_name dhcp-options [code option_number [16-bit value1 {value2 {value3 {value4}}} | 32-bit value1 {value2 {value3 {value4}}} | flag [on | off] | hex string_value | ipaddress ipaddress1 {ipaddress2 {ipaddress3 {ipaddress4}}} | string string_value] | default-gateway | dns-server {primary | secondary} | wins-server] ipaddress


Configures the DHCP options returned as part of the DHCP response by a switch configured as a DHCP server.

Syntax Description

vlan_name Specifies the VLAN on which to configure DHCP.
code Specifies the generic DHCP option code.
option_number Specifies the DHCP Option number.
16-bit Specifies that one to four 16-bit unsigned integer values associated with selected DHCP option.
32-bit Specifies that one to four 32-bit unsigned integer values associated with selected DHCP option.
flag Specifies that 1 byte value associated with selected DHCP option number.
hex Specifies that hexadecimal string associated with selected DHCP option number.
string Specifies that a string is associated with selected DHCP option number.
string_value The string value associated with specified option.
default-gateway Specifies the router option.
dns-server Specifies the Domain Name Server (DNS) option.
primary Specifies the primary DNS option.
secondary Specifies the secondary DNS option.
wins-server Specifies the NetBIOS name server (NBNS) option.
ipaddress The IP address associated with the specified option.



Usage Guidelines

This command configures the DHCP options that can be returned to the DHCP client. For the default-gateway option you are only allowed to configure an IP address that is in the VLAN's network range. For the other options, any IP address is allowed.

The options below represent the following BOOTP options specified by RFC2132:
  • default-gateway—Router option, number 3.

  • dns-server—Domain Name Server option, number 6.

  • wins-server—NetBIOS over TCP/IP Name Server option, number 44.


The following command configures the DHCP server to return the IP address as the router option:

configure vlan <name> dhcp-options default-gateway


This command was first available in ExtremeXOS 11.0.

The primary and secondary DNS options were added in ExtremeXOS 12.1.

Platform Availability

This command is available on ExtremeSwitching 5320, 5420, 5520, and 5720 series switches.