Changing hostname on Callmanager 6.1 and generate new SSL

[kenlorenzo]

I'm looking to change the hostname of our Callmanager because of a change in the naming convention for all our servers.

Is it as easy as it seems or are there any precautions I need to be aware of?

My thoughts were to just Change hostname under Cisco Unified CM Configuration for both PUB and SUB

Since I use mostly IP address for most of my configuration, are there anything else I need to be concerned about?

Also, how do I generate a new SSL cert based on this change so admins and users won't get a certificate mismatch prompt?

Thanks!

[Rob Huffman · Accepted solution]

Hi Ken,

***Note Prior to Cisco Unified Communications Manager Release 6.1(2), you cannot change the host name of either the publisher node or subscriber node after it is installed. If you must apply a new host name to a server, you can delete the server from Cisco Unified Communications Manager Administration (System > Server) and then reinstall the server with a new host name.

Changing the IP Address and Host Name for Cisco Unified Communications Manager 5.x and 6.x Servers

http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/install/6_1_2/ipchange/ipchg612.html

Hope this helps!
Rob

[kenlorenzo]

Thanks for the quick response, that was quite helpful.

What does this exactly mean?

"Changing the host name triggers an automatic, self-signed Certificate Regeneration. After the server reboots  automatically, secure  connections to this server will fail until the CTL client is rerun and the  CTL file is updated."

How do I run the CTL client?

[Aaron Harrison]

Hi

It means that the trust list would be updated - i.e. the list of servers that the phones know are legitimate CCMs you are using encryption and authentication on your cluster.

If you aren't running endpoint encryption and authentication then it's not to worry about.

As you have said you don't want a cert mismatch being presented to admins and users after the change, you'll have to go through the CSR process (from http://publisher/cmplatform - Certificate Management menu).

It's very important to pay a lot of attention to that document Rob posted - all the verification steps are important and if you miss anything it's not so much the phones that have a problem (as you say, they're normally more interested in IPs) but the actual services and replication configs on the server that will break. The most common one is that the DB just doesn't start...

Aaron

Please rate helpful posts...

[Rob Huffman]

Hi Ken,

Thought you might want to see this

CSCtf23432 Bug Details	Bug #11 of 38 | < Previous | Next >

CUCM Hostname change does not update self-signed certificates

None Symptom: After a hostname change, self-signed certificates are not regenerated.  Web browser may indicate that the CUCM certificate is not valid. Conditions: hostname change procedure. Workaround: From the os admin page: 1) security->certificate management 2) select "find" 3) for all the self-signed certs (identified by the description field), select regenerate. Further Problem Description: n/a

Status Fixed              Severity 3 - moderate Last Modified In Last Year         Product Cisco Unified Communications Manager (CallManager)          Technology 1st Found-In 7.1(2)                    Fixed-In 8.0(2.98000.25) 8.0(2.10000.4) 7.1(4.98000.167) 8.0(2.98000.31) 8.0(2.10000.24) 7.1(5.10000.12)

Cheers!

Rob