Hello,
I would 1st Recommend you to Migrate to the Latest version of Symantec Endpoint Protection of 11.0.6300
Here is the List of SEP along with its Versions.
Symantec Endpoint Protection 11.0.780.1109/11.0.776.942 (RTM), 11.0.1000.1375 (MR1), 11.0.1006 (MR1 MP1), 11.0.2000.1567 (MR2), 11.0.2010.25 (MR2 MP1), 11.0.2020.56 (MR2 MP2), 11.0.3001.2224 (MR3), 11.0.4000.2295 (MR4), 11.0.4010.19 (MR4 MP1), 11.0.4014.26 (MR4 MP1a), 11.0.4202.75 (MR4 MP2), 11.0.5002.333 (RU5), 11.0.6000.550 (RU6), 11.0.6005.562 (RU6a), 11.0.6100.645 (RU6MP1), and 11.0.6200.754 (RU6 MP2), 11.0.6300.803 (RU6 MP3)
Now, Since you are carrying Older version 11.0.3001
We recommend you to upgrade the Symantec Endpoint Protection Manager and all clients to Latest version.
You can download the latest software from Fileconnect.
https://fileconnect.symantec.com/
Since you are carrying older version than 11.0.6005 (RU6a), there would be 2 upgrades you will have to go through. Please check the steps below:
1) From Symantec Endpoint Protection 11.0.3001 to Symantec Endpoint Protection 11.0.6005 (RU6a)
http://www.symantec.com/business/support/index?page=content&id=TECH131653
2) From Symantec Endpoint Protection 11.0.6005 (RU6a) to Symantec Endpoint Protection 11.0.6300 (RU6 MP3)
http://www.symantec.com/business/support/index?page=content&id=TECH155655
Once, you have followed the Articles above, go for autoupgrade of all the clients.
Upgrading clients by using AutoUpgrade
http://www.symantec.com/business/support/index?page=content&id=TECH96789
Also, check the Symantec Article below:
Release notes for Symantec Endpoint Protection 11.0.x and Symantec Network Access Control 11.0.x
About Maintaining Consistency of Software Versions throughout a SEP 11 Organization