I was going through your blog
How to Automatically Upgrade SCCM Clients to Newer version

Create and Deploy a package and Program !
I have created a package using the option create package from Definition and I have question about the command line you have mentioned

The default command line “CCMSETUP.EXE /noservice SMSSITECODE=AUTO” – will this command also upgrade the client or is it necessary to replace auto with my site code

Also this package will install in silent like Auto upgrade ?