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New Member

DHCP for Wireless IP Phone


I have a wireless IP Phone that is not getting a DHCP address. When we configure a laptop for DHCP, it gets an address OK. Also, if we configure the phone with a static address, it does not work either. LEAP authentication is enabled on the phone and laptop, they both authenticate OK. This phone did work until we reloaded the PIX firewall on-site to which the CallManager is at the other end, since then it has not been able to receive DHCP. Please advise. Thanks!


Re: DHCP for Wireless IP Phone

Check if while rebooting the PIX, if you had any unsaved configuration on the PIX. If so it would be lost now and and could be leading to this problem.

New Member

Re: DHCP for Wireless IP Phone

Did you ever get this problem resolved. I am running into the same problem with the IP Phone.


Cisco Employee

Re: DHCP for Wireless IP Phone

This is the sequence of what happens:

1-Authntication with AP

2-Association with AP

3-Getting dhcp address +tftp address

4-Connecting to tftp server (on CM server typically) to get config and FW.

5-Registering with CM

If you say that authentication is ok, I assume on the AP you can see the phone associated and the phone-AP part is going well. (If it's not the case you can check that TKIP/MIC are not enabled on the AP for that vlan).

To start if you suspect a dhcp + pix issue:

Verify that you have the latest FW for the phone (1.0.7), there was a bug with 1.0.6 and PIX or VPN3002 that could prevent the dhcp packets to be passed.

However if setting a static ip address on the phone you still can't get the phone to register with Call Manager means that is not related to DHCP but to connectivity.

Test with static ip address on the phone and set the tftp server, default GW and DNS values manually on the phone as well.

Go to the ädmin menu on the phone (you get there pressing menu *## and then the key with the green phone) and you will see under Network Config a new "traceroute" menu. Use it to see until where are you able to reach,identifying where the connectivity is broken. If it's the PIX you may need to verify if other voice and signalling voice traffic are passing or if nothing else voice related is passing. If nothing is passing maybe the signalling voice ports are not enabled. Check with a PIX expert.

New Member

Re: DHCP for Wireless IP Phone


Did You try to disable 'MIC' (message integration check), and 'Per Packet Keying'.

The Wireless Phone does not support these features.


Kristian Gyldenvang

New Member

Re: DHCP for Wireless IP Phone

Issue w/ VPN3002 or PIX providing DHCP is that those messages are unicast and 7920 didn't support that. This is fixed in the latest 7920 code on CCO.

New Member

Re: DHCP for Wireless IP Phone

Mahalo! =0)