[cisco-voip] Ip phone are not able to pull address from new DHCP server

[Mike Armstrong]

Random thoughts: You said early on that the DHCP server believes it's had 
its offer accepted, since it lists an address for the phone. This implies 
pretty strongly that the server saw a DHCP Request at some point, but it 
might have been a long time ago.  All this really means now, though, is 
there's an entry in the DHCP database.  When you replaced the old server, 
did you move the DHCP database from it to the new server, or did you just 
start the new server from scratch?  When you run the test with both the 
sniffers going, have you manually deleted the entry in the DHCP database and 
reset the phone?  Are you certain the phone sees the Offer?  What sniffers 
are you using?  Are they configured to sniff and analyze VLAN data properly? 
I remember a recent note in the Ethereal forum describing a problem that 
could arise sniffing VLANs if the VLAN parameter had been inadvertently 
omitted, but I don't remember the details.  It's a real stretch, but if the 
helper device isn't tagging the Offer properly, the phone will never see it, 
although a sniffer might.

mike

Date: Thu, 24 Mar 2005 11:32:57 -0800
From: "Rossella Mariotti-Jones" <rossella at chemeketa.edu>
Subject: RE: [PACUG] RE: [cisco-voip] Ip phone are not able to pull
addressfrom new DHCPserver
To: "Marc Hering" <mhering at reval.com>, <cisco-voip at puck.nether.net>
Message-ID:
<D74DDBFF74F65945B233D80D11E52C090B13D524 at cccmail.chemeketa.network>
Content-Type: text/plain; charset="US-ASCII"

The DHCP discover message gets to the server, the DHCP offer gets back,
I can see it going through the gateway, but no DHCP request originates
from the phone.