Upgrade SEP 12.1 RU4 MP1a to SEP 12.1 RU2

Hi,

http://www.symantec.com/business/support/index?pag...

Refer to upper link, Symantec Endpoint Protection affected by the Heartbleed OpenSSL vulnerability.

Since I am using SEPM12.1 RU2 (12.1.2015.2015), thus I have planned to upgrade SEPM12.1 RU4 MP1a (12.1.4104.4130) to fix this problem.

After I blocked port 8445 on the firewall, then I can directly upgrade SEPM12.1 RU4 MP1a (12.1.4104.4130) ??

What's the procedure ??

Thanks