Hi All,

Please explain your expertise that whether Symantec releasing definition for 11.0or not? In documentation symantec says from 5th of jan end of service for sep 11.0but dear expert i have seen our few clients 11.0 still have latest defintion periodically not all? please explain

On January 5th, 2015, Symantec Endpoint Protection 11.0.x and Symantec Endpoint Protection Small Business Edition 12.0 will reach End-of-Support-Life and no longer be entitled to support, LiveUpdate, virus definitions and security updates. To remain protected, ensure all of your endpoints have been migrated to version 12.1 and activate the advanced protection available through Insight reputation scoring and SONAR behavioral monitoring. Endpoints that continue to run Endpoint Protection 11.x and SBE 12.0 after End-of-Support Life (EOSL) will no longer receive virus definitions, content updates, break fixes, patches, workarounds or technical support

You are require to upgrade in 12.1.5

Blog

https://www-secure.symantec.com/connect/blogs/did-you-get-security-memo-symantec-endpoint-protection-11-eosl

Symantec is end of support for 11.x version

Support life extension for Endpoint Protection 11.x and Endpoint Protection Small Business Edition 12.0.x

I have find the rapid release defintion is release for 11.x client as well, may be it is the reason that your some client is shown updated

http://www.symantec.com/security_response/definitions/download/detail.jsp?gid=rr

Does you have SEPM 12.x ?

See Kari Ann comments

SEPM 12.1.x update SEP 11.x client.But SEP 11 clients may receive untested definitions via the 12.1 SEPM for a few additional month

https://www-secure.symantec.com/connect/blogs/did-you-get-security-memo-symantec-endpoint-protection-11-eosl

see some of thread

https://www-secure.symantec.com/connect/forums/symantec-endpoint-protection-110x-eosl

https://www-secure.symantec.com/connect/forums/client-not-update-0

SEP 11 has gone end of life from 6th January so last definitions release by symantec for a SEPM 11 were 2015/01/05 rev.19

But if you have SEP 11 clients connected to a SEPM 12 they will recieve antivirus and antispyware definitions until July. Although symantec are releasing these definitions they are not being fully tested like currently supported definitions. So any issues on clients on SEP 11 there will be no support. SEP 11 clients will only pick up these updates directly from the SEPM. 

I'd start getting all clients upgraded to 12.1 RU5 asap so any issues can be dealt with prior to complete cut off date. 

Hi Ajay,

Thank you for posting in Symantec community.

I would be glad to answer your query.

On January 5th, 2015, Symantec Endpoint Protection version 11.0.x reached end of support life. Virus definitions and security updates ceased to be published to LiveUpdate and general support for the product is no longer provided.

The initial end of support life date was originally scheduled for January 5th, 2014. All customers were provided a complimentary extention. No further extentions will be provided.

There is not any workaround available to update definitions because Symantec is not releasing 11 definitions anymore.

It's strongly recommended to upgrade to SEP 12.1, RU5 is the latest release.

To know the best practice I would recommend you to go through the following article.

https://www-secure.symantec.com/connect/articles/sep-11x-sep-121-upgrade-process-graphical-overview

Migration of 11 clients to 12.1 is fully supported. Reboot is required to complete the upgrade. Reboot is required because SEP 12.1 employs a side-by-side, replace on reboot installation strategy. Side-by-side means that new files are written to a new folder, referred to as a silo, isolated from the existing operational folder. Because the two versions are separated from each other, during a migration the older software is left running unchanged until the next reboot.

The primary benefit of side-by-side installation and replace on reboot is that the system continues to be protected by the existing software until the new version is in operation after the reboot.

This technique enables you to change the normal portion of the installation path during a migration, when applicable. 

Check these article also:

Upgrade or migrate to Symantec Endpoint Protection 12.1.5

http://www.symantec.com/docs/TECH224034

FAQ: Upgrading Symantec Endpoint Protection 11.x to version 12.1.x

http://www.symantec.com/docs/TECH207274

Defs are not released anymore as it is end of support life since January 5th 2015.

It is possible for 11.x client to receive untested definitions if connected to a 12.1 SEPM though occasionally.