Step 4 Add the option 43 line using the following syntax:
option 43 hex <hex string>
The hex string is assembled by concatenating the TLV values shown below:
Type + Length + Value
Type is always f1(hex). Length is the number of controller management IP addresses times 4 in hex. Value is the IP address of the controller listed sequentially in hex.
For example, suppose that there are two controllers with management interface IP addresses, 10.126.126.2 and 10.127.127.2. The type is f1(hex). The length is 2 * 4 = 8 = 08 (hex). The IP addresses translate to 0a7e7e02 and 0a7f7f02. Assembling the string then yields f1080a7e7e020a7f7f02. The resulting Cisco IOS command added to the DHCP scope is option 43 hex f1080a7e7e020a7f7f02.
