Endpoint Protection

I have a SEPM on 12.1.4104.4130 and have been migrating clients over to the new SEPM by pushing communications package everything has been going well as have a mixture of SEP 12 and SEP 11 clients on the manager. I noticed that on the 25/06/14 all the SEP 11 clients have stopped updating checked the manager and defintions are up to date and SEP 12 clients are updating fine. Prior to this date they were updating with no issue. 

There are no GUPs and these cleints are picking up directly from the SEPM itself. There is no LUA the SEPM goes directly out to the internet for updates. 

mind posting sylink.log and Lue.Log from one of the problematic endpoint ?

Unfortunatly I don't have direct access to the endpoints only the SEPM 

Same problem thread

https://www-secure.symantec.com/connect/forums/sep-1107-cant-update-virus-definition-sep1214

Replcae the sylink of any system which is not communicate

Restoring client-server communications with Communication Update Package Deployment

Troubleshooting Client Communication with SEPM

http://www.symantec.com/docs/TECH95789

Troubleshooting communication problems between the management server and the client

http://www.symantec.com/docs/HOWTO80740

Testing Communication from an Endpoint Protection client to the Endpoint Protection Manager

http://www.symantec.com/docs/TECH102682

The sylink debug file will be most telling.

Aside from that is anything showing in the System log for the affected clients? Any errors about not being able to download content?

Clients are communicating/checking in fine with the SEPM that's the strange thing. I log onto the SEP client and GUI says defintions out of date I lauch liveupdate and only place it goes for updates is the SEPM then it reports everything is up to date. Case now raised with symantec who have told me it's a known issue in the way SEPM 12 updates SEP 11 clients even though everything was fine up until the 25/06/14 when they all stopped updating. Further investigation going on will update when I have further information. 

Ok unusual one the machines have all started to update with no intervention or adjustments hmmmm