Showing results for 
Search instead for 
Did you mean: 

Cisco Community Designated VIP Class of 2020


Issue with Upgrading IP Phones

Heys guys,

I am facing a serious issue with some IP Phone - 7942/61/41 . I did some hardware changes last week and did a reset on every phone, which should be stored in our stock. Most of the phones restarted and loaded the software without any issues (all of the sucessful ones are the mentioned models above) , but some phones just stuck at the "upgrading"-phase without any reason. I have already experimented with a own TFTP and modified config files, but no sucess. It really drives me nuts ;-). Do you have an idea what the problem could be?



Re: Issue with Upgrading IP Phones


I have experienced similar (but not equal issues) and I had to put the phone in a switch with out any vlan or CDP, with DHCP with tftp option, and put tftp pointing to CUCM. Then, I did a factory reset of the phone.

Hope this helps.


Cisco Employee

Re: Issue with Upgrading IP Phones

Do you see the Phone switch on and then switch back on..?.

If yes, Do you have DHCP enabled on that VLAN?.

Is the phone getting an IP Address?.

Is DHCP Server giving an option 150 to the phone[TFTP]. This is where the phone will download its Firmware files.

Once  you have done these checks and if that doesn't solve the problem. Could  you configure a monitor session on the switchport where the phones are  connected and collect a sniffer capture?.

Monitor session config

Connect a PC to the Monitor sesion destination port  and run wireshark on it. capture from the LAN port.

Ideally you should see DHCP Discover, Offer, Request, ACK.

You need DHCP, plus OPTION 150 to be given to the phone.


PS:Rate useful posts.!


Re: Issue with Upgrading IP Phones


We also ran in upgrade problems with IP phones. Maybe this info helps a bit.

Try to upgrade your affected phones to firmware 8.4.2 first (change "Phone Load" on Phone Admin page for that).

After they register with this firmware they are able to handle the newer firmwares.

When the phones register, delete the info you entered above so the phones can download the default load.

Good luck,



Re: Issue with Upgrading IP Phones

Regular I upgrade the phones to 8-5-2 and then I can go higher. But those phones do not react to anything, even if I change the phoneload to a lower version. I have already check them with a own TFTP server. They obtain the default config file, but nothing happened. It is really annoying as there are already around ~15 phones totally useless.

CreatePlease to create content
Content for Community-Ad
FusionCharts will render here