User's Manual

Chapter 7: Configuration
Zero Touch Configuration Using DHCP Option 66
Page 7-203
Zero Touch Configuration Using DHCP Option 66
This feature allows an SM to get its configuration via DHCP option 66. This can be used for the
initial configuration of an SM as well as managing the configuration of SMs on an ongoing basis.
Here is how it works in brief:
 When the SM boots up, if it is set to use DHCP client, it will send out a DHCP Discover packet
which includes a request for DHCP Option 66.
 In case of a brand new SM out of the box, the DHCP Discover packet is sent out if the SM
connects to an AP using Installation Color Code (ICC), even though DHCP client is not enabled
in factory default config.
 An appropriately configured DHCP server will respond with a DHCP Offer and include a URL in
response to the Option 66 request. The URL should point to the configuration file.
 The device will download the configuration file and apply it. The device will reboot
automatically if needed. (Note: this requires “rebootIfRequired” flag to be added to the config
file. See Creating a Golden config file on page 7-204.
Configuration Steps
Procedure 23 Zero Touch Configuration steps
1
Create the golden config file(s)
2
Host it on an TFTP/FTP/HTTP/HTTPS server
3
Configure the DHCP server to return the URL of the golden config file in option 66
When the SM boots up, it will get the URL for the golden config from the DHCP server via option
66, download it and apply it.
If all the SMs are configured exactly the same, then you can create just new golden config file that
can be used with all SMs.
If the SMs are not configured the same, see if it is possible to group the SMs such that SMs with
the same configuration are served by the same DHCP pool. User can then create multiple golden
config files and configure the DHCP server to use the appropriate config file for each pool.
User can also create one config file per SM. This provides the most flexibility, but is practical only
if you have a software tool/script to generate the config files for each MAC address. The files
should be named <mac>.cfg where <mac> is the MAC address of the SM, and stored in the same
directory on the file server. The DHCP server should be configured to return the directory name
ending with a ‘/’ in option 66. The SM will automatically add “<mac>.cfg” to the path and get its
config file.