Gatekeeper config can affect DHCP's work?

[eigrpy]

Hi, After the following commands are entered, the phone turns into Not registered status. The phone cannot get ip address again. I am not sure if the "Not registered" is related with these commands. Anyone have comments? Thank you in advance. 

gatekeeper
zone local VIAGK voice.com
zone remote BBGK Cisco.com 10.26.1.253 invia VIAGK outvia VIAGK
zone prefix BBGK 01132

[Manish Gogna · Accepted solution]

The ip phone registration to cucm or cme would not be affected by these commands. You can enable packet capture on one of the phones while trying to reproduce the issue so that it can be checked why the phone unregistered.

Manish

[eigrpy]

Thank you for your reply. Can you tell a little bit more about enable packet capture or what commands can enable packet capture? 

[Manish Gogna]

Hi,

Please check this

https://supportforums.cisco.com/document/44741/collecting-packet-capture-cisco-ip-phone

Manish

[eigrpy]

2. Enable the Span to PC port feature.

 From the IP phone configuration page, scroll down to the Protocol Specific Configuration section, and enable the "Span to PC Port" configuration option.   This will trigger a change to the phone's TFTP configuration file.   Save and reset the phone so it can retrieve the new configuration file.

The link document mentioned "IP phone configuration page". Where is it? Is it in CUCM or other place? Thank you

[Carlo Poggiarelli]

Hi,

where is configured the DHCP server? In a vg or cucm?

Is the unregistered phone on a remote site or in the same site of CUCM?

Please let me know 

Regards

Carlo

[eigrpy]

The DHCP is in CUCM. the phone is in the same site with cucm. Now the phone cannot get ip address

The phone was registered before. The phone is unregisted just after setting up gatekeeper. Thank you!

[Carlo Poggiarelli · Accepted solution]

Hi, 

No... gatekeeper is not the issue in this case even because is not an element that influence phone registration.

You should look at network topology and routing.

Maybe , in this case, gatekeeper is also the gateway for phones vlan and you are missing ip helper-address command on ip interface in phones vlan.

Please let us know 

Regards

Carlo

[eigrpy]

I check connection and ip-helper etc. Everything is Ok. I think the DHCP cannot work even since PC connecting the vlan cannot get the ip address. I am going to reinstall the DHCP. Thank you 

[eigrpy]

I have not reinstalled DHCP in CUCM yet, but after I assigned ip address to the phone manually, it is registered. Strange, the DHCP server in cucm cannot work. I checked its configuration in cucm and router several times. All config are correct. 

[Carlo Poggiarelli]

Hi, 

I don't know which version of CUCM you are running but you don't need to reinstall just restart dhcp monitoring service and try again to enable dhcp client on the IP Phone 

Let me know 

Regards

Carlo

[eigrpy]

Excellent idea! after unchecking and checking of dhcp munitoring service, the phone can get ip add. Thank you. 

 I checked some documents. seems like Cisco recommend using external dhcp if cucm is 10.5, but I am using 9....

[Carlo Poggiarelli]

Hi,

As per SRND 10.5 but even for 9.0, for small deployments (below 1000 users) you can configure DHCP on CUCM server. 

Larger deployments require an external DHCP server

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab10/collab10/netstruc.html#14097

HTH

Regards

Carlo