We just installed a new IP phone system. The phones get their configuration via DHCP, which includes an option to set the phone to a different VLAN. The phone then requests an address via DHCP on that VLAN.
So now I have two registrations for the phone in my DHCP database: one in the "computer" VLAN, and one in the "Phone" VLAN.
Is there a standard way of cleaning up the extra DHCP registrations for the phones?
In my case, the answer was LLDP. By enabling LLDP on my Cisco switches, the phones were able to learn of the Voice VLAN before they started the DHCP process.