Call manager and Unity Server IP address change and move

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Jun 5th, 2009
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Hello Guys,

I was advised to comeup with a plan to change IP address of Call managers and Unity servers. We are moving to another Data Center with new subnet. (Planing a staging test)

I have two Call managers version and two Unitys version 5.0.

Publisher and Subcriber and Primary/Backup Unity.

I was told to change the Unity IP addres first.

Please what is your expert advice?

pros and cons

Should I change the Unity first and why?

or CCM first and why? My last stop



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Overall Rating: 4.8 (5 ratings)
Dennis Mink Fri, 06/05/2009 - 05:28
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I cant see why there would a preferred sequence of steps.

I would approach it as a 2 stepped process.

I would move the CUCM cluster first, but that is a personal preference (when it comes to reIP-ing your CUCM cisco has some good step by step documentation on this).

the the next round do your unity servers ( at this stage the servers are already pointing to the new IP addresses of your CUCM cluster, so you only need to change the IP addresses of the Unity boxes themselves)

jjohnston1127 Fri, 06/05/2009 - 05:29
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I personally haven't done a re-IP involving Unity, but I wouldn't see why it would matter.

Keep in mind that when you re-ip call manager, do it inside of the Call Manager administration page first because you need to update the database before you do a command-line re-IP of the call manager servers.

Rob Huffman Fri, 06/05/2009 - 05:40
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Hi Eric,

Just to add a note to the great tips from Dennis and James (+5 points each, guys, for your excellent work!)

I don't remember ever seeing a preferred method for this type of change and I think either conversion/order will work if done with care. I also like the Two-Step method that Dennis suggested :)

Here are the related docs;

Changing the IP Address of a Cisco Unity or Voice-Recognition Server

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

Hope this helps! And best of luck with your changes.


Eric Boadu Fri, 06/05/2009 - 05:49
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Thanks Rob! I will check the link and compare with my current instructions.

parshah Fri, 06/05/2009 - 09:59
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Like everyone else has stated in their posts, there is no specific order in which you change the IP. There are a few things I would like you to consider.

1. For CUCM, if in CCMAdmin under System>Server you have IP address than change that entry first before you change the IP in the OS. If you have host name there than make sure that you update/add that info in the DNS servers. If this is not done properly, there is a possibility that DB will not start and you will loose web access to the CCMAdmin page.

2. Make sure the system is completely stable before you begin changing the IP, especially replication.

3. Like I said there is no particular order in which you can change the IP but this is what I would suggest.

a. Change the IP of the Unity backup server first and move it to the new data center.

b. Then move the primary Unity server.

c. Finally you can move the 2 CUCM servers together.

This is a staggered approach and take a while but I think this is the best way to avoid any major outages that could be business impacting.

cplatt01 Fri, 07/24/2009 - 11:31
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A few notes:

1) I would do this after hours

2) Pull the Call Manager that you are changing out of the group, as not to affect any calls.

3) Pull the Call Manager you are changing out of the redundant hosts on the gateway.

Anyone have similar thoughts? When I changed my IP Address on System->Server, I lost all calls and the phones all re-registered.


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