Configure Host-Specific Options

In addition to configuring global and subnet options, you can also configure host-specific options. This configuration is used for specific hosts as a configuration parameter. See RFC 2132 for the complete list of DHCP options and their corresponding codes.

In this example, the address pool is pool 1, the MAC address is 00:11:22:33:44:55, and the subnet mask option is 255.255.0.0. This option is offered to DHCP clients with a hardware address of 00:11:22:33:44:55 even if there is a pool-specific option or global option with this option code.

1. Create the address pool.

   SEFOS# configure terminal
   SEFOS(config)# ip dhcp pool 1

2. Configure option 1 (subnet mask) and the MAC address.

   SEFOS(dhcp-config)# host hardware-type 1 client-identifier 00:11:22:33:44:55 option 1 ip 255.255.0.0
   SEFOS(dhcp-config)# end

3. View the options configured in the switch.

   SEFOS# show ip dhcp server pools

   The output in switch 1 is:

   Pool Id                         : 1
   -------------------------------------------
   Subnet                          : 12.0.0.0
   Subnet Mask                     : 255.0.0.0
   Lease time                      : 3600 secs
   Utilization threshold           : 75%
   Start Ip                        : 12.0.0.1
   End Ip                          : 12.255.255.255
    
   Host Options
   --------------
   Client Identifier     Hardware type     Code      Value
   00:11:22:33:44:55     1                 1         255.255.255.0