I keep getting an Ack Error with my Avaya IP phones. I have no VLan's configured for either voice or data. This is simply a testing environment with a server 2008 DHCP server and an IP Office. Some of my IP phones come up using DHCP fine, and thers will continuously loop with the DHCP Ack error. I've gone in a cleared the phones using the Mute - Clear sequence. I'm not sure what needs to be done. I dont know if I need to configure anything on my switch (cisco 3550) or not. Any help is appreciated.