Phones on some switches cannot complete DHCP process
I fixed the problem today by removing the vlan tag for the phone vlan on the port connecting to our dhcp server. It's very strange to me that this worked, as other systems that use a similar scheme (aka: Wifi SSIDs using 802.1q) require the tag or clients cannot get addresses. It worked, so I won't look too hard, but I would be interested in seeing answers with theories for why this is the way it is.