Security Updates

Hi,

Think my lack of understanding is a fault here so I'm hoping it can be cleared up here.

We have decided to patch some of servers with security updates only. However, when I type:

% yum update --security

I see no patches returned. Only the following output:

Setting up Update Process
Resolving Dependencies
Limiting packages to security relevant ones
No packages needed for security; 355 packages available

What is this telling me? Is it basically there are no security updates available within our repository? Do I need to subscribe to a separate security channel for example. I've searched on RedHat customer portal and come across the errata web page. Is this the aspect I need to update from to appease our security needs?

Any help and/or advise will be greatly appreciated.

Thanks,
DJC.