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Cisco 7945 Will Not Register With CUCM using Alternate TFTP


Trying to register a 7945 with an alternate call manager, if i set it via the DHCP scope Option 150 and point it to the alternate TFTP all works, however, when testing this is not what i want to happen, i would like to be able to set the alternate TFTP server and leave it at that, whats happening

1. Change the setting to use an alternate TFTP server

2. Set the new TFTP address

3. Save the settings

4. Delete the ITL file

5. Phone reboots yet when you brown to the phone it still has the old CUCM listed?


Anyone any idea's?

4 Replies 4


Should also mentions i have also tried factory defaulting the phone

Take a packet capture from the phone ( use span to PC port) from the CUCM the phone is registered to currently. Attach the pcap file here. It is possible the phone is not able to connect to the alternate tftp server. A packet capture will tell us whats going on

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Maren Mahoney
VIP Advocate VIP Advocate
VIP Advocate

I'm pretty sure that with DHCP enabled, any locally set ip-related settings will be overridden by what is learned via DHCP. (Correct me if I'm wrong.)


If it is just one phone, can you create a manual entry for that MAC address in the DHCP server with the settings you want? I've done this in a router with the following:


ip dhcp pool main
 option 150 ip
 dns-server <whatever>
 domain <whatever>

ip dhcp pool special
 client-identifier <>
 option 150 ip

The one phone with that mac address will get the IP and option 150 from the "special" dhcp pool and will pick up any remaining settings from the "main" pool.


You can do the same thing in a Windows DHCP server by creating a reservation and adding the Cisco Option 150 to the reservation after it is created.



Found the issue, the phone was looking for a version of firmware we didn't have on the CCM

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