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HP Procurve - VLANs and DHCP Helper Address

Last Modified: 2012-08-07
I've predominately used Cisco and Enterasys, and for the life of me I cannot get this to work properly on an HP Pro Curve 2910al switch.  The scope here:  I've got a Windows 2003 DHCP server.  IP address is  This server has two DHCP scopes - (VLAN 10) and (VLAN 100).  

On the switch level, I have all ports set to use VLAN 10 untagged and VLAN 100 as tagged.  I've setup both VLANs with ip-helper address of  

This is the setup for us to be able to daisy chain a PC behind a Phone, and have the two on separate networks (VLAN 10= data, VLAN100=Voice).  Using a custom DHCP option, I can force the phone to turn on Layer 2 tagging and assign itself to VLAN 100.  

So, when I attach the phone, it hits DHCP and takes an IP in the data range.  It then see's it needs to change it's VLAN and goes through a network re-configure.  It reboots and attempts DHCP (trying to get an address in VLAN 100).  The phone never get's an IP.

Note: There is a default VLAN that I was using to stack the switches.  I've cut back to using a single switch and changed the primary VLAN to VLAN10, which has done nothing.

What is the proper (port) setup to allow DHCP for both subnets?
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