SPA122 - How to turn off "DHCP Option To Use" in the Provisioning tab using the XML configuration file?

[Moises Ortiz]

As default, SPA122 and SPA112 have DHCP Options 66, 160, 159 and 150 turned on.

Our pre-provisioning process includes adding our default profile rule to our provisioning server for the device to pull its configuration files once the device has been added to an account.

However, it seems like some customers have had problems with the device downloading the definite configuration file and manually turning off option Option 66 in the provisioning tab in the device solves this issue.

Is there any option we could add to our pre-provisioning file so that it removes 66 from the "DHCP Option to Use" field in the provisioning tab?

Please advise...

[Dan Lukes]

As default, SPA122 and SPA112 have DHCP Options 66, 160, 159 and 150 turned on

Not true. The default values depend on firmware version. There are SPA112 distributed with old firmware. Such firmware understand DHCP option 66 only by default.

some customers have had problems with the device downloading the definite configuration file and manually turning off option Option 66 in the provisioning tab in the device solves this issue.

I assume that it affect those customers with misconfiguration DHCP server. DHCP server should be configured to send Option 66 to appropriate class of device (different classes require different value of option 66 or require no option 66 at all). If the DHCP server is misconfigured and is sending option 66 to inappropriate class of devices, the affected devices may have issues.

The solution of the first choice is to correct configuration of DHCP server.

Is there any option we could add to our pre-provisioning file so that it removes 66 from the "DHCP Option to Use" field in the provisioning tab

You missed how the provisioning file works. You can't add nor delete parts of existing value. The provisioning file allow you to just configure an option value to anything you wish. So if you like no 66 to be listed in the option, then just configure it to something that contain no 66.

[Dan Miley]

Thanks Dan,

I didn't know the dhcp server could serve different options to different classes of clients, I'll have to look that up!

Moises

so if your provisioning file has this line below (this is from a spa5xx config I had in my temp folder, so use the line from your provisioning file, or use the SPC tool to create a new default config for that device type)

<DH<DHCP_Option_To_Use group="Provisioning/Configuration_Profile">66,160,159,150,60,43,125</DHCP_Option_To_Use>

change it to

<DH<DHCP_Option_To_Use group="Provisioning/Configuration_Profile">160,159,150,60,43,125</DHCP_Option_To_Use>

Hope it helps,

Provisioning guide is here

Cisco IP Telephony Devices Provisioning Guide - Cisco Support Community

Dan

[Dan Lukes]

Yes, it can. It is the purpose the DHCP option #60 (Vendor Class Identifier) has been designed for. It allow me supply file suitable for particular device based on it's model.  It allow us to properly bootstrap even the devices unknown to the system.

Some DHCP servers allow even more complex logic (so I'm sending #66 option in response to request sent by SPA112 with old firmware version, but option #160 in response to request by SPA112 with recent firmware). Of course, the exact capability of particular DHCP server depends on it's supplier.

change it to

<DHCP_Option_To_Use group="Provisioning/Configuration_Profile">160,159,150,60,43,125</DHCP_Option_To_Use>

I recommend do be more conservative. Configure just the option number used by DHCP server in particular network. So if you are using option 160 to bootstrap Cisco phones in particular network, then mention only option 160 in provisioning file. There is no reason to mention other options unless you are using them to deliver bootstrap configuration to phone. And I assume you use one option only in any particular LAN.