Dhcp timeout on 7921G phone

[mburguk1000]

I currently have an issue with a 7921G phone which authenticates with the access point ok but is showing DHCP timout on the phone itself

Our setup is as follows a Cisco 4400 Wireless Lan controller, a 4510 chassis based switch which supplys dhcp range for IP telephony and this is setup on the lan controller as dhcp relay

There is a binding shown on the switch for mac to ip adress but somehow this is not filtering through to the phone

The phone also shows on the client detail on the nearest access point but i have noticed that policy manager state is showing Dhcp_reqd

I would appreciate help with this very much

Thanks

[dancampb · Accepted solution]

Do you have DHCP required unabled under the WLAN?  You shouldn't have it enabled on the WLANs being used by the 7921's.  The phone doesn't re-DHCP with every layer-2 change so the phone can get stuck in DHCP_Req after a roam.

[mburguk1000]

Thank you for your response it cured the

issue

[George Stefanick]

For your further reading i posted info my site about this subject

http://www.my80211.com/voip-labs/2009/12/31/wlc-dhcp-address-assignment-required-option.html

[mburguk1000]

This worked worked for about a week and now we have the same issue, When I saw we had issues again with the phone showing configuring IP I looked at the controller and saw the option for DHCP Addr, Assignment had been checked again and I know, no one else has access to the controleller so now im thinking im going crazy lol

I then unchecked the box again and when you look at client detail the policy manager state is showing DHCP_Reqd even though when you look at CLI it definitely shows disabled

Please can some one helpo restore my sanity

Thanks

Mark