[Asterisk-Users] Push VLAN to Polycom via DHCP

[Jerry]

On Mar 27, 2005, at 12:10 AM, Matt Darnell wrote:

>>> Has anyone been succesful pushing a VLAN setting to a Polycom phone 
>>> via DHCP?
>
>>  Chicken or the egg!  How can the Polycom reach the proper DHCP server
>> if it is not on the correct VLAN?  That's why Ciscos and Polycoms
>> support CDP, so the CDP-capable switch can supply the correct voice 
>> VLAN.
>
> I 'assumed' the phone would reboot with the new VLAN setting and get a
> new IP address from the DHCP server on the phone VLAN - there would be
> two DHCP servers.
>
> I can't think of any other way to make it work with DHCP.  If it isn't
> designed to work that way, why would they put the option in the DHCP
> section.
>
> -Matt

I had always understood that they only supported VLAN discovery via 
CDP. But reading the 1.4 admin guide it says this...

VLAN ID
See 2.2.1.2.2
DHCP Menu
on page 7
Special Case: Cisco Discovery Protocol (CDP)a overrides
Local FLASH which overrides DHCP VLAN
Discovery.
a. Can be obtained from a connected Ethernet switch if the switch 
supports CDP.

This seems to imply that DHCP can be used to spec a VLAN.

I too would like to find a way to make this work.

I also do not think the phone would need to reboot. I have noticed 
being able to change the VLAN and have the tag applied or not without 
the phone rebooting. Actually about the only thing I can do and not 
have it reboot:-)