Change CUCM domain name

[JAMES WEST]

Hello All,

I hope you all enjoyed time off over the festive period.

I am looking to change the domain name on CUCM but looking for clarification if doing this will change the ITL certificates for all IP Phones?

I have reference the following doc's, and one looks like DNS domain name change is OK, and only the Hostname or IP Address would change the ITL file, but Jason Burns doc indicates that the domain will re-generate new ITL certs.

https://supportforums.cisco.com/t5/ip-telephony/change-domain-name-on-cucm-8-5-1/td-p/2302938

https://supportforums.cisco.com/t5/collaboration-voice-and-video/communications-manager-security-by-default-and-itl-operation-and/ta-p/3129362#toc-hId-692415780

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/install/10_0_1/ipchange/CUCM_BK_C3782AAB_00_change-ipaddress-hostname-100/CUCM_BK_C3782AAB_00_change-ipaddress-hostname-100_chapter_0100.html

"The above URL looks like only changing the Hostname or IP Address affects the ITL file?"

If you could let me know your thoughts, it would be greatly appreciated.

Thanks,

James

[Slavik Bialik]

Hi,

I can say for sure that changing the domain name will trigger all the certificates to be re-generated.

Also, if you change the host name of course. About the IP address, it'll NOT re-generate the certificates.

You can type the command that is changing the domain name, but before it'll change it'll ask you for confirmation and will explain in you what are the implications of changing the domain name. ;)

[JAMES WEST]

Hi Slavik,

Thanks for the quick response and the detailed information on what will change the ITL certificates.

I hope you have a good weekend.

James

[pkinane]

In this video I talk about how to add a domain name to CUCM. Changing the domain has all the same impact and would require the same prechange/postchange checks/confirmations.

https://supportforums.cisco.com/t5/collaboration-voice-and-video/how-to-enable-dns-for-cucm-versions-9-through-11-after/ta-p/3159005

[JAMES WEST]

Hi thanks for sharing the link and the excellent content in the video.

In regards to my change, l have 3 nodes in the CUCM cluster, 1 Pub and 2 Sub's. Phone are registered to Sub01, then fall over too Sub02, followed by Pub. Would you make the following changes:

Pub: (no change to phones ITL)

set network dns primary x.x.x.x
set network dns secondary x.x.x.x

set network domain "domain.name"

reboot

Sub01: (no change to phones ITL, phones failover onto Sub02)

set network dns primary x.x.x.x
set network dns secondary x.x.x.x

set network domain "domain.name"

reboot

Sub02: (phones failover onto Sub01, do the phones now download the new ITL certificate when the server reboots)

set network dns primary x.x.x.x
set network dns secondary x.x.x.x

set network domain "domain.name"

reboot

I am just looking to confirm once the last server in the cluster is rebooted, how the phones re-register to CUCM and download their new ITL certificate?

Thanks,

James