CUCM, how long CallManager holds IP of phone in database

[dworzynskimarek]

Good day,

at the beginning I wanted to apologize for my English.

I have a question with the topic of this discussion. Namely.

I remove the phone from the CallManager, and after a while I add it back. Less about the wisdom of such action. When I add it back, CallManager automatically assigns IP, which previously the phone had . During this time, the phone gets another address from DHCP (not from CUCM-a), and the phone does not want to register.

How to remove relation between phone and IP on CallManager.

[Jaime Valencia]

CUCM doesn't do any bind of a certain IP to a phone/device, you can go to any phone, change the IP to something else that can reach CUCM and it will register and reflect the new IP it's using for registration.

[Georgios Fotiadis]

What you see in the IP column when re-adding the phone is the entry that used to exist in the RIS db. Though, as @Jaime Valencia said there is no such bind that CUCM holds and that you need to clear. There must be some other reason that your phone does not register; verify that your new DHCP pool deliver that correct option 150 (or 66) and that the new subnet can communicate with the CUCM.

[dworzynskimarek]

I checked everything what You wrote Georgios. ( option 150, communication with CUCM ).
Its not new DHCP pool, or new subnet, others phone working correct.
Just like You say, about RIS db., tell me why CUCM always added, in this case, the same IP, when I removed and added the same MAC addres - IP phone, when phone gets newes IP. Is in it, that in RIS.db the MAC adres is the key?

[Georgios Fotiadis]

RIS db only holds real-time information about the phones. Once the phone register it will be updated. Don't bother about RIS db, it just explains why re-adding the phone appears with an IP address.

Do you verify that the phone receives proper IP settings and TFTP server (through local settings, CDP or phone GUI)?

[dworzynskimarek]

Yes i check.
When i click on the new IP of the phone, added from DCHP, then opened on the browser via http phone page, like should be.
When phone is in unregistered state in CUCM, is this real-time information? added in RIS? maybe the issue is in updated RIS

[Georgios Fotiadis]

Can you collect packet capture logs from CUCM, only, for the corresponding phone (based on IP)?

Packet Capture on CUCM Appliance Model

Have you performed a factory reset on the phone?