side note - i did a quick google search but it brought up different methods, and I perfer this approch more.

have the DB backup as well as certificate backup then double click exe. The client will communicate since there will not be any change in certificate.

Check this link, it gives details information on upgrade to SEP 12.1 RU1

http://www.symantec.com/business/support/index?page=content&id=TECH174545

Hello,

In your case, it is good to have a backup of the database of SEP 11.x and others as shown in the Disaster recovery document  http://www.symantec.com/docs/TECH102333. This would be a backup, just incase.

Here are the Documents below which would give you more indepth. 

1) Planning for Migration to Symantec Endpoint Protection Manager 12.1

http://www.symantec.com/docs/TECH162730

2) Symantec Endpoint Protection 12.1: Installing the Manager for the first time and deploying clients

http://www.symantec.com/docs/TECH163580

3) Upgrading and migrating to Symantec Endpoint Protection 12.1

http://www.symantec.com/docs/TECH163602

4) Steps to prepare computers to install Symantec Endpoint Protection 12.1 client

http://www.symantec.com/docs/TECH163112

Reference:

https://www-secure.symantec.com/connect/articles/quick-access-symantec-knowledgebase-articles-symantec-endpoint-protection-121

Hope that helps!!

The basic answer to your question is YES.

You should be able to just launch the SEPM 12 EXE file on your SEPM 11 machine.
All your clients will re-connect after the migration.

Of course, it's always a good a backup, especially the communication files noted in the disaster recovery plan. A new feature in SEPM 12 is that the Disaster Recovery Data is automatically created so you shouldn't have to go around manually collecting the important disaster files and passwords.

After the SEPM server has been upgraded to version 12, you can use the Auto-Upgrade feature to update all you clients.

I think you'll like the new SEP 12.

Hi,

STEP 1: Login into the SEPM and Disable the auto up gradation of the SEP client package.

Clients Tab -> Select the group-> on the right hand as shown in the snapshot -> Install packages

Select the existing Install package and right click and Delete it.

STEP 2: Now take a fresh BACKUP of the database of the SEPM.

Go to start and select all programs-->symantec-->symantec endpoint protection manager and select the Select Database Backup and Restore tool.

Now Select Backup option.

If you like to take Backup of the SEPM logs then you can put a check mark and click on YES.

Then the tool starts taking backup and stores in the below location

X:\Program Files\Symantec\Symantec Endpoint Protection Manager\data\backup

Backup is done you see this above message after it is completed.

Later go the services window and select the Symantec Endpoint protection Manager Service and STOP the service and close the window.

STEP 3: Start the setup to upgrade SEPM 12.1 

Symantec_Endpoint_Protection_12.1.671.4971_Xplat_EN_DVD/ Setup.exe

Select the Install Symantec Endpoint protection .which will allow you to start up gradation or a fresh Installation 

Click on NEXT

Click on NEXT

Select I accept and Click on NEXT

If you have not taken Backup then it will prompt you to take Backup at this point of the time.

If not you can Click on NEXT

Click on Install

Click on NEXT

Click on NEXT

Click on NEXT

Click on NEXT

Click on NEXT

Now the Up gradation of the SEPM wizard will appear Click on NEXT

Click on NEXT

Click on the FINISH

STEP 4: Activating SEPM 12.1 licenses

Now Log in to the SEPM for the first time after up gradation, type in your credentials and login

NOTE: Do not restart or shutdown the machine for at least 15 minutes. Because after the up gradation the server need to rebuilt the new files so it requires some time.

For the first time this wizard will appear for activation of License. So selectActivate your product

Select if you have a serial no. or a .slf file . You can activate using any of them

Type the serial no. and the click on submit.

Type your contact details this will be help full at the time of support.

Finally you are done the upgread from 11.x to 12.1